WorldWideScience

Sample records for fibre reinforced cement

  1. Isotropic Compression Behaviour of Fibre Reinforced Cemented Sand

    Directory of Open Access Journals (Sweden)

    Salahuddin

    2013-07-01

    Full Text Available Fibre-reinforced cemented sands have many applications in improving the response of soils. In this paper, an experimental investigation for the analysis of fiber-reinforced cemented sand in the framework of isotropic compression is presented. The experimental investigations were carried out using a high pressure triaxial apparatus having the capacity of 64 MPa of confining pressure. Tests have been conducted on Portaway sand specimens reinforced with randomly oriented discrete polypropylene fibers with different percentages of fiber and cement contents. Results are presented in the form of e-logp` curves as well as SEM (Scanning Electron Microscopy micrographs. The effects of the addition of fibre in sand and cemented sand for different initial void ratios were investigated. The results demonstrate that the influence of fibre is not significant in both cemented and uncemented sand during the isotropic compression stage. Moreover, from the SEM micrographs it could be seen that there is breakage of sand particles and cement bonds. The fiber threads were seen pinched and found rarely broken in the specimen exhumed after isotropic compression.

  2. Fibre-reinforced calcium phosphate cements: a review.

    Science.gov (United States)

    Canal, C; Ginebra, M P

    2011-11-01

    Calcium phosphate cements (CPC) consist of one or more calcium orthophosphate powders, which upon mixing with water or an aqueous solution, form a paste that is able to set and harden after being implanted within the body. Different issues remain still to be improved in CPC, such as their mechanical properties to more closely mimic those of natural bone, or their macroporosity to favour osteointegration of the artificial grafts. To this end, blends of CPC with polymer and ceramic fibres in different forms have been investigated. The present work aims at providing an overview of the different approaches taken and identifying the most significant achievements in the field of fibre-reinforced calcium phosphate cements for clinical applications, with special focus on their mechanical properties.

  3. Glass fibre reinforced cement based composite: fatigue and fracture parameters

    Directory of Open Access Journals (Sweden)

    Seitl S.

    2009-12-01

    Full Text Available This paper introduces the basic fracture mechanics parameters of advanced building material – glass fibres reinforced cement based composite and its fracture and fatigue behaviour is investigated. To this aim three-point bend (3PB specimens with starting notch were prepared and tested under static (l–d diagram and cyclic loading (Paris law and Ẅöhler curve. To evaluate the results, the finite element method was used for estimation of the corresponding values of stress intensity factor for the 3PB specimen used. The results obtained are compared with literature data.

  4. THE USE OF SISAL FIBRE AS REINFORCEMENT IN CEMENT BASED COMPOSITES

    Directory of Open Access Journals (Sweden)

    Romildo Dias Tolêdo Filho

    1999-08-01

    Full Text Available ABSTRACT The inclusion of fibre reinforcement in concrete, mortar and cement paste can enhance many of the engineering properties of the basic materials, such as fracture toughness, flexural strength and resistance to fatigue, impact, thermal shock and spalling. In recent years, a great deal of interest has been created worldwide on the potential applications of natural fibre reinforced, cement based composites. Investigations have been carried out in many countries on various mechanical properties, physical performance and durability of cement based matrices reinforced with naturally occurring fibres including sisal, coconut, jute, bamboo and wood fibres. These fibres have always been considered promising as reinforcement of cement based matrices because of their availability, low cost and low consumption of energy. In this review, the general properties of the composites are described in relation to fibre content, length, strength and stiffness. A chronological development of sisal fibre reinforced, cement based matrices is reported and experimental data are provided to illustrate the performance of sisal fibre reinforced cement composites. A brief description on the use of these composite materials as building products has been included. The influence of sisal fibres on the development of plastic shrinkage in the pre-hardened state, on tensile, compressive and bending strength in the hardened state of mortar mixes is discussed. Creep and drying shrinkage of the composites and the durability of natural fibres in cement based matrices are of particular interest and are also highlighted. The results show that the composites reinforced with sisal fibres are reliable materials to be used in practice for the production of structural elements to be used in rural and civil construction. This material could be a substitute asbestos-cement composite, which is a serious hazard to human and animal health and is prohibited in industrialized countries. The

  5. Effects of fibre reinforcement on the mechanical properties of brushite cement.

    Science.gov (United States)

    Gorst, N J S; Perrie, Y; Gbureck, U; Hutton, A L; Hofmann, M P; Grover, L M; Barralet, J E

    2006-01-01

    In this study the effect of structure and amount of polyglactin fibre incorporation into a brushite forming calcium phosphate cement system and the effect of mechanical compaction on the fibre modified system were investigated. In comparison the effect of resorbable polycaprolactone surface coating of cement specimens was investigated. The results showed that, apart from the mechanical properties of the reinforcing material, the structure of the incorporated fibres, regular or random, is crucial for the resulting flexural strength and modulus of elasticity. Fibre reinforcement could also be combined with mechanical compaction of the cement/fibre composite paste leading to a possible 7-fold increase in flexural strength or an almost 5-fold increase in modulus of elasticity. Reinforcement of the tensile surface of cement grafts may ultimately improve strength where required, especially in conjunction with bone fixation devices.

  6. Sisal fibre pull-out behaviour as a guide to matrix selection for the production of sisal fibre reinforced cement matrix composites

    CSIR Research Space (South Africa)

    Mapiravana, Joe

    2011-12-01

    Full Text Available Natural fibre reinforced cement composites are promising potential materials for use in panelised construction. The structural properties of these composite materials are yet to be fully understood. As the role of the natural fibre is to reinforce...

  7. Micromechanics of the Interface in Fibre-Reinforced Cement Materials

    DEFF Research Database (Denmark)

    Stang, Henrik; Shah, S.P.

    1996-01-01

    the strength and ductility of the brittlematrix material rather than changing the overall stiffness,the ability of the fibres to interact with cracking processes in thematrix material is essential. Furthermore, since matrix cracking in afibre reinforced material can only take place with simultaneousinterfacial...

  8. Expansive cement couplers: A means of pre-tensioning fibre-reinforced plastic tendons

    OpenAIRE

    1995-01-01

    This is the peer reviewed version of: Lees J.M., Gruffydd-Jones, B. and Burgoyne C.J. (1995) "Expansive Cement Couplers - A Means of Pre-tensioning Fibre-Reinforced Plastic Tendons", published in 'Construction and Building Materials', v. 9, is. 6, pp. 413-423 December 1995. The published version is at http://dx.doi.org/10.1016/0950-0618(95)00070-4 Fibre reinforced plastics describes a group of materials composed of inorganic or organic fibres embedded in a resin matrix. frps are strong, n...

  9. Behaviour of alkaline cement mortars reinforced with acrylic and polypropylene fibres

    Directory of Open Access Journals (Sweden)

    Puertas, P.

    2000-09-01

    Full Text Available In the present work, the behaviour of alkaline cement mortars reinforced with fibres of different nature (acrylic and polypropylene fibres is studied. Also the chemical stability of those fibres in strong alkaline medium has been investigated. Three different matrixes have been used: glass blast furnace slag activated with NaOH 2M (room temperature, 22 ºC; fly ash activated with NaOH 8M, cured at 85ºC during 24 hours and 50% fly ash / 50% slag activated with NaOH 8M, room temperature. The fibre content was 0,2 and 1% in mortar volume. The tests carried out were: tenacity and tenacity index, impact resistance and drying shrinkage. On the specimens tested, a microstructural study by SEM/EDX was carried out. The results obtained have demonstrated the following: a The acrylic and polypropylene fibres are stable in strong basic media, although the first undergo hydrolysis/ hydration processes showed by the alteration of the surface texture, b with low fibre contents (0,2% in volume, tenacity and tenacity index of these mortars remain unaffected. With higher contents (1%, an increase of the corresponding values is produced. This increment is higher in mortars with alkaline activated slag, c For the three matrixes studied, the polypropylene fibres increase the impact strength in higher degree than the acrylic ones. The reinforcement effect is more significative in matrix A and when the fibre content is 1% in volume, d the shrinkage of these mortars is modified depending on the matrix and fibre type. In mortars of activated slag, fibres do not reduce the shrinkage. In mortars of activated fly ash reinforced with acrylic fibres, shrinkage is lower than those containing polypropylene fibres are. Finally, in mortars of fly ash/ activated slag, the two fibres decrease the drying shrinkage.

    En el presente trabajo se estudia el comportamiento de morteros de cementos alcalinos reforzados con fibras de distinta naturaleza (acrílica y de polipropileno

  10. Strengthening of concrete structures using carbon fibre reinforced polymers and cement-based adhesives

    OpenAIRE

    Hashemi, Siavash

    2017-01-01

    The research project conducted in this study concerns the investigation of the application of cement-based adhesives in CFRP strengthening of reinforced concrete members. The results demonstrate that mineral-based adhesives can provide the desired matrices for CFRP reinforcement. The literature review covers the background of CFRP application with conventional techniques. The bond characteristics of CFRP to concrete substrate, the flexural performance of retrofitted RC beams, and the fa...

  11. Fibre reinforced polymer nanocomposites

    NARCIS (Netherlands)

    Vlasveld, D.P.N.

    2005-01-01

    In this thesis the results are described of the research on a combination of two types of composites: thermoplastic nanocomposites and continuous fibre composites. In this three-phase composite the main reinforcing phase are continuous glass or carbon fibres, and the matrix consists of a polyamide 6

  12. Caractérisation microstructurale et mécanique d’un composite cimentaire renforcé par des fibres de lin Characterizations mechanical and microstructural of flax fibre cement composite reinforced

    Directory of Open Access Journals (Sweden)

    Boutouil M.

    2012-09-01

    Full Text Available Dans la perspective de valorisation des fibres de lin dans les matériaux de construction, la présente étude s’intéresse à la caractérisation microstructurale et mécanique d’un composite cimentaire renforcé par des fibres de lin. Les analyses microstructurales au MEB ont été menées pour évaluer l’homogénéité de la distribution des fibres, la qualité de l’interaction fibre/matrice et l’influence de leur présence sur les défauts microstructuraux. Le comportement mécanique en flexion du mortier renforcé par les fibres de lin est étudié en fonction de la longueur et la teneur en fibres. Les résultats indiquent une bonne adhésion entre les fibres et la matrice à l’état frais. Mais les fibres étant hydrophiles, elles gonflent pendant la prise du ciment et le retrait lors du séchage engendre alors des déchaussements. Les résultats de caractérisation mécanique sont encourageants. Tout d’abord, la fissuration du mortier due au retrait au jeune âge est fortement réduite du fait de la présence des fibres. Ensuite, la rupture brutale de la matrice en monolithe laisse place à un comportement quasi-ductile quand la teneur ou la longueur de fibre augmente. Ce changement de comportement, analysé en termes d’indice de ténacité, illustre la capacité remarquable des fibres de lin à renforcer les matrices cimentaires du fait de leurs bonnes propriétés mécaniques. With the purpose of the flax fibre valuing in construction materials, this study focuses on the characterizations mechanical and microstructural of flax fibre cement composite reinforced. The mechanical strength was studied as the function of fibre volume ratio and length. Meanwhile, the microstructural analysis investigated the homogeneity of fibre scattering, the interaction fibre/cement matrix and the influence of flax fibres on the defects microstructures. The results show the interesting mechanical properties of flax fibre in comparison with

  13. Glass Fibre Reinforced Polymers

    NARCIS (Netherlands)

    Nikolaou, N.; Karagianni, L.; Sarakiniatti, M.V.

    2014-01-01

    This "designers' manual" is made during the TIDO-course AR0533 Innovation & Sustainability. Fibre reinforced polymers (FRPs) have been used in many applications over the years, from new construction to retrofitting. They are lightweight, no-corrosive, exhibit high specific strength and specific

  14. Glass Fibre Reinforced Polymers

    NARCIS (Netherlands)

    Nikolaou, N.; Karagianni, L.; Sarakiniatti, M.V.

    2014-01-01

    This "designers' manual" is made during the TIDO-course AR0533 Innovation & Sustainability. Fibre reinforced polymers (FRPs) have been used in many applications over the years, from new construction to retrofitting. They are lightweight, no-corrosive, exhibit high specific strength and specific sti

  15. Self-compacting fibre-reinforced concrete

    NARCIS (Netherlands)

    Grunewald, S.; Walraven, J.C.

    2001-01-01

    The project 'self-compacting fibre-reinforced concrete (SCFRC)' is part of the Dutch STW/PPM program - 'cement-bonded materials' - DCT.4010. Subproject III to which the project ,SCFRC' belongs deals with the development of new high performance concretes. The project 'SCFRC' aims at investigating the

  16. FOAM CONCRETE REINFORCEMENT BY BASALT FIBRES

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    Zhukov Aleksey Dmitrievich

    2012-10-01

    Full Text Available The authors demonstrate that the foam concrete performance can be improved by dispersed reinforcement, including methods that involve basalt fibres. They address the results of the foam concrete modeling technology and assess the importance of technology-related parameters. Reinforcement efficiency criteria are also provided in the article. Dispersed reinforcement improves the plasticity of the concrete mix and reduces the settlement crack formation rate. Conventional reinforcement that involves metal laths and rods demonstrates its limited application in the production of concrete used for thermal insulation and structural purposes. Dispersed reinforcement is preferable. This technology contemplates the infusion of fibres into porous mixes. Metal, polymeric, basalt and glass fibres are used as reinforcing components. It has been identified that products reinforced by polypropylene fibres demonstrate substantial abradability and deformability rates even under the influence of minor tensile stresses due to the low adhesion strength of polypropylene in the cement matrix. The objective of the research was to develop the type of polypropylene of D500 grade that would demonstrate the operating properties similar to those of Hebel and Ytong polypropylenes. Dispersed reinforcement was performed by the basalt fibre. This project contemplates an autoclave-free technology to optimize the consumption of electricity. Dispersed reinforcement is aimed at the reduction of the block settlement in the course of hardening at early stages of their operation, the improvement of their strength and other operating properties. Reduction in the humidity rate of the mix is based on the plasticizing properties of fibres, as well as the application of the dry mineralization method. Selection of optimal parameters of the process-related technology was performed with the help of G-BAT-2011 Software, developed at Moscow State University of Civil Engineering. The authors also

  17. Durability of cracked fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    1998-01-01

    Durability studies are carried out at BKM as part of the research project "Design Methods for Fibre Reinforced Concrete" (FRC) involving BKM, The Concrete Research Center at DTI, Building Technology at Aalborg University, Rambøll, 4K-Beton and Rasmussen & Schiøtz. Concrete beams with or without...... structure are made on specimens drilled or sawed from beams after unloading (mechanical load). The pore structure of the concretes will be studied by microscopy, sorption and suction curves. The test programme involves three different concrete qualities (water-cement ratios). Both steel fibres (ZP...

  18. Applications and Properties of Fibre Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Amit Rai1 ,

    2014-05-01

    Full Text Available In conventional concrete, micro-cracks develop before structure is loaded because of drying shrinkage and other causes of volume change. When the structure is loaded, the micro cracks open up and propagate because of development of such micro-cracks, results in inelastic deformation in concrete. Fibre reinforced concrete (FRC is cementing concrete reinforced mixture with more or less randomly distributed small fibres. In the FRC, a numbers of small fibres are dispersed and distributed randomly in the concrete at the time of mixing, and thus improve concrete properties in all directions. The fibers help to transfer load to the internal micro cracks. FRC is cement based composite material that has been developed in recent years. It has been successfully used in construction with its excellent flexural-tensile strength, resistance to spitting, impact resistance and excellent permeability and frost resistance. It is an effective way to increase toughness, shock resistance and resistance to plastic shrinkage cracking of the mortar. These fibers have many benefits. Steel fibers can improve the structural strength to reduce in the heavy steel reinforcement requirement. Freeze thaw resistance of the concrete is improved. Durability of the concrete is improved to reduce in the crack widths. Polypropylene and Nylon fibers are used to improve the impact resistance. Many developments have been made in the fiber reinforced concrete.

  19. Ductile Cement-Based Composites with Wood Fibres - material design and experimental approach

    NARCIS (Netherlands)

    Sierra-Beltran, M.G.

    2011-01-01

    In order to turn a brittle cement matrix into a ductile composite different types of man-made fibres such as steel, glass and polyvinyl alcohol are currently used as reinforcement, as well as some natural fibres. Compared to synthetic fibres, natural fibres are more easily available worldwide and th

  20. A mild alkali treated jute fibre controlling the hydration behaviour of greener cement paste

    Science.gov (United States)

    Jo, Byung-Wan; Chakraborty, Sumit

    2015-01-01

    To reduce the antagonistic effect of jute fibre on the setting and hydration of jute reinforced cement, modified jute fibre reinforcement would be a unique approach. The present investigation deals with the effectiveness of mild alkali treated (0.5%) jute fibre on the setting and hydration behaviour of cement. Setting time measurement, hydration test and analytical characterizations of the hardened samples (viz., FTIR, XRD, DSC, TGA, and free lime estimation) were used to evaluate the effect of alkali treated jute fibre. From the hydration test, the time (t) required to reach maximum temperature for the hydration of control cement sample is estimated to be 860 min, whilst the time (t) is measured to be 1040 min for the hydration of a raw jute reinforced cement sample. However, the time (t) is estimated to be 1020 min for the hydration of an alkali treated jute reinforced cement sample. Additionally, from the analytical characterizations, it is determined that fibre-cement compatibility is increased and hydration delaying effect is minimized by using alkali treated jute fibre as fibre reinforcement. Based on the analyses, a model has been proposed to explain the setting and hydration behaviour of alkali treated jute fibre reinforced cement composite.

  1. Natural Fibre-Reinforced Biofoams

    Directory of Open Access Journals (Sweden)

    Anne Bergeret

    2011-01-01

    Full Text Available Starches and polylactic acids (PLAs represent the main biobased and biodegradable polymers with potential industrial availability in the next decades for “bio” foams applications. This paper investigates the improvement of their morphology and properties through processing and materials parameters. Starch foams were obtained by melt extrusion in which water is used as blowing agent. The incorporation of natural fibres (hemp, cellulose, cotton linter, sugarcane, coconut in the starch foam induced a density reduction up to 33%, a decrease in water absorption, and an increase in mechanical properties according to the fibre content and nature. PLA foams were obtained through single-screw extrusion using of a chemical blowing agent that decomposed at the PLA melting temperature. A void content of 48% for PLA and 25% for cellulose fibre-reinforced PLA foams and an improvement in mechanical properties were achieved. The influence of a fibre surface treatment was investigated for both foams.

  2. Influence of curing conditions on durability of alkali-resistant glass fibres in cement matrix

    Indian Academy of Sciences (India)

    Arabi Nourredine

    2011-07-01

    Glass fibres in concrete material often increase the flexural strength. However, these fibres when in contact with cement are altered by alkali reactions due to the presence of portlandite. This study presents the results of investigation to show the effect of curing conditions on the durability of alkali-resistant glass fibres in cement matrix. Test results show that even alkali resistant fibres treated with zirconium oxide present the same degradation phenomenon. They also show that the nature of the cement has a large influence on the protection of the fibres: the Portland CEM II is less damaging than the CEM I. The substitutions of a part of cement by silica fume gave no substantial improvements to the mechanical strength of the glass fibre reinforced cement (GFRC). However, the observed microstructures in the samples show that the degradation is weakened with the addition of silica fumes. The analytical techniques used in this study are scanning electron microscope (SEM) and X-ray diffraction.

  3. Ductility Performance of Hybrid Fibre Reinforced Concrete

    OpenAIRE

    S. Eswari; P.N. Raghunath; Suguna, K

    2008-01-01

    This study presents a study on the ductility performance of hybrid fibre reinforced concrete. The influence of fibre content on the ductility performance of hybrid fibre reinforced concrete specimens having different fibre volume fractions was investigated. The parameters of investigation included modulus of rupture, ultimate load, service load, ultimate and service load deflection, crack width, energy ductility and deflection ductility. A total of 27 specimens, 100×100×500 mm, were tested to...

  4. Characterisation of Natural Fibre Reinforcements and Composites

    Directory of Open Access Journals (Sweden)

    Richard K. Cullen

    2013-01-01

    Full Text Available Recent EU directives (e.g., ELV and WEEE have caused some rethinking of the life cycle implications of fibre reinforced polymer matrix composites. Man-made reinforcement fibres have significant ecological implications. One alternative is the use of natural fibres as reinforcements. The principal candidates are bast (plant stem fibres with flax, hemp, and jute as the current front runners. The work presented here will consider the characterisation of jute fibres and their composites. A novel technique is proposed for the measurement of fibre density. The new rule of mixtures, extended for noncircular cross-section natural fibres, is shown to provide a sensible estimate for the experimentally measured elastic modulus of the composite.

  5. Continuous jute fibre reinforced laminated paper composite and reinforcement-fibre free paper laminate

    Indian Academy of Sciences (India)

    B B Verma

    2009-12-01

    Plastic bags create a serious environmental problem. The proposed jute fibre reinforced laminated paper composite and reinforcement-fibre free paper laminate may help to combat the war against this pollutant to certain extent. The paper laminate, without reinforcement fibre, exhibited a few fold superiority in tensile properties than single paper strip. The studies further show that an appreciable improvement in tensile properties can be achieved by introducing continuous jute fibre in paper laminates.

  6. Corrosion Effects on the Strength Properties of Steel Fibre Reinforced Concrete Containing Slag and Corrosion Inhibitor

    OpenAIRE

    Sivakumar Anandan; Sounthararajan Vallarasu Manoharan; Thirumurugan Sengottian

    2014-01-01

    Corrosion in steel can be detrimental in any steel rebar reinforced concrete as well as in the case of steel fibre reinforced concrete. The process of corrosion occurring in steel fibre incorporated concrete subjected to corrosive environment was systematically evaluated in this study. Concrete specimens were prepared with steel fibre inclusions at 1.5% Vf (volume fraction) of concrete and were added in slag based concrete (containing manufactured sand) and replaced with cement at 20%, 40%, ...

  7. Caracterização mecânica de laminados cimentíceos esbeltos reforçados com fibras de sisal Mechanical characterization of cement-based thin-walled laminates reinforced with sisal fibre

    Directory of Open Access Journals (Sweden)

    Paulo R. L. Lima

    2007-12-01

    Full Text Available Com a proibição progressiva do uso de fibras de asbesto na fabricação de laminados à base de cimento, novos produtos têm sido desenvolvidos para suprir esta demanda do setor construtivo. A utilização de fibras de sisal como substituto ao asbesto, além de ser uma proposta ecológica tem grande importância socioeconômica, pois agregará valor a um produto cultivado com sucesso no semi-árido nordestino. Produziram-se, neste trabalho, placas laminadas com matriz de argamassa reforçadas com fibras longas de sisal. Ensaios de flexão em três pontos foram realizados com o objetivo de se estudar a influência da adição de fibras (3%, do número de camadas (2 e 3, da orientação das camadas (0 e 90° e da pressão de moldagem (0 e 2 MPa sobre o comportamento à flexão dos laminados. Os resultados indicam que a adição de fibras de sisal aumentou, para todos os casos estudados, a capacidade de absorver energia, a resistência à flexão pós-fissuração e a deflexão última do material. Os laminados reforçados com 3% de fibras de sisal, distribuídas em três camadas ortogonais à direção do carregamento e submetidos à pressão de moldagem de 2 MPa, apresentaram o melhor comportamento mecânico.Because of hazards to human and animal health, the use of asbestos and its products is being prohibited all around the world and academic institutions and fibre cement producers have been engaged in intensive research to find asbestos-free cement products. The application of natural fibres such as sisal to replace asbestos fibres can bring economical and ecological benefits due to their availability, low cost, low consumption of energy and suitability to the semi-arid area of the Northeast of Brazil (where not many plants can grow. In this paper, cement-based laminates reinforced with continuous sisal fibre were produced. Three point bending tests were carried out to evaluate the influence of addition of fibre (3%, number of layers of

  8. Fundamentals of fibre-reinforced soil engineering

    CERN Document Server

    Shukla, Sanjay Kumar

    2017-01-01

    This book is intended to serve as a one-stop reference on fibre-reinforced soils. Over the past 30-35 years, the engineering behaviour of randomly distributed/oriented fibre-reinforced soil, also called simply fibre-reinforced soil, has been investigated in detail by researchers and engineers worldwide. Waste fibres (plastic waste fibres, old tyre fibres, etc.) create disposal and environmental problems. Utilization of such fibres in construction can help resolve these concerns. Research studies and some field applications have shown that the fibres can be utilized in large quantities in geotechnical and civil engineering applications in a cost-effective and environmentally friendly manner. This book covers a complete description of fibres, their effects when included within a soil or other similar materials such as the fly ash, and their field applications. It gives a detailed view of fibre-reinforced soil engineering. The book will be useful to students, professional, and researchers alike, and can also ser...

  9. Design Methods for Fibre Reinforced Concrete

    DEFF Research Database (Denmark)

    Stang, Henrik

    1996-01-01

    The present paper describes the outline of a research project on Fibre Reinforced Concrete (FRC) currently being carried out in Denmark under the supervision of Danish Council of Technology, Danish Technical Research Council and Danish Natural Science Research Counsil....

  10. Frost resistance of fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    1999-01-01

    Frost resistance of fibre reinforced concrete with 2.5-4.2% air and 6-9% air (% by volume in fresh concrete) casted in the laboratory and in-situ is compared. Steel fibres with hooked ends (ZP, length 30 mm) and polypropylene fibres (PP, CS, length 12 mm) are applied. It is shown that· addition...... of 0.4-1% by volume of fibres cannot replace air entrainment in order to secure a frost resistant concrete; the minimum amount of air needed to make the concrete frost resistant is not changed when adding fibres· the amount of air entrainment must be increased when fibres are added to establish...... the same amount of air pores as in the corresponding concrete without fibres...

  11. STRAIN HARDENING PROPERTIES OF STEEL FIBRE REINFORCED LATEX CONCRETE COMPOSITE

    Directory of Open Access Journals (Sweden)

    V.M. Sounthararajan

    2013-04-01

    Full Text Available Steel fibre addition in concrete possesses high merits in terms of achieving homogeneity and tensile strength properties. Polymeric addition in concrete has high advantages in terms of pore fillingeffect and subsequent increase in durability index. The combined addition of steel and polymeric latex additions in concrete leads to increased strength, durability, toughness, resistance to cracking and crack propagation. Studies were conducted in the present study to analyse the properties of concrete that can be further improved with the addition of polymer styrene butadiene rubber emulsion (SBR along with steel fibres. In this research analysis, styrene-butadiene rubber (SBR latex as a polymeric admixture was used in steel fibre reinforced concrete. The effect of curing conditions on the strength gain properties of composite steel fibre latex matrix on the compressive, flexural strength, and split tensile test of polymermodified steel fibre reinforced concrete (PSFC concrete was examined. Including SBR latex at a certain % of binder in the PSFC concrete improves the bonds within the cement matrix and steel fibres (SF. This is due to the SBR films formed in the matrix. By the comparison of properties of SFC and PSFC, it can be shown that a tremendous increase in compressive strength when 4% and 8% SBR is added along with 0.75% and 1.5% SF. The increase in flexural strength was noticed and post cracking ductility is imparted to concrete.

  12. Frost resistance of fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    1999-01-01

    of 0.4-1% by volume of fibres cannot replace air entrainment in order to secure a frost resistant concrete; the minimum amount of air needed to make the concrete frost resistant is not changed when adding fibres· the amount of air entrainment must be increased when fibres are added to establish......Frost resistance of fibre reinforced concrete with 2.5-4.2% air and 6-9% air (% by volume in fresh concrete) casted in the laboratory and in-situ is compared. Steel fibres with hooked ends (ZP, length 30 mm) and polypropylene fibres (PP, CS, length 12 mm) are applied. It is shown that· addition...

  13. STUDIES OF DURABILITY ASPECTS OF FIBRE REINFORCED CONCRETE

    Directory of Open Access Journals (Sweden)

    D. MARUTHACHALAM

    2012-02-01

    Full Text Available This paper presents a detailed experimental study on sulphate attack, depth of carbonation, alkalinity measurement on fibre reinforced concrete at ages 28 days, 56 days, and 90 days. The main variable investigated in this study is variation of fibre dosage of 0.1%, 0.2%, and 0.3%. The concrete produced by the addition of fly ash and metakaolin as a partial replacement of cement. The compressive strength, weight loss and hardness of concrete were studied. Test results indicate that use of fibre in concrete has improved performance of concrete. A simple regression equation has been proposed to study the behaviour of concrete under sulphate attack, depth of carbonation.

  14. Ductility Performance of Hybrid Fibre Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    S. Eswari

    2008-01-01

    Full Text Available This study presents a study on the ductility performance of hybrid fibre reinforced concrete. The influence of fibre content on the ductility performance of hybrid fibre reinforced concrete specimens having different fibre volume fractions was investigated. The parameters of investigation included modulus of rupture, ultimate load, service load, ultimate and service load deflection, crack width, energy ductility and deflection ductility. A total of 27 specimens, 100×100×500 mm, were tested to study the above parameters. The specimens incorporated 0.0 to 2.0% volume fraction of polyolefin and steel fibres in different proportions. The ductility performance of hybrid fibre reinforced concrete specimens was compared with that of plain concrete. The test results show that addition of 2.0% by volume of hybrid fibres improves the ductility performance appreciably. An adaptive Neuro-Fuzzy based model has been proposed to predict the ductility performance characteristics. A reasonably close agreement has been obtained between the experimental and predicted results.

  15. Plastic Fibre Reinforced Soil Blocks as a Sustainable Building Material

    Science.gov (United States)

    Prasad, C. K. Subramania; Nambiar, E. K. Kunhanandan; Abraham, Benny Mathews

    2012-10-01

    Solid waste management, especially the huge quantity of waste plastics, is one of the major environmental concerns nowadays. Their employability in block making in the form of fibres, as one of the methods of waste management, can be investigated through a fundamental research. This paper highlights the salient observations from a systematic investigation on the effect of embedded fibre from plastic waste on the performance of stabilised mud blocks. Stabilisation of the soil was done by adding cement, lime and their combination. Plastic fibre in chopped form from carry bags and mineral water bottles were added (0.1% & 0.2% by weight of soil) as reinforcement. The blocks were tested for density, and compressive strength, and observed failure patterns were analysed. Blocks with 0.1% of plastic fibres showed an increase in strength of about 3 to 10%. From the observations of failure pattern it can be concluded that benefits of fibre reinforcement includes both improved ductility in comparison with raw blocks and inhibition of crack propogation after its initial formation.

  16. Applicability of the Waste Fibres in Cement Paste

    Directory of Open Access Journals (Sweden)

    Regina KALPOKAITĖ DIČKUVIENĖ

    2013-09-01

    Full Text Available Fibres produced from waste catalyst together with commercially available polypropylene fibres were incorporated into ordinary Portland cement paste. The effects of fibre content as well as a mix of different type of fibres on mechanical and physical properties of wet and dry samples were investigated. The results showed that presence of fibres reduced compressive strength of the plain cement in wet and dry state. Contrary, when the combination of 1.5 wt% waste and 1.5 wt% polypropylene fibres was used flexural strength of cement mixture increased by up to 9 % at the age of 28 days. It was observed that addition of 1.5 wt% of only waste fibres improved flexural strength after long hydration period as well. However, the lowest mechanical strength results showed samples with 3 wt% of waste fibres. It was also observed that higher content of waste fibres reduced porosity of the cement mixture and consequently, decreased water absorption capacity. Presence of fibres reduced drying shrinkage of samples and they were lower than plain cement after 28 days of hydration. DOI: http://dx.doi.org/10.5755/j01.ms.19.3.1992

  17. Waste Plastic Fibre Reinforced Self Compacting Concrete

    Directory of Open Access Journals (Sweden)

    Mrs. Vijaya G.S Assistant Professor

    2016-05-01

    Full Text Available Self-compacting concrete is high performance concrete which is highly flowable, non-segregating, spread on its own weight and doesn‟t need any compaction. This paper deals with flow and strength characteristics such as compressive strength, split tensile strength, flexural strength and impact strength of Self-compacting concrete with various percentages of waste plastic fibres like 0%, 0.25%, 0.5%, 0.75%, 1.0%, 1.1%, 1.20%, 1.3% and 1.4% is added by weight of cement. The mix proportion for M40 grade of concrete was done by using Nan Su method (Cement: GGBS: Fine aggregate: Course aggregate 1: 0.705: 3.34: 2.62. Water powder (W/P ratio 0.36, cement content 280kg/m3 , GGBS 220 kg/m3 was calculated and maintained as constant throughout the experimental work for all eight mixes, only the superplastizers dosage was varied for different percentage of fibres. In this experimental investigation one control mix and eight (8 different mixes were considered. Totally 81 Cube, beam, Cylindrical specimens and square plates were casted, cured and tested as per IS specifications. For determining impact strength drop weight method was used. The results obtained indicate that fresh (workability characteristics satisfy the lower and upper limit as suggested by EFNARC. The tests on hardened properties indicate that the compressive strength, split tensile strength, flexural strength was improved proportionally with the addition of waste plastic fibers upto 1.0% by weight of cement and then decreases. The impact strength improved proportionally with addition of fibres upto 1.2% by weight of cement and then decreases.

  18. Strength Evaluation of Steel-Nylon Hybrid Fibre Reinforced Concrete

    OpenAIRE

    Maniram Kumar; Er. Ankush Khadwal

    2014-01-01

    When fibres like steel, glass, polypropylene, nylon, carbon, aramid, polyester, jute, etc are mixed with concrete known as fibre reinforced concrete. To overcome the deficiencies of concrete; fibres are added to improve the performance of concrete. In this research hybrid reinforced concrete is made by using steel and nylon 6 fibres. The inclusion of both steel and nylon 6 fibres are used in order to combine the benefits of both fibers; structural improvements provided by stee...

  19. Modelling the influence of age of steel fibre reinforced self : compacting concrete on its compressive behaviour

    OpenAIRE

    Cunha, Vitor M. C. F.; Barros, Joaquim A.O.; Sena-Cruz, José

    2008-01-01

    Documento submetido para revisão pelos pares. A publicar na revista "Materials and Structures Journal". ISSN 1359-5997. Steel fibre reinforced self-compacting concrete (SFRSCC) can combine the benefits of self-consolidating concrete technology with those derived from adding steel fibres to quasi-brittle cement based materials. In a recent applied research project joining pre-casting industry, private and public research institutions, a method was developed to design cost-...

  20. Surface treated polypropylene (PP) fibres for reinforced concrete

    Energy Technology Data Exchange (ETDEWEB)

    López-Buendía, Angel M., E-mail: buendia@uv.es [AIDICO Technological Institute of Construction, Benjamin Franklin 17, 46380 Paterna, Valencia (Spain); Romero-Sánchez, María Dolores [AIDICO Technological Institute of Construction, Marble Technical Unit, Camí de Castella 4, 03660 Novelda. Alicante (Spain); Climent, Verónica [Lafarge Cementos, Polígono Sepes, Isaac Newton s/n, 46500 Sagunto, Valencia (Spain); Guillem, Celia [AIDICO Technological Institute of Construction, Marble Technical Unit, Camí de Castella 4, 03660 Novelda. Alicante (Spain)

    2013-12-15

    Surface treatments on a polypropylene (PP) fibre have contributed to the improvement of fibre/concrete adhesion in fibre-reinforced concrete. The treatments to the PP fibre were characterized by contact angle measurements, ATR-IR and XPS to analyse chemical alterations. The surface topography and fibre/concrete interaction were analysed by several microscopic techniques, namely optical petrographic, and scanning electron microscopy. Treatment modified the surface chemistry and topography of the fibre by introducing sodium moieties and created additional fibre surface roughness. Modifications in the fibre surface led to an increase in the adhesion properties between the treated fibres and concrete and an improvement in the mechanical properties of the fibre-reinforced concrete composite as compared to the concrete containing untreated PP fibres. Compatibility with the concrete and increased roughness and mineral surface was also improved by nucleated portlandite and ettringite mineral association anchored on the alkaline PP fibre surface, which is induced during treatment.

  1. Design of fibre reinforced PV concepts for building integrated applications

    NARCIS (Netherlands)

    Reinders, Angelina H.M.E.; de Wit, H.; de Boer, Andries; Ossenbrink Sinke, W.; Helm, P.

    2009-01-01

    Fibre reinforced polymers present an interesting encapsulation medium for PV-modules. Glass fibres can provide increased strength and stiffness to thin polymer layers overcoming the brittleness and limited deformability of glass-panes. Glass fibre reinforced polymers allows for transparency over a

  2. Design of fibre reinforced PV concepts for building integrated applications

    NARCIS (Netherlands)

    Reinders, A.H.M.E.; Wit, de H.; Boer, de A.

    2009-01-01

    Fibre reinforced polymers present an interesting encapsulation medium for PV-modules. Glass fibres can provide increased strength and stiffness to thin polymer layers overcoming the brittleness and limited deformability of glass-panes. Glass fibre reinforced polymers allows for transparency over a b

  3. Applications for fibre-reinforced plastic

    Energy Technology Data Exchange (ETDEWEB)

    Teuschler, V. [Fiberdur-Vanck (Germany)

    1999-07-01

    The outstanding mechanical properties of fibre-reinforced plastic are extolled. It has strength comparable with that of steel, and other physical properties that give it advantages over ferrous materials for use in pipelines, shipbuilding and offshore conduits. It has well established uses in aircraft, automobiles and boats and is probably more resistant to weathering and corrosion than any other material. The electricity-conducting Navicon pipe, the Fiberdur-vinyl ester/epoxy system and the Fiberdur-DOS system are described.

  4. Comparison of two novel approaches to model fibre reinforced concrete

    NARCIS (Netherlands)

    Radtke, F.K.F.; Simone, A.; Sluys, L.J.

    2009-01-01

    We present two approaches to model fibre reinforced concrete. In both approaches, discrete fibre distributions and the behaviour of the fibre-matrix interface are explicitly considered. One approach employs the reaction forces from fibre to matrix while the other is based on the partition of unity f

  5. Strength improvement of fibre cement product

    Directory of Open Access Journals (Sweden)

    Waranya Sonphuak

    2013-10-01

    Full Text Available This paper presents a methodology to improve the strength or the Modulus of Rupture (MOR of fibre cement. The Six Sigma approach with the DMAIC steps was applied to a case study company. This research started from defining problem, setting the project objective and the project scope. Next, the measurement system was analyzed and the process map was set up. The potential factors of the problem was then determined. Due to there were many factors that affect the MOR, the Cause and Effect Matrix and the Failure Mode and Effect Analysis technique were then used to reduce the number of factors to be studied further. Next, three process factors, which were the pulp slurry freeness, the film-layer thickness, and the pressure step, were optimized using the results from the Box-Behnken experimental design. Other 13 remaining factors were improved by creating or revising the standard work instructions and training the operators. After that, the statistical process control and the control plan were set up to control the production processes. After improvement, the process capability index (Ppk significantly increased from 0.26 to 1.35.

  6. REINFORCING FIBRES AS PART OF TECHNOLOGY OF CONCRETES

    Directory of Open Access Journals (Sweden)

    Zhukov Aleksey Dmitrievich

    2012-07-01

    It was identified that the basalt fibre consumption rate influences both the strength and the density of products made of cellular concrete. The length of the basalt fibre impacts the strength of products. A nomogram was developed to identify the consumption rate of the basalt fibre driven by the strength of products and the Portland cement consumption rate. The authors also studied the influence of the consumption rate of Portland cement and basalt fibre onto the structural quality ratio of the foamed fibre concrete.

  7. EVALUATION OF CHEMICALS INCORPORATED WOOD FIBRE CEMENT MATRIX PROPERTIES

    Directory of Open Access Journals (Sweden)

    MST. SADIA MAHZABIN

    2013-08-01

    Full Text Available Wood fibre cement (WFC boards are well established commercially and widely used in many developed countries. The combination of the properties of two important materials, i.e., cement, and previously treated fibrous materials like wood or agricultural residues; which made up the board, contributed in the performance of the board as building material. In this work, the WFC matrix (WFCM samples are produced to determine the physical properties of WFCM such as the density and water absorption. The wood fibres are incorporated/treated with three different chemical additives; calcium formate (Ca(HCOO2, sodium silicate (Na2.SiO3 and magnesium chloride (MgCl2 prior to mixing with cement. The mechanical properties of the WFCM, with or without chemicals treatment of fibres, such as the compressive strength and flexural strength are evaluated. Three wood/cement ratios (50:50, 40:60, 30:70 are used and the percentages of water and accelerator were 80% and 3% based on the cement weight, respectively. Three moisture-conditioned samples; accelerated aging, dry and wet conditions are used for flexural test. The results reveal that the wood/cement ratio, chemical additives and moisture content had a marked influence on the physical and mechanical properties of the matrix. Finally, it has been shown that the 40:60 wood/cement ratio samples with prior chemicals treatment of the fibres that undergo accelerated aging conditioning achieve higher strength then dry and wet-conditioned boards.

  8. Mechanical properties of thermoplastic composites reinforced with Entada Mannii fibre

    Directory of Open Access Journals (Sweden)

    Oluwayomi BALOGUN

    2017-06-01

    Full Text Available The mechanical properties and fracture mechanisms of thermoplastic composites reinforced with Entada mannii fibres was investigated. Polypropylene reinforced with 1, 3, 5, and 7 wt% KOH treated and untreated Entada mannii fibres were processed using a compression moulding machine. The tensile properties, impact strength, and flexural properties of the composites were evaluated while the tensile fracture surface morphology was examined using scanning electron microscopy. The results show that reinforcing polypropylene with Entada mannii fibres resulted in improvement of the tensile strength and elastic modulus. This improvement is remarkable for 5 wt% KOH treated Entada mannii fibre reinforced composites by 28 % increase as compared with the unreinforced polypropylene. The composites reinforced with Entada mannii fibres also had impact strength values of 70 % higher than the unreinforced polypropylene. However, the polypropylene reinforced with 5 and 7wt% KOH treated fibres exhibited significantly higher flexural strength and Young’s modulus by 53% and 52% increase as compared with the unreinforced polypropylene. The fracture surface of the polypropylene composites reinforced with untreated Entada mannii fibres were characterized by fibre debonding, fibre pull-out and matrix yielding while less voids and fibre pull-outs are observed in the composites reinforced with KOH treated Entada mannii fibres. v

  9. Drying Shrinkage Behaviour of Fibre Reinforced Concrete Incorporating Polyvinyl Alcohol Fibres and Fly Ash

    Directory of Open Access Journals (Sweden)

    Amin Noushini

    2014-01-01

    Full Text Available The current study assesses the drying shrinkage behaviour of polyvinyl alcohol fibre reinforced concrete (PVA-FRC containing short-length (6 mm and long-length (12 mm uncoated monofilament PVA fibres at 0.125%, 0.25%, 0.375%, and 0.5% volumetric fractions. Fly ash is also used as a partial replacement of Portland cement in all mixes. PVA-FRC mixes have been compared to length change of control concrete (devoid of fibres at 3 storage intervals: early-age (0–7 days, short-term (0–28 days, and long-term (28–112 days intervals. The shrinkage results of FRC and control concrete up to 112 days indicated that all PVA-FRC mixes exhibited higher drying shrinkage than control. The shrinkage exhibited by PVA-FRC mixes ranged from 449 to 480 microstrain, where this value was only 427 microstrain in the case of control. In addition, the longer fibres exhibited higher mass loss, thus potentially contributing to higher shrinkage.

  10. Seating load parameters impact on dental ceramic reinforcement conferred by cementation with resin-cements.

    LENUS (Irish Health Repository)

    Addison, Owen

    2010-09-01

    Cementation of all-ceramic restorations with resin-cements has been demonstrated to reduce the incidence of fracture in service. The aim was to investigate the influence of loading force and loading duration applied during cementation on the reinforcement conferred by a resin-cement on a leucite reinforced glass-ceramic.

  11. Experimental Investigation and Analysis of Mechanical Properties of Palm fibre reinforced Epoxy composites and Sisal fibre reinforced Polyester composites

    Directory of Open Access Journals (Sweden)

    B. Muthu Chozha Rajan

    2015-12-01

    Full Text Available The objective of this paper was investigated to evaluate tensile, flexural and Impact properties of Palm fibre reinforced Epoxy composites (PFRP and compared with Sisal fibre reinforced Polyester composites (SFRP. Untreated chopped Palmyra Palm fruit fibre was used as reinforcement in Epoxy resin matrix and chopped sisal fibre was used as reinforcement in Polyester resin matrix. The chopped palm fibrereinforced composite were prepared in volume fractions (Vf such as 10 %, 20 % and 30 % of specimens by using Epoxy and the chopped sisalfibre reinforced composite were prepared in volume fractions (Vf such as 10 %, 20 % and 30 % of specimens by using Polyester. The specimens are tested for their mechanical Properties strictly as per ASTM procedures. Static analysis is performed by FEA based software ANSYS R15 with design constraints as Equivalent stress, Shear stress and deflection.The experimental result and analysis shows that the fibre volume fraction increases the tensile, flexural, Impact strength and modulus of the fibre reinforced composites

  12. Investigation of digital light processing using fibre-reinforced polymers

    DEFF Research Database (Denmark)

    Hofstätter, Thomas; Pedersen, David Bue; Nielsen, Jakob Skov

    2016-01-01

    of fibre length and shape compared to layer thickness has been investigated including concepts to circumvent clustering of the fibres.This research contributes to the implementation of fibre-reinforced polymers in additive manufacturing technologies. Digital light processing allows generation...... of miniaturized objects with relatively high surface quality compared to other additive manufacturing technologies. This paper aim to move fibre reinforced resin parts one step closer towards mechanically strong production-quality components.......-reinforced polymers in digital light processing (DLP) are limited. Fibre-reinforced polymer composites were manufactured into test objects using digital light processing. Short fibres were used in an unordered manner. An anisotropic property due to fibre orientation within the material was observed. The importance...

  13. Investigation of digital light processing using fibre-reinforced polymers

    DEFF Research Database (Denmark)

    Hofstätter, Thomas; Pedersen, David Bue; Nielsen, Jakob Skov

    2016-01-01

    of fibre length and shape compared to layer thickness has been investigated including concepts to circumvent clustering of the fibres.This research contributes to the implementation of fibre-reinforced polymers in additive manufacturing technologies. Digital light processing allows generation...... of miniaturized objects with relatively high surface quality compared to other additive manufacturing technologies. This paper aim to move fibre reinforced resin parts one step closer towards mechanically strong production-quality components.......-reinforced polymers in digital light processing (DLP) are limited. Fibre-reinforced polymer composites were manufactured into test objects using digital light processing. Short fibres were used in an unordered manner. An anisotropic property due to fibre orientation within the material was observed. The importance...

  14. Bond behaviour of GFRP reinforced geopolymer cement concrete

    Directory of Open Access Journals (Sweden)

    Hailu Tekle Biruk

    2017-01-01

    Full Text Available Bond plays a key role in the performance of reinforced concrete structures. Glass fibre reinforced polymer (GFRP reinforcing bar and Geopolymer cement (GPC concrete are promising alternative construction materials for steel bars and Ordinary Portland Cement (OPC concrete respectively. In this study, the bond behaviour between these two materials is investigated by using beam-end specimen tests. The bond behaviour of 15.9 mm diameter sand-coated GFRP bar was investigated. An embedment length of six and nine times the bar diameter were used. The free end and the loaded end bond-slip-relationships, the bond failure mode and the average bond stress were used to analyse each of the specimens. Additionally, the distribution of tensile and bond stress along the embedment length was investigated by installing strain gauges along the embedment length in some of the specimens. Test results indicate that a significant difference exists between the free end and loaded end bond-slip curves, which is due to the lower elastic modulus of the GFRP bars. Furthermore, it was found that the tensile and bond stress distribution along the embedment length is nonlinear and the nonlinearity changes with the load.

  15. Assessment of L/D Ratio of Eco Fibre - Bamboo as a Reinforcement Material in Concrete

    Directory of Open Access Journals (Sweden)

    Kavitha.s

    2016-10-01

    Full Text Available Fibres are commonly used in concrete to control the cracks, shrinkage and to improve the strength and performance of the concrete. Generally various types of fibres are used like natural and artificial fibres in the concrete mix to produce the expected strength and crack resistance. an attempt is made to innovate a natural, eco friendly fibre which is available to the common man. In this paper, tests are carryout on bamboo fibre reinforced concrete to evaluate aspect ratio (l/d of bamboo fibres. Different ages of bamboo is collected, the extraction of fibres is done by mechanical method. Once the bamboo fibres are extracted the various lengths and diameters are selected and SEM analysis is carried out to find out the microstructure of bamboo fibres to know the failure analysis .these selected bamboo fibres add at the fixed rate of 0.1% to 1.5%(0.5,0.75,1,1.25,1.5 by the cement weight to the concrete mix. Then the samples of cubes, beams and cylinders are casted from the concrete mix and curing will be done for required period. Experimental investigations are carried out using most commonly used tests in laboratory, which includes concrete workability test, compressive test, split tensile test, and test for flexure from the various test results the aspect ratio (l/d ratio and also the effectiveness of bamboo fibres usage in concrete has been evaluated.

  16. Strength Evaluation of Steel-Nylon Hybrid Fibre Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Maniram Kumar

    2014-07-01

    Full Text Available When fibres like steel, glass, polypropylene, nylon, carbon, aramid, polyester, jute, etc are mixed with concrete known as fibre reinforced concrete. To overcome the deficiencies of concrete; fibres are added to improve the performance of concrete. In this research hybrid reinforced concrete is made by using steel and nylon 6 fibres. The inclusion of both steel and nylon 6 fibres are used in order to combine the benefits of both fibers; structural improvements provided by steel fibers and the resistance to plastic shrinkage improvements provided by nylon fibers. So the aim of this project is to investigate the mechanical properties (compressive strength, flexure strength and split tensile strength of hybrid fiber reinforced concrete under compression, flexure & tension. The total volume of fibre was taken 0.75 % of total volume of concrete. In this experimental work, four different concrete mix proportions were casted with fibres and one mix without fibres. Four different mix combinations of steel- nylon 6 fibres were 100-00%, 75-25%, 50-50% and 25-75%. Superplasticizer was used in all mixes to make concrete more workable. The results shown that compressive, split tensile and flexural strength of hybrid fibre reinforced concrete increase by increasing quantity of steel and nylon 6 fibres. The increase in compressive and tensile strength due to incorporation of steel fibre is greater than that of using nylon fibre. For the nylon 6 fibres, adding more fibres into the concrete has a limited improvement on splitting tensile strength. Inclusion of nylon 6 fibres along with steel fibres results in considerable improvement in flexural strength as compared to solo steel fibre.

  17. Fatigue damage propagation in unidirectional glass fibre reinforced composites

    DEFF Research Database (Denmark)

    Hansen, Jens Zangenberg; Alzamora Guzman, Vladimir Joel; Østergaard, R.C.

    2012-01-01

    Damage progression in unidirectional glass fibre reinforced composites exposed to tension fatigue is investigated, and a quantitative explanation is given for the observed stiffness loss. The stiffness degradation during fatigue is directly related to fibre breaks in the load-carrying axial fibre...... needs further attention and understanding in order to improve the fatigue life-time of glass fibre reinforced composites....... bundles. The underlying mechanisms are examined using digital microscopy, and it is postulated that fatigue damage initiates due to stress concentrations between the backing (transverse) layer and the unidirectional layer, followed by a cyclic fretting and axial fibre debonding. This fretting mechanism...

  18. Treatments of non-wood plant fibres used as reinforcement in composite materials

    Directory of Open Access Journals (Sweden)

    Marie-Ange Arsène

    2013-01-01

    Full Text Available This paper presents a summary of the knowledge on fibres and pulps of non wood tropical plants used as reinforcement in cementitious composites accumulated during the recent years by Guadeloupean and Brazilian teams participating in collaborative work. Vegetable fibres represent a good alternative as non-conventional materials for the construction of ecological and sustainable buildings. The use of such renewable resources contributes to the development of sustainable technologies. The main objective of the paper is to emphasize the use of agricultural wastes in the production of cement based composites. The botanical, chemical, physical, morphological and mechanical properties of fibres from various plants are described. The effects of different treatments on physical, chemical and mechanical properties of fibres are presented. The most effective treatments in influencing the mechanical and physical properties are pyrolysis and alkaline ones, according to the type of plant. The final choice will have to consider fibre availability, and treatment costs.

  19. Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders

    NARCIS (Netherlands)

    De Kanter, J.L.C.G.

    2006-01-01

    Summary accompanying the thesis: Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders by Jens de Kanter This thesis presents the investigation of the crush behaviour of both monolithic aluminium cylinders and externally fibre reinforced aluminium cylinders. The research is based

  20. Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders

    NARCIS (Netherlands)

    De Kanter, J.L.C.G.

    2006-01-01

    Summary accompanying the thesis: Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders by Jens de Kanter This thesis presents the investigation of the crush behaviour of both monolithic aluminium cylinders and externally fibre reinforced aluminium cylinders. The research is based

  1. Design of macro-synthetic fibre reinforced concrete pipes

    OpenAIRE

    Fuente, Albert de la; Escariz, Renata Campos; Figueiredo,Antonio Domingues de; Aguado, Antonio

    2013-01-01

    This paper presents an experimental campaign in which concrete pipes were manufactured using plastic fibres as the sole reinforcement material. In this regard, it has been demonstrated that the use of plastic fibres is compatible with pipe production systems, and that, when subjected to the crushing test (CT), plastic fibre reinforced pipes yield strength classes that are attractive in terms of the growth of this material in the concrete pipe industry. Moreover, the results obtained from b...

  2. Structural Engineering Properties of Fibre Reinforced Concrete Based On Recycled Glass Fibre Polymer (GFRP)

    OpenAIRE

    Adetiloye A; Ephraim M. E

    2015-01-01

    Glass fibre reinforced plastics (GFRP) based on resin recovered from recycling plastic waste has been shown to possess mechanical properties satisfying normative requirements. This paper investigates the flexural behavior of concrete beams reinforced with GFRP produced from resin recovered from recycled plastic wastes. A total of twelve of beams of sizes 150 ×150 ×900mm and 100 × 100 × 500mm reinforced with GFRP made from recycled glass fibre reinforced polymer was tested. The fle...

  3. Microanalytical investigation of fibre-reinforced ceramic materials

    Energy Technology Data Exchange (ETDEWEB)

    Meier, B.; Grathwohl, G.

    1989-03-01

    Microanalytical investigations have been made on samples of ceramic fibres (SiC fibres, (Nicalon) C fibre coated with TiN) and fibre-reinforced ceramics (SiC-and glass-matrices). High resolution Auger electron spectroscopy (HRAES), electron probe microanalysis (EPMA) and scanning electron microscopy were employed for these examinations. Analysis was best performed with HRAES on account of its lateral and depth resolution. Some of the problems involved in this technique are discussed e.g. electron beam effects. AES depth profiles of ceramic fibres are reported and compared with the surface analysis of fibres in the composites after being broken in situ.

  4. Effect of discrete fibre reinforcement on soil tensile strength

    Directory of Open Access Journals (Sweden)

    Jian Li

    2014-04-01

    Full Text Available The tensile behaviour of soil plays a significantly important role in various engineering applications. Compacted soils used in geotechnical constructions such as dams and clayey liners in waste containment facilities can suffer from cracking due to tensile failure. In order to increase soil tensile strength, discrete fibre reinforcement technique was proposed. An innovative tensile apparatus was developed to determine the tensile strength characteristics of fibre reinforced soil. The effects of fibre content, dry density and water content on the tensile strength were studied. The results indicate that the developed test apparatus was applicable in determining tensile strength of soils. Fibre inclusion can significantly increase soil tensile strength and soil tensile failure ductility. The tensile strength basically increases with increasing fibre content. As the fibre content increases from 0% to 0.2%, the tensile strength increases by 65.7%. The tensile strength of fibre reinforced soil increases with increasing dry density and decreases with decreasing water content. For instance, the tensile strength at a dry density of 1.7 Mg/m3 is 2.8 times higher than that at 1.4 Mg/m3. It decreases by 30% as the water content increases from 14.5% to 20.5%. Furthermore, it is observed that the tensile strength of fibre reinforced soil is dominated by fibre pull-out resistance, depending on the interfacial mechanical interaction between fibre surface and soil matrix.

  5. Mechanical properties of natural fibre reinforced polymer composites

    Indian Academy of Sciences (India)

    A S Singha; Vijay Kumar Thakur

    2008-10-01

    During the last few years, natural fibres have received much more attention than ever before from the research community all over the world. These natural fibres offer a number of advantages over traditional synthetic fibres. In the present communication, a study on the synthesis and mechanical properties of new series of green composites involving Hibiscus sabdariffa fibre as a reinforcing material in urea–formaldehyde (UF) resin based polymer matrix has been reported. Static mechanical properties of randomly oriented intimately mixed Hibiscus sabdariffa fibre reinforced polymer composites such as tensile, compressive and wear properties were investigated as a function of fibre loading. Initially urea–formaldehyde resin prepared was subjected to evaluation of its optimum mechanical properties. Then reinforcing of the resin with Hibiscus sabdariffa fibre was accomplished in three different forms: particle size, short fibre and long fibre by employing optimized resin. Present work reveals that mechanical properties such as tensile strength, compressive strength and wear resistance etc of the urea–formaldehyde resin increases to considerable extent when reinforced with the fibre. Thermal (TGA/DTA/DTG) and morphological studies (SEM) of the resin and biocomposites have also been carried out.

  6. Effect of discrete fibre reinforcement on soil tensile strength

    Institute of Scientific and Technical Information of China (English)

    Jian Li; Chaosheng Tang; Deying Wang; Xiangjun Pei; Bin Shi

    2014-01-01

    The tensile behaviour of soil plays a significantly important role in various engineering applications. Compacted soils used in geotechnical constructions such as dams and clayey liners in waste containment facilities can suffer from cracking due to tensile failure. In order to increase soil tensile strength, discrete fibre reinforcement technique was proposed. An innovative tensile apparatus was developed to deter-mine the tensile strength characteristics of fibre reinforced soil. The effects of fibre content, dry density and water content on the tensile strength were studied. The results indicate that the developed test apparatus was applicable in determining tensile strength of soils. Fibre inclusion can significantly in-crease soil tensile strength and soil tensile failure ductility. The tensile strength basically increases with increasing fibre content. As the fibre content increases from 0%to 0.2%, the tensile strength increases by 65.7%. The tensile strength of fibre reinforced soil increases with increasing dry density and decreases with decreasing water content. For instance, the tensile strength at a dry density of 1.7 Mg/m3 is 2.8 times higher than that at 1.4 Mg/m3. It decreases by 30% as the water content increases from 14.5% to 20.5%. Furthermore, it is observed that the tensile strength of fibre reinforced soil is dominated by fibre pull-out resistance, depending on the interfacial mechanical interaction between fibre surface and soil matrix.

  7. Serviceability and Reinforcement of Low Content Whisker in Portland Cement

    Institute of Scientific and Technical Information of China (English)

    CAO Mingli; WEI Jianqiang; WANG Lijiu

    2011-01-01

    In order to explore the serviceability and reinforcement of CaCO3 whisker in portland cement matrix,the durability of CaCO3 whisker and effect of low whisker content(0%-4.0%)on the working performance and mechanical properties of portland cement were investigated.The experimental results show that CaCO3 whiskers have a good stability and serviceability in cement,and should not significantly alter the rheological properties of the cement paste.The flexural and compressive strength of portland cement reinforced by CaCO3 whiskers was increased by 33.3% and 12.83%,respectively.

  8. Fabrication and characterization of S. cilliare fibre reinforced polymer composites

    Indian Academy of Sciences (India)

    A S Singha; Vijay Kumar Thakur

    2009-02-01

    In the recent times, there has been an ever-increasing interest in green composite materials for its applications in the field of industries, aerospace, sports, household etc and in many other fields. In this paper, fabrication of Saccharum cilliare fibre reinforced green polymer composites using resorcinol formaldehyde (RF) as a novel matrix has been reported. A systematic approach for processing of polymer is presented. Effect of fibre loading on mechanical properties like flexural, tensile, compressive and wear resistances has also been determined. Reinforcing of the RF resin with Saccharum cilliare (SC) fibre was done in the form of particle size (200 micron). Present work reveals that mechanical properties of the RF resin have been found to increase up to 30% fibre loading and then decreases. Morphological and thermal studies of the resin, fibre and particle reinforced (P-Rnf) green composites have also been studied.

  9. Thermoforming of Continuous Fibre Reinforced Thermoplastic Composites

    Science.gov (United States)

    McCool, Raurí; Murphy, Adrian; Wilson, Ryan; Jiang, Zhenyu; Price, Mark

    2011-05-01

    The introduction of new materials, particularly for aerospace products, is not a simple, quick or cheap task. New materials require extensive and expensive qualification and must meet challenging strength, stiffness, durability, manufacturing, inspection and maintenance requirements. Growth in industry acceptance for fibre reinforced thermoplastic composite systems requires the determination of whole life attributes including both part processing and processed part performance data. For thermoplastic composite materials the interactions between the processing parameters, in-service structural performance and end of life recyclability are potentially interrelated. Given the large number and range of parameters and the complexity of the potential relationships, understanding for whole life design must be developed in a systematic building block approach. To assess and demonstrate such an approach this article documents initial coupon level thermoforming trials for a commercially available fibre reinforced thermoplastic laminate, identifying the key interactions between processing and whole life performance characteristics. To examine the role of the thermoforming process parameters on the whole life performance characteristics of the formed part requires a series of manufacturing trials combined with a series of characterisation tests on the manufacturing trial output. Using a full factorial test programme and considering all possible process parameters over a range of potential magnitudes would result in a very large number of manufacturing trials and accompanying characterisation tests. Such an approach would clearly be expensive and require significant time to complete, therefore failing to address the key requirement for a future design methodology capable of rapidly generating design knowledge for new materials and processes. In this work the role of mould tool temperature and blank forming temperature on the thermoforming of a commercially available

  10. Abaca fibre reinforced PP composites and comparison with jute and flax fibre PP composites

    Directory of Open Access Journals (Sweden)

    2007-11-01

    Full Text Available Abaca fibre reinforced PP composites were fabricated with different fibre loadings (20, 30, 40, 50wt% and in some cases 35 and 45 wt%. Flax and jute fibre reinforced PP composites were also fabricated with 30 wt% fibre loading. The mechanical properties, odour emission and structure properties were investigated for those composites. Tensile, flexural and Charpy impact strengths were found to increase for fibre loadings up to 40 wt% and then decreased. Falling weight impact tests were also carried out and the same tendency was observed. Owing to the addition of coupling agent (maleated polypropylene -MAH-PP, the tensile, flexural and falling weight impact properties were found to increase in between 30 to 80% for different fibre loadings. When comparing jute and flax fibre composites with abaca fibre composites, jute fibre composites provided best tensile properties but abaca fibre polypropylene composites were shown to provide best notch Charpy and falling weight impact properties. Odours released by flax fibre composites were smaller than jute and abaca fibre composites.

  11. AR-Glass Fibre-Cement Interfacial Transition Zone

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The microstructure of ITZ (Interfacial Transition Zone) in single glass fibre-cement was investigated by SEM (Scanning Electron Microscope), EPXM (Electron Probe X-ray Microanalyzer) and ESEM (Environmental Scanning Electron Microscope). The surface morphology of glass fibres and the hydration products in the vicinity of the interfaces were observed.Chemical element (Zr, Ca and Si) distributions over the ITZ thickness were determined by line-scanning with EPXM.The results show that a low-density transition zone existed in the vicinity of glass fibres. The shape of the fibre-cement ITZ was non-symmetrical and its thickness was variable. In the present study, the width of the zone ranged from 1-5μm.Locally, it came to 10μm.Occasionally, some hydration products with high alkalinity were embedded inside the ITZ, and attached on the glass surface,making the ITZ denser and causing local glass to corrode.The test results are helpful for the further understanding of the GRC degradation.

  12. Carbon fibre-reinforced, alkali-activated slag mortars

    Directory of Open Access Journals (Sweden)

    Garcés, P.

    2007-12-01

    Full Text Available The paper describes the effect of carbon fibre on alkaliactivated slag mortar (AAS mechanical strength, volume stability and reinforcing steel corrosion, compared to its effect on the same properties in Portland cement (PC properties. Mechanical strength and volume stability tests were performed as set out in the respective Spanish UNE standards. The corrosion rate of steel embedded in the specimens studied was determined from polarization resistance analysis. One of the findings of the study performed was that carbon fibre failed to improve AAS or CP mortar strength. As far as volume stability is concerned, the inclusion of carbon fibres in AAS with a liquid/solid ratio of 0.5 reduced drying shrinkage by about 50%. The effect of carbon fibre on PC mortars differed from its effect on AAS mortars. Studies showed that in the presence of carbonation, steel corrosion reached higher levels in carbon-fibre reinforced AAS mortars; the inclusion of 1% carbon fibre improved corrosion resistance perceptibly in these same mortars, however, when exposed to chloride attack.Se ha estudiado el efecto de la incorporación de fibras de carbón en el comportamiento mecánico, estabilidad de volumen y nivel de corrosión de la armadura en morteros de escorias activadas alcalinamente (AAS. Se evalúa la influencia de las fibras de carbón en el comportamiento de morteros alcalinos en comparación con el efecto que producen en morteros de Portland (CP. Los ensayos mecánicos y de estabilidad de volumen se han realizado según lo establecido en la norma UNE que los regula. Se ha utilizado la técnica de la Resistencia a la Polarización para determinar la velocidad de corrosión del acero embebido en las muestras estudiadas. Como consecuencia del estudio realizado, se ha podido concluir que la adición de fibras de carbón a morteros de AAS y CP no mejora las características resistentes de los mismos. En relación con la estabilidad de volumen, la incorporación de

  13. An application of asymmetrical glass fibre-reinforced plastics for the manufacture of curved fibre reinforced concrete

    OpenAIRE

    Funke, Henrik; Gelbrich, Sandra; Ulke-Winter , Lars; Kroll, Lothar; Petzoldt, Carolin

    2015-01-01

    There was developed a novel technological and constructive approach for the low-cost production of curved freeform formworks, which allow the production of single and double-curved fibre reinforced concrete. The scheduled approach was based on a flexible, asymmetrical multi-layered formwork system, which consists of glass-fibre reinforced plastic (GFRP). By using of the unusual anisotropic structural behavior, these GFRP formwork elements permitted a specific adjustment of defined curvature. ...

  14. Tensile properties of glass/natural jute fibre-reinforced polymer bars for concrete reinforcement

    Science.gov (United States)

    Han, J. W.; Lee, S. K.; Kim, K. W.; Park, C. G.

    2015-12-01

    The tensile performance of glass/natural jute fibre-reinforced polymer (FRP) bar, intended for concrete reinforcement was evaluated as a function of volume fraction of natural jute fibre. Natural jute fibre, mixed at a ratio of 7:3 with vinyl ester, was surface-treated with a silane coupling agent and used to replaced glass fibre in the composite in volume fractions of 0%, 30%, 50%, 70%, and 100%. The tensile load-displacement curve showed nearly linear elastic behaviour up to 50% natural jute fibre, but was partially nonlinear at a proportion of 70%. However, the glass/natural jute FRP bars prepared using 100% natural jute fibre showed linear elastic behaviour. Tensile strength decreased as the natural jute fibre volume fraction increased because the tensile strength of natural jute fibre is much lower than that of glass fibre (about 1:8.65). The degree of reduction was not proportional to the natural jute fibre volume fraction due to the low density of natural jute fibre (1/2 that of glass fibre). Thus, as the mix proportion of natural jute fibre increased, the amount (wt%) and number of fibres used also increased.

  15. Compressive behaviour at High Temperatures of Fibre Reinforced Concretes

    Directory of Open Access Journals (Sweden)

    S. O. Santos

    2009-01-01

    Full Text Available This paper summarizes the research that is being carried out at the Universities of Coimbra and Rio de Janeiro, on fibre reinforced concretes at high temperatures. Several high strength concrete compositions reinforced with fibres (polypropylene, steel and glass fibres were developed. The results of compressive tests at high temperatures (300 °C, 500 °C and 600 °C and after heating and cooling down of the concrete are presented in the paper. In both research studies, the results indicated that polypropylene fibers prevent concrete spalling. 

  16. Service life prediction and fibre reinforced cementitious composites

    DEFF Research Database (Denmark)

    Stoklund Larsen, E.

    The present Ph.D.thesis addresses the service life concept on the fibre reinforced cementitious composites. The advantages and problems of adding fibre to a cementitious matrix and the influence on service life are described. In SBI Report 221, Service life prediction and cementitious somposites......, the factors affecting the pure cementitious composite are described. Different sizes and types of fibre reinforced crmentitious composites have been chosen to illustrate different ageing and deterioration mechanisms. Some ageing mechanisms can be accelerated and others cannot which is demonstrated in a test...

  17. Shear Capacity of Steel and Polymer Fibre Reinforced Concrete Beams

    DEFF Research Database (Denmark)

    Kragh-Poulsen, Jens C.; Hoang, Cao Linh; Goltermann, Per

    2011-01-01

    This paper deals with the application of a plasticity model for shear strength estimation of fibre reinforced concrete beams without stirrups. When using plastic theory to shear problems in structural concrete, the so-called effective strengths are introduced, usually determined by calibrating...... the plastic solutions with tests. This approach is, however, problematic when dealing with fibre reinforced concrete (FRC), as the effective strengths depend also on the type and the amount of fibres. In this paper, it is suggested that the effective tensile strength of FRC can be determined on the basis...

  18. Dynamic Properties of Fiber Reinforced Cement Mortar

    Institute of Scientific and Technical Information of China (English)

    唐志平; 徐松林; 胡晓军; 廖香丽; 蔡建

    2004-01-01

    Based on the shear wave tracing(SWT) technique proposed by Tang Z P, particle velocity gauge and the dual internal measurement for pressure and shear waves (IMPS) system are applied to investigate the responses of fiber reinforced cement subjected to impact loading. Series of experiments are conducted. The results show that there exist four critical points, A, B, C, D, in p-V Hugoniot curves. They correspond to the Hugoniot elastic limit (HEL) of the material, the critical point for shear strength limit and transition from damage state to failure state, void collapse, and solid compression, respectively. The critical point B is difficult to be aware of and never reported. However, it can be clearly disclosed with SWT method. Based on the analyses of shear strength, it can be concluded that the transversal wave, especially the unloading transversal wave, is especially important for the dynamic damage investigation of brittle materials.

  19. A validation of the fibre orientation and fibre length attrition prediction for long fibre-reinforced thermoplastics

    Science.gov (United States)

    Hopmann, Ch.; Weber, M.; van Haag, J.; Schöngart, M.

    2015-05-01

    To improve the mechanical performance of polymeric parts, fibre reinforcement has established in industrial applications during the last decades. Next to the widely used Short Fibre-reinforced Thermoplastics (SFT) the use of Long Fibre-reinforced Thermoplastics (LFT) is increasingly growing. Especially for non-polar polymeric matrices like polypropylene (PP), longer fibres can significantly improve the mechanical performance. As with every kind of discontinuous fibre reinforcement the fibre orientations (FO) show a high impact on the mechanical properties. On the contrary to SFT where the local fibre length distribution (FLD) can be often neglected, for LFT the FLD show a high impact on the material's properties and has to be taken into account in equal measure to the FOD. Recently numerical models are available in commercial filling simulation software and allow predicting both the local FOD and FLD in LFT parts. The aim of this paper is to compare i.) the FOD results and ii) the FLD results from available orientation- and fibre length attrition-models to those obtained from experimental data. The investigations are conducted by the use of different injection moulded specimens made from long glass fibre reinforced PP. In order to determine the FOD, selected part sections are examined by means of Computed Tomographic (CT) analyses. The fully three dimensional measurement of the FOD is then performed by digital image processing using grey scale correlation. The FLD results are also obtained by using digital image processing after a thermal pyrolytic separation of the polymeric matrix from the fibres. Further the FOD and the FLD are predicted by using a reduced strain closure (RSC) as well as an anisotropic rotary diffusion - reduced strain closure model (ARD-RSC) and Phelps-Tucker fibre length attrition model implemented in the commercial filling software Moldflow, Autodesk Inc., San Rafael, CA, USA.

  20. A validation of the fibre orientation and fibre length attrition prediction for long fibre-reinforced thermoplastics

    Energy Technology Data Exchange (ETDEWEB)

    Hopmann, Ch.; Weber, M.; Haag, J. van; Schöngart, M. [Institute of Plastics Processing (IKV) at RWTH Aachen University, Pontstr. 49, 52062 Aachen (Germany)

    2015-05-22

    To improve the mechanical performance of polymeric parts, fibre reinforcement has established in industrial applications during the last decades. Next to the widely used Short Fibre-reinforced Thermoplastics (SFT) the use of Long Fibre-reinforced Thermoplastics (LFT) is increasingly growing. Especially for non-polar polymeric matrices like polypropylene (PP), longer fibres can significantly improve the mechanical performance. As with every kind of discontinuous fibre reinforcement the fibre orientations (FO) show a high impact on the mechanical properties. On the contrary to SFT where the local fibre length distribution (FLD) can be often neglected, for LFT the FLD show a high impact on the material’s properties and has to be taken into account in equal measure to the FOD. Recently numerical models are available in commercial filling simulation software and allow predicting both the local FOD and FLD in LFT parts. The aim of this paper is to compare i.) the FOD results and ii) the FLD results from available orientation- and fibre length attrition-models to those obtained from experimental data. The investigations are conducted by the use of different injection moulded specimens made from long glass fibre reinforced PP. In order to determine the FOD, selected part sections are examined by means of Computed Tomographic (CT) analyses. The fully three dimensional measurement of the FOD is then performed by digital image processing using grey scale correlation. The FLD results are also obtained by using digital image processing after a thermal pyrolytic separation of the polymeric matrix from the fibres. Further the FOD and the FLD are predicted by using a reduced strain closure (RSC) as well as an anisotropic rotary diffusion - reduced strain closure model (ARD-RSC) and Phelps-Tucker fibre length attrition model implemented in the commercial filling software Moldflow, Autodesk Inc., San Rafael, CA, USA.

  1. Crack Growth Monitoring by Embedded Optical Fibre Bragg Grating Sensors: Fibre Reinforced Plastic Crack Growing Detection

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira; Mikkelsen, Lars Pilgaard; McGugan, Malcolm

    2015-01-01

    This article presents a novel method to asses a crack growing/damage event in fibre reinforced plastic, or adhesive using Fibre Bragg Grating (FBG) sensors embedded in a host material. Different features of the crack mechanism that induce a change in the FBG response were identified. Double Canti...

  2. Analytical Evaluation of Fibre-Reinforced Plastic Corrugated Sheet

    Directory of Open Access Journals (Sweden)

    C. K. Gautam

    1998-01-01

    Full Text Available Fibre-reinforced' composites playa lead role as advanced materials in modem day structures.This paper reports fabrication and testing offibre-reinforced corrugated sheet employing 4-point bend loading. An in-depth analysis has been carried out using ANSYS, a finite element method package.The theoretical results obtained are compared with the experimental values. The values ofboth inputsshowed similar results. conforming at a particular boundary condition. However, more similarexperiments "on such fibre-reinforced plastic corrugated sheets have been suggested for -better comparison.

  3. Influence of fibre volume fraction and temperature on fatigue life of glass fibre reinforced plastics

    Directory of Open Access Journals (Sweden)

    Konrad Wegener

    2016-07-01

    Full Text Available The influence of fibre volume fraction and temperature on fatigue life of continuous glass fibre reinforced plastics is investigated in detail. The physical causes of the two effects on the slope of the S-N-curve in fibre direction at R = 0.1 are researched and can be explained with help of micrographs. A new phenomenological approach is presented to model both effects in fibre dominated laminates with different stacking sequences using only the static ultimate strength as an input. Static and fatigue tests of different layups and fibre volume fractions are performed at different temperatures to validate the fatigue life predictions. Additionally it is derived that there is an optimal fibre volume fraction regarding a minimum damage sum. This fibre volume fraction is dependent on a given loading spectra and can be calculated using the phenomenological model.

  4. Flow modelling of steel fibre reinforced self-compacting concrete

    DEFF Research Database (Denmark)

    Svec, Oldrich

    Concrete is one of the most widely used materials in the world. Ordinary concrete composition makes the material strong in compression yet weak and brittle in tension. Steel reinforced concrete successfully eliminates the weak tensile properties of the ordinary concrete. Steel fibres dispersed...... in concrete can efficiently substitute or supplement conventional steel reinforcement, such as reinforcement bars. Ordinary concrete composition further makes the material stiff and non-flowable. Self-compacting concrete is an alternative material of low yield stress and plastic viscosity that does flow...... and fills the formwork with a little or no effort. Steel fibre reinforced self-compacting concrete is a logical combination of the two types of concrete. The combination nevertheless creates several challenges. It has been observed by many authors that steel fibres orient and distribute according...

  5. Selected Bibliography on Fiber-Reinforced Cement and Concrete. Supplement Number 4.

    Science.gov (United States)

    1982-08-01

    Building Industry," L’Industria Italiana del Cemento , Vol 50, No. 12, Dec 1980, pp 1135-1144. 19. Bartos, P., "Pullout Failure of Fibres Embedded in Cement...Vol 43, No. 11, Nov 1977, pp 561-564. 21. Bassan, M., "Model of Behavior of Fiber-Reinforced Concretes Under Impact Stresses," il Cemento , Vol 74, No...Pastes," il Cemento , Vol 75, No. 3, Jul-Sep 1978, pp 277-284. 210. Mills, R. H., "Age-Embrittlement of Glass-Reinforced Concrete Containing Blastfurance

  6. Electron beam irradiation in natural fibres reinforced polymers (NFRP)

    Energy Technology Data Exchange (ETDEWEB)

    Kechaou, B. [LaMaCoP - Faculte des sciences de Sfax, 3018 Sfax (Tunisia); LTDS-UMR 5513 - Ecole Centrale de Lyon, B.P 163 69134 Ecully Cedex (France); Salvia, M. [LTDS-UMR 5513 - Ecole Centrale de Lyon, B.P 163 69134 Ecully Cedex (France); Fakhfakh, Z. [LaMaCoP - Faculte des sciences de Sfax, 3018 Sfax (Tunisia); Juve, D. [LTDS-UMR 5513 - Ecole Centrale de Lyon, B.P 163 69134 Ecully Cedex (France); Boufi, S. [LSME-Faculte des Sciences de Sfax, 3018 Sfax (Tunisia); Kallel, A. [LaMaCoP - Faculte des sciences de Sfax, 3018 Sfax (Tunisia); Treheux, D. [LTDS-UMR 5513 - Ecole Centrale de Lyon, B.P 163 69134 Ecully Cedex (France)], E-mail: daniel.treheux@ec-lyon.fr

    2008-11-15

    This study focuses on the electric charge motion in unsatured polyester and epoxy composites reinforced by natural fibres of Alfa type, treated by different coupling agents. The electric charging phenomenon is studied by scanning electron microscopy mirror effect (SEMME) coupled with the induced current method (ICM). Previously, using the same approach, glass fibre reinforced epoxy (GFRE) was studied to correlate mechanical [B. Kchaou, C. Turki, M. Salvia, Z. Fakhfakh, D. Treheux, Composites Science and Technology 64 (2004) 1467], or tribological [B. Kchaou, C. Turki, M. Salvia, Z. Fakhfakh, D. Treheux, Dielectric and friction behaviour of unidirectionalglass fibre reinforced epoxy (GFRE), Wear, 265 (2008) 763.] properties and dielectric properties. It was shown that the dielectric properties of the fibre-matrix interfaces play a significant role in the optimization of the composite. This result seems to be the same for natural fibre composites: the fibre-matrix interfaces allow a diffusion of the electric charges which can delocalize the polarization energy and consequently delay the damage of the composite. However, a non-suited sizing can lead to a new trapping of electric charges along these same interfaces with, as a consequence, a localization of the polarisation energy. The optimum composite is obtained for one sizing which helps, at the same time, to have a strong fibre-matrix adhesion and an easy flow of the electric charges along the interface.

  7. Durability of cracked fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place; Nielsen, Laila

    1997-01-01

    (capillary water uptake) is used, involving an in-situ method and a laboratory method. Three different concrete qualities as well as steel fibres (ZP) and polypropylene fibres (PP) are used. Results of the durability tests on cracked FRC-beams are compared to results for uncracked FRC-beams and beams without...

  8. ELASTICITY of SHORT FIBRE REINFORCED POLYAMIDE: MORPHOLOGICAL AND NUMERICAl ANALYSIS OF FIBRE ORIENTATION EFFECTS

    Directory of Open Access Journals (Sweden)

    Francesca Cosmi

    2010-10-01

    Full Text Available The fatigue behaviour of injection moulded short fibre reinforced polymers depends upon fibre orientation, as shown in experiments conducted with notched specimens injected through different injection gates. The different fatigue behaviour is mainly related to the different local elastic properties, as determined by the different fibre orientation patterns, resulting into different strain distributions. In order to quantify the relationship between fibre orientation and elastic constants, the Cell Method was applied to volumes extracted from the specimens, reconstructed by micro-tomography.

  9. INFLUENCE OF FIBRE VOLUME REINFORCEMENT IN DRILLING GFRP LAMINATES

    Directory of Open Access Journals (Sweden)

    D. ABDUL BUDAN

    2011-12-01

    Full Text Available This paper presents an investigation on the influence of fiber volume reinforcement on various aspects of machining. Drilling experiments were conducted to study the tool wear, surface finish, delamination factor and hole quality on GFRP composites. The work reports the variation of tool wear, surface roughness, hole quality, chip characteristics, delamination factor with the variation of fibre volume reinforcement. Results revealed that the increase in fiber percentage increased the tool wear, delamination factor, surface roughness value and decreased hole quality. Minimum surface roughness, tool wear and better hole quality was obtained for 30% fibre content composites. 70% Fibre content composites produced hazardous surface roughness. Pull out of fibres and fibril formation are significant in decreasing the hole quality and increased surface roughness. Increased tool – fibre interaction and thermal softening of the tool causes increased tool wear. In higher fibre content composites, extensive plasticity was absent consequently brittle ceramic fibres were fractured easily. Hence small segment type chips were obtained. The fibre pull out and fibrils present near the hole exit forms the remainder of the laminate causes increased damage zone near the hole exit. Hence high delamination factor was obtained.

  10. Topological calculation of key parameters of fibre for production of foam concrete based on cement-free nanostructured binder

    Directory of Open Access Journals (Sweden)

    KHARKHARDIN Anatoly Nikolaevich

    2016-08-01

    Full Text Available Fiber reinforcement is the process of introduction of fibers of different origins into binding system to enhance strength, stress-strain behavior of products and structures. Maximal effect of reinforcing process is possible when optimal parameters (length and consumption of fibre are determined. Moreover one need to consider particle-size composition and hardening process of binding system. In this paper the critical length of natural and sinthesized fibres as well as minimally required content in cellular systems is calculated with the mathematical apparatus of structural topology. As an example the foam concrete based on cement-free nanostructured binder with basalt fibre and microreinforcing constructional polymeric fibre is studied. Fiber diameter, refined with microstructure analysis, accomplished by SEM-microscopy and experimentally determined packing density in loose and compact state are applied as input parameters. Measurement of the fibre topological characteristics with acceptable is accomplished according to material porosity and pore size. So the minimal effective fibre length taking into account homogeneous distribution in bulk of composite matrix is less of 1 mm; minimal fibre consumption is 0,2–0,5 (by wt. %. Irrational optimization leads to unreasonable cost growth of final materials as well as formation of balling inclusions that negatively affects on final performance of composite.

  11. Dynamic fracture behaviour in fibre-reinforced cementitious composites

    Science.gov (United States)

    Yu, Rena C.; Cifuentes, Héctor; Rivero, Ignacio; Ruiz, Gonzalo; Zhang, Xiaoxin

    2016-08-01

    The object of this work is to simulate the dynamic fracture propagation in fibre-reinforced cementitious composites, in particular, in steel fibre reinforced concrete (SFRC). Beams loaded in a three-point bend configuration through a drop-weight impact device are considered. A single cohesive crack is assumed to propagate at the middle section; the opening of this crack is governed by a rate-dependent cohesive law; the fibres around the fracture plane are explicitly represented through truss elements. The fibre pull-out behaviour is depicted by an equivalent constitutive law, which is obtained from an analytical load-slip curve. The obtained load-displacement curves and crack propagation velocities are compared with their experimental counterparts. The good agreement with experimental data testifies to the feasibility of the proposed methodology and paves the way to its application in a multi-scale framework.

  12. Woven Structures from Natural Fibres for Reinforcing Composites

    OpenAIRE

    Maniņš, M; Bernava, A; Strazds, G.

    2015-01-01

    The increase of production of woven structures from natural fibres for reinforced composites can be noticed in different sectors of economy. This can be explained by limited sources of raw materials and different environmental issues, as well as European Union guidelines for car manufacture [4]. This research produced 2D textile structures of hemp yarn and polypropylene yarn and tested the impact of added glass fibre yarn on the mechanical properties of the woven structures and the composites...

  13. Mechanical properties of pineapple leaf fibre reinforced polypropylene composites

    Energy Technology Data Exchange (ETDEWEB)

    Arib, R.M.N. [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Sapuan, S.M. [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia)]. E-mail: sapuan@eng.upm.edu.my; Ahmad, M.M.H.M. [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Paridah, M.T. [Faculty of Forestry, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Zaman, H.M.D. Khairul [Radiation Processing Technology Division, Malaysian Institute for Nuclear Technology Research (MINT), Bangi 43000 Kajang, Selangor (Malaysia)

    2006-07-01

    Pineapple leaf fibre, which is rich in cellulose, relative inexpensive and abundantly available has the potential for polymer-reinforced composite. The present study investigates the tensile and flexural behaviours of pineapple leaf fibre-polypropylene composites as a function of volume fraction. The tensile modulus and tensile strength of the composites were found to be increasing with fibre content in accordance with the rule of mixtures. The tensile modulus and tensile strength with a volume fraction 10.8% are 687.02 and 37.28 MPa, respectively. The flexural modulus gives higher value at 2.7% volume fraction. The flexural strength of the composites containing 5.4% volume fraction was found to be higher than that of pure polypropylene resin by 5.1%. Scanning electron microscopic studies were carried out to understand the fibre-matrix adhesion and fibre breakage.

  14. Durability of cracked fibre reinforced concrete structures exposed to chlorides

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place; Ekman, Tom; Hansen, Kurt Kielsgaard

    1999-01-01

    is used as environmental load. The chloride penetration is characterized both qualitatively (UV-test) and quantitatively (chloride profile) and by microscopy. The test programme involves three different concrete qualities. Both steel fibres and polypropylene fibres are used in the concrete beams as well......Durability studies are carried out by subjecting FRC-beams to combined mechanical and environmental load. Mechanical load is obtained by exposing beams to 4-point bending until a predefined crack width is reached, using a newly developed test setup. Exposure to a concentrated chloride solution...... as main reinforcement. The effect of the cracks, the fibres and the concrete quality on the chloride penetration is studied....

  15. Investigation of crack paths in natural fibre-reinforced composites

    Directory of Open Access Journals (Sweden)

    S. Keck

    2015-10-01

    Full Text Available Nowadays, fibre-reinforced composite materials are widely used in many fields, e.g. automotive and aerospace. Natural fibres such as flax and hemp provide good density specific mechanical properties. Additionally, the embodied production energy in natural fibres is much smaller than in synthetic ones. Within this paper the fracture mechanical behaviour of flax fibre-reinforced composites is discussed. Especially, this paper focuses on the determination and investigation of crack paths in compact tension specimens with three different fibre directions under a static as well as fatigue load. Differences and similarities in the obtained crack paths under different loading conditions are presented. Due to the pronounced orthotropic behaviour of those materials the crack path is not only governed by the stress state, but practically determined by the fibre direction and fibre volume fraction. Therefore, the well-known stress intensity factor solutions for the standard specimens are not applicable. It is necessary to carry out extensive numerical simulations to evaluate the stress intensity factor evolution along the growing crack in order to be able to determine fatigue crack growth rate curves. Those numerical crack growth simulations are performed with the three-dimensional crack simulation program ADAPCRACK3D to gain energy release rates and in addition stress intensity factors

  16. Design Basis for Fibre Reinforced Concrete (FRC) Pavements

    DEFF Research Database (Denmark)

    Bendixen, Søren; Stang, Henrik

    1996-01-01

    -crack opening relationship can beused to descibe the properties of fibre reinforced concrete (FRC) intension and how the stress-crack opening relationship can beapplied in a simple design scheme for pavements. The projectincludes development of design tools, experiments to determine thestress-crack opening......The paper summarises a Ph.D. project on development of a new design basis for fibre reinforced concrete ground slabs. The stress-crack openingrelationship is a well know basic material property of theso-called fictitious crack model for concrete. In the presentstudy it is shown how the stress...

  17. Observations on the electrical resistivity of steel fibre reinforced concrete

    DEFF Research Database (Denmark)

    Solgaard, Anders Ole Stubbe; Geiker, Mette Rica; Edvardsen, Carola;

    2014-01-01

    Steel fibre reinforced concrete (SFRC) is in many ways a well-known construction material, and its use has gradually increased over the last decades. The mechanical properties of SFRC are well described based on the theories of fracture mechanics. However, knowledge on other material properties......, including the electrical resistivity, is sparse. Among others, the electrical resistivity of concrete has an effect on the corrosion process of possible embedded bar reinforcement and transfer of stray current. The present paper provides experimental results concerning the influence of the fibre volume...

  18. Fatigue behaviour of infrared welded joints in fibre reinforced thermoplastics

    OpenAIRE

    De Baere, Ives; Allaer, Klaas; Van Paepegem, Wim; Degrieck, Joris

    2012-01-01

    Due to the increasing interest in fibre reinforced thermoplastics, there is also a need for a reliable means of bonding them. As thermoplastics have a high chemical inertness, adhesive bonding is not always an option and thus, fusion bonding might prove an interesting solution. This manuscript presents an infrared welding process for a carbon fabric reinforced polyphenylene sulphide. A one sided and a two sided welding process is described and the welding parameters are optimised by performin...

  19. Analytical Evaluation of Fibre-Reinforced Plastic Corrugated Sheet

    OpenAIRE

    C. K. Gautam; R. C. Pathak

    1998-01-01

    Fibre-reinforced' composites playa lead role as advanced materials in modem day structures.This paper reports fabrication and testing offibre-reinforced corrugated sheet employing 4-point bend loading. An in-depth analysis has been carried out using ANSYS, a finite element method package.The theoretical results obtained are compared with the experimental values. The values ofboth inputsshowed similar results. conforming at a particular boundary condition. However, more similarexperiments "on ...

  20. Modeling of properties of fiber reinforced cement composites

    Directory of Open Access Journals (Sweden)

    Jevtić Dragica

    2008-01-01

    Full Text Available This paper presents the results of authors' laboratory testing of the influence of steel fibers as fiber reinforcement on the change of properties of cement composite mortar and concrete type materials. Mixtures adopted - compositions of mortars had identical amounts of components: cement, sand and silica fume. The second type of mortar contained 60 kg/m3 of fiber reinforcement, as well as the addition of the latest generation of superplasticizer. Physical and mechanical properties of fiber reinforced mortars and etalon mixtures (density, flexural strength, compressive strength were compared. Tests on concrete type cement composites included: density, mechanical strengths and the deformation properties. The tests showed an improvement in the properties of fiber reinforced composites.

  1. High Performance Fiber Reinforced Cement Composites 6 HPFRCC 6

    CERN Document Server

    Reinhardt, Hans; Naaman, A

    2012-01-01

    High Performance Fiber Reinforced Cement Composites (HPFRCC) represent a class of cement composites whose stress-strain response in tension undergoes strain hardening behaviour accompanied by multiple cracking, leading to a high strain prior to failure. The primary objective of this International Workshop was to provide a compendium of up-to-date information on the most recent developments and research advances in the field of High Performance Fiber Reinforced Cement Composites. Approximately 65 contributions from leading world experts are assembled in these proceedings and provide an authoritative perspective on the subject. Special topics include fresh and hardening state properties; self-compacting mixtures; mechanical behavior under compressive, tensile, and shear loading; structural applications; impact, earthquake and fire resistance; durability issues; ultra-high performance fiber reinforced concrete; and textile reinforced concrete. Target readers: graduate students, researchers, fiber producers, desi...

  2. Compressive Failure of Fibre Reinforced Materials

    DEFF Research Database (Denmark)

    Jensen, Henrik Myhre

    2003-01-01

    Compressive failure of uni-directional fibre composites by the kink band mechanism is analysed taking into account effects of residual stresses. Two criteria for determining the strength of the composite material have been investigated: Kink band formation at a bifurcation stress in a composite...

  3. Crack Growth Monitoring by Embedded Optical Fibre Bragg Grating Sensors: Fibre Reinforced Plastic Crack Growing Detection

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira; Mikkelsen, Lars Pilgaard; McGugan, Malcolm

    2015-01-01

    This article presents a novel method to asses a crack growing/damage event in fibre reinforced plastic, or adhesive using Fibre Bragg Grating (FBG) sensors embedded in a host material. Different features of the crack mechanism that induce a change in the FBG response were identified. Double...... Cantilever Beams specimens made with glass fibre glued with structural adhesive, were instrumented with an array of FBG sensors embedded in the material and tested using an experimental fracture procedure. A digital image correlation technique was used to determine the presence of the specific phenomena...

  4. Transporting fibres as reinforcement in self-compacting concrete

    NARCIS (Netherlands)

    Grünewald, S.; Walraven, J.C.

    2009-01-01

    The development of self-compacting concrete (SCC) was an important step towards efficiency at building sites, rationally producing prefabricated concrete elements, better working conditions and improved quality and appearance of concrete structures. By adding fibres to SCC bar reinforcement can be

  5. Finite element modelling of fibre-reinforced brittle materials

    NARCIS (Netherlands)

    Kullaa, J.

    1997-01-01

    The tensile constitutive behaviour of fibre-reinforced brittle materials can be extended to two or three dimensions by using the finite element method with crack models. The three approaches in this study include the smeared and discrete crack concepts and a multi-surface plasticity model. The tensi

  6. The Compressive Strength of Carbon Fibre Reinforced Plastics.

    Science.gov (United States)

    1982-08-01

    and resin properties . Therefore, throughout this Report the term compressive failure will imply a microbuckling failure mode. A microbuckling failure...Compressive strength of fibre reinforced composite materials. ASTM STP 580, pp 364-377 (1975) 16 D.B.S. Berry Handbook of resin properties . Part A - cast

  7. GLASS-FIBRE REINFORCED COMPOSITES: THE EFFECT OF ...

    African Journals Online (AJOL)

    HOD

    reported the impact of orientation on the manufacturing of polymer composite. ... strength when compared with the neat resin and other oriented (G10E30) fibre reinforced composite. ..... curing process on the properties of carbon fiber/epoxy composite fabricated using vacuum assisted resin infusion molding," Materials &.

  8. Understanding and Improving the Elastic Compressive Modulus of Fibre Reinforced Soy-Based Polyurethane Foams

    Science.gov (United States)

    Hussain, Sadakat

    Soy-based polyurethane foams (PUFs) were reinforced with fibres of different aspect ratios to improve the compressive modulus. Each of the three fibre types reinforced PUF differently. Shorter micro-crystalline cellulose fibres were found embedded inside the cell struts of PUF and reinforced them. The reinforcement was attributed to be stress transfer from the matrix to the fibre by comparing the experimental results to those predicted by micro-mechanical models for short fibre reinforced composites. The reinforced cell struts increased the overall compressive modulus of the foam. Longer glass fibres (470 microns, length) provided the best reinforcement. These fibres were found to be larger than the cell diameters. The micro-mechanical models could not predict the reinforcement provided by the longer glass fibres. The models predicted negligible reinforcement because the very low modulus PUF should not transfer load to the higher modulus fibres. However, using a finite element model, it was determined that the fibres were providing reinforcement through direct fibre interaction with each other. Intermediate length glass fibres (260 microns, length) were found to poorly reinforce the PUF and should be avoided. These fibres were too short to interact with each other and were on average too large to embed and reinforce cell struts. In order to produce natural fibre reinforced PUFs in the future, a novel device was invented. The purpose of the device is to deliver natural fibres at a constant mass flow rate. The device was found to consistently meter individual loose natural fibre tufts at a mass flow rate of 2 grams per second. However, the device is not robust and requires further development to deliver a fine stream of natural fibre that can mix and interact with the curing polymeric components of PUF. A design plan was proposed to address the remaining issues with the device.

  9. Development of Flax Fibre based Textile Reinforcements for Composite Applications

    Science.gov (United States)

    Goutianos, S.; Peijs, T.; Nystrom, B.; Skrifvars, M.

    2006-07-01

    Most developments in the area of natural fibre reinforced composites have focused on random discontinuous fibre composite systems. The development of continuous fibre reinforced composites is, however, essential for manufacturing materials, which can be used in load-bearing/structural applications. The current work aims to develop high-performance natural fibre composite systems for structural applications using continuous textile reinforcements like UD-tapes or woven fabrics. One of the main problems in this case is the optimisation of the yarn to be used to manufacture the textile reinforcement. Low twisted yarns display a very low strength when tested dry in air and therefore they cannot be used in processes such as pultrusion or textile manufacturing routes. On the other hand, by increasing the level of twist, a degradation of the mechanical properties is observed in impregnated yarns (e.g., unidirectional composites) similar to off-axis composites. Therefore, an optimum twist should be used to balance processability and mechanical properties. Subsequently, different types of fabrics (i.e., biaxial plain weaves, unidirectional fabrics and non-crimp fabrics) were produced and evaluated as reinforcement in composites manufactured by well established manufacturing techniques such as hand lay-up, vacuum infusion, pultrusion and resin transfer moulding (RTM). Clearly, as expected, the developed materials cannot directly compete in terms of strength with glass fibre composites. However, they are clearly able to compete with these materials in terms of stiffness, especially if the low density of flax is taken into account. Their properties are however very favourable when compared with non-woven glass composites.

  10. Effects of fibre content on mechanical properties and fracture behaviour of short carbon fibre reinforced geopolymer matrix composites

    Indian Academy of Sciences (India)

    Tiesong Lin; Dechang Jia; Meirong Wang; Peigang He; Defu Liang

    2009-02-01

    Geopolymer matrix composites reinforced with different volume fractions of short carbon fibres (Cf/geopolymer composites) were prepared and the mechanical properties, fracture behaviour and microstructure of as-prepared composites were studied and correlated with fibre content. The results show that short carbon fibres have a great strengthening and toughening effect at low volume percentages of fibres (3.5 and 4.5 vol.%). With the increase of fibre content, the strengthening and toughening effect of short carbon fibres reduce, possibly due to fibre damage, formation of high shear stresses at intersect between fibres and strong interface cohesion of fibre/matrix under higher forming pressure. The property improvements are primarily based on the network structure of short carbon fibre preform and the predominant strengthening and toughening mechanisms are attributed to the apparent fibre bridging and pulling-out effect.

  11. Development of Genetic Algorithm Based Macro Mechanical Model for Steel Fibre Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Gopala Krishna Sastry, K, V.S ,

    2014-01-01

    Full Text Available This paper presents the applicability of hybrid networks that combine Artificial Neural Network (ANN and Genetic Algorithm (GA for predicting the strength properties of Steel Fibre Reinforced concrete (SFRC with different water-cement ratio (0.4,0.45,0.5,0.55, aggregate-cement ratio (3,4,5, % of fibres (0.75,1.0,1.5 and aspect ratio of fibres (40,50,60 as input vectors. Strength properties of SFRC such as compressive strength, flexural strength, split tensile strength and compaction factor are considered as output vector. The network has been trained with data obtained from experimental work. The hybrid neural network model learned the relation between input and output vectors in 1900 iterations. After successful learning GA based BPN model predicted the strength characteristics satisfying all the constrains with an accuracy of about 95%.The various stages involved in the development of genetic algorithm based neural network model are addressed at length in this paper.

  12. A multi-purpose optical fibre sensor design for fibre reinforced composite materials

    Science.gov (United States)

    Fernando, G. F.; Liu, T.; Crosby, P.; Doyle, C.; Martin, A.; Brooks, D.; Ralph, B.; Badcock, R.

    1997-10-01

    This paper reports on the evaluation of a multi-functional extrinsic Fabry - Pérot optical fibre-based sensor design. The sensor was constructed using multimode and single mode optical fibres and a precision bore capillary tube. Fusion joints were used to secure the optical fibres into the capillary tube. The separation between the cleaved end-faces of the optical fibres defined the cavity length for the Fabry - Pérot sensor and the distance between the fusion joints defined the gauge length for this strain and temperature sensor. The sensor design was modified to: (i) monitor the progress of cure in an epoxy/amine resin system; (ii) detect the ingress of moisture in a cured epoxy/amine resin system; (iii) monitor the vibration characteristics of a pre- and post-impact damaged carbon fibre reinforced epoxy panel; and (iv) discriminate between strain and temperature measurements. The feasibility of using this type of sensor for cure monitoring, strain, temperature, residual stress measurements and damage detection in advanced fibre reinforced composites is demonstrated.

  13. Structural Engineering Properties of Fibre Reinforced Concrete Based On Recycled Glass Fibre Polymer (GFRP

    Directory of Open Access Journals (Sweden)

    Adetiloye A

    2015-04-01

    Full Text Available Glass fibre reinforced plastics (GFRP based on resin recovered from recycling plastic waste has been shown to possess mechanical properties satisfying normative requirements. This paper investigates the flexural behavior of concrete beams reinforced with GFRP produced from resin recovered from recycled plastic wastes. A total of twelve of beams of sizes 150 ×150 ×900mm and 100 × 100 × 500mm reinforced with GFRP made from recycled glass fibre reinforced polymer was tested. The flexural test results yielded lower ultimate load, lower stiffness and larger deflections at the same load when compared with the control steel reinforced beam. However, the ultimate flexural strength of beams, reinforced with GFRP from recycled resin was at least four times higher than that of the control unreinforced beam. This is in agreement, quantitatively and qualitatively, with the trend of these parameters in GFRP reinforced concrete based on virgin resins. The results therefore confirm the applicability for structural uses of GFRP reinforcement made from recycled plastic waste, with the accompanying benefits of wealth creation, value addition and environmental sustainability.

  14. Apatite bone cement reinforced with calcium silicate fibers.

    Science.gov (United States)

    Motisuke, Mariana; Santos, Verônica R; Bazanini, Naiana C; Bertran, Celso A

    2014-10-01

    Several research efforts have been made in the attempt to reinforce calcium phosphate cements (CPCs) with polymeric and carbon fibers. Due to their low compatibility with the cement matrix, results were not satisfactory. In this context, calcium silicate fibers (CaSiO3) may be an alternative material to overcome the main drawback of reinforced CPCs since, despite of their good mechanical properties, they may interact chemically with the CPC matrix. In this work CaSiO3 fibers, with aspect ratio of 9.6, were synthesized by a reactive molten salt synthesis and used as reinforcement in apatite cement. 5 wt.% of reinforcement addition has increased the compressive strength of the CPC by 250% (from 14.5 to 50.4 MPa) without preventing the cement to set. Ca and Si release in samples containing fibers could be explained by CaSiO3 partial hydrolysis which leads to a quick increase in Ca concentration and in silica gel precipitation. The latter may be responsible for apatite precipitation in needle like form during cement setting reaction. The material developed presents potential properties to be employed in bone repair treatment.

  15. Toughened carbon fibre fabric-reinforced thermoplastic composites

    OpenAIRE

    Abt, Tobias Martin; Sánchez Soto, Miguel; Maspoch Rulduà, Mª Lluïsa; Velasco Perero, José Ignacio

    2014-01-01

    Toughened carbon fibre fabric-reinforced composites were obtained by compression moulding of powder prepregs, using a modified cyclic butylene terephthalate (pCBT) matrix and a bi-directional [0°/90°] carbon fibre fabric. Modification of the pCBT matrix was done by adding small amounts of epoxy resin or isocyanates, acting as toughening agents. Homogeneous CBT/epoxy and CBT/isocyanate blends were obtained by melt blending in a lab-scale batch mixer by applying low temperatures and short proce...

  16. FASEP ultra-automated analysis of fibre length distribution in glass-fibre-reinforced products

    Science.gov (United States)

    Hartwich, Mark R.; Höhn, Norbert; Mayr, Helga; Sandau, Konrad; Stengler, Ralph

    2009-06-01

    Reinforced plastic materials are widely used in high sophisticated applications. The length distribution of the fibres influences the mechanical properties of the final product. A method for automatic determination of this length distribution was developed. After separating the fibres out of the composite material without any damage, and preparing them for microscopical analysis, a mosaic of microscope pictures is taken. After image processing and analysis with mathematical methods, a complete statistic of the fibre length distribution could be determined. A correlation between fibre length distribution and mechanical properties, measured e.g. with material test methods, like tensile and impact tests, was found. This is a method to optimize the process and selection of material for the plastic parts. In result this enhances customer satisfaction and, maybe much more important, reduces costs for the manufacturer.

  17. ESTIMATING FIBRE DIRECTION DISTRIBUTIONS OF REINFORCED COMPOSITES FROM TOMOGRAPHIC IMAGES

    Directory of Open Access Journals (Sweden)

    Oliver Wirjadi

    2016-12-01

    Full Text Available Fibre reinforced composites constitute a relevant class of materials used chiefly in lightweight constructions for example in fuselages or car bodies. The spatial arrangement of the fibres and in particular their direction distribution have huge impact on macroscopic properties and, thus, its determination is an important topic of material characterisation. The fibre direction distribution is defined on the unit sphere, and it is therefore preferable to work with fully three-dimensional images of the microstructure as obtained, e.g., by computed micro-tomography. A number of recent image analysis algorithms exploit local grey value variations to estimate a preferred direction in each fibre point. Averaging these local results leads estimates of the volume-weighted fibre direction distribution. We show how the thus derived fibre direction distribution is related to quantities commonly used in engineering applications. Furthermore, we discuss four algorithms for local orientation analysis, namely those based on the response of anisotropic Gaussian filters, moments and axes of inertia derived from directed distance transforms, the structure tensor, or the Hessian matrix. Finally, the feasibility of these algorithms is demonstrated for application examples and some advantages and disadvantages of the underlying methods are pointed out.

  18. Alginate fibres containing discrete liquid filled vacuoles for controlled delivery of healing agents in fibre reinforced composites

    NARCIS (Netherlands)

    Mookhoek, S.D.; Fischer, H.R.; Zwaag, S. van der

    2012-01-01

    The work addressed involves the preparation and application of a compartmented polymer fibre, containing multiple separated domains with liquid agent for controlled release. The created fibre is a design for improvement to the existing liquid encapsulated self-healing systems such as fibre reinforce

  19. Experimental and numerical thermal analysis of a balcony board with integrated glass fibre reinforced polymer GFRP elements

    Energy Technology Data Exchange (ETDEWEB)

    Ghazi Wakili, K.; Simmler, H.; Frank, T. [Swiss Federal Laboratories for Materials Testing and Research (Empa), Duebendorf (Switzerland)

    2007-07-01

    The thermal behaviour of a balcony board with integrated glass fibre reinforced plastic (GFRP) elements replacing the compression reinforcement rods, is investigated by means of measurement as well as numerical analysis. For this reason a specimen consisting of an externally insulated brick wall and a representative part of a balcony is tested under a steady state temperature gradient of 30 K in a guarded hot box. Additionally to the normative requirements, temperature sensors are placed on critical sites within the construction, prior to the pouring of cement, to help the verification of the numerical analysis carried out simultaneously. Measured and calculated results are compared and some numerical parameter studies are carried out to quantify the advantage of glass fibre reinforced plastic elements over conventional balcony boards from a thermal point of view. (author)

  20. Effects of hybrid composition of LCP and glass fibres on abrasive wear of reinforced LLDPE

    Indian Academy of Sciences (India)

    S A R Hashmi; Ajay Naik; Navin Chand

    2006-02-01

    The hybrid of liquid crystalline polymer (LCP) fibres and glass fibres (GF) provide a combination of modulus and toughness to semi-crystalline linear-low-density-polyethylene (LLDPE). LCP and GF fibres reinforced composites were studied using two-body abrasion tester under different applied loads. Two sets of fibre reinforced LLDPE, 10 and 20 vol%, were investigated. The contents of LCP and glass fibres were varied as 25, 50, 75 and 100 vol% of overall volume of fibres in LLDPE. The effect of replacing glass fibre with LCP fibre on wear is reported. Wear loss increased with the applied loads and glass fibre contents in LLDPE. The replacements of glass fibres with LCP fibres improved abrasive wear resistance of composite. The composite containing 20 vol% of glass fibres in LLDPE showed the specific wear rate nearly double to that of LCP fibre reinforced LLDPE. Incorporation of LCP fibre improved wear resistance of glass fibre reinforced LLDPE. Worn surfaces were studied using SEM. Glass fibres were broken in small debris and removed easily whereas LCP fibres yielded to fibrillation during abrasive action. The overall wear rate was governed by the composition and test conditions.

  1. Stimuli-responsive cement-reinforced rubber.

    Science.gov (United States)

    Musso, Simone; Robisson, Agathe; Maheshwar, Sudeep; Ulm, Franz-Josef

    2014-05-14

    In this work, we report the successful development of a cement-rubber reactive composite with reversible mechanical properties. Initially, the composite behaves like rubber containing inert filler, but when exposed to water, it increases in volume and reaches a stiffness that is intermediate between that of hydrogenated nitrile butadiene rubber (HNBR) and hydrated cement, while maintaining a relatively large ductility characteristic of rubber. After drying, the modulus increases even further up to 400 MPa. Wet/drying cycles prove that the elastic modulus can reversibly change between 150 and 400 MPa. Utilizing attenuated total reflection Fourier transform infrared spectroscopy), we demonstrate that the high pH produced by the hydration of cement triggers the hydrolysis of the rubber nitrile groups into carboxylate anions. Thus, the salt bridges, generated between the carboxylate anions of the elastomer and the cations of the filler, are responsible for the reversible variations in volume and elastic modulus of the composite as a consequence of environmental moisture exposure. These results reveal that cement nanoparticles can successfully be used to accomplish a twofold task: (a) achieve an original postpolymerization modification that allows one to work with carboxylate HNBR (HXNBR) not obtained by direct copolymerization of carboxylate monomers with butadiene, and (b) synthesize a stimuli-responsive polymeric composite. This new type of material, having an ideal behavior for sealing application, could be used as an alternative to cement for oil field zonal isolation applications.

  2. Mechanical behaviour of steel fibre-reinforced alkali activated slag concrete

    Directory of Open Access Journals (Sweden)

    Puertas, F.

    2009-03-01

    Full Text Available This study addressed the mechanical behaviour of a steel fibre-reinforced alternative concrete made from waterglass (Na2SiO3.nH2O+NaOH- activated Colombian blast furnace slag. The mixes studied were prepared with 400 kg of cement and the fibres were added in proportions of 40 and 120 kg per cubic metre of concrete. 7-, 14- and 28-day concrete was tested for compressive, splitting tensile and flexural strength. The results obtained showed that adding steel fibre to alkaline concrete lowered early age compressive strength, and that this decline was more intense with rising volumes of steel. Flexural and splitting tensile strength grew, however, enhancing the toughness of the material. As a general rule, the mechanical strength of the plain and fibre-reinforced alkaline concretes studied was higher than exhibited by conventional ordinary Portland cement concrete prepared with similar proportions of cement and fibre.En este estudio se investigó el comportamiento mecánico de hormigones alternativos reforzados con fibras de acero, basados en una escoria siderúrgica colombiana activada alcalinamente con waterglass (Na2SiO3.nH2O+NaOH. Las mezclas en estudio fueron preparadas con 400 kg de cemento y las fibras fueron incorporadas en proporciones de 40 kg y 120 kg por metro cúbico de hormigón, respectivamente. Se evaluó el comportamiento mecánico de los hormigones frente a esfuerzos de compresión, tracción indirecta y flexión a edades de curado de 7, 14 y 28 días. Los resultados obtenidos indican que la incorporación de fibras de acero en los hormigones alcalinos reduce la resistencia a la compresión a edades tempranas siendo superior la pérdida de resistencia a mayores volúmenes de fibra incorporados, mientras que la resistencia a la flexión y tracción indirecta se incrementan significativamente, mejorando la tenacidad del material. En términos generales, es posible concluir que el comportamiento mecánico exhibido por los hormigones

  3. A viscoelastic-viscoplastic model for short-fibre reinforced polymers with complex fibre orientations

    Directory of Open Access Journals (Sweden)

    Nciri M.

    2015-01-01

    Full Text Available This paper presents an innovative approach for the modelling of viscous behaviour of short-fibre reinforced composites (SFRC with complex distributions of fibre orientations and for a wide range of strain rates. As an alternative to more complex homogenisation methods, the model is based on an additive decomposition of the state potential for the computation of composite’s macroscopic behaviour. Thus, the composite material is seen as the assembly of a matrix medium and several linear elastic fibre media. The division of short fibres into several families means that complex distributions of orientation or random orientation can be easily modelled. The matrix behaviour is strain-rate sensitive, i.e. viscoelastic and/or viscoplastic. Viscoelastic constitutive laws are based on a generalised linear Maxwell model and the modelling of the viscoplasticity is based on an overstress approach. The model is tested for the case of a polypropylene reinforced with short-glass fibres with distributed orientations and subjected to uniaxial tensile tests, in different loading directions and under different strain rates. Results demonstrate the efficiency of the model over a wide range of strain rates.

  4. Characterization of fibre-reinforced light metals; Charakterisierung faserverstaerker Leichtmetalle

    Energy Technology Data Exchange (ETDEWEB)

    Tietz, H.-D. [Hochschule fuer Technik und Wirtschaft Zwickau (Germany); Behrends, A. [Hochschule fuer Technik und Wirtschaft Zwickau (Germany); Palm, T. [Hochschule fuer Technik und Wirtschaft Zwickau (Germany)

    1996-10-01

    Metal-matrix composites combine the properties of metals with those of ceramic fibres. Pistons of highly stressed Diesel engines are reinforced in their bottom zones by the implantation of a preform of fibres. Investigations concentrate on the nondestructive detection of inclusions and defects of fibre distribution. Due to the very small dimensions of the defects test methods capable of responding sensitively to such small defect dimensions have to be applied. Good prerequisites to solve the task of defect detection are provided in first line by ultrasonic inspection within the high-frequency range in connection with scanning methods. Natural defects up to a size of 120 {mu}m could be detected by ultrasonics. With artificial test defects, the limit was reached at 100 {mu}m. Eddy-current inspection, another test procedure, was applied for the detection of fibreless zones, as there exist differences of conductivity between fibreless and fibre-reinforced zones. The use of scanning methods with special probes allows to depict fibreless zones up to a size of 100 {mu}m on the specimen surface. (orig.)

  5. Advanced Fibre Reinforced Methyl Nadicimide Resins .

    Directory of Open Access Journals (Sweden)

    Sarfaraz Alam

    1996-07-01

    Full Text Available Glass/carbon/kevlar-reinforced composites were fabricated using two structurally different methl nadicimide resins. The resin content of the laminates was in the range of 32-39 per cent. Interlaminar shear strength (ILSSand flexual strength (FS depended on the structure of the methyl nadicimide resins. A significant decrease in the ILSS was observed on treatment with boiling water for 500 h and on isothermal ageing at 300 degree celsius for 100,250 and 500 h. The limiting oxygen index (LOI was the lowest for laminates based on Kevlar fabrics (i.e.54 whereas the laminates based on glass/carbon showed very high LOI(>90.

  6. Fibre Reinforced Plastic Concepts for Structural Chassis Parts

    OpenAIRE

    Deißer, Oliver; Friedrich, Horst E.; Kopp, Gundolf

    2014-01-01

    Abstract Fibre reinforced plastics (FRP) have a high potential for reducing masses of automotive parts, but are seldom used for structural parts in the chassis. If the whole chassis concept is adapted to the new material, then a high weight saving potential can be gained and new body concepts can result. DLR Institute of Vehicle Concepts designed and dimensioned a highly stressed structural part in FRP. A topology optimisation of a defined working space with the estimated loads was perform...

  7. UNIFORMITY ASSESSMENT OF CARBON FIBRES DISPERSION IN CEMENT PASTE BY IMPEDANCE MEASUREMENTS

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    An alternating current was applied to measure the impedance of a hardened cement paste with various contents of carbon fibres.When the free water content in the hardened cement paste is 90%-98%,and the measuring frequency 500Hz,an approximate linear relationship was found between fibre content and impedance of the composite.Based on this relationship,a new attempt was made to evaluate the dispersion uniformity of carbon fibres in cement paste by impedance measurement.The standard deviation S and the coefficient of vriation S/(X-)i of impedance of the fibre-cement specimens randomly taken locating in different points were used as main parameters for the uniformity assessment.As a case,four different mixing processes were designed for dispersing carbon fibres into the cement paste.The results demonstrate that the relative longer mixing time increases the dispersion uniformity of carbon fibres in cement paste,and the addition of the water reducer dramatically improves the uniformity due to the change of the fluidity of the paste.The ground fly ash can increase the uniformity to a certain extent.

  8. Proportioning of Steel Fibre Reinforced Concrete Mixes for Pavement Construction and Their Impact on Environment and Cost

    Directory of Open Access Journals (Sweden)

    Stelios Kallis

    2011-07-01

    Full Text Available Steel fibre reinforced concrete (SFRC is a construction material investigated for more than 40 years including for pavement applications. A number of studies have demonstrated the technical merits of SFRC pavements over conventional concrete pavements; however little work has been carried out on the environmental and economical impact of SFRC during the pavement’s life cycle. Therefore, extended research was undertaken within the framework of the EU funded project “EcoLanes” to estimate the environmental and economical loadings of SFRC pavements. The innovative concept of the project is the use of recycled steel tyre-cord wire as concrete fibre reinforcement, which provides additional environmental benefits for tyre recycling over landfilling. Within the project framework a demonstration of a steel-fibre-reinforced roller-compacted concrete (SFR-RCC pavement was constructed in a rural area in Cyprus. In order to assess the economical and environmental picture of the demonstration pavement, life cycle cost analysis (LCCA and life cycle assessment (LCA studies were undertaken, which also compared the under study pavement design with four conventional alternatives. The main output of the studies is that SFR-RCC is more environmentally and economically sustainable than others. In addition, various concrete mix designs were investigated by considering parameters such as fibre type and dosage, cement type, and transportation distances to the construction site. Fibre dosage has been highlighted as a crucial factor compared with economical and environmental loadings in SFR-RCC pavement construction.

  9. Further development of the tungsten-fibre reinforced tungsten composite

    Energy Technology Data Exchange (ETDEWEB)

    Gietl, Hanns; Hoeschen, Till; Riesch, Johann [Max-Planck-Institut fuer Plasmaphysik, 85748 Garching (Germany); Aumann, Martin; Coenen, Jan [Forschungszentrum Juelich, IEK4, 52425 Juelich (Germany); Huber, Philipp [Lehrstuhl fuer Textilmaschinenbau und Institut fuer Textiltechnik (ITA), 52062 Aachen (Germany); Neu, Rudolf [Max-Planck-Institut fuer Plasmaphysik, 85748 Garching (Germany); Technische Universitaet Muenchen, 85748 Garching (Germany)

    2016-07-01

    For the use in a fusion device tungsten has a unique property combination. The brittleness below the ductile-to-brittle transition temperature and the embrittlement during operation e.g. by overheating, neutron irradiation are the main drawbacks for the use of pure tungsten. Tungsten fibre-reinforced tungsten composites utilize extrinsic mechanisms to improve the toughness. After proofing that this idea works in principle the next step is the conceptual proof for the applicability in fusion reactors. This will be done by producing mock-ups and testing them in cyclic high heat load tests. For this step all constituents of the composite, which are fibre, matrix and interface, and all process steps need to be investigated. Tungsten fibres are investigated by means of tension tests to find the optimum diameter and pretreatment. New interface concepts are investigated to meet the requirements in a fusion reactor, e.g. high thermal conductivity, low activation. In addition weaving processes are evaluated for their use in the fibre preform production. This development is accompanied by an extensive investigation of the materials properties e.g. single fibre tension tests.

  10. Mechanical Property Analysis on Sandwich Structured Hybrid Composite Made from Natural Fibre, Glass Fibre and Ceramic Fibre Wool Reinforced with Epoxy Resin

    Science.gov (United States)

    Bharat, K. R.; Abhishek, S.; Palanikumar, K.

    2017-06-01

    Natural fibre composites find wide range of applications and usage in the automobile and manufacturing industries. They find lack in desired properties, which are required for present applications. In current scenario, many developments in composite materials involve the synthesis of Hybrid composite materials to overcome some of the lacking properties. In this present investigation, two sandwich structured hybrid composite materials have been made by reinforcing Aloe Vera-Ceramic Fibre Wool-Glass fibre with Epoxy resin matrix and Sisal fibre-Ceramic Fibre Wool-Glass fibre with Epoxy resin matrix and its mechanical properties such as Tensile, Flexural and Impact are tested and analyzed. The test results from the two samples are compared and the results show that sisal fibre reinforced hybrid composite has better mechanical properties than aloe vera reinforced hybrid composite.

  11. Reinforcement of cement-based matrices with graphite nanomaterials

    Science.gov (United States)

    Sadiq, Muhammad Maqbool

    Cement-based materials offer a desirable balance of compressive strength, moisture resistance, durability, economy and energy-efficiency; their tensile strength, fracture energy and durability in aggressive environments, however, could benefit from further improvements. An option for realizing some of these improvements involves introduction of discrete fibers into concrete. When compared with today's micro-scale (steel, polypropylene, glass, etc.) fibers, graphite nanomaterials (carbon nanotube, nanofiber and graphite nanoplatelet) offer superior geometric, mechanical and physical characteristics. Graphite nanomaterials would realize their reinforcement potential as far as they are thoroughly dispersed within cement-based matrices, and effectively bond to cement hydrates. The research reported herein developed non-covalent and covalent surface modification techniques to improve the dispersion and interfacial interactions of graphite nanomaterials in cement-based matrices with a dense and well graded micro-structure. The most successful approach involved polymer wrapping of nanomaterials for increasing the density of hydrophilic groups on the nanomaterial surface without causing any damage to the their structure. The nanomaterials were characterized using various spectrometry techniques, and SEM (Scanning Electron Microscopy). The graphite nanomaterials were dispersed via selected sonication procedures in the mixing water of the cement-based matrix; conventional mixing and sample preparation techniques were then employed to prepare the cement-based nanocomposite samples, which were subjected to steam curing. Comprehensive engineering and durability characteristics of cement-based nanocomposites were determined and their chemical composition, microstructure and failure mechanisms were also assessed through various spectrometry, thermogravimetry, electron microscopy and elemental analyses. Both functionalized and non-functionalized nanomaterials as well as different

  12. A combined corrosion protection system for reinforced concrete structures using a carbon fibre mesh

    Energy Technology Data Exchange (ETDEWEB)

    Bruns, M.; Raupach, M. [Institut fuer Bauforschung der RWTH Aachen, IBAC, Institute of Building Materials Research of the Technical University of Aachen, Schinkelstrasse 3 Aachen (Germany)

    2004-07-01

    Cathodic Protection (CP) has become a world-wide used method to protect reinforced concrete structures against reinforcement corrosion. Another method to stop or reduce reinforcement corrosion, at least in case of lower chloride contents is the reduction of the water content of the concrete by applying sealing coatings on the concrete surface. At the Institute of Building Materials Research of Aachen University (IBAC) actually a surface protection system is investigated based on the combination of both methods mentioned above. The idea is to protect the reinforcement within the first years after system installation by cathodic protection until the water content of the concrete has decreased to a level due to the surface coating where the corrosion rate of the reinforcement is uncritical and does not lead to any damage. The system investigated, consists of a carbon fibre net embedded in a special mortar layer as impressed current anode for cathodic protection, covered by a 'dense' cement based polymer modified surface coating. In order to investigate the system, it has been installed on a test area on the weathered upper deck of a parking garage in Aachen, Germany. To investigate the effectiveness regarding the reduction of the water content of the concrete the test area was equipped with so called Multiring-Electrodes (MRE) for depth depended measurement of the concrete resistivity. Reference electrodes for potential and depolarization measurements as well a device for automatic measurement of the protection current were installed to investigate the effectiveness of the impressed current cathodic protection. Additionally 3 re bars were embedded into the concrete of the test area using mortar containing 1, 2 or 3 M.-% chloride by weight of cement respectively, to investigate the influence of the chloride content. First results of the MRE-measurements showing already within the first months after system installation a distinct drying of the concrete cover

  13. Study of the shear behaviour of fibre reinforced concrete beams

    Directory of Open Access Journals (Sweden)

    Barragán, B.

    2008-12-01

    Full Text Available This study presents a series of tests for characterizing the structural behaviour of fibre reinforced concrete beams subjected to shear loading. The experimental program involves three types of fibres; two steel fibres and a polypropylene fibre. As a reference, plain concrete and conventionally reinforced concrete specimens have also been tested. The ultimate shear capacity of the beams is calculated and these values compared with those predicted by existing formulations. The study confirms that the toughness and shear crack resistance of the material is greatly enhanced by the fibres. However, the incorporation of 1% of fibres yielded lower shear strength than conventionally reinforced beams with the same amount of steel in the form of transversal stirrups. Existing design methods seem sufficiently robust to estimate the maximum shear load, even when using material properties (toughness, tensile strength extrapolated from code formulae.Este trabajo presenta una serie de ensayos para caracterizar el comportamiento estructural de vigas realizadas con hormigón reforzado con fibras sometidas a cortante. El programa de ensayos incluía tres tipos de fibras, dos de acero y una de polipropileno. Asimismo, se realizó una serie de ensayos con una viga confeccionada con hormigón armado convencional. La resistencia a cortante de las vigas es comparada con los valores que la formulación existente predice. El estudio confirma que la tenacidad y la resistencia a cortante son incrementadas tras la adición de fibras al hormigón. Sin embargo, la incorporación de un 1% en volumen de fibras conduce a valores de resistencia última a cortante inferiores a los obtenidos con vigas de hormigón convencional con la misma cantidad de acero dispuesta en forma de cercos de cortante. Los actuales métodos de cálculo parecen lo suficientemente precisos para evaluar la carga de cortante último, incluso cuando los parámetros mecánicos utilizados en las f

  14. THERMOMECHANICAL PROPERTIES OF JUTE/BAGASSE HYBRID FIBRE REINFORCED EPOXY THERMOSET COMPOSITES

    Directory of Open Access Journals (Sweden)

    Sudhir Kumar Saw

    2009-11-01

    Full Text Available Natural fibres are partly replacing currently used synthetic fibres as reinforcement for polymer composites. Jute fibre bundles were high-cellulose-content modified by alkali treatment, while the bagasse fibre bundles were modified by creating quinones in the lignin portions of fibre surfaces and reacting them with furfuryl alcohol (FA to increase their adhesiveness. The effects of different fibre bundle loading and modification of bagasse fibre surfaces in hybrid fibre reinforced epoxy composites have been studied. The role of fibre/matrix interactions in chemically modified hybrid composites were investigated using Differential Scanning Calorimeter, Differential Thermo Gravimetry, and a Universal Tensile Machine and compared with those of unmodified bagasse fibre bundles incorporated with modified jute fibre bundles reinforced hybrid composites. Fibre surface modification reduced the hydrophilicity of fibre bundles, and significantly increased mechanical properties of hybrid composites were observed in conjunction with SEM images. The SEM analysis of the fibre and the composite fractured surfaces have confirmed the FA grafting and shown a better compatibility at the interface between chemically modified fibre bundles and epoxy resin. This paper incorporates interesting results of thermomechanical properties and evaluation of fibre/matrix interactions.

  15. Interface and internal compatibility in a copper fibre cement composite

    Directory of Open Access Journals (Sweden)

    Kittl, P.

    1993-09-01

    Full Text Available This paper presents the mechanical behaviour of a compacted composite formed by short ductile copper fibres randomly distributed in portland cement matrix. The samples, a half with fibres and the other without them, were subjected to compression fatigue. So, 1 hertz and the value of stress corresponding to the 1% of the probability of fracture by gradual load were used. Diagrams of cumulative probability of fracture against cycles are obtained for both types of samples. Scanning electron microscopy shows that the mechanisms of fracture are different in each case. Samples of compacted neat-cement paste finish their life with a catastrophic fracture whereas samples of composite behave like a pseudoductile material devoid of catastrophic failure. The results are discussed and compared with the ones obtained by thermal shock and by the interface brittleness theory, as well as with the statistical theory of time-dependent fracture for cementitious materials subjected to cyclic loading. So, in the thermal shock microcracks are generated in the interface matrix-fibre which simultaneously act as emmitings and sumps of cracks whereas this does not occur in mechanical fatigue.

    Este trabajo presenta el comportamiento mecánico de un compuesto fabricado por compactación y constituido por fibras de cobre distribuidas aleatoriamente en una matriz de cemento portland. Las muestras, la mitad con fibras y la otra sin ellas, se sometieron a fatiga por compresión. El ciclo de carga fue de 1 hertz y la carga aplicada aquella correspondiente a la tensión asociada a un 1% de probabilidad de fractura cuando la carga se aplica gradualmente. Para ambos tipos de muestras se graficaron los diagramas de probabilidad acumulativa de fractura en función del número de ciclos. Con microscopía electrónica de barrido se observó que el mecanismo de fractura es diferente para cada tipo de muestras. Aquellas de pasta pura de cemento compactada terminaron su ciclo de

  16. Synthesis and Characterization of Short Saccaharum Cilliare Fibre Reinforced Polymer Composites

    Directory of Open Access Journals (Sweden)

    A. S. Singha

    2009-01-01

    Full Text Available This paper deals with the synthesis of short Saccaharum Cilliare fibre (SC reinforced Urea-Formaldehyde (UF matrix based polymer composites. Present work reveals that mechanical properties such as: tensile strength, compressive strength, flexural strength and wear resistance of the UF matrix increase up to 30% fibre loading(in terms of weight and then decreases for higher loading when fibers are incorporated into the matrix polymer. Morphological and Thermal studies of the matrix, fibre and short fibre reinforced (SF-Rnf green composites have also been carried out. The results obtained emphasize the applications of these fibres, as potential reinforcing materials in bio based composites.

  17. Creep behavior of abaca fibre reinforced composite material

    Energy Technology Data Exchange (ETDEWEB)

    Tobias, B.C.; Lieng, V.T. [Victoria Univ. of Technology, Victoria (Australia)

    1996-12-31

    This study investigates the creep behavior of abaca fibre reinforced composite lamina. The optimum proportions of constituents and loading conditions, temperature and stresses, are investigated in terms of creep properties. Lamina with abaca fibre volume fractions of 60, 70 and 80 percent, embedded in polyester resin were fabricated. Creep tests in tension at three temperature levels 20{degrees}C, 100{degrees}C and 120{degrees}C and three constant stress levels of 0. 1 MPa, 0. 13 Mpa and 0. 198 MPa using a Dynamic Mechanical Analyzer (DMA) were performed. The creep curves show standard regions of an ideal creep curve such as primary and secondary creep stage. The results also show that the minimum creep rate of abaca fibre reinforced composite increases with the increase of temperature and applied stress. Plotting the minimum creep rate against stress, depicts the variations of stress exponents which vary from 1.6194 at 20{degrees}C to 0.4576 at 120{degrees}C.

  18. Advanced Laser Transmission Welding Strategies for Fibre Reinforced Thermoplastics

    Science.gov (United States)

    Wippo, V.; Jaeschke, P.; Brueggmann, M.; Suttmann, O.; Overmeyer, L.

    Laser transmission welding can be used to join endless fibre reinforced thermoplastics. The welding temperature is affected by the heat conduction along carbon fibresand depends on the local orientation of the fibres in the weld seam and the laser welding technique itself. In these investigations the heat development during the welding with quasi-static temperature fields, which is a combination of two laser welding techniques, is evaluated and compared to welding with a homogenized intensity distribution. In order to optimize the temperature distribution over the weld seam width for both linear and curved weld seams, different scanning structures have beenadapted. The experiments were conducted with a diode laser emitting at a wavelength of 940 nm and the process was monitored by aninfrared camera. The used thermoplastics consist of laminates based on unidirectional carbon fibre reinforced polyphenylenesulfide. With the developed scanning structures, a near-homogeneous temperature distribution was generated over the width of the weld seam for curved weld seams, which is not possible by welding with a homogenized laser radiation intensity distribution.

  19. Life Cycle Assessment of Biobased Fibre-Reinforced Polymer Composites (Levenscyclusanalyse van biogebaseerde, vezelversterkte polymeercomposieten)

    OpenAIRE

    Deng, Yelin

    2014-01-01

    Today, global environmental issues, such as global warming and fossil depletion, drive a paradigm shift in material applications from conventional fossil sources to renewable sources. Following this trend, the topic of this thesis is to analyse the use of biobased resources for fibre reinforced composite fabrication. Currently the most widely used fibre reinforced composites are composed of glass fibre reinforcements and polymeric matrices. In this thesis, the biobased alternative, i.e. flax ...

  20. Effect of Moisture Absorption Behavior on Mechanical Properties of Basalt Fibre Reinforced Polymer Matrix Composites

    OpenAIRE

    Amuthakkannan Pandian; Manikandan Vairavan; Winowlin Jappes Jebbas Thangaiah; Marimuthu Uthayakumar

    2014-01-01

    The study of mechanical properties of fibre reinforced polymeric materials under different environmental conditions is much important. This is because materials with superior ageing resistance can be satisfactorily durable. Moisture effects in fibre reinforced plastic composites have been widely studied. Basalt fibre reinforced unsaturated polyester resin composites were subjected to water immersion tests using both sea and normal water in order to study the effects of water absorption behavi...

  1. Cellulose Fibre-Reinforced Biofoam for Structural Applications

    Directory of Open Access Journals (Sweden)

    Jasmina Obradovic

    2017-06-01

    Full Text Available Traditionally, polymers and macromolecular components used in the foam industry are mostly derived from petroleum. The current transition to a bio-economy creates demand for the use of more renewable feedstocks. Soybean oil is a vegetable oil, composed mainly of triglycerides, that is suitable material for foam production. In this study, acrylated epoxidized soybean oil and variable amounts of cellulose fibres were used in the production of bio-based foam. The developed macroporous bio-based architectures were characterised by several techniques, including porosity measurements, nanoindentation testing, scanning electron microscopy, and thermogravimetric analysis. It was found that the introduction of cellulose fibres during the foaming process was necessary to create the three-dimensional polymer foams. Using cellulose fibres has potential as a foam stabiliser because it obstructs the drainage of liquid from the film region in these gas-oil interfaces while simultaneously acting as a reinforcing agent in the polymer foam. The resulting foams possessed a porosity of approximately 56%, and the incorporation of cellulose fibres did not affect thermal behaviour. Scanning electron micrographs showed randomly oriented pores with irregular shapes and non-uniform pore size throughout the samples.

  2. Roughness and fibre reinforcement effect onto wettability of composite surfaces

    Science.gov (United States)

    Bénard, Quentin; Fois, Magali; Grisel, Michel

    2007-03-01

    Wettability of glass/epoxy and carbon/epoxy composites materials has been determined via sessile drop technique. Good-Van Oss approach has been used to evaluate surface free energy parameters of smooth and rough surfaces. Results obtained point out the influence of fibre reinforcement on surface free energy of composite materials. In addition, the interest of surface treatment to increase surface roughness has been discussed in terms of wettability. To sum up, results obtained clearly demonstrate the necessity of considering properties of a given composite surface not only as a polymer but a fibre/polymer couple. The drawn conclusions are of great interest as it may have numerous consequences in applications such as adhesion.

  3. Constructive applications of composite gypsum reinforced with Typha Latifolia fibres

    Directory of Open Access Journals (Sweden)

    Garcia Santos, A.

    2004-03-01

    Full Text Available The present research analyses the possibility to reinforce gypsum using enea fibres (Typha Latifolia creating a compound material in wich the fibres contribute to increase mechanical resistance, producing as well a reduction of the weight and a possible regulation of the set time.

    La investigación presente analiza la posibilidad de reforzar los morteros de escayola mediante la utilización dé fibras de Typha Latifolia, creando un material compuesto en el que las fibras contribuyen al aumento de resistencia mecánica, a la vez que se produce una reducción del peso y una regulación de los tiempos de fraguado. Las propiedades de estos materiales hacen que, en determinadas aplicaciones, su utilización resulte ventajosa con respecto a materiales tradicionales.

  4. Drilling analysis of coir–fibre-reinforced polyester composites

    Indian Academy of Sciences (India)

    S Jayabal; U Natarajan

    2011-12-01

    An investigation has been carried out to make use of coir, a natural fibre abundantly available in India. Coir–polyester composites were prepared and their mechanical and machinability characteristics were studied. The short coir–fibre-reinforced composites exhibited the tensile, flexural and impact strength of 16.1709 MPa, 29.2611 MPa and 46.1740 J/m, respectively. The regression equations were developed and optimized for studying drilling characteristics of coir–polyester composites using the Taguchi approach. A drill bit diameter of 6 mm, spindle speed of 600 rpm and feed rate of 0.3 mm/rev gave the minimum value of thrust force, torque and tool wear in drilling analysis.

  5. Machining analysis of natural fibre reinforced composites using fuzzy logic

    Science.gov (United States)

    Balasubramanian, K.; Sultan, M. T. H.; Cardona, F.; Rajeswari, N.

    2016-10-01

    In this work, a new composite plate with natural jute fibre as the reinforcement fibres and isophthalic polyester as the resin was manufactured and subjected to a series of end milling operation by changing three input factors namely speed, feed rate and depth of cut. During each operation, the output responses namely thrust force and torque were measured. The responses were analyzed using Taguchi method to examine the relation between the input factors and output responses, and also to know the most influencing factors on the responses. The data was also analyzed using fuzzy rule model for prediction of responses for a range of input factors. The results showed that all three factors chosen have significant effect on the responses. The fuzzy model data in comparison with the experimental values shows only a marginal error and hence the prediction was highly satisfactory.

  6. Fatigue behaviour of carbon fibre reinforced plastic under spectrum loading

    Energy Technology Data Exchange (ETDEWEB)

    Sudha, J. [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012 (India)], E-mail: sudhaj@platinum.materials.iisc.ernet.in; Kumar, Subodh [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012 (India); Srinivasan, Prabha; Vijayaraju, K. [Aeronautical Development Agency, Bangalore (India)

    2009-02-15

    In the present investigation the fatigue behaviour of carbon fibre reinforced plastic laminates under realistic service loading conditions has been examined. Laminates with different lay-up sequences have been tested for fatigue under spectrum loading with three different peak load levels. The damage in the laminates was characterized by using ultrasonic C-Scan as well as dynamic mechanical analysis and the damage mechanism was analyzed using scanning electron microscope. A similar investigation was also conducted on laminates with a hole. The results indicate that the spectrum loading did affect the modulus and fibre/matrix interfacial properties of all type of laminates investigated and also caused delamination in the laminate with a hole due to stress concentration around the hole.

  7. Electron processing of fibre-reinforced advanced composites

    Science.gov (United States)

    Singh, Ajit; Saunders, Chris B.; Barnard, John W.; Lopata, Vince J.; Kremers, Walter; McDougall, Tom E.; Chung, Minda; Tateishi, Miyoko

    1996-08-01

    Advanced composites, such as carbon-fibre-reinforced epoxies, are used in the aircraft, aerospace, sporting goods, and transportation industries. Though thermal curing is the dominant industrial process for advanced composites, electron curing of similar composites containing acrylated epoxy matrices has been demonstrated by our work. The main attraction of electron processing technology over thermal technology is the advantages it offers which include ambient temperature curing, reduced curing times, reduced volatile emissions, better material handling, and reduced costs. Electron curing technology allows for the curing of many types of products, such as complex shaped, those containing different types of fibres, and up to 15 cm thick. Our work has been done principally with the AECL's 10 MeV, 1 kW electron accelerator; we have also done some comparative work with an AECL Gammacell 220. In this paper we briefly review our work on the various aspects of electron curing of advanced composites and their properties.

  8. Natural fibres-based polymers: Part I—Mechanical analysis of Pine needles reinforced biocomposites

    Indian Academy of Sciences (India)

    Vijay Kumar Thakur; A S Singha

    2010-06-01

    Lack of resources and increasing environmental pollution has evoked great interest in the research of materials that are friendly to our health and environment. Polymer composites fabricated from natural fibres is currently the most promising area in polymer science. Keeping in view the various advantages of natural fibres, in current series of green composites a study on natural fibre reinforced polymer composites has been made. This paper presents the results of an experimental series designed to assess the possibility of Pine needles as reinforcing material in polymer composites. First of all, urea–formaldehyde resin was synthesized and optimized by evaluating its mechanical properties. Optimized resin was reinforced with employing Pine needles of different dimensions such as particle reinforcement, short fibre reinforcement and long fibre reinforcement. Experimental results obtained shows that mechanical properties such as tensile strength, compressive strength and wear resistance of UF resin increases to a considerable extent when reinforced with Pine needles. Further it has been observed that particle reinforcement is more effective as compared to short fibre and long fibre reinforcement. These results suggest that Pine needles can be potential candidates for use in natural fibre reinforced polymer composites. Thermal and morphological studies of these composites have also been carried out.

  9. Strength Modeling of High-Strength Concrete with Hybrid Fibre Reinforcement

    Directory of Open Access Journals (Sweden)

    A. Ravichandran

    2009-01-01

    Full Text Available The low tensile strength and limited ductility, the unavoidable deficiency, of concrete can be overcome by the addition of fibres. High strength concrete (HSC of 60 MPa containing hybrid fibres, combination of steel and polyolefin fibres, at different volume fraction of 0.5, 1.0, 1.5 and 2.0% were compared in terms of compressive, splitting tensile strength and flexural properties with HSC containing no fibres. Test results showed that the fibres when used in hybrid form could result in enhanced flexural toughness compared to steel fibre reinforced concrete [HSFRC]. The compressive strength of the fibre-reinforced concrete reached maximum at 1.5% volume fractions and the splitting tensile strength and modulus of rupture improved with increasing volume fraction. Strength models were established to predict the compressive and splitting tensile strength and modulus of rupture of the fibre-reinforced concrete. The models give prediction matching the measurements.

  10. Seebeck effect in carbon fiber-reinforced cement

    Energy Technology Data Exchange (ETDEWEB)

    Wen, S.; Chung, D.D.L.

    1999-12-01

    The Seebeck effect in carbon fiber-reinforced cement paste was found to involve electrons from the cement matrix and holes from the biers. The two contributions were equal at the percolation threshold, with a fiber content between 0.5 and 1.0% by mass of cement. The hole contribution increased monotonically with increasing fiber content below and above the percolation threshold. The fiber addition increased the linearity and reversibility of the Seebeck effect. Silica fume and latex as admixtures had minor influence on the Seebeck effect. The Seebeck effect in concrete is of interest because it gives the concrete the ability to sense its own temperature. No attached or embedded sensor is needed since the concrete itself is the sensor. This means low cost, high durability, large sensing volume, and absence of mechanical property degradation due to embedded sensors. As the temperature affects the performance and reliability of concrete, its detection is valuable.

  11. Smart Behavior of Carbon Fiber Reinforced Cement-based Composite

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The electrical characteristics of cement-based material can be remarkably improved by the addition of short carbon fibers.Carbon fiber reinforced cement composite (CFRC) is an intrinsically smart material that can sense not only the stress andstrain, but also the temperature. In this paper, variations of electrical resistivity with external applied load, and relationof thermoelectric force and temperature were investigated. Test results indicated that the electrical signal is related to theincrease in the material volume resistivity during crack generation or propagation and the decrease in the resistivity duringcrack closure. Moreover, it was found that the fiber addition increased the linearity and reversibility of the Seebeck effect inthe cement-based materials. The change of electrical characteristics reflects large amount of information of inner damage andtemperature differential of composite, which can be used for stress-strain or thermal self-monitoring by embedding it in theconcrete structures.

  12. Corrosion inhibitor mechanisms on reinforcing steel in Portland cement pastes

    Science.gov (United States)

    Martin, Farrel James

    2001-07-01

    The mechanisms of corrosion inhibitor interaction with reinforcing steel are investigated in the present work, with particular emphasis on effects associated with corrosion inhibitors admixed into Portland cement paste. The principal objective in reinforcing steel corrosion inhibition for Portland cement concrete is observed to be preservation of the naturally passive steel surface condition established by the alkaline environment. Introduction of chloride ions to the steel surface accelerates damage to the passive film. Excessive damage to the passive film leads to loss of passivity and a destabilization of conditions that facilitate repair of the passive film. Passive film preservation in presence of chloride ions is achieved either through stabilization of the passive film or by modification of the chemical environment near the steel surface. Availability of inhibitors to the steel surface and their tendency to stabilize passive film defects are observed to be of critical importance. Availability of admixed corrosion inhibitors to the passive film is affected by binding of inhibitors during cement paste hydration. It is determined that pore solution concentrations of inorganic admixed inhibitors tend to be lower than the admixed concentration, while pore solution concentrations of organic admixed inhibitors tend to be higher than the admixed concentration. A fundamental difference of inhibitor function is observed between film-forming and defect stabilizing corrosion inhibitors. Experiments are conducted using coupons of reinforcing steel that are exposed to environments simulating chloride-contaminated Portland cement concrete. A study of the steel/cement paste interface is also performed, and compounds forming at this interface are identified using X-Ray diffraction.

  13. The new structure of fibre glass reinforced plastics bolt

    Institute of Scientific and Technical Information of China (English)

    马念杰; 刘社育

    2003-01-01

    The develop actuality and direction of FRP(fibre glass reinforced plastics) bolt in the world are analyzed. The new type structure of FRP bolt was designed. Trial data indicate that, all kinds of capability target of this FRP bolt all achieve and exceed the country standard, substitute present metal bolt,wood bolt and bamboo bolt and other side bolt, it can gain magnitude technology and economy benefit. FRP bolt mechanization product line produce efficiency is high, its throughput a day are 750 base, this can meet demand of hit-small mining company.

  14. The fracture of boron fibre-reinforced 6061 aluminium alloy

    Science.gov (United States)

    Wright, M. A.; Welch, D.; Jollay, J.

    1979-01-01

    The fracture of 6061 aluminium alloy reinforced with unidirectional and cross-plied 0/90 deg, 0/90/+ or - 45 deg boron fibres has been investigated. The results have been described in terms of a critical stress intensity, K(Q). Critical stress intensity factors were obtained by substituting the failure stress and the initial crack length into the appropriate expression for K(Q). Values were obtained that depended on the dimensions of the specimens. It was therefore concluded that, for the size of specimen tested, the values of K(Q) did not reflect any basic materials property.

  15. Fabrication and tribological properties of Al reinforced with carbon fibres

    Energy Technology Data Exchange (ETDEWEB)

    Estrems Amestoy, M.; Faura Mateu, F. [Universidad Politecnica de Cartagena (Spain); Froyen, L. [Department of Metallurgy and Materials Engineering. Katholieke Universiteit Lewen. Heverlee. Belgium (Belgium)

    2000-07-01

    The present work studies the manufacturing process of Al reinforced with Carbon Fibres (CF) by Squeeze Casting, establishing the variables for obtaining and acceptable product with little Al{sub 4}C{sub 3} at the interface. Friction and wear tests are performed and the necessary conditions for the formation of a tribofilm are established. The tests how an increasing resistance to abrasion due to their own wear mechanism. Certain design criteria for those components subjected to friction are recommended in order to maximize the mechanical performance of the tribological system. (Author ) 16 refs.

  16. STUDIES ON STRESS TRANSFERENCE MECHANISM OF STEEL FIBRE REINFORCED CONCRETE

    Institute of Scientific and Technical Information of China (English)

    杨佑发; 许绍乾; 钟正华

    2001-01-01

    The stress transfer mechanism of steel fibre reinforced concrete is studied. The solutions for the stress and displacement were regarded as the superposition of "the elementary solutions" and "the improved solutions". The elementary solutions were found by using two-dimensional elastic theory and the improved solutions were found by using the Love displacement function method. The calculated results indicate that the solutions possess good convergence. By comparing the three-dimensional solutions with the shear-lag solutions, evident difference may be found.

  17. Study of injection moulded long glass fibre-reinforced polypropylene and the effect on the fibre length and orientation distribution

    Science.gov (United States)

    Parveeen, B.; Caton-Rose, P.; Costa, F.; Jin, X.; Hine, P.

    2014-05-01

    Long glass fibre (LGF) composites are extensively used in manufacturing to produce components with enhanced mechanical properties. Long fibres with length 12 to 25mm are added to a thermoplastic matrix. However severe fibre breakage can occur in the injection moulding process resulting in shorter fibre length distribution (FLD). The majority of this breakage occurs due to the melt experiencing extreme shear stress during the preparation and injection stage. Care should be taken to ensure that the longer fibres make it through the injection moulding process without their length being significantly degraded. This study is based on commercial 12 mm long glass-fibre reinforced polypropylene (PP) and short glass fibre Nylon. Due to the semi-flexiable behaviour of long glass fibres, the fibre orientation distribution (FOD) will differ from the orientation distribution of short glass fibre in an injection molded part. In order to investigate the effect the change in fibre length has on the fibre orientation distribution or vice versa, FOD data was measured using the 2D section image analyser. The overall purpose of the research is to show how the orientation distribution chnages in an injection moulded centre gated disc and end gated plaque geometry and to compare this data against fibre orientation predictions obtained from Autodesk Moldflow Simulation Insight.

  18. The effects of steel fibre reinforced concrete on system ductility

    Directory of Open Access Journals (Sweden)

    Yilmaz, U. S.

    2007-03-01

    Full Text Available Steel fibre-reinforced concrete is being used extensively today in both field applications and experimental studies on concrete strength and ductility. The state of passive confinement generated by the fibre delays cracking and enhances ductility. The present paper reports on both experimental and analytical studies. In the former, a series of 16 steel-fibre reinforced concrete prismatic specimens were subjected to axial loads and the respective axial load-unit strain diagrams were subsequently plotted to determine the effect of steel fibres on reinforced concrete column ductility. Secondly, an analytical study was run to determine the additional ductility accruing to a frame system when steel fibres are included in the concrete. Analytical models were generated for 16 two-storey, single-span reinforced concrete frames. The columns in these frames were designed to the same characteristics as the specimens used in the experimental tests. Non-linear static (pushover analyses were performed for each frame to obtain load-displacement curves and determine the effect of steel fibres on reinforced concrete column ductility.El hormigón reforzado con fibra de acero se emplea actualmente tanto en obra como en los trabajos experimentales para estudiar la resistencia mecánica y ductilidad del hormigón. El estado de confinamiento pasivo producido por la fibra retrasa la fisuración y aumenta la ductilidad. El presente trabajo es de índole tanto experimental como analítica. En primer lugar, en la parte experimental se aplica una fuerza axial a 16 probetas prismáticas (160 x 160 x 840 mm de hormigón reforzado con fibra de acero para determinar su comportamiento, obteniéndose las curvas de fuerza axial-deformación unitaria correspondientes a partir de los resultados observados. A partir de una evaluación de dichos resultados experimentales, se determina el efecto que ejercen las fibras de acero sobre la ductilidad de las probetas de hormigón armado

  19. Plasma treatment of carbon fibres and glass-fibre-reinforced polyesters at atmospheric pressure for adhesion improvement

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Løgstrup Andersen, Tom; Toftegaard, Helmuth Langmaack

    2014-01-01

    composites before assembling them to build wind turbine blades. In the present work, unsized carbon fibres are continuously treated using a dielectric barrier discharge plasma in helium at atmospheric pressure, and carbon fibre reinforced epoxy composite plates are manufactured for the mechanical test...

  20. The effect of fibre content, fibre size and alkali treatment to Charpy impact resistance of Oil Palm fibre reinforced composite material

    Science.gov (United States)

    Fitri, Muhamad; Mahzan, Shahruddin

    2016-11-01

    In this research, the effect of fibre content, fibre size and alkali treatment to the impact resistance of the composite material have been investigated, The composite material employs oil palm fibre as the reinforcement material whereas the matrix used for the composite materials are polypropylene. The Oil Palm fibres are prepared for two conditions: alkali treated fibres and untreated fibres. The fibre sizes are varied in three sizes: 5mm, 7mm and 10mm. During the composite material preparation, the fibre contents also have been varied into 3 different percentages: 5%, 7% and 10%. The statistical approach is used to optimise the variation of specimen determined by using Taguchi method. The results were analyzed also by the Taguchi method and shows that the Oil Palm fibre content is significantly affect the impact resistance of the polymer matrix composite. However, the fibre size is moderately affecting the impact resistance, whereas the fibre treatment is insignificant to the impact resistance of the oil palm fibre reinforced polymer matrix composite.

  1. Durability of Cement Composites Reinforced with Sisal Fiber

    Science.gov (United States)

    Wei, Jianqiang

    This dissertation focuses mainly on investigating the aging mechanisms and degradation kinetics of sisal fiber, as well as the approaches to mitigate its degradation in the matrix of cement composites. In contrast to previous works reported in the literature, a novel approach is proposed in this study to directly determine the fiber's degradation rate by separately studying the composition changes, mechanical and physical properties of the embedded sisal fibers. Cement hydration is presented to be a crucial factor in understanding fiber degradation behavior. The degradation mechanisms of natural fiber consist of mineralization of cell walls, alkali hydrolysis of lignin and hemicellulose, as well as the cellulose decomposition which includes stripping of cellulose microfibrils and alkaline hydrolysis of amorphous regions in cellulose chains. Two mineralization mechanisms, CH-mineralization and self-mineralization, are proposed. The degradation kinetics of sisal fiber in the cement matrix are also analyzed and a model to predict the degradation rate of cellulose for natural fiber embedded in cement is outlined. The results indicate that the time needed to completely degrade the cellulose in the matrix with cement replacement by 30wt.% metakaolin is 13 times longer than that in pure cement. A novel and scientific method is presented to determine accelerated aging conditions, and to evaluating sisal fiber's degradation rate and durability of natural fiber-reinforced cement composites. Among the static aggressive environments, the most effective approach for accelerating the degradation of natural fiber in cement composites is to soak the samples or change the humidity at 70 °C and higher temperature. However, the dynamic wetting and drying cycling treatment has a more accelerating effect on the alkali hydrolysis of fiber's amorphous components evidenced by the highest crystallinity indices, minimum content of holocellulose, and lowest tensile strength. Based on the

  2. Glass fibres reinforced polyester composites degradation monitoring by surface analysis

    Energy Technology Data Exchange (ETDEWEB)

    Croitoru, Catalin [“Transilvania” University of Brasov, Materials Engineering and Welding Department, Eroilor 29 Str., 500036 Brasov (Romania); Patachia, Silvia, E-mail: st.patachia@unitbv.ro [“Transilvania” University of Brasov, Product Design Environment and Mechatronics Department, Eroilor 29 Str., 500036 Brasov (Romania); Papancea, Adina [“Transilvania” University of Brasov, Product Design Environment and Mechatronics Department, Eroilor 29 Str., 500036 Brasov (Romania); Baltes, Liana; Tierean, Mircea [“Transilvania” University of Brasov, Materials Engineering and Welding Department, Eroilor 29 Str., 500036 Brasov (Romania)

    2015-12-15

    Highlights: • Glass fibre-reinforced polyester composites surface analysis by photographic method. • The composites are submitted to accelerated ageing by UV irradiation at 254 nm. • The UV irradiation promotes differences in the surface chemistry of the composites. • MB dye is differently adsorbed on surfaces with different degradation degrees. • Good correlation between the colouring degree and surface chemistry. - Abstract: The paper presents a novel method for quantification of the modifications that occur on the surface of different types of gel-coated glass fibre-reinforced polyester composites under artificial UV-ageing at 254 nm. The method implies the adsorption of an ionic dye, namely methylene blue, on the UV-aged composite, and computing the CIELab colour space parameters from the photographic image of the coloured composite's surface. The method significantly enhances the colour differences between the irradiated composites and the reference, in contrast with the non-coloured ones. The colour modifications that occur represent a good indicative of the surface degradation, alteration of surface hydrophily and roughness of the composite and are in good correlation with the ATR-FTIR spectroscopy and optical microscopy results. The proposed method is easier, faster and cheaper than the traditional ones.

  3. Review of current strategies to induce self-healing behaviour in fibre reinforced polymer based composites

    NARCIS (Netherlands)

    Zwaag, van der S.; Grande, A.M.; Post, W.; Garcia, S.J.; Bor, T.C.

    2014-01-01

    This paper addresses the various strategies to induce self-healing behaviour in fibre reinforced polymer based composites. A distinction is made between the extrinsic and intrinsic healing strategies. These strategies can be applied at the level of the fibre, the fibre/matrix interface or at the lev

  4. A Micro Raman Investigation of Viscoelasticity in Short Fibre Reinforced Polymer Matrix Composites

    DEFF Research Database (Denmark)

    Schjødt-Thomsen, Jan

    The purpose of the present Ph.D. project is to investigate the load transfer mechanisms between the fibre and matrix and the stress/strain fields in and around single fibres in short fibre reinforced viscoelastic polymer matrix composites subjected to various loading histories. The materials...

  5. Application of fibre reinforced metals in internal combustion engines. Anwendung faserverstaerkter Metalle in Verbrennungsmotoren

    Energy Technology Data Exchange (ETDEWEB)

    Essig, G.; Mielke, S.; Bloschies, G. (Kolbenschmidt AG, Neckarsulm (Germany, F.R.))

    1990-05-01

    Completely using the many advantages of aluminium silicon alloys presupposes technical pregnant methods to counteract the decrease in hot strength at temperatures above 300deg C. Reinforcing the metallic alloy by ceramic fibres presents itself for strength increase. Therefore the qualities of fibres and fibre preforms being used are of great importance. (orig.).

  6. Connections in Precast Buildings using Ultra High-Strength Fibre Reinforced Concrete

    DEFF Research Database (Denmark)

    Hansen, Lars Pilegaard

    1995-01-01

    Ultra high-strength concrete adds new dimensions to the design of concrete structures. It is a brittle material but introducing fibres into the matrix changes the material into a highly ductile material. Furthermore, the fibre reinforcement increases the anchorage of traditional reinforcement bars...

  7. Fatigue Micromechanism Characterization in Carbon Fibre Reinforced Polymers Using Synchrotron Radiation Computed Tomography

    Science.gov (United States)

    2014-12-18

    AFRL-AFOSR-UK-TR-2015-0002 Fatigue micromechanism characterization in carbon fibre reinforced polymers using synchrotron radiation computed...SUBTITLE Fatigue micromechanism characterization in carbon fibre reinforced polymers using synchrotron radiation computed tomography 5a. CONTRACT...particularly within the aerospace sector due to their high specific stiffness and strength. CFRPs are widely identified as being very fatigue resistant, but

  8. The High-Frequency Dielectric Properties of Glass Fibre Reinforced Plastic and Honeycomb Layers

    Science.gov (United States)

    1989-06-29

    The dielectric constant and the dielectric loss angle tangent of glass fibre reinforced plastic are both relatively small; it is a good wave...practical value. This paper introduces the work we have done in this area. The dielectric properties of glass fibre reinforced plastic have a close

  9. Self Healing Fibre-reinforced Polymer Composites: an Overview

    Science.gov (United States)

    Bond, Ian P.; Trask, Richard S.; Williams, Hugo R.; Williams, Gareth J.

    Lightweight, high-strength, high-stiffness fibre-reinforced polymer composite materials are leading contenders as component materials to improve the efficiency and sustainability of many forms of transport. For example, their widespread use is critical to the success of advanced engineering applications, such as the Boeing 787 and Airbus A380. Such materials typically comprise complex architectures of fine fibrous reinforcement e.g. carbon or glass, dispersed within a bulk polymer matrix, e.g. epoxy. This can provide exceptionally strong, stiff, and lightweight materials which are inherently anisotropic, as the fibres are usually arranged at a multitude of predetermined angles within discrete stacked 2D layers. The direction orthogonal to the 2D layers is usually without reinforcement to avoid compromising in-plane performance, which results in a vulnerability to damage in the polymer matrix caused by out-of-plane loading, i.e. impact. Their inability to plastically deform leaves only energy absorption via damage creation. This damage often manifests itself internally within the material as intra-ply matrix cracks and inter-ply delaminations, and can thus be difficult to detect visually. Since relatively minor damage can lead to a significant reduction in strength, stiffness and stability, there has been some reticence by designers for their use in safety critical applications, and the adoption of a `no growth' approach (i.e. damage propagation from a defect constitutes failure) is now the mindset of the composites industry. This has led to excessively heavy components, shackling of innovative design, and a need for frequent inspection during service (Richardson 1996; Abrate 1998).

  10. Feasibility of Using High-Performance Steel Fibre Reinforced Concrete for Simplifying Reinforcement Details of Critical Members

    Directory of Open Access Journals (Sweden)

    Seok-Joon Jang

    2015-01-01

    Full Text Available This paper addresses the effects of hooked-end steel fibre contents on the mechanical properties of high-performance concrete (HPC and investigates the feasibility of utilizing steel fibres to simplify the complicated reinforcement detailing of critical HPC members under high shear stress. Mechanical properties of HPCs with specified compressive strength of 60 and 100 MPa include the flow, air content, compressive strength, and flexural strength. The effectiveness of 1.50% steel fibre content on the shear behaviour of diagonally reinforced concrete coupling beam without additional transverse reinforcement was investigated to alleviate complex reinforcing details for the full section confinement of diagonal bar groups. The test results revealed the incorporation of steel fibres significantly affected the mechanical properties of the HPCs. For diagonally reinforced coupling beam (SFRCCB without additional transverse reinforcement, the addition of 1.5% steel fibre content into 60 MPa HPC coupling beam provides similar cracking and structural behaviours compared to those of diagonally reinforced coupling beam (CCB with full section confinement details. However, the ductility of SFRCCB was less than that of CCB. It is recommended that both stirrups and steel fibre should be used for fully confining the diagonal bar groups of coupling beams to achieve the ductile behaviour.

  11. Performance and Durability Evaluation of Bamboo Reinforced Cement Concrete Beams

    Directory of Open Access Journals (Sweden)

    Ankit Singh Mehra

    2016-04-01

    Full Text Available A big part of population in India is still homeless due to raising unaffordability of housing structures. People sleeping on roadsides and living in slums is a common sight in Indian cities. To overcome this problem India today needs millions of houses for their growing population, making concrete as the most widely to be used material in the country. Concrete has found to have excellent compressive strength but poor in tensile strength, to take care of the tensile stresses steel is commonly used as reinforcing material in concrete. Production of steel is a very costly business and its use in concrete as reinforcing material increases the cost of construction by many folds. Also production of steel emits a large amount of green house gases causing considerable deterioration of the environment. The above mentioned socio-economic and environmental factors creates a necessity for finding an appropriate environment friendly and cheap material that can successfully substitute steel as reinforcement in concrete elements of a low cost dwelling for the poor and homeless people of the country. It is here that engineered bamboo can be of great value to Civil Engineers owning to its several net worthy features. Production of every tone of bamboo consumes about a tone of atmospheric CO2 in addition to releasing fresh O2. From structural point of view bamboo has been used as a structural material from the earlier times as it possesses excellent flexure and tensile strength as well as high strength to weight ratio. All this necessitates examining bamboo-reinforced cement concrete in detail for its appropriateness as a structural material for construction of a low cost dwelling unit. The study focuses on evaluating the mechanical and durability properties of cement-concrete beams both singly and doubly reinforced with bamboo splints.

  12. Feasibility of Using High-Performance Steel Fibre Reinforced Concrete for Simplifying Reinforcement Details of Critical Members

    OpenAIRE

    Seok-Joon Jang; Dae-Hyun Kang; Kyung-Lim Ahn; Wan-Shin Park; Sun-Woong Kim; Hyun-Do Yun

    2015-01-01

    This paper addresses the effects of hooked-end steel fibre contents on the mechanical properties of high-performance concrete (HPC) and investigates the feasibility of utilizing steel fibres to simplify the complicated reinforcement detailing of critical HPC members under high shear stress. Mechanical properties of HPCs with specified compressive strength of 60 and 100 MPa include the flow, air content, compressive strength, and flexural strength. The effectiveness of 1.50% steel fibre conten...

  13. REPAIR AND STRENGTHENING OF REINFORCED CONCRETE BEAMS USING FIBRE REINFORCED POLIMER (FRP MATERIALS

    Directory of Open Access Journals (Sweden)

    Nihat ÇETİNKAYA

    2004-03-01

    Full Text Available The use of Fibre Reinforced Polimer (FRP materials for the repair and strengthening of Reinforced Concrete structures has become widespread recently. FRP materials are being prefered because they have very high tensile strength, resistance to corrosion and they do not affect the use of the building during the repair and strengthening process. Four reinfoced concrete beams repaired and strengthened with FRP materials have been used in this study which were performed at Pamukkale University-Faculty of Engineering- Civil Engineering Department- Structural Engineering Laboratuary. The behaviour of the beams before and after repair and strengthening was compared by obtaining the load- displacement curves under static loading. In this study, it was observed that the repair and strengthening of reinforced concrete beams by using FRP materials had increased the load carrying capacity significantly.

  14. Glass fibres reinforced polyester composites degradation monitoring by surface analysis

    Science.gov (United States)

    Croitoru, Catalin; Patachia, Silvia; Papancea, Adina; Baltes, Liana; Tierean, Mircea

    2015-12-01

    The paper presents a novel method for quantification of the modifications that occur on the surface of different types of gel-coated glass fibre-reinforced polyester composites under artificial UV-ageing at 254 nm. The method implies the adsorption of an ionic dye, namely methylene blue, on the UV-aged composite, and computing the CIELab colour space parameters from the photographic image of the coloured composite's surface. The method significantly enhances the colour differences between the irradiated composites and the reference, in contrast with the non-coloured ones. The colour modifications that occur represent a good indicative of the surface degradation, alteration of surface hydrophily and roughness of the composite and are in good correlation with the ATR-FTIR spectroscopy and optical microscopy results. The proposed method is easier, faster and cheaper than the traditional ones.

  15. Impact Resistance of Short Fibre/Particle Reinforced Epoxy

    Science.gov (United States)

    Chang, L.; Zhang, Z.; Breidt, C.

    2004-01-01

    The influence of temperature on the fracture behaviour of epoxy-based composites was studied using an instrumented Charpy impact approach. A series of epoxy reinforced with short carbon fibres (SCF) and additionally filled with various amounts of PTFE and graphite particles was considered in this study. Unnotched specimens were tested at -196°C, 20°C, and 70°C, respectively. It was found that, for specimens with the same matrix content, a proper hybridisation of composites was possible to achieve a better impact performance compared to single-filler/epoxy. For example, 10 vol.%PTFE+10 vol.%SCF/epoxy exhibited a higher impact resistance than that of 20 vol.%SCF/epoxy at all measured temperatures. Failure mechanisms at different temperatures were discussed with SEM fractography.

  16. Evaluation on mechanical properties of woven aloevera and sisal fibre hybrid reinforced epoxy composites

    Indian Academy of Sciences (India)

    A Shadrach Jeya Sekaran; K Palani Kumar; K Pitchandi

    2015-09-01

    Natural fibres as reinforcement in polymer composite for making low-cost materials are growing day by day. Researcher’s main attention is to apply appropriate technology to utilize these natural fibres as effectively and economically as possible to produce good quality fibre-reinforced polymer composites for various engineering applications. In this research, the experiments of tensile, flexural and impact tests were carried out for woven aloevera and sisal fibre hybrid-reinforced epoxy composites. The hand layup method of fabrication was employed in preparing the composites. The surface morphology of the composites was examined through scanning electron microscope. Due to the low-density and high-specific properties of sisal fibre composites, it offer cost savings when compared with synthetic fibres. Hence it has very good implications in the automotive and transportation industry.

  17. Unidirectional Cordenka Fibre-Reinforced Furan Resin Full Biocomposite: Properties and Influence of High Fibre Mass Fraction

    Directory of Open Access Journals (Sweden)

    Talent Malaba

    2015-01-01

    Full Text Available A full biocomposite was fabricated from Cordenka CR fibre and furan resin. High fibre mass fractions (FMF were achieved by pressing the CR fibres into unidirectional sheets prior to incorporation into the resin. Results of testing indicated that the tensile properties of the biocomposite were improved by the initial increase of FMF from 51 to 64%, with a subsequent increase of FMF to 75% resulting in a deterioration of those properties. Examination of the tensile fracture surfaces with a scanning electron microscope (SEM revealed moderate deterioration in fibre-matrix adhesion after the initial increase of FMF. Further increase of the FMF to 75% was shown by SEM to result in worse fibre-matrix adhesion. On the other hand, the flexural, interlaminar-shear, and dynamic mechanical properties were adversely affected by the increase in fibre-mass fraction from 51 through 75%. These effects were mainly attributed to reduced fibre wetting that resulted in weakened fibre-matrix interfacial bonding and subsequent poor stress exchange at the fibre-matrix interface. Observations made with a digital microscope revealed normal crack behaviour in the laminated composite, and the shear fracture modes were I and II. This biocomposite has mechanical properties comparable to those of flax and glass fibre-reinforced furan resin biocomposites.

  18. Tribological behaviour of unidirectional carbon fibre-reinforced epoxy composites

    Science.gov (United States)

    Şahin, Y.; De Baets, P.

    2017-02-01

    Tribological behaviour of unidirectional carbon fibre-reinforced epoxy composites containing 42wt.% (CU42) and 52wt.% (CU52) carbon fibres fabricated by moulding technique was investigated on a pin-on-flat plate configuration. It is the first time to measure static and dynamic coefficient of frictions and wear rates of epoxy composites under heavy loading conditions. Microstructures of composites were examined by scanning electron microscopy (SEM). The experimental results indicated the carbon fiber improved the tribological properties of thermoset epoxy by reducing wear rate, but increased the coefficient of friction. At higher load, average wear rates were about 10.8x10-5 mm3/N.m for composites while it was about 38.20x10-5 mm3/N.m for epoxy resin. The wear rate decreased with decreasing load while friction coefficient increased with decreasing load. Moreover, friction coefficient of composites of CU42 tested at 90 N load was measured to be in the range 0.35 and 0.13 for static and dynamic component, respectively.

  19. Mechanical and electrical performance of Roystonea regia/glass fibre reinforced epoxy hybrid composites

    Indian Academy of Sciences (India)

    Govardhan Goud; R N Rao

    2012-08-01

    The present paper investigates mechanical and electrical properties of Roystonea regia/glass fibre reinforced epoxy hybrid composites. Five varieties of hybrid composites have been prepared by varying the glass fibre loading. Roystonea regia (royal palm), a natural fibre was collected from the foliage of locally available royal palm tree through the process of water retting and mechanical extraction. Roystonea regia, -glass short fibres were used together as reinforcement in epoxy matrix to form hybrid composites. It has been observed that tensile, flexural, impact and hardness properties of hybrid composites considerably increased with increase in glass fibre loading. But electrical conductivity and dielectric constant values decreased with increase in glass fibre content in the hybrid composites at all frequencies. Scanning electron microscopy of fractured hybrid composites has been carried out to study the fibre matrix adhesion.

  20. A Review of the Flammability Factors of Kenaf and Allied Fibre Reinforced Polymer Composites

    Directory of Open Access Journals (Sweden)

    C. H. Lee

    2014-01-01

    Full Text Available Natural fibre is a well-known reinforcement fibre in polymer-matrix Composites (PMC lately. Natural fibre has fast growing and abundance properties which make it available at very low cost. For kenaf fibre there is long lists of research projects which have been done regarding its behaviour, and properties and modification made to it. In this paper, fire flammability is the main concern for natural fibre reinforced polymer (NFRP composites especially kenaf fibre. To estimate its flammability, a wide range of factors can be considered such as fibre content, type of matrices, pH conditions, treatment, and fire retardant (FR filler’s type. The most important criteria are the ignition time, rate of propagation, and fire behavior. thermogravimetric analysis (TGA, different scanning calorimetric (DSC, and dynamic mechanical analysis (DMA are the three most famous methods used to investigate the fire behaviour of composites.

  1. Blast impact behaviour of concrete with different fibre reinforcement

    Directory of Open Access Journals (Sweden)

    Drdlová Martina

    2015-01-01

    Full Text Available The paper summarizes the results of the development of special concrete intended for the explosion resistance applications, with the emphasis on minimal secondary fragments formation at the explosion. The fine-grained concrete matrix has been reinforced by various types of short dispersed fibers (metallic, mineral and polymer of different sizes and by their combination and the effect of the fibre reinforcement on the physico-mechanical properties and blast resistance was observed. The concrete prism specimens have been subjected to the determination of mechanical parameters (compressive and flexural strength at quasi-static load. The blast tests were conducted on the slab specimens prepared from selected mixtures. The material characteristics and explosion test data have been used for numerical investigation, which defined the optimal wall composition and dimensions of the concrete element which should resist the explosion defined by type, size, weight and placement of the blast. In the next step the test elements resistance was verified by real explosion test.

  2. Reinforcement of tungsten carbide grains by nanoprecipitates in cemented carbides.

    Science.gov (United States)

    Liu, Xingwei; Song, Xiaoyan; Wang, Haibin; Hou, Chao; Liu, Xuemei; Wang, Xilong

    2016-10-14

    In contrast to the conventional method that obtains a high fracture strength of tungsten carbide-cobalt (WC-Co) cemented carbides by reducing WC grain size to near-nano or nanoscale, a new approach has been developed to achieve ultrahigh fracture strength by strengthening the WC grains through precipitate reinforcement. The cemented carbides were prepared by liquid-state sintering the in situ synthesized WC-Co composite powders with a little excess carbon and pre-milled Cr3C2 particles having different size scales. It was found that the nanoscale dispersed particles precipitate in the WC grains, which mainly have a coherent or semi-coherent interface with the matrix. The pinning effect of the nanoparticles on the motion of dislocations within the WC grains was observed. The mechanisms for the precipitation of nanoparticles in the WC grains were discussed, based on which a new method to enhance the resistance against the transgranular fracture of cemented carbides was proposed.

  3. Reinforcement of tungsten carbide grains by nanoprecipitates in cemented carbides

    Science.gov (United States)

    Liu, Xingwei; Song, Xiaoyan; Wang, Haibin; Hou, Chao; Liu, Xuemei; Wang, Xilong

    2016-10-01

    In contrast to the conventional method that obtains a high fracture strength of tungsten carbide-cobalt (WC-Co) cemented carbides by reducing WC grain size to near-nano or nanoscale, a new approach has been developed to achieve ultrahigh fracture strength by strengthening the WC grains through precipitate reinforcement. The cemented carbides were prepared by liquid-state sintering the in situ synthesized WC-Co composite powders with a little excess carbon and pre-milled Cr3C2 particles having different size scales. It was found that the nanoscale dispersed particles precipitate in the WC grains, which mainly have a coherent or semi-coherent interface with the matrix. The pinning effect of the nanoparticles on the motion of dislocations within the WC grains was observed. The mechanisms for the precipitation of nanoparticles in the WC grains were discussed, based on which a new method to enhance the resistance against the transgranular fracture of cemented carbides was proposed.

  4. CRAG (Composite Research Advisory Group) Test Methods for the Measurement of the Engineering Properties of Fibre Reinforced Plastics

    Science.gov (United States)

    1988-02-01

    coefficients in fibre reinforced plastic laminates. RAE Technical Report 81105, August 1981. UNLIMITED fig 900.1 00 Z a r40 N 6)l I...through- thickness moisture distribution and diffusion coefficients in fibre reinforced plastic laminates. RAE Technical Report 81105, August 1981. 4 C...procedures to be used to determine the fibre volume fraction (Vf) and the resin volume fraction (Vr) of cured fibre reinforced plastic laminates. It is not

  5. Life cycle strain monitoring in glass fibre reinforced polymer laminates using embedded fibre Bragg grating sensors from manufacturing to failure

    DEFF Research Database (Denmark)

    Nielsen, Michael Wenani; Schmidt, Jacob Wittrup; Høgh, Jacob Herold

    2013-01-01

    failure. The internal process-induced strain development is investigated through use of different cure schedules and tool/part interactions. The fibre Bragg grating sensors successfully monitor resin flow front progression during infusion, and strain development during curing, representative...... of the different cure temperatures and tool/part interfaces used. Substantial internal process-induced strains develop in the transverse fibre direction, which should be taken into consideration when designing fibre-reinforced polymer laminates. Flexure tests indicate no significant difference in the mechanical...

  6. Mechanical properties of kenaf bast and core fibre reinforced unsaturated polyester composites

    Energy Technology Data Exchange (ETDEWEB)

    Ishak, M R; Leman, Z; Sapuan, S M [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Edeerozey, A M M; Othman, I S, E-mail: zleman@eng.upm.edu.my [Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, 76109 Durian Tunggal, Melaka (Malaysia)

    2010-05-15

    Kenaf fibre has high potential to be used for composite reinforcement in biocomposite material. It is made up of an inner woody core and an outer fibrous bark surrounding the core. The aim of this study was to compare the mechanical properties of short kenaf bast and core fibre reinforced unsaturated polyester composites with varying fibre weight fraction i.e. 0%, 5%, 10%, 20%, 30% and 40%. The compression moulding technique was used to prepare the composite specimens for tensile, flexural and impact tests in accordance to the ASTM D5083, ASTM D790 and ASTM D256 respectively. The overall results showed that the composites reinforced with kenaf bast fibre had higher mechanical properties than kenaf core fibre composites. The results also showed that the optimum fibre content for achieving highest tensile strength for both bast and core fibre composites was 20%wt. It was also observed that the elongation at break for both composites decreased as the fibre content increased. For the flexural strength, the optimum fibre content for both composites was 10%wt while for impact strength, it was at 10%wt and 5%wt for bast and core fibre composites respectively.

  7. Characterisation of natural fibre reinforced PLA foams prepared by supercritical CO2 assisted extrusion

    Directory of Open Access Journals (Sweden)

    K. Bocz

    2016-09-01

    Full Text Available Natural fibre reinforced polylactic acid (PLA foams, as potential green replacements for petroleum-based polymer foams, were investigated. Highly porous (ε > 95% microcellular PLA foams were manufactured by supercritical CO2 assisted extrusion process. To overcome the inherently low melt strength of PLA, epoxy-functionalized chain extender was applied, while talc was added to improve its crystallization kinetics. The combined application of chain extender and talc effectively promoted the formation of uniform cell structures. The effect of cellulose and basalt fibre reinforcement on the foamability, morphology, structure and mechanical properties of the PLA foams were investigated as well. The addition of 5 wt% natural fibres promoted the cell nucleation, but caused non-uniform distribution of cell size due to the microholes induced by local fibre-matrix debonding. The compression strength of the manufactured basalt fibre reinforced PLA foams reached 40 kPa.

  8. Effect of Moisture Absorption Behavior on Mechanical Properties of Basalt Fibre Reinforced Polymer Matrix Composites

    Directory of Open Access Journals (Sweden)

    Amuthakkannan Pandian

    2014-01-01

    Full Text Available The study of mechanical properties of fibre reinforced polymeric materials under different environmental conditions is much important. This is because materials with superior ageing resistance can be satisfactorily durable. Moisture effects in fibre reinforced plastic composites have been widely studied. Basalt fibre reinforced unsaturated polyester resin composites were subjected to water immersion tests using both sea and normal water in order to study the effects of water absorption behavior on mechanical properties. Composites specimens containing woven basalt, short basalt, and alkaline and acid treated basalt fibres were prepared. Water absorption tests were conducted by immersing specimens in water at room temperature for different time periods till they reached their saturation state. The tensile, flexural, and impact properties of water immersed specimens were conducted and compared with dry specimens as per the ASTM standard. It is concluded that the water uptake of basalt fibre is considerable loss in the mechanical properties of the composites.

  9. Jute fibre reinforced plastic: evaluation of application based properties

    Directory of Open Access Journals (Sweden)

    J. B. Sajin

    2015-01-01

    Full Text Available A fibre extracted from jute is a budding component identified for its potential application in composites. It is imperative to evaluate the parametric and property based features to determine its suitability. In this research study, considering the possible application of the fibre composites, the aptness of these fibres are examined with respect to their physical, mechanical [by layered manufacturing technique(LM] and thermal properties. This study focuses on evaluating the properties and behaviour of raw Jute fibres and NaOH surface treated fibres. Subsequently, the fibres are subjected to thermo-gravimetry tests. The outcome of the thermal analysis clearly indicates that the temperature peak shifts to a higher region in the treated fibre compared to raw fibre. The overall observation strongly emphasize that the physical properties and the thermal behaviour of jute fibre are enhanced after surface treatments which makes it more feasible for its application in composite structures.

  10. FLEXURAL PROPERTIES OF ALKALINE TREATED SUGAR PALM FIBRE REINFORCED EPOXY COMPOSITES

    Directory of Open Access Journals (Sweden)

    D. Bachtiar

    2010-06-01

    Full Text Available A study of the effect of alkaline treatment on the flexural properties of sugar palm fibre reinforced epoxy composites is presented in this paper. The composites were reinforced with 10% weight fraction of the fibres. The fibres were treated using sodium hydroxide (NaOH with 0.25 M and 0.5 M concentration solution for 1 hour, 4 hours and 8 hours soaking time. The purpose of treating fibres with alkali was to enhance the interfacial bonding between matrix and fibre surfaces. The maximum flexural strength occurred at 0.25 M NaOH solution with 1 hour of soaking time, i.e 96.71 MPa, improving by 24.41% from untreated fibre composite. But, the maximum flexural modulus took place at 0.5 M NaOH solution with 4 hours soaking time, i.e. 6948 MPa, improving by 148% from untreated composite.

  11. Influence of geometry on the fracturing behavior of textile reinforced cement monitored by acoustic emission

    Science.gov (United States)

    Aggelis, D. G.; Blom, J.; El Kadi, M.; Wastiels, J.

    2014-03-01

    In this work the flexural behavior of textile reinforced cement (TRC) laminate is examined using acoustic emission (AE). The TRC composite is a combination of inorganic phosphate cement (IPC) with randomly distributed glass fibres. IPC has been developed at the "Vrije Universiteit Brussel" and shows a neutral pH meaning that glass fibers are hardly attacked. During bending, stresses lead to the activation of damage mechanisms like matrix cracking, delaminations and fiber pull-out being in succession or overlapping in time. AE records the responses of the damage propagation events and allows the monitoring of the fracture behavior from the onset to the final stage. The effect of the span in three-point bending tests, which is varied to create different stress fields, is targeted. Parameters like duration and frequency reveal information about the mode of the damage sources in relation to the span. Results show that as the span decreases, the dominant damage mode shifts away from bending and acquires more shear characteristics by increasing the interlaminar shearing events.

  12. Use of coconut fibre reinforced concrete and coconut-fibre ropes for seismic-resistant construction

    Directory of Open Access Journals (Sweden)

    Ali, Majid

    2016-03-01

    Full Text Available Earthquake-resistant and economical housing is the most desirable need in rural areas of developing countries. These regions often suffer significant loss of life during a seismic event. To enable an efficient and cost-effective solution, a new concept of construction, i.e. a wallette of interlocking blocks with movability at the interface and rope reinforcement, is investigated. The novel interlocking block is made of coconut fibre reinforced concrete (CFRC. The reason for using coconut fibre is their highest toughness amongst natural fibres. This paper describes the in-plane behaviour of the interlocking wallette under earthquake loadings. The wallette response is measured in terms of induced acceleration, block uplift, top maximum relative displacement and rope tension. The applied earthquake loadings cannot produce any damage in the structure, i.e. blocks and/or ropes. The response of the wallette is explained in detail along with correlation of materials aspect with structural behaviour.En las zonas rurales de los países en desarrollo, entre las características principales que deben reunir las viviendas es que sean tanto económicas como sismoresistentes, ya que en estas zonas la pérdida de vidas humanas debido a los terremotos es aun elevada. A fin de hallar una solución que cumple con estos requisitos de manera técnica y económicamente efectiva, se ha investigado un nuevo concepto constructivo: un murete de bloques conjugados con movilidad en el interfaz y reforzado con cuerda. Este novedoso bloque conjugable está realizado en hormigón reforzado con fibra de coco (CFRC, elegida por su alta tenacidad, la mayor de entre las fibras naturales. El artículo describe el comportamiento dentro del plano del murete conjugado frente a las cargas sísmicas. La respuesta de esta estructura se ha medido en función de la aceleración inducida, el levantamiento de los bloques, el desplazamiento relativo máximo y la tensión de las cuerdas

  13. UV radiation effect towards mechanical properties of Natural Fibre Reinforced Composite material: A Review

    Science.gov (United States)

    Mahzan, Shahruddin; Fitri, Muhamad; Zaleha, M.

    2017-01-01

    The use of natural fibres as reinforcement material have become common in human applications. Many of them are used in composite materials especially in the polymer matrix composites. The use of natural fibres as reinforcement also provide alternative solution of usage instead of being a waste materials. In some applications, these natural reinforced polymer composites were used as the outer layer, making them exposed to ultra violet exposure, hence prone to UV radiation. This paper reviews the effect of UV radiation towards the mechanical properties of natural fibre reinforced polymer matrix composite material. The effect of chemical treatment towards the natural fibre is also investigated. One of the important features that was critically explored was the degradation of the composite materials. The influence of UV radiation on the degradation rate involve several parameters such as wavelength, intensity and exposure time. This review highlights the influence of these parameters in order to provide better solution for polymer matrix composite’s development.

  14. Prediction of process induced shape distortions and residual stresses in large fibre reinforced composite laminates

    DEFF Research Database (Denmark)

    Nielsen, Michael Wenani

    The present thesis is devoted to numerical modelling of thermomechanical phenomena occurring during curing in the manufacture of large fibre reinforced polymer matrix composites with thick laminate sections using vacuum assisted resin transfer moulding (VARTM). The main application of interest...

  15. In vitro degradation of porous nano-hydroxyapatite/collagen/PLLA scaffold reinforced by chitin fibres

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiaoming [Biomaterials Laboratory, Department of Materials Science and Engineering, Tsinghua University, Beijing, 100084 (China); Feng Qingling [Biomaterials Laboratory, Department of Materials Science and Engineering, Tsinghua University, Beijing, 100084 (China)]. E-mail: biomater@mail.tsinghua.edu.cn; Cui Fuzhai [Biomaterials Laboratory, Department of Materials Science and Engineering, Tsinghua University, Beijing, 100084 (China)

    2006-05-15

    In this paper, a novel porous scaffold for bone tissue engineering was prepared with nano-hydroxyapatite/collagen/Poly-L-lactic acid (PLLA) composite reinforced by chitin fibres. To enhance the strength of the scaffold further, PLLA was linked with chitin fibres by Dicyclohexylcarbodimide (DCC). The structures of the reinforced scaffold with and without linking were characterized by Scanning Electron Microscopy (SEM). The chemical characteristics of the chitin fibres with and without linking were evaluated by Fourier-transformed infrared (FTIR) spectroscopy. The mechanical performance during degradation in vitro was investigated. The results indicated that the nano-hydroxyapatite/collagen/PLLA composite reinforced by chitin fibres with linking kept better mechanical properties than that of the composite without linking. These results denoted that the stronger interfacial bonding strength of the scaffold with linking could decrease the degradation rate in vitro. The reinforced composite with the link-treatment can be severed as a scaffold for bone tissue engineering.

  16. Enhancement of mechanical properties and interfacial adhesion by chemical odification of natural fibre reinforced polypropylene composites

    CSIR Research Space (South Africa)

    Erasmus, E

    2008-11-01

    Full Text Available Natural fibres are often used for reinforcing thermoplastics, like polypropylene, to manufacture composite materials exhibiting numerous advantages such as high mechanical properties, low density and biodegradability. The mechanical properties of a...

  17. Foundation Design for a High Bay Warehouse with a Steel Fibre Reinforced Concrete Slab

    DEFF Research Database (Denmark)

    Kasper, T.; Sørensen, Carsten Steen; Nielsen, J. B.

    2008-01-01

    concrete slabs, while a 69 x 77 m and 40 cm thick steel fibre reinforced concrete (SFRC) slab forms the inner part of the foundation. Steel fibre reinforcement has been chosen mainly due to approximately 15 % lower construction costs than a comparable solution with conventional rebar reinforcement......The high bay warehouse at the Carlsberg brewery in Fredericia, Denmark, is 40 m high and is founded with a 83 x 116 m foundation slab on clay till and sand layers. Due to the wind loads on the tall building, the edges of the foundation require 80 cm and 60 cm thick conventionally reinforced...

  18. Influence of Portland Cement Class on the Corrosion Rate of Steel Reinforcement in Cement Mortar Caused by Penetrating Chloride and Sulfate from the Environment

    OpenAIRE

    Bikić, F.; Cacan, M.; Rizvanović, M.

    2013-01-01

    The influence of portland cement class on the corrosion rate of steel reinforcement in cement mortar caused by penetrating chloride or sulfate from the environment in already hardened cement mortar is investigated in this paper. Three classes of portland cement have been used for the tests, PC 35, PC 45 and PC 55. Cylindrical samples of cement mortar with steel reinfor- cement in the middle were treated 6 months at room temperature in the follow...

  19. Static and dynamic testing of concrete beams reinforced with fibres and continuous bars

    NARCIS (Netherlands)

    Körmeling, H.A.; Reinhardt, H.W.; Shah, S.P.

    1979-01-01

    The main purpose of the testing program was to get an idea about the influence of steel fibres on the fatigue performance of conventionally reinforced concrete beams. The influence of three types of steel fibres with three various percentages on the failure load, the cycles to failure, the crack wid

  20. Application of the fluid dynamics model to the field of fibre reinforced self-compacting concrete

    DEFF Research Database (Denmark)

    Svec, Oldrich; Skocek, Jan; Stang, Henrik;

    Ability to properly simulate a form filling process with steel fibre reinforced self-compacting concrete is a challenging task. Such simulations may clarify the evolution of fibre orientation and distribution which in turn significantly influences final mechanical properties of the cast body. We ...

  1. Hardening in Two-Phase Materials. I. Strength Contributions in Fibre-Reinforced Copper-Tungsten

    DEFF Research Database (Denmark)

    Lilholt, Hans

    1977-01-01

    Cyclic tests (Bauschinger tests) were conducted at 77 K and at room temperature on the fibre-reinforced material of single crystal Cu with long W-fibres of diameter 20 mum and volume fractions up to 4%. These tests enabled two important contributions to the total strength of the unrelaxed materia...

  2. Utilisation of fibre reinforced polymer (FRP) composites in the confinement of concrete

    OpenAIRE

    Ciupala, Mihaela Anca; Pilakoutas, K.; Mortazavi, A.A.

    2007-01-01

    This paper presents an experimental investigation carried out on concrete cylinders\\ud confined with fibre reinforced polymers (FRP), subjected to monotonic and cyclic loading.\\ud Carbon fibres (CFRP) were used as confining material for the concrete specimens. The failure\\ud mode, reinforcement ratio based on jacket thickness and type of loading are examined. The study\\ud shows that external confinement of concrete can enhance its strength and ductility as well as result\\ud in large energy ab...

  3. The Influence of Moisture on the Performance of Polymer Fibre-Reinforced Asphalt Mixture

    Directory of Open Access Journals (Sweden)

    Kamaruddin Ibrahim

    2016-01-01

    Full Text Available A number of researches have been done worldwide to evaluate the damage caused by water in bituminous pavements. The use of the retained strength ratios obtained from laboratory moisture damage tests is a useful tool in making quantitative predictions of the related damage caused by water. This study involved laboratory work on the effect of water on the performance of bituminous mixtures. Comparisons are made between the performances of Hot-rolled Asphalt (HRA bituminous mixtures containing base bitumen of 50 pen grade to that of a polymer-fibre reinforced HRA mixture. Two types of polymer fibre were studied, namely polypropylene and polyester and these fibre were added in different concentrations in the bituminous mixtures. Changes in both the cohesive properties of the bitumen and the adhesion of the bitumen to the aggregate surface were observed as a result of exposing the bituminous mixtures to moisture. The effect of polymer fibre reinforcement in bituminous mixtures helps reduce the level of moisture damage. This was evident in the lower moisture susceptibility achieved in the polymer fibre reinforced bituminous mixtures as compared to the control mixture. The additional bitumen in the fibre reinforced mixtures also afforded an increased film thickness on the aggregate particles, thus affording additional protection of the mixtures from moisture. The reinforcement of polymer fibres in bituminous mixtures also acts to decrease the moisture sensitivity of the bitumen to aggregate bonding. This may be due to the strengthening of the wetted binder matrix that helps promote both adhesion and cohesion retention.

  4. Comparison of impact strength of acrylic resin reinforced with kevlar and polyethylene fibres.

    Science.gov (United States)

    Kamath, G; Bhargava, K

    2002-01-01

    The present study was done to evaluate the impact strengths of heat-activated acrylic resins reinforced with Kevlar fibres, polyethylene fibres and unreinforced heat activated acrylic resin. Each of three groups had 25 specimens. Brass rods of uniform length of 40 mm and diameter of 8 mm were used to prepare the moulds. A combination of long fibres (40 mm length) and short fibres (6 mm length) were used. The total amount of fibres incorporated was limited to 2% by weight of the resin matrix. Short and long fibres of equal weight were incorporated. The short fibres were mixed with polymer and monomer and packed into the mould, while, the long axis of the specimen, perpendicular to the applied force. The specimens were then processed. Impact strength testing was done on Hounsfield's impact testing machine. Kevlar fibre reinforced heat activated acrylic resin specimens recorded higher mean impact strength of 0.8464 Joules, while polyethylene fibres reinforced heat activated acrylic resin recorded mean impact strength of 0.7596 joules. The unreinforced heat activated acrylic resin recorded mean impact strength of 0.3440 Joules.

  5. Influence of steady shear flow on dynamic viscoelastic properties of un-reinforced and Kevlar, glass fibre reinforced LLDPE

    Indian Academy of Sciences (India)

    Takeshi Kitano; S A R Hashmi; Navin Chand

    2004-10-01

    An experimental study was conducted to observe the effects of parallel-superposed flow condition on viscoelastic properties of LLDPE, Kevlar fibre reinforced LLDPE and hybrid of short glass fibre and Kevlar fibre reinforced LLDPE. Parallel-plate rheometer was employed for these tests. Rheological parameters such as loss modulus (″) and dynamic viscosity (′) do not vary significantly on superposing steady state shear with oscillatory shear in the studied range of experiment at 185°C in un-reinforced LLDPE. Kevlar fibre reinforced LLDPE and Kevlar/glass fibre reinforced LLDPE showed significant changes in the flow behaviour under various sets of superposed conditions. Storage modulus (′), and ″ become highly sensitive to low oscillatory angular frequencies () under superposed conditions. These curves show two different regions with increased value. At low values, parameters ′ and ″ change sharply reaching a certain value, thereafter, changes are moderate with increased . In case of ′ a maxima is observed, position of which, depends upon the value of steady shear rate. Maxima shifts towards higher frequencies with the increased steady shear rate.

  6. Computational modelling of fibre-reinforced cementitious composites: An analysis of discrete and mesh-independent techniques

    NARCIS (Netherlands)

    Radtke, F.K.F.

    2012-01-01

    Failure patterns and mechanical behaviour of high performance fibre-reinforced cementitious composites depend to a large extent on the distribution of fibres within a specimen. A discrete treatment of fibres enables us to study the influence of various fibre distributions on the mechanical propertie

  7. Mechanical properties of short-flax-fibre reinforced compounds

    NARCIS (Netherlands)

    Bos, H.L.; Müssig, J.; Oever, van den M.J.A.

    2006-01-01

    The mechanical properties of flax/polypropylene compounds, manufactured both with a batch kneading and an extrusion process were determined and compared with the properties of Natural fibre Mat Thermoplastic (NMT) composites. The fibre length and width distributions of the fibres from the compounds

  8. Crack Detection in Fibre Reinforced Plastic Structures Using Embedded Fibre Bragg Grating Sensors: Theory, Model Development and Experimental Validation

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira; Mikkelsen, Lars Pilgaard; McGugan, Malcolm

    2015-01-01

    properties. When applying this concept to different structures, sensor systems and damage types, a combination of damage mechanics, monitoring technology, and modelling is required. The primary objective of this article is to demonstrate such a combination. This article is divided in three main topics......In a fibre-reinforced polymer (FRP) structure designed using the emerging damage tolerance and structural health monitoring philosophy, sensors and models that describe crack propagation will enable a structure to operate despite the presence of damage by fully exploiting the material’s mechanical...... a crack growth/damage event in fibre-reinforced polymer or structural adhesive-bonded structures using embedded fibre Bragg grating (FBG) sensors is presented by combining conventional measured parameters, such as wavelength shift, with parameters associated with measurement errors, typically ignored...

  9. Piezoresistivity in Carbon Fiber Reinforced Cement Based Composites

    Institute of Scientific and Technical Information of China (English)

    Bing CHEN; Keru WU; Wu YAO

    2004-01-01

    The resu lts of some i nteresti ng investigation on the piezoresistivity of ca rbon fi ber reinforced cement based com posites (CFRC) are presented with the prospect of developing a new nondestructive testing method to assess the integrity of the composite. The addition of short carbon fibers to cement-based mortar or concrete improves the structural performance and at the same time significantly decreases the bulk electrical resistivity. This makes CFRC responsive to the smart behavior by measuring the resistance change with uniaxial pressure. The piezoresistivity of CFRC under different stress was studied, at the same time the damage occurring inner specimens was detected by acoustic emission as well. Test results show that there exists a marking pressure dependence of the conductivity in CFRC, in which the so-called negative pressure coefficient of resistive (NPCR) and positive pressure coefficient of resistive (PPCR) are observed under low and high pressure. Under constant pressures, time-dependent resistivity is an outstanding characteristic for the composites, which is defined as resistance creep. The breakdown and rebuild-up process of conductive network under pressure may be responsible for the pressure dependence of resistivity.

  10. Deflection analysis of reinforced concrete beams strengthened with carbon fibre reinforced polymer under long-term load action

    Institute of Scientific and Technical Information of China (English)

    Mykolas DAUGEVI(C)IUS; Juozas VALIVONIS; Gediminas MAR(C)IUKAITIS

    2012-01-01

    This paper presents the results of an experimental research on reinforced concrete beams strengthened with an external carbon fibre reinforced polymer (CFRP) layer under long-term load action that lasted for 330 d.We describe the characteristics of deflection development of the beams strengthened with different additional anchorages of the external carbon fibre composite layer during the period of interest.The conducted experiments showed that the additional anchorage influences the slip of the extemal layer with respect to the strengthened element.Thus,concrete and carbon fibre composite interface stiffness decreases with a long-term load action.Therefore,the proposed method of analysis based on the built-up-bars theory can be used to estimate concrete and carbon fibre composite interface stiffness in the case of long-term load.

  11. Fibres reinforced dentures investigated with en-face optical coherence tomography

    Science.gov (United States)

    Negrutiu, Meda L.; Sinescu, Cosmin; Hughes, Michael; Bradu, Adrian; Goguta, Luciana; Rominu, Mihai; Negru, Radu; Podoleanu, Adrian Gh.

    2008-04-01

    The complete dentures are currently made using different technologies. In order to avoid deficiencies of the prostheses made using the classical technique, several alternative procedures have been devised. In order to enhance the mechanical strength, complete denture bases are reinforced with fibres. Their material and structure vary wildly, which makes the investigation difficult. In this study, optical coherence tomography (OCT) is evaluated as a possible non-invasive technique to assess the biomechanical behaviour of the reinforcing fibres. OCT images demonstrate structural defects between fibres and the acrylic material in all dentures bases investigated. We conclude that OCT can successfully be used as a noninvasive analysis method.

  12. Effects of moisture on the mechanical properties of glass fibre reinforced vinylester resin composites

    Indian Academy of Sciences (India)

    Rita Roy; B K Sarkar; N R Bose

    2001-02-01

    Glass fibre reinforced vinylester resin composites incorporating varying amounts of fibres (63.5, 55.75, 48.48, 38.63 and 27.48 wt%) were characterized for their mechanical properties both as prepared and after treatment with boiling water for 2, 4, 6, 8 and 24 h. Weights of the samples were found to increase to a saturation at about 8 h with boiling water treatment. In keeping with the composite principle, the mechanical properties improved with fibre loading. However, the properties were relatively inferior when treated with boiling water for longer hours attributing to ingress of moisture by capillary action through the interface between the fibre and the resin matrix. Considering the rates of moisture absorption and correlating with the mechanical properties, it was observed that the deteriorating effects were predominant up to 4 h treatment with boiling water. Estimation of defect concentrations for 63.5 wt% of nascent fibre reinforced composites as well as those composites treated with boiling water for 24 h were 56.93% and 64.16% respectively. Similarly, 27.48 wt% nascent fibre reinforced composites and those composites with boiling water treatment showed the estimation of defect concentrations of 39.94% and 50.55% respectively. SEM study of the fractured surfaces showed heavy fibre pull-out in the tensile zone whilst shear fracture of the fibre bundles was predominant at the compressive zone of the samples tested for flexural strength properties.

  13. Dimensional change of acrylic resin plate after the reinforcement of glass fibre

    Directory of Open Access Journals (Sweden)

    Dwiyanti Feriana Ratwita

    2007-06-01

    Full Text Available The effect of fibre reinforcement of polymethyl methacrylate was investigated. Glass fibres have been studied as strengthening material added to polymethyl methacrylate. The purpose of this study was to evaluate dimensional change of acrylic resin plate after glass fibre reinforcement. As a research subject is an acrylic resin plate of 65 × 10 × 2.5 mm with the number of 32 samples were distributed randomly in 4 experimental groups. Each group consisted of 8 samples and control groups. Group 1: acrylic resin plate and 1 sheet glass fibre; group 2: acrylic resin plate and 2 sheet glass fibre; group 3: acrylic resin plate and 3 sheet glass fibre. Control group which was not given treatment. Dimensional change was measured by profile projector. The data was analyzed by One-Way ANOVA and LSD test showed that there was significant difference in dimensional change (p < 0.005. The conclusion suggested that dimensional change of the acrylic resin plates after glass fibre reinforcement minimally done 1 sheet glass fibre.

  14. Fatigue damage propagation in unidirectional glass fibre reinforced composites made of a non-crimp fabric

    DEFF Research Database (Denmark)

    Hansen, Jens Zangenberg; Brøndsted, Povl; Gillespie Jr., John W.

    2014-01-01

    Damage progression in unidirectional glass fibre reinforced composites manufactured of a non-crimp fabric subjected to tension-tension fatigue is investigated, and a quantitative explanation is given for the experimentally observed stiffness degradation. The underlying damage-mechanisms are exami......Damage progression in unidirectional glass fibre reinforced composites manufactured of a non-crimp fabric subjected to tension-tension fatigue is investigated, and a quantitative explanation is given for the experimentally observed stiffness degradation. The underlying damage...... fatigue, gives rise to axial fibre fractures and a loss of stiffness, eventually leading to final failure. The uniqueness of the present work is identification of the mechanisms associated with tension fatigue failure of unidirectional non-crimp fabrics used for wind turbine blades. The observed damage...... mechanisms need further attention and understanding in order to improve the fatigue life-time of unidirectional glass fibre reinforced non-crimp fabrics....

  15. Strength and toughness of structural fibres for composite material reinforcement.

    Science.gov (United States)

    Herráez, M; Fernández, A; Lopes, C S; González, C

    2016-07-13

    The characterization of the strength and fracture toughness of three common structural fibres, E-glass, AS4 carbon and Kevlar KM2, is presented in this work. The notched specimens were prepared by means of selective carving of individual fibres by means of the focused ion beam. A straight-fronted edge notch was introduced in a plane perpendicular to the fibre axis, with the relative notch depth being a0/D≈0.1 and the notch radius at the tip approximately 50 nm. The selection of the appropriate beam current during milling operations was performed to avoid to as much as possible any microstructural changes owing to ion impingement. Both notched and un-notched fibres were submitted to uniaxial tensile tests up to failure. The strength of the un-notched fibres was characterized in terms of the Weibull statistics, whereas the residual strength of the notched fibres was used to determine their apparent toughness. To this end, the stress intensity factor of a fronted edge crack was computed by means of the finite-element method for different crack lengths. The experimental results agreed with those reported in the literature for polyacrylonitrile-based carbon fibres obtained by using similar techniques. After mechanical testing, the fracture surface of the fibres was analysed to ascertain the failure mechanisms. It was found that AS4 carbon and E-glass fibres presented the lower toughness with fracture surfaces perpendicular to the fibre axis, emanating from the notch tip. The fractured region of Kevlar KM2 fibres extended along the fibre and showed large permanent deformation, which explains their higher degree of toughness when compared with carbon and glass fibres. This article is part of the themed issue 'Multiscale modelling of the structural integrity of composite materials'.

  16. Life cycle assessment of biofibres replacing glass fibres as reinforcement in plastics

    Energy Technology Data Exchange (ETDEWEB)

    Corbiere-Nicollier, T.; Gfeller Laban, B.; Jolliet, O. [Laboratory of Ecosystem Management GECOS-EPFL, Swiss Federal Institute of Technology, CH-1015 Lausanne (Switzerland); Lundquist, L.; Leterrier, Y.; Manson, J.A.E. [Composite and Polymer Technology Laboratory, LTC-EPFL, Swiss Federal Institute of Technology Lausanne, EPFL, CH-1015 Lausanne (Switzerland)

    2001-11-01

    This article aims to determine the environmental performance of China reed fibre used as a substitute for glass fibre as reinforcement in plastics and to identify key environmental parameters. A life cycle assessment (LCA) is performed on these two materials for an application to plastic transport pallets. Transport pallets reinforced with China reed fibre prove to be ecologically advantageous if they have a minimal lifetime of 3 years compared with the 5-year lifetime of the conventional pallet. The energy consumption and other environmental impacts are strongly reduced by the use of raw renewable fibres, due to three important factors: (a) the substitution of glass fibre production by the natural fibre production; (b) the indirect reduction in the use of polypropylene linked to the higher proportion of China reed fibre used and (c) the reduced pallet weight, which reduces fuel consumption during transport. Considering the whole life cycle, the polypropylene production process and the transport cause the strongest environmental impacts during the use phase of the life cycle. Since thermoplastic composites are hardly biodegradable, incineration has to be preferred to discharge on landfills at the end of its useful life cycle. The potential advantages of the renewable fibres will be effective only if a purer fibre extraction is obtained to ensure an optimal material stiffness, a topic for further research. China reed biofibres are finally compared with other usages of biomass, biomaterials, in general, can enable a three to ten times more efficient valorisation of biomass than mere heat production or biofuels for transport.

  17. Experimental study of bamboo using banana and linen fibre reinforced polymeric composites

    Directory of Open Access Journals (Sweden)

    Ramachandran M.

    2016-09-01

    Full Text Available The application of natural fibres such as bamboo, jute, banana, coir, linen and the like in Fibre Reinforced Polymeric (FRP composites have become so vital due to their high effective stiffness and strength, availability, low cost, specific strength, better dimensional stability and mechanical properties, eco-friendly and biodegradable as compared with synthetic fibres. The interest in natural fibre reinforced polymeric composites is rapidly springing up in terms of research and industrial applications. The increased applications of these natural fibres in such composites are a proof to this claim. The paper deals with the detailed study of bamboo fibre, banana fibre and linen fibre cut into 2−4 mm of length with epoxy resin having random orientations. Various tests like Impact test (IZOD and CHARPY test, Fourier Transform Infra-Red (FTIR test and Rockwell Hardness test were conducted on 10 specimens of bamboo epoxy resin composite, bamboo−banana epoxy resin composite and bamboo−linen epoxy resin composite. It is analysed and proved that bamboo−banana epoxy resin composite shows better results in Impact test with values of 4 Joules for Izod test and 5 Joules for Charpy test and in FTIR test, compatibility of fibres with polymers in bamboo−banana epoxy resin composite are the best while bamboo−linen epoxy resin composite shows better result in Rockwell hardness test with value of 40 RHN.

  18. Determination of material properties for short fibre reinforced C/C-SiC

    Directory of Open Access Journals (Sweden)

    Hausherr J.-M.

    2015-01-01

    Full Text Available Determining the mechanical properties of short fibre reinforced CMC using standard sized coupons has always been a challenge due to a high statistical scattering of the measured values. Although the random orientation of short fibres results in a quasi-isotropic material behavior of 2D-structures with a sufficiently large volume, the small volume typical for test coupons usually results in a non-isotropic fibre orientation in the tested volume. This paper describes a method for manufacturing unidirectional oriented short fibre reinforced CMC materials and presents material properties of UD-C/C-SiC. After verifying the fibre orientation of the CMC using micro-computed tomography, coupons were extracted to determine the orthotropic material properties. These orthotropic material properties were then used to predict the properties of C/C-SiC with randomly distributed short fibres. To validate the method, micro-computed tomography is used to quantitatively determine the fibre orientation within coupons extracted from randomly distributed short fibre C/C-SiC. After mechanical three-point-bending tests, the measured stiffness and bending strength is compared with the predicted properties. Finally, the data are used to devise a method suited for reducing the inherent large spread of material properties associated with the measurement of CMC materials with randomly distributed short fibres.

  19. A new method of making metal matrix fibre reinforced materials

    Energy Technology Data Exchange (ETDEWEB)

    Schaupp, J. (Inst. fuer Werkzeugmaschinen und Betriebstechnik, Univ. Karlsruhe (Germany)); Pruemmer, R. (Inst. fuer Werkzeugmaschinen und Betriebstechnik, Univ. Karlsruhe (Germany) Ernst-Mach-Inst., Freiburg (Germany))

    1993-11-01

    MMC (metal matrix composites) made of ceramic fibres and metal matrix are suitable for high strength and high temperature applications. New types of ceramic fibres usually are incorporated into a metal matrix by means of liquid infiltration or by hot pressing techniques. The disadvantage of these methods is the chemical reaction sometimes occurring between fibre and matrix, resulting in an interlayer which is degrading the mechanical properties of the MMC. A new method is described starting with an arrangement of metal powder or metal foils with ceramic fibres. Dynamic pressures, released by detonation of proper explosives, are used for consolidation. At very high strain rates during plastic deformation of the powder or metal foils hydrodynamic flow of the matrix around the ceramic fibres allows a complete consolidation and to prevent cracking. Fibres made of SiC are embedded into a metal matrix of aluminum. (orig.).

  20. Determination of dominant fibre orientations in fibre-reinforced high-strength concrete elements based on computed tomography scans

    Science.gov (United States)

    Vicente, Miguel A.; González, Dorys C.; Mínguez, Jesús

    2014-04-01

    Computed tomography (CT) is a nondestructive technique, based on absorbing X-rays, that permits the visualisation of the internal structure of materials in micron-range resolution. In this paper, the CT scan is used to determine the position and orientation of the fibres in steel fibre-reinforced high-strength concrete elements. The aim of this paper was to present a numerical procedure, automated through a MATLAB routine specially developed by the authors, which enables, fast and reliable, to obtain the orientation of each and every one of the fibres and their centre of gravity. The procedure shown is directly extrapolated to any type of fibre-reinforced material, only if there is a wide difference between density of fibres and density of matrix. The mathematical basis of this procedure is very simple and robust. The result is a fast algorithm and a routine easy to use. In addition, the validation tests show that the error is almost zero. This algorithm can help the industry to implement the technology of CT in the protocols of product quality control.

  1. Properties of drawn W wire used as high performance fibre in tungsten fibre-reinforced tungsten composite

    Science.gov (United States)

    Riesch, J.; Almanstötter, J.; Coenen, J. W.; Fuhr, M.; Gietl, H.; Han, Y.; Höschen, T.; Linsmeier, Ch; Travitzky, N.; Zhao, P.; Neu, R.

    2016-07-01

    High strength and creep resistance also at high temperature, combined with a high thermal conductivity and high melting point make tungsten (W) an ideal material for highly loaded areas in future fusion reactors. However, as a typical bcc metal tungsten features an intrinsic brittleness up to very high temperature and is prone to operational embrittlement. Tungsten fibre-reinforced tungsten composite (Wf/W) utilizes extrinsic toughening mechanisms similar to ceramic fibre-reinforced ceramics and therefore overcomes the brittleness problem. The properties of the composite are to a large extend determined by the properties of the drawn tungsten wire used as reinforcement fibres. W wire exhibits a superior strength and shows ductile behaviour with exceptional local plasticity. Beside the typical mechanisms observed for ceramic composites the ductile deformation of the fibres is therefore an additional very effective toughening mechanism. Tension tests were used to investigate this phenomenon in more detail. Results show that there is a region of enhanced localized plastic deformation. The specific energy consumption in this region was estimated and used to suggest optimisation options for Wf/W composites.

  2. Effects of chemical-physical pre-treatment processes on hemp fibres for reinforcement of composites and textiles

    DEFF Research Database (Denmark)

    Thomsen, Anne Belinda; Thygesen, Anders; Bohn, Vibeke

    2006-01-01

    of base and oxidant. These treatments were performed to make fibres that are useful as reinforcement in composite materials and for textiles. All pre-treatments tested increased the content of cellulose in the fibres by degrading and dissolving non-cell wall material (NCWM, e.g., pectin and waxes), lignin......, the pre-treatments gave fibre colours ranging from white to dark brown. Alkaline wet oxidation produced the brightest fibres with potential for use in textiles. Use of retted fibres in the pre-treatment resulted in fibres with high cellulose content (86-90%) of potential as reinforcement in composite...

  3. TESTS ON STRUCTURALLY DEFICIENT RC SLABS STRENGTHENED WITH FIBRE REINFORCED POLYMER (FRP) COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    S.T. Smith; S.J. Kim

    2004-01-01

    This paper reports the results of a series of tests on fibre reinforced polymer (FRP) strengthened reinforced concrete (RC) slabs, which were recently undertaken at the University of Technology,Sydney. The slabs were reinforced with high-strength low-ductile steel reinforcement and strengthened with either carbon FRP (CFRP) or glass FRP (GFRP) composites. The unstrengthened control slabs failed by fracture of the steel tension reinforcement while the FRP strengthened slabs failed by debonding of the FRP followed by rupture of the tension steel. The FRP-strengthened slabs were stronger than their unstrengthened counterparts and displayed considerable ductility.

  4. A new resin-reinforced glass ionomer cement for use with orthodontic attachments.

    Science.gov (United States)

    Cohen, M; Silverman, E

    1997-08-01

    Resin cements are commonly used to bond orthodontic appliances. However, etching enamel and bracket bonding is an extremely technique-sensitive process. Moisture and saliva control, particularly in the gingival third of posterior teeth, is difficult and time-consuming, but is critical to success. Recently, a light-cure resin-reinforced glass ionomer cement was shown to perform with equal bonding capacity. This is accomplished in a wet field, without etching, and with the glass ionomer feature of fluoride release. Now, a self-cure resin-reinforced glass ionomer cement has been introduced. The self-cure cement will provide equal clinical success in areas where light curing is not possible or desired. This article compares traditional resin cements and glass ionomer cements for bonding orthodontic appliances.

  5. Cellulose kraft pulp reinforced polylactic acid (PLA composites: effect of fibre moisture content

    Directory of Open Access Journals (Sweden)

    Elias Retulainen

    2016-06-01

    Full Text Available PLA offers a competitive and CO2 neutral matrix to commonly used polyolefin polymer based composites. Moreover, the use of PLA reduces dependency on oil when producing composite materials. However, PLA has a tendency of hydrolytic degradation under melt processing conditions in the presence of moisture, which remains a challenge when processing PLA reinforced natural fibre composites. Natural fibres such as cellulose fibres are hygroscopic with 6–10 wt% moisture content at 50–70% relative humidity conditions. These fibres are sensitive to melt processing conditions and fibre breakage (cutting also occur during processing. The degradation of PLA, moisture absorption of natural fibres together with fibre cutting and uneven dispersion of fibres in polymer matrix, deteriorates the overall properties of the composite. In the given research paper, bleached softwood kraft pulp (BSKP reinforced PLA compounds were successfully melt processed using BSKP with relatively high moisture contents. The effect of moist BSKP on the molecular weight of PLA, fibre length and the mechanical properties of the composites were investigated. By using moist never-dried kraft pulp fibres for feeding, the fibre cutting was decreased during the melt compounding. Even though PLA degradation occurred during the melt processing, the final damage to the PLA was moderate and thus did not deteriorate the mechanical properties of the composites. However, comprehensive moisture removal is required during the compounding in order to achieve optimal overall performance of the PLA/BSKP composites. The economic benefit gained from using moist BSKP is that the expensive and time consuming drying process steps of the kraft pulp fibres prior to processing can be minimized.

  6. Microstructure of a cement matrix composite reinforced with polypropylene fibers

    Directory of Open Access Journals (Sweden)

    Rincón, J. M.

    2004-06-01

    Full Text Available The present investigation deals with the microstructural characterization of a composite material, which is comprised of polypropylene fibers in an cement matrix, by means of environmental scanning electron microscopy (ESEM and field emission scanning electron microscopy (FESEM. The microstructure of the different phases that compose the matrix is very heterogeneous, though there is a uniform distribution of the fibers inside it. The surface of this composite is different after setting, cured and hardening depending if the zone is or not in touch with the walls of the mould. The interface between the different crystalline regions of the cement matrix and the dispersed fibers shows compatibility between the matrix and the polymeric fibers. The mechanical properties (compression and bending strength have also been evaluated. The use of melamine formaldehyde as additive leads to a reinforcement of the cement matrix and to the improvement of the mechanical properties.

    Se ha llevado a cabo una observacíón microestructural detallada de un material compuesto de fibras de polipropileno embebidas en una matriz de cemento usando los nuevos tipos de microscopía electrónica de barrido, tales como: un microscopio electrónico medioambiental (acrónimo en inglés: ESEM y uno de emisión de campo (acrónimo en inglés: FESEM. La microestructura de las diferentes fases que componen la matriz es muy heterogénea, aunque hay una distribución uniforme de las fibras dentro de ellas. La superficie de este material compuesto es diferente después del fraguado, curado y endurecimiento según qué zonas estén o no en contacto con las paredes del molde. La interfase entre las diferentes fases cristalinas de la matriz de cemento y las fibras dispersadas se ha observado a diferentes aumentos, comprobándose compatibilidad entre la matriz y las fibras poliméricas. Las propiedades de resistencia mecánica (tanto a flexión como a compresión han sido tambi

  7. Development of textile-reinforced carbon fibre aluminium composites manufactured with gas pressure infiltration methods

    Directory of Open Access Journals (Sweden)

    W. Hufenbach

    2009-08-01

    Full Text Available Purpose: The aim of his paper is to show potential of textile-reinforced carbon fibre aluminium composite with advantage of the lightweight construction of structural components subjected to thermo-mechanical stress.Design/methodology/approach: The manufacture of specimens of the carbon fibre-reinforced aluminium was realised with the aid of an advanced differential gas pressure infiltration technique, which was developed at ILK, TU Dresden.Findings: The gas pressure infiltration technology enables to fabricate complex carbon aluminium composites with fibre or textile reinforcement using moulds of graphite, but in future development the optimization of infiltration process is required. The load-adapted combination of 3D reinforced semi-finished fibre products (textile preforms made from carbon fibres (CF with aluminium light metal alloys (Al offers a considerable lightweight construction potential, which up to now has not been exploited.Research limitations/implications: Gas pressure infiltration technology enables to fabricate complex carbon aluminium composites with fibre or textile reinforcement using precision moulds of graphite, but in future development the optimization of infiltration process is required.Practical implications: Load-adapted CF/Al-MMC, due to the relatively high stiffness and strength of the metal matrix, allow the introduction of extremely high forces, thereby enabling a much better exploitation of the existing lightweight construction potential of this material in comparison to other composite materials.Originality/value: Constantly rising demands on extremely stressed lightweight structures, particularly in traffic engineering as well as in machine building and plant engineering, increasingly require the use of endless fibre-reinforced composite materials which, due to their selectively adaptable characteristics profiles, are clearly superior to conventional monolithic materials.

  8. Behaviour of fibre-reinforced high-performance concrete in exterior beam-column joint

    Science.gov (United States)

    Muthupriya, P.; Boobalan, S. C.; Vishnuram, B. G.

    2014-09-01

    This paper presents the effect of reinforced high performance concrete (HPC) in exterior beam-column joint with and without fibre under monotonic loading. In this experimental investigation, cross-diagonal bars have been provided at the joint for reducing the congestion of reinforcement in joints, and also M75 grade of concrete with optimum mix proportion of 10 % silica fume and 0.3 % glass fibre was used. Four exterior beam-column joint sub-assemblages were tested. The specimens were divided into two types based on the reinforcement detailing. Type A comprises two joint sub-assemblages with joint detailing as per construction code of practice in India (IS 456-2000), and Type B comprises two joint sub-assemblages with joint detailing as per ductile detailing code of practice in India (IS 13920-1993). In each group there was one specimen of control mix and the remaining one specimen of fibre-reinforced mix. All the test specimens were designed to satisfy the strong column-weak beam concept. The performances of specimens were compared with the control mix and the fibre-reinforced mix. The results show that exterior beam-column joint specimens with silica fume and glass fibre in the HPC mix showed better performance.

  9. Effects of Hybrid Fibre Reinforcement on Fire Resistance Performance and Char Morphology of Intumescent Coating

    Directory of Open Access Journals (Sweden)

    Amir N.

    2016-01-01

    Full Text Available Recent researches of fire retardant intumescent coatings reinforced by single Rockwool and single glass wool fibre at various weight percentages and lengths showed some improvements to the mechanical properties of the coatings and the char produced. Therefore, in this research the fibres were combined together in intumescent coating formulation at several weight percentages and fibre lengths to study their effects towards fire resistance performance and char morphology. The hybrid fibre reinforced intumescent coatings were subjected to two types of fire tests; Bunsen burner at 1000°C and the electric furnace at 800°C for 1 hour, respectively. Steel temperature of the coated samples during Bunsen burner test was recorded to determine the fire resistance performance. Thermal stability of the intumescent coatings and chars was determined by Thermogravimetric Analysis (TGA. The morphology of the coatings and char was then examined by using Scanning Electron Microscopy (SEM and Energy Dispersive Spectrometry (EDS was conducted to obtain elemental composition of the samples. This research concluded that long-hybrid fibre at 12-mm length and 0.6% fibre-weight produced the top performing hybrid fibre intumescent formulation. The hybrid fibres form survived at elevated temperature, hence helped to provide structure and strengthen the char with the highest fire resistance was recorded at steel temperature of 197°C.

  10. Mechanical property analysis of kenaf–glass fibre reinforced polymer composites using finite element analysis

    Indian Academy of Sciences (India)

    M Ramesh; S Nijanthan

    2016-02-01

    Nowadays, natural fibres are used as a reinforcing material in polymer composites, owing to severe environmental concerns. Among many different types of natural resources, kenaf plants have been extensively exploited over the past few years. In this experimental study, partially eco-friendly hybrid composites were fabricated by using kenaf and glass fibres with two different fibre orientations of 0° and 90°. The mechanical properties such as tensile, flexural and impact strengths of these composites have been evaluated. From the experiment, it was observed that the composites with the 0° fibre orientation can withstand the maximum tensile strength of 49.27 MPa, flexural strength of 164.35 MPa, and impact strength of 6 J. Whereas, the composites with the 90° fibre orientation hold the maximum tensile strength of 69.86 MPa, flexural strength of 162.566 MPa and impact strength of 6.66 J. The finite element analysis was carried out to analyse the elastic behaviour of the composites and to predict the mechanical properties by using NX Nastran 9.0 software. The experimental results were compared with the predicted values and a high correlation between the results was observed. The morphology of the fractured surfaces of the composites was analysed using a scanning electron microscopy analysis. The results indicated that the properties were in the increasing trend and comparable with pure synthetic fibre reinforced composites, which shows the potential for hybridization of kenaf fibre with glass fibre.

  11. Influence of reprocessing on fibre length distribution, tensile strength and impact strength of injection moulded cellulose fibre-reinforced polylactide (PLA composites

    Directory of Open Access Journals (Sweden)

    N. Graupner

    2016-08-01

    Full Text Available The present study focuses on the reprocessing behaviour of recycled injection moulded polylactide (PLA composites. The composites are reinforced with regenerated cellulose fibres (lyocell of variable fineness and a fibre mass content of 30%. They were reprocessed up to three times. The influence of reprocessing on the fibre length distribution and the resulting composite mechanical properties (tensile and impact strength was analysed. While the first reprocessing cycle does not affect the mechanical characteristics of the neat PLA matrix, the strength of the composites decreases significantly due to a decreasing fibre aspect ratio. It was shown that fibres having a larger cross-sectional area display a lower aspect ratio than finer fibres, after reprocessing. This phenomenon leads to a larger decrease in tensile strength of composites reinforced with coarser fibres when compared to composites reinforced with finer fibres. A comparison of virgin composites and threefold reprocessed composites with a similar fibre length distribution resulted in a significantly higher tensile strength compared to the virgin sample. This result leads to the conclusion that not only the fibre length is drastically reduced by reprocessing but also that the fibres and the matrix were damaged.

  12. Comparative Environmental Sustainability Assessment of Bio-Based Fibre Reinforcement Materials for Wind Turbine Blades

    DEFF Research Database (Denmark)

    Corona, Andrea; Markussen, Christen Malte; Birkved, Morten;

    2015-01-01

    impact categories, than the conventional materials. This observation may seem contra-intuitive (i.e. most people would expect the bio-based to be most sustainable), but is primarily caused by the fact that the resin demand of biobased reinforcement materials is by far larger than that of conventional...... reinforcement materials. Since the environmental burden of the resin in addition is comparable to that of the fibres (especially in terms human health related impacts), the higher resin demand counterbalances the environmental sustainability improvements, obtained with the application of natural fibres....... turbines have therefore partially been focused on substitution of conventional fibre materials with bio-fibres assuming that this substitution was in the better for the environment and human health. The major question is if this material substitution, taking into account a multitude of environmental impact...

  13. Shear Strengthening of Corbels with Carbon Fibre Reinforced Polymers (CFRP

    Directory of Open Access Journals (Sweden)

    Nawaz, A.

    2010-09-01

    Full Text Available Corbels constitute what are known as “disturbed” regions in concrete structures, where typical shear failure may be anticipated on the grounds of small shear span-to-depth ratios. The concentration of stress induced by the weight of girders on the very small loadbearing areas in corbels often causes cracking in bridges and other structures. Little experimental research can be found in the literature on the shear strengthening of corbels. In the present study, nine such members were tested. Two had no carbon fibre reinforced polymers attached, while CFRP laminates were externally bonded to the other seven, in a number of different spatial arrangements. Ultimate shear strength was found and compared for all specimens. The results showed that CFRP configuration and geometry directly affected corbel shear strength, which was higher in all the CFRPstrengthened corbels than in the controls. The highest strength values were recorded for specimens whose shear-critical area was wrapped in CFRP.

    Las ménsulas constituyen lo que conocemos como regiones de “distorsión” en las estructuras de hormigón, zonas en que pueden preverse roturas por cortante debido a las bajas relaciones luz de cortante-canto presentes en ellas. La concentración de solicitaciones producida por el peso de las vigas sobre superficies de carga muy reducidas en las ménsulas a menudo provoca el agrietamiento de puentes y otras estructuras de obra civil. En la literatura especializada sobre el refuerzo a cortante de las ménsulas existen escasos ejemplos de estudios experimentales. Para la presente investigación se han realizado ensayos con nueve elementos de este tipo. Dos de ellos no incluían polímeros reforzados con fibra de carbono (CFRP, mientras que los siete restantes llevaban láminas externas de CFRP, dispuestas siguiendo distintas configuraciones espaciales. Los resultados indican que la configuración y la disposición geométrica de los CFRP repercuten

  14. Processing, structure and flexural strength of CNT and carbon fibre reinforced, epoxy-matrix hybrid composite

    Indian Academy of Sciences (India)

    K Chandra Shekar; M Sai Priya; P K Subramanian; Anil Kumar; B Anjaneya Prasad; N Eswara Prasad

    2014-05-01

    Advanced materials such as continuous fibre-reinforced polymer matrix composites offer significant enhancements in variety of properties, as compared to their bulk, monolithic counterparts. These properties include primarily the tensile stress, flexural stress and fracture parameters. However, till date, there are hardly any scientific studies reported on carbon fibre (Cf) and carbon nanotube (CNT) reinforced hybrid epoxy matrix composites (unidirectional). The present work is an attempt to bring out the flexural strength properties along with a detailed investigation in the synthesis of reinforced hybrid composite. In this present study, the importance of alignment of fibre is comprehensively evaluated and reported. The results obtained are discussed in terms of material characteristics, microstructure and mode of failure under flexural (3-point bend) loading. The study reveals the material exhibiting exceptionally high strength values and declaring itself as a material with high strength to weight ratio when compared to other competing polymer matrix composites (PMCs); as a novel structural material for aeronautical and aerospace applications.

  15. PREPARATION OF CEMENT MORTAR REINFORCED BY MODIFIED MICROFIBER IN A TURBULENT MIXER

    Directory of Open Access Journals (Sweden)

    Belova Tat’yana Konstantinovna

    2016-03-01

    Full Text Available The improvement of the structure of cement mortars on micro- and nanolevels by means of disperse reinforcement by modified microfibers promotes the considerable improvement of operational characteristics of the designs made on their basis. However, the absence of the developed technology of preparing the cement mortars reinforced by the modified microfiber providing the uniform distribution of the microfibres in volume of a composite constrains the widespread introduction of such solutions in the construction practice. The results of the researches of the technological parameters of preparing the microfiber reinforced cement mortars in the turbulent mixer are presented in article. The results of the production experiment on determining the bending durability are reflected as well as the variation coefficient of the durability of the reinforced samples prepared by means of the turbulent mixer. The results of the influence of the water-cement relation of the mortar mix and influence of the time of mixing the components in the turbulent mixer on change of mobility of the mix and strength characteristics of the hardened solution are presented. The results of the tests indicated the efficiency of preparing cement mortar reinforced by modified microfiber in the turbulent mixer. The reinforced samples are characterized by the increased bending durability and high uniformity of the strength characteristics. In case of turbulent mixing of the components of mortar mix its mobility increases from 5 to 25% in comparison with the mix prepared manually. The time of mixing the components in the turbulent mixer has an impact on the strength characteristics of the fiber reinforced solution. The optimum time of mixing the components contributes to a certain water-cement relation of the mortar mix. Therefore, the preparation of the cement mortar reinforced by the modified microfiber in the turbulent mixer is characterized by high efficiency and productivity, the

  16. Regenerated thermosetting styrene-co-acrylonitrile sandwich composite panels reinforced by jute fibre: structures and properties

    Indian Academy of Sciences (India)

    Jinglong Li; Qin Peng; Anrong Zeng; Junlin Li; Xiaole Wu; Xiaofei Liu

    2016-02-01

    Jute fibres-reinforced sandwich regenerated composite panels were fabricated using industrial waste thermosetting styrene-co-acrylonitrile (SAN) foam scraps via compression moulding for the purpose of recycling waste SAN foam and obtaining high physical performance. The jute fibres were, respectively, treated by heat, sodium hydroxide (NaOH) solution (5.0 wt%), and N,N-dimethylacetamide (DMAc) in order to improve the mechanical properties of the composites. The structures and mechanical properties of the composites were studied. The SAN matrix got compact and some crystalline region formed in SAN matrix via compression moulding. The composite reinforced by DMAc-treated jute fibres performed optimum mechanical properties among the regenerated panels whose impact strength, flexural strength, and compressive strength were 19.9 kJ m−2, 41.7 MPa, and 61.0 MPa, respectively. Good interfacial bonding between DMAc-treated fibres and SAN matrix was verified by peel test and exhibited in SEM photographs. Besides, the water absorption of DMAc-treated fibres composite was lower than other SAN/jute fibre-reinforced sandwich composite panels.

  17. Kenaf Fibre Reinforced Polypropylene Composites: Effect of Cyclic Immersion on Tensile Properties

    Directory of Open Access Journals (Sweden)

    W. H. Haniffah

    2015-01-01

    Full Text Available This research studied the degradation of tensile properties of kenaf fibre reinforced polypropylene composites due to cyclic immersion into two different solutions, as well as comparison of the developed composites’ tensile properties under continuous and cyclic immersion. Composites with 40% and 60% fibre loadings were immersed in tap water and bleach for 4 cycles. Each cycle consisted of 3 days of immersion and 4 days of conditioning in room temperature (28°C and 55% humidity. The tensile strength and modulus of composites were affected by fibre composition, type of liquid of immersion, and number of cycles. The number of immersion cycles and conditioning caused degradation to tensile strength and modulus of kenaf fibre reinforced polypropylene composites. Continuous and cyclic immersion in bleach caused tensile strength of the composites to differ significantly whereas, for tensile modulus, the difference was insignificant in any immersion and fibre loadings. However, continuous immersion in the bleach reduced the tensile strength of composites more compared to cyclic immersion. These preliminary results suggest further evaluation of the suitability of kenaf fibre reinforced polypropylene composites for potential bathroom application where the composites will be exposed to water/liquid in cyclic manner due to discontinuous usage of bathroom.

  18. Post-cracking Behaviour and Fracture Energy of Synthetic Fibre Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Marta KOSIOR-KAZBERUK

    2016-11-01

    Full Text Available The paper reports the results of experimental programme focused on the effect of various synthetic fibres on fracture properties and ductility of concrete. The fracture energy was assessed on beams with initial notches in three-point bend test. The incorporation of synthetic fibres had a slight effect on mechanical properties of concrete but, at the same time, it had a significant influence on the fracture energy by modification of post-cracking behaviour of concrete. It was found that the modern synthetic fibres might be able to impart significant toughness and ductility to concrete. However, the beneficial effect of fibres depends on their length and flexibility. The analysis of load-deflection curves obtained made it possible to fit the simple function, describing the post-peak behaviour of fibre reinforced concrete, which can be useful for the calculation of GF value.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.13246

  19. Experimental investigation of fibre reinforced plastics with hybrid layups under high-velocity impact loads

    Directory of Open Access Journals (Sweden)

    Marco Romano

    2014-07-01

    Full Text Available This paper deals with experimental investigations concerning energy dissipation capacity of different kinds of reinforcement fibres in monolithic and hybrid layups under high-velocity impact loads. The investigated kinds of fibres are carbon, glass and basalt fibres. Therefore test panels, using the same thermoset resin, were built up and cured by autoclave processing. The fibre volume content of the test panels has been determined. Furthermore the influence of a separating layer at selected positions in the hybrid stacked panels was investigated. The results show the influence and the energy dissipation capacity of each single kind of fibre and the enhanced properties for the hybrid layups by hybrid stacking sequences and the use of a separating core material.

  20. Numerical modelling of elastic behaviour of concrete reinforced with steel short fibres in plane stress conditions

    Directory of Open Access Journals (Sweden)

    Fabian Lamus

    2011-01-01

    Full Text Available This work describes a numerical model of fibre reinforced concrete elastic behaviour implemented using the finite elements method (Hughes, 2000. In structures made of this material, each point is formed by steel fibres embedded into a simple concrete matrix. The reinforced concrete is represented inside a finite element as an orthotropic material having random material direction based on the vanishing diameter fibre model (Dvorak and Bahei-el-Din, 1982 and the mixing theory modified for short length reinforcement (Oller, 2003. Statistical analysis consisted of repeating the problem’s numerical simulation where the direction of fibres was modified by a random function to set up a sampling database from the results and measure their variability. A sensitivity study of finite element size and the number of sampling data was then carried out in terms of total strain energy. Finite element size and sampling data are recommended. The average structural response of a reinforced concrete beam with different quantities of steel fibres where minimum data dispersion was observed is given as an example of applying the above.

  1. Low-weight Impact Behaviour of Carbon Fibre Reinforced Methyl Methacrylate Nanocomposites

    Directory of Open Access Journals (Sweden)

    Virginija Jankauskaitė

    2015-06-01

    Full Text Available Inthis study, the carbon fibre reinforced methyl methacrylate (CF/MMA compositetoecap for safety shoes was manufactured to increase the energy absorptioncapacity during impact. Different types of nanofillers such as organic andinorganic nanotubes, unmodified and organically modified nanoclays were appliedto modify matrix impact properties. The drop-weight impact tests of thenanocomposite toecap were performed with respect to nanofiller nature andcarbon fibre stacking sequence. It was found that the most influence on thestiffness and impact damage of the carbon fibre methyl methacrylatenanocomposite toecaps besides stacking sequence show organic and inorganic nanotubesor unmodified nanoclay.DOI: http://dx.doi.org/10.5755/j01.ms.21.2.7075

  2. Recent Development of Flax Fibres and Their Reinforced Composites Based on Different Polymeric Matrices

    Directory of Open Access Journals (Sweden)

    Hrushikesh Abhyankar

    2013-11-01

    Full Text Available This work describes flax fibre reinforced polymeric composites with recent developments. The properties of flax fibres, as well as advanced fibre treatments such as mercerization, silane treatment, acylation, peroxide treatment and coatings for the enhancement of flax/matrix incompatibility are presented. The characteristic properties and characterizations of flax composites on various polymers including polypropylene (PP and polylactic acid, epoxy, bio-epoxy and bio-phenolic resin are discussed. A brief overview is also given on the recent nanotechnology applied in flax composites.

  3. The Integration of EIS parameters and bulk matrix characterization in studying reinforced cement-based materials

    NARCIS (Netherlands)

    Koleva, D.A.; Van Breugel, K.

    2012-01-01

    Corrosion in reinforced concrete is a major and costly concern, arising from the higher complexity of involved phenomena on different levels of material science (e.g. electrochemistry, concrete material science) and material properties (macro/micro/ nano). Reinforced cement-based systems (e.g. reinf

  4. The integration of eis parameters and bulk matrix characteristics in studying reinforced cement-based materials

    NARCIS (Netherlands)

    Koleva, D.A.; Van Breugel, K.

    2011-01-01

    Corrosion in reinforced concrete is a major and costly concern, arising from the higher complexity of involved phenomena on different levels of material science (e.g. electrochemistry, concrete material science) and material properties (macro/micro/ nano). Reinforced cement-based systems (e.g. reinf

  5. The integration of eis parameters and bulk matrix characteristics in studying reinforced cement-based materials

    NARCIS (Netherlands)

    Koleva, D.A.; Van Breugel, K.

    2011-01-01

    Corrosion in reinforced concrete is a major and costly concern, arising from the higher complexity of involved phenomena on different levels of material science (e.g. electrochemistry, concrete material science) and material properties (macro/micro/ nano). Reinforced cement-based systems (e.g.

  6. The Integration of EIS parameters and bulk matrix characterization in studying reinforced cement-based materials

    NARCIS (Netherlands)

    Koleva, D.A.; Van Breugel, K.

    2012-01-01

    Corrosion in reinforced concrete is a major and costly concern, arising from the higher complexity of involved phenomena on different levels of material science (e.g. electrochemistry, concrete material science) and material properties (macro/micro/ nano). Reinforced cement-based systems (e.g.

  7. Fibre reinforced self-compacting concrete flow simulations in comparison with l-box experiments using carbopol

    DEFF Research Database (Denmark)

    Svec, Oldrich; Skocek, Jan; Olesen, John Forbes

    An evolution of distribution and orientation of fibres in the fibre reinforced self-compacting concrete during the casting process is an important matter as the final orientation and distribution of fibres can significantly influence mechanical properties of the structural elements. A two-way cou...

  8. Strength and Deformability of Fiber Reinforced Cement Paste on the Basis of Basalt Fiber

    Directory of Open Access Journals (Sweden)

    Yury Barabanshchikov

    2016-01-01

    Full Text Available The research object of the paper is cement paste with the particulate reinforcement of basalt fiber. Regardless of fibers’ length at the same fiber cement mix workability and cement consumption equality compressive solidity of the specimens is reduced with increasing fiber content. This is due to the necessity to increase the water-cement ratio to obtain a given workability. The flexural stability of the specimens with increasing fiber content increments in the same conditions. There is an optimum value of the fibers’ dosage. That is why stability has a maximum when crooking. The basaltic fiber particulate reinforcement usage can abruptly increase the cement paste level limiting extensibility, which is extremely important in terms of crack resistance.

  9. Continuous fibre reinforced thermoplastic pipes for transport and distribution of fluids for the oil and gas industries

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, E.H.; Gibson, A.G. [Newcastle upon Tyne Univ., Centre for Composite Materials Engineering, Newcastle upon Tyne (United Kingdom)

    1998-07-01

    This paper discusses the fabrication and properties of continuous fibre reinforced thermoplastic pipe systems. Such products can be manufactured by various winding processes involving reinforcing fibres or prepreg tape and have the potential to form the basis of a new range of high added value pipe products. (Author)

  10. Crack Detection in Fibre Reinforced Plastic Structures Using Embedded Fibre Bragg Grating Sensors: Theory, Model Development and Experimental Validation.

    Science.gov (United States)

    Pereira, G F; Mikkelsen, L P; McGugan, M

    2015-01-01

    In a fibre-reinforced polymer (FRP) structure designed using the emerging damage tolerance and structural health monitoring philosophy, sensors and models that describe crack propagation will enable a structure to operate despite the presence of damage by fully exploiting the material's mechanical properties. When applying this concept to different structures, sensor systems and damage types, a combination of damage mechanics, monitoring technology, and modelling is required. The primary objective of this article is to demonstrate such a combination. This article is divided in three main topics: the damage mechanism (delamination of FRP), the structural health monitoring technology (fibre Bragg gratings to detect delamination), and the finite element method model of the structure that incorporates these concepts into a final and integrated damage-monitoring concept. A novel method for assessing a crack growth/damage event in fibre-reinforced polymer or structural adhesive-bonded structures using embedded fibre Bragg grating (FBG) sensors is presented by combining conventional measured parameters, such as wavelength shift, with parameters associated with measurement errors, typically ignored by the end-user. Conjointly, a novel model for sensor output prediction (virtual sensor) was developed using this FBG sensor crack monitoring concept and implemented in a finite element method code. The monitoring method was demonstrated and validated using glass fibre double cantilever beam specimens instrumented with an array of FBG sensors embedded in the material and tested using an experimental fracture procedure. The digital image correlation technique was used to validate the model prediction by correlating the specific sensor response caused by the crack with the developed model.

  11. Crack Detection in Fibre Reinforced Plastic Structures Using Embedded Fibre Bragg Grating Sensors: Theory, Model Development and Experimental Validation.

    Directory of Open Access Journals (Sweden)

    G F Pereira

    Full Text Available In a fibre-reinforced polymer (FRP structure designed using the emerging damage tolerance and structural health monitoring philosophy, sensors and models that describe crack propagation will enable a structure to operate despite the presence of damage by fully exploiting the material's mechanical properties. When applying this concept to different structures, sensor systems and damage types, a combination of damage mechanics, monitoring technology, and modelling is required. The primary objective of this article is to demonstrate such a combination. This article is divided in three main topics: the damage mechanism (delamination of FRP, the structural health monitoring technology (fibre Bragg gratings to detect delamination, and the finite element method model of the structure that incorporates these concepts into a final and integrated damage-monitoring concept. A novel method for assessing a crack growth/damage event in fibre-reinforced polymer or structural adhesive-bonded structures using embedded fibre Bragg grating (FBG sensors is presented by combining conventional measured parameters, such as wavelength shift, with parameters associated with measurement errors, typically ignored by the end-user. Conjointly, a novel model for sensor output prediction (virtual sensor was developed using this FBG sensor crack monitoring concept and implemented in a finite element method code. The monitoring method was demonstrated and validated using glass fibre double cantilever beam specimens instrumented with an array of FBG sensors embedded in the material and tested using an experimental fracture procedure. The digital image correlation technique was used to validate the model prediction by correlating the specific sensor response caused by the crack with the developed model.

  12. In-plane shear test of fibre reinforced concrete panels

    DEFF Research Database (Denmark)

    Solgaard, Anders Ole Stubbe; Stang, Henrik; Goltermann, Per

    2008-01-01

    contributes to the investigation of fibers as reinforcement in panels with experimental results and a consistent approach to material characterization and modeling. The proposed model draws on elements from the classical yield line theory of rigid, perfectly plastic materials and the theory of fracture......The present paper concerns the investigation of polymer Fiber Reinforced Concrete (FRC) panels subjected to in-plane shear. The use of fibers as primary reinforcement in panels is a new application of fiber reinforcement, hence test methods, design bases and models are lacking. This paper...

  13. Fatigue mechanisms in unidirectional glass-fibre-reinforced polypropylene

    DEFF Research Database (Denmark)

    Gamstedt, E.K.; Berglund, L.A.; Peijs, T.

    1999-01-01

    of interfacial strength on fatigue performance and on the underlying micromechanisms have been studied for these composite systems. Tension-tension fatigue tests (R = 0.1) were carried out on 0 degrees glass-fibre/PP and glass-fibre/ MA-PP coupons. The macroscopic fatigue behaviour was characterized in terms...... of stiffness reduction and fatigue-life curves. The results showed that the longitudinal Young's modulus degraded more rapidly for glass-fibre/PP, which was caused by a higher degree of damage growth and accumulation. The improvement in monotonic strength was negligible, but the fatigue life was prolonged...... by about one decade for the composite with the stronger interface by use of the maleic-anhydride grafted polypropylene matrix. During the fatigue testing, the microscopic mechanisms were monitored intermittently by a surface replication technique. From microscopic observations, it could be concluded...

  14. Injection moulding of long glass fibre reinforced polyamide 6-6: guidelines to improve flexural properties

    Directory of Open Access Journals (Sweden)

    2007-07-01

    Full Text Available Based on a previous optimisation of set-up parameters for injection moulding of polyamide 6-6 (PA 6-6 reinforced with 40-wt% of 10 mm long glass fibre, the aim of this paper is to define suitable guidelines to further improve the mechanical performances of PA 6-6/glass long fibre thermoplastic (LFT injection mouldings. Different solutions have been considered: screw and non-return valve design modification so as to adapt them to LFT processing, increase of the initial fibre content (up to 50 wt% and length (up to 25 mm in the LFT pellets. Using a LFT dedicated plasticating unit has allowed decreasing the fibre breakage amount by about 80% at the nozzle exit, however without improving the flexural properties. Increasing the initial fibre content has logically permitted to improve the flexural properties. Increasing the initial fibre length has not brought any improvement of the properties and has even amplified the structural heterogeneities and anisotropy of the parts. These trends have been explained on the basis of cavity pressure records highlighting significantly different rheological behaviours, and of resulting residual fibre lengths and through-the-thickness fibre orientation profiles modifications.

  15. Mullite-zirconium composites reinforced with ceramic fibres resistant to 1450 C; obtaining and properties

    Energy Technology Data Exchange (ETDEWEB)

    Cerchez, L.; Constantinescu, S. [PROCEMA S.A. Bucharest - Research, Design and Experimental Production, Bucharest (Romania). Inst. for Construction and Construction Materials; Muntean, M. [Universitatea Politehnica, Bucharest (Romania). Faculty of Industrial Chemistry

    2002-07-01

    The purpose of this paper was the obtaining of some mullite-zirconium matrix composites, reinforced with ceramic fibres resistant to 1450 C. In order to establish the compositions, the raw materials were ground, depending on their nature, in many ways, and there were established the characteristics of ground resulted powders. On the obtained materials it was followed the evolution of the ceramic, mechanical and structural characteristics, depending on the heat treatment temperature, for various reinforcing coefficients. (orig.)

  16. Viscoelastic properties of short aramid fibres-reinforced rubbers

    NARCIS (Netherlands)

    Sadatshirazi, S.; Talma, Auke; Noordermeer, Jacobus W.M.

    2013-01-01

    Among short fiber-reinforced composites, those with rubber matrices have gained great importance due to the advantages they have in processing and low cost, coupled with high strength. These composites combine the elastic behavior of rubbers with strength and stiffness of fibers. Reinforcement with

  17. Viscoelastic properties of short aramid fibres-reinforced rubbers

    NARCIS (Netherlands)

    Shirazi, S.; Talma, A.G.; Noordermeer, J.W.M.

    2013-01-01

    Among short fiber-reinforced composites, those with rubber matrices have gained great importance due to the advantages they have in processing and low cost, coupled with high strength. These composites combine the elastic behavior of rubbers with strength and stiffness of fibers. Reinforcement with

  18. Corn gluten meal as a biodegradable matrix material in wood fibre reinforced composites

    Energy Technology Data Exchange (ETDEWEB)

    Beg, M.D.H. [Department of Materials and Process Engineering, University of Waikato, Private Bag 3105, Hamilton (New Zealand); Pickering, K.L. [Department of Materials and Process Engineering, University of Waikato, Private Bag 3105, Hamilton (New Zealand)]. E-mail: klp@waikato.ac.nz; Weal, S.J. [Department of Materials and Process Engineering, University of Waikato, Private Bag 3105, Hamilton (New Zealand)

    2005-12-05

    This study was undertaken to investigate corn gluten meal (CGM) as a biodegradable matrix material for wood fibre reinforced composites. CGM was used alone, as well as hybridized with polypropylene, and reinforced with radiata pine (Pinus Radiata) fibre using a twin-screw extruder followed by injection moulding. Tensile testing, scanning electron microscopy and differential scanning calorimetry were carried out to assess the composites. For composites from CGM and wood fibres, extrusion was carried out with the aid of the following plasticizers: octanoic acid, glycerol, polyethylene glycol and water. Windows of processability for the different plasticizers were obtained for all plasticizers. These were found to lie between 20 and 50 wt.% of plasticizer with a maximum of approximately 20% wood fibre reinforcement. The best mechanical properties were obtained with a matrix containing 10 wt.% octanoic acid and 30 wt.% water, which gave a tensile strength and Young's modulus of 18.7 MPa and 4 GPa, respectively. Hybrid matrix composites were compounded with a maleated polypropylene coupling agent and benzoyl peroxide as a cross-linking agent. The highest tensile strength and Young's modulus obtained from hybrid matrix composites were 36.9 MPa and 5.8 GPa with 50 wt.% fibre.

  19. Water Absorption Behaviour and Its Effect on the Mechanical Properties of Flax Fibre Reinforced Bioepoxy Composites

    Directory of Open Access Journals (Sweden)

    E. Muñoz

    2015-01-01

    Full Text Available In the context of sustainable development, considerable interest is being shown in the use of natural fibres like as reinforcement in polymer composites and in the development of resins from renewable resources. This paper focuses on eco-friendly and sustainable green composites manufacturing using resin transfer moulding (RTM process. Flax fibre reinforced bioepoxy composites at different weight fractions (40 and 55 wt% were prepared in order to study the effect of water absorption on their mechanical properties. Water absorption test was carried out by immersion specimens in water bath at room temperature for a time duration. The process of water absorption of these composites was found to approach Fickian diffusion behavior. Diffusion coefficients and maximum water uptake values were evaluated; the results showed that both increased with an increase in fibre content. Tensile and flexural properties of water immersed specimens were evaluated and compared to dry composite specimens. The results suggest that swelling of flax fibres due to water absorption can have positive effects on mechanical properties of the composite material. The results of this study showed that RTM process could be used to manufacture natural fibre reinforced composites with good mechanical properties even for potential applications in a humid environment.

  20. Development of hemp fibre reinforced polypropylene composite - Journal Article

    CSIR Research Space (South Africa)

    Hargitai, H

    2005-06-01

    Full Text Available , Vol. 2, 1998, pp 133-140. 3. Young, R. A., “Utilization of Natural Fibres: Characterization, Modification and Application”, Lignocellulosic-Plastic Composites (Rowell, R. M., Schultz, T. P., Narayan, R. eds.), VSP, Sao Paulo, Brazil, 1997, pp. 1...

  1. The study of mechanical properties of pineapple leaf fibre reinforced tapioca based bioplastic resin composite

    Directory of Open Access Journals (Sweden)

    Mathivanan D.

    2016-01-01

    Full Text Available Natural fibre reinforced composite has brought the material engineering to a high new level of research. Natural fibres are compatible with matrices like polypropylene and can be used as reinforcement material to reduce the composition of plastic in a material. Natural fibres such as kenaf, pineapple leaf, and coir already found its importance in reducing the dependence of petroleum based products. However the biodegradability of the product at the end of the intended lifespan is still questionable. This has led many researches to look for a suitable replacement for synthetic fibres and achieve better adhesion between fibre and matrix. In this study, fiber and matrix which are hydrophilic in nature was used and the mixture was extruded and hot compressed to acquire better mechanical properties. The specimens were fabricated and tested according to ASTM D638. The 30% composition illustrates the best average modulus value among other composition and from this result it can be concluded that the increase of PALF fibre in TBR composite increases the modulus strength of the composite.

  2. GROWTH OF CARBON NANOTUBES ON CARBON FIBRES AND THE TENSILE PROPERTIES OF RESULTING CARBON FIBRE REINFORCED POLYPROPYLENE COMPOSITES

    Directory of Open Access Journals (Sweden)

    A.R. SURAYA

    2009-12-01

    Full Text Available Carbon nanotubes were grown directly on carbon fibres using the chemical vapor deposition technique. The effects of reaction temperature (800-900oC and hydrogen gas flowrate (100-300 ml/min on the morphology of the carbon nanotube coating were investigated. Carbon nanotubes produced were characterized using scanning electron microscope and transmission electron microscope. The resulting fibres were compounded with polypropylene to produce carbon fibre reinforced polypropylene composites. The tensile properties of these composites were determined to investigate the effects of the carbon nanotubes on the overall performance of the composites. The optimum treatment condition that produced the thickest coating of carbon nanotubes was obtained at 800oC and 300 ml/min hydrogen gas flowrate. The composite sample obtained under these conditions demonstrated remarkable enhancement in tensile properties compared to composites made from as-received carbon fibres, whereby an increment of up to 52% and 133% was observed for the tensile strength and modulus respectively.

  3. Bond Mechanisms in Fiber Reinforced Cement-Based Composites

    Science.gov (United States)

    1989-08-01

    Symposium on "Cement Based Composites: Bonding in Cementitious Composites," S. Mindess and S. Shah, Editors. 44. Nilson, A. H., "Bond Stress-Slip...Society Symposium on "Cement Based Composites: Bonding in Cementitious Composites," held in Boston, December 2 to 4, 1987, S. Mindess and S. Shah, 0

  4. Asset management business model for design, realization, and maintenance of fibre reinforced polymer bridges

    NARCIS (Netherlands)

    Sebastian, R.

    2013-01-01

    This paper particularly addresses the market implementation of Fibre Reinforced Polymer (FRP) for bridges. It presents the concept of demand and supply chain innovation as being investigated within two ongoing European collaborative research projects (FP7) titled Trans-IND and PANTURA. FRP has emerg

  5. A bio-based fibre-reinforced plastic pedestrian bridge for Schiphol

    NARCIS (Netherlands)

    Smits, J.E.P.; Gkaidatzis, R.

    2015-01-01

    The present paper investigates Bio-based fibre-reinforced plastics, used as a load-bearing element of a bridge. We aim to increase the renewable content and decreasing the embodied energy of FRP. To achieve that, the consisting raw materials of these plastics which are based on non-renewable resourc

  6. Long-fibre reinforced thermoplastics. Applications and limitations of a new type of material

    Energy Technology Data Exchange (ETDEWEB)

    Neise, E.

    1986-06-01

    New processing possibilities are offered by long-fibre reinforced thermoplastics, because - contrary to thermoset processing - no chemical reaction occurs and thermoforming and welding of prepregs is possible. Processing techniques like filament winding, tape laying or pultrusion are in development at different institutes.

  7. A bio-based fibre-reinforced plastic pedestrian bridge for Schiphol

    NARCIS (Netherlands)

    Smits, J.E.P.; Gkaidatzis, R.

    2015-01-01

    The present paper investigates Bio-based fibre-reinforced plastics, used as a load-bearing element of a bridge. We aim to increase the renewable content and decreasing the embodied energy of FRP. To achieve that, the consisting raw materials of these plastics which are based on non-renewable resourc

  8. Gliding arc discharge — Application for adhesion improvement of fibre reinforced polyester composites

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Teodoru, Steluta; Leipold, Frank;

    2008-01-01

    production, and surface treatment. However, the application for adhesion improvement of structural materials has been rarely reported. In the present work, glass fibre reinforced polyester plates were treated using atmospheric pressure gliding arcs with high speed air flow for adhesion improvement...

  9. Static And Dynamic Characteristics Of Waste Ceramic Aggregate Fibre Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Cichocki Krzysztof

    2015-12-01

    Full Text Available There are multiple obstacles associated both with technology and properties of waste ceramic aggregate concrete preventing its wide production and application. In the research programme these limitations were addressed through utilizing steel fibre reinforcement and the phenomenon of internal curing. After laboratory tests of mechanical properties a numerical analysis of composites in question was conducted.

  10. Recycling of Glass Fibre Reinforced Aluminium Laminates and Silicon Removal from Aerospace Al Alloy

    NARCIS (Netherlands)

    Zhu, G.

    2012-01-01

    Aerospace aluminium alloys (7xxx and 2xxx series Al alloy) is one of the important Al alloys in our life. The recycling of aerospace Al alloy plays a significant role in sustainable development of Al industry. The fibre reinforced metal laminates GLARE including 67 wt.% 2024 Al alloy was used as upp

  11. Prediction of thermal strains in fibre reinforced plastic matrix by discretisation of the temperature exposure history

    Science.gov (United States)

    Ngoy, E. K.

    2016-07-01

    Prediction of environmental effects on fibre reinforced plastics habitually is made difficult due to the complex variability of the natural service environment. This paper suggests a method to predict thermal strain distribution over the material lifetime by discretisation of the exposure history. Laboratory results show a high correlation between predicted and experimentally measured strain distribution

  12. A bio-based fibre-reinforced plastic pedestrian bridge for Schiphol

    NARCIS (Netherlands)

    Smits, J.E.P.; Gkaidatzis, R.

    2015-01-01

    The present paper investigates Bio-based fibre-reinforced plastics, used as a load-bearing element of a bridge. We aim to increase the renewable content and decreasing the embodied energy of FRP. To achieve that, the consisting raw materials of these plastics which are based on non-renewable

  13. Asset management business model for design, realization, and maintenance of fibre reinforced polymer bridges

    NARCIS (Netherlands)

    Sebastian, R.

    2013-01-01

    This paper particularly addresses the market implementation of Fibre Reinforced Polymer (FRP) for bridges. It presents the concept of demand and supply chain innovation as being investigated within two ongoing European collaborative research projects (FP7) titled Trans-IND and PANTURA. FRP has

  14. Mechanical spectroscopy of thermal stress relaxation in aluminium alloys reinforced with short alumina fibres

    Energy Technology Data Exchange (ETDEWEB)

    Carreno-Morelli, E.; Schaller, R. [Ecole Polytechnique Federale, Lausanne (Switzerland). Inst. de Genie Atomique; Urreta, S.E.

    1998-05-01

    The mechanical behaviour under low temperature thermal cycling of aluminium-based composites reinforced with short Al{sub 2}O{sub 3} SAFFIL fibres has been investigated by mechanical spectroscopy (mechanical loss and elastic shear modulus measurements). A mechanical loss maximum has been observed during cooling which originates in the relaxation of thermal stresses at the interfaces due to the differential thermal expansion between matrix and reinforcement. The maximum height increases with the volumetric fibre content. In addition, if the matrix strength is increased by the appropriated choice of alloy and thermal treatment, the maximum diminishes and shifts to lower temperatures. No damage accumulation at the interfaces has been detected during long period thermal cycling in the range 100 to 500 K. A description of the damping behaviour is made in terms of the development of microplastic zones which surround the fibres. (orig.) 9 refs.

  15. The influence of self-compacting steel fibre reinforced concrete infill on the flexure strength and ductility of masonry walls

    OpenAIRE

    Oliveira, Luiz António Pereira de; Bernardo, Luís Filipe Almeida

    2010-01-01

    This paper presents an experimental study on the influence of longitudinal reinforcement ratio and steel fibre volume in self-compacting concrete infill on the strength and ductility of reinforced masonry walls subjected to flexure. Flexure tests were performed as four-point bending tests on twelve walls. The analysis of the concrete infill contribution to the walls capacity is made considering recent recommendations for steel fibre reinforced concrete design. A ductility...

  16. Strong and tough magnesium wire reinforced phosphate cement composites for load-bearing bone replacement.

    Science.gov (United States)

    Krüger, Reinhard; Seitz, Jan-Marten; Ewald, Andrea; Bach, Friedrich-Wilhelm; Groll, Jürgen

    2013-04-01

    Calcium phosphate cements are brittle biomaterials of low bending strength. One promising approach to improve their mechanical properties is reinforcement with fibers. State of the art degradable reinforced composites contain fibers made of polymers, resorbable glass or whiskers of calcium minerals. We introduce a new class of composite that is reinforced with degradable magnesium alloy wires. Bending strength and ductility of the composites increased with aspect ratio and volume content of the reinforcements up to a maximal bending strength of 139±41MPa. Hybrid reinforcement with metal and polymer fibers (PLA) further improved the qualitative fracture behavior and gave indication of enhanced strength and ductility. Immersion tests of composites in SBF for seven weeks showed high corrosion stability of ZEK100 wires and slow degradation of the magnesium calcium phosphate cement by struvite dissolution. Finally, in vitro tests with the osteoblast-like cell line MG63 demonstrate cytocompatibility of the composite materials.

  17. Properties of High-Volume Fly Ash Concrete Reinforced with Natural Fibres

    Directory of Open Access Journals (Sweden)

    Rafat SIDDIQUE

    2012-12-01

    Full Text Available Properties of high-volume fly ash concrete incorporating san fibres are presented in this paper. For this investigation, initially, three concrete mixtures were made with 35%, 45%, and 55% of Class F fly as partial replacement of cement. After this, three percentages (0.25, 0.50, and 0.75% of san fibres (25 mm length were added in each of the fly ash concrete mixtures. San is a natural bast fibre, and is also known as Sunn Hemp (Botanical name: Crotalaria Juncea. It is grown in Indian Sub-Continent, Brazil, Eastern and Southern Africa, and also in some parts of U.S.A. Tests were performed for compressive strength, splitting tensile strength, flexural strength, and impact strength at the ages of 28, 91 and 365 days. Tests were also performed for fresh concrete properties. 28 days test results indicated that san fibres reduced the compressive strength of high-volume fly ash concrete by 2 to 13%, increased splitting tensile strength by 6 to 26%, flexural strength by 5 to 14%, and enhanced impact strength tremendously (by 100 to 300% depending upon the fly ash content and fibre percentage. Later age (91 and 365 days results showed continuous increase in strength properties of high-volume fly ash concrete. This was probably be possible due to the pozzolanic action of fly ash, leading to more densification of the concrete matrix, and development of more effective bond between fibres and fly ash concrete matrix.

  18. Assessment of solvent capsule-based healing for woven E-glass fibre-reinforced polymers

    Science.gov (United States)

    Manfredi, Erica; Cohades, Amaël; Richard, Inès; Michaud, Véronique

    2015-01-01

    Vacuum Assisted Resin Infusion Molding (VARIM) with low vacuum pressure difference was used to manufacture woven glass fibre-reinforced epoxy resin plates, with a fibre volume fraction of approx. 50 vol% and containing ethyl phenylacetate (EPA)-filled capsules for self-healing purposes. Capsules were introduced by functionalising the fabrics through manual dispersion. We investigated the capability of autonomously healing delaminations induced by static loading in Mode I and II. Healing did not take place for composite samples; this was attributed to the presence of bare fibres on the crack plane and to the reduction of EPA diffusion into the matrix in the presence of fibres both of which hinder the swelling mechanism responsible for healing the cracks.

  19. Corrosion resistance of steel fibre reinforced concrete – a literature review

    DEFF Research Database (Denmark)

    Marcos Meson, Victor; Michel, Alexander; Solgaard, Anders

    2016-01-01

    the existence of a critical crack width, below 0.20 mm, where corrosion of carbon-steel fibres is not critical and the structural integrity of the exposed SFRC can be ensured over the long-term. A doctoral project investigating chloride-induced corrosion of steel fibres on cracked SFRC has been initiated......Steel fibre reinforced concrete (SFRC) is increasingly being used in the construction of prefabricated segmental linings for bored tunnels, since it entails simplified production processes and higher quality standards. However, international standards and guidelines are not consistent regarding...... the consideration of steel fibres for the structural verification of SFRC elements exposed to corrosive environments, hampering the development of civil infrastructure built of SFRC. In particular, the long-term effect of exposure to chlorides is in focus and under discussion. This paper reviews the existing...

  20. Numerical and Experimental Investigation of the Hydrostatic Performance of Fibre Reinforced Tubes

    Science.gov (United States)

    Pavlopoulou, S.; Roy, S. S.; Gautam, M.; Bradshaw, L.; Potluri, P.

    2017-04-01

    The increasing demands in subsea industry such as oil and gas, led to a rapidly growing need for the use of advanced, high performance, lightweight materials such as composite materials. E-glass fibre laminated pre-preg, filament wound and braided tubes were tested to destruction under hydrostatic external pressure in order to study their buckling and crushing behaviour. Different fibre architectures and wind angles were tested at a range of wall thicknesses highlighting the advantage that hoop reinforcement offers. The experimental results were compared with theoretical predictions obtained from classic laminate theory and finite element analysis (ABAQUS) based on the principal that the predominant failure mode was buckling. SEM analysis was further performed to investigate the resulting failure mechanisms, indicating that the failure mechanisms can be more complex with a variety of observed modes taking place such as fibre fracture, delamination and fibre-matrix interface failure.

  1. Numerical and Experimental Investigation of the Hydrostatic Performance of Fibre Reinforced Tubes

    Science.gov (United States)

    Pavlopoulou, S.; Roy, S. S.; Gautam, M.; Bradshaw, L.; Potluri, P.

    2016-12-01

    The increasing demands in subsea industry such as oil and gas, led to a rapidly growing need for the use of advanced, high performance, lightweight materials such as composite materials. E-glass fibre laminated pre-preg, filament wound and braided tubes were tested to destruction under hydrostatic external pressure in order to study their buckling and crushing behaviour. Different fibre architectures and wind angles were tested at a range of wall thicknesses highlighting the advantage that hoop reinforcement offers. The experimental results were compared with theoretical predictions obtained from classic laminate theory and finite element analysis (ABAQUS) based on the principal that the predominant failure mode was buckling. SEM analysis was further performed to investigate the resulting failure mechanisms, indicating that the failure mechanisms can be more complex with a variety of observed modes taking place such as fibre fracture, delamination and fibre-matrix interface failure.

  2. Strength and durability of mixed glass-fibre-reinforced laminates

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Ya.; Limonov, V.A.; Mikel`son, M.; Tamuzh, V. [Inst. Mekhaniki Polimerov AN Latvii, Riga (Russian Federation)

    1994-01-01

    For unidirectional fabric-reinforced and mixed fiber glass plastics the results of static and fatigue tests are presented. Elastic and strength properties have been determined using plain and tubular specimens. Combination of unidirectional and glass fabric reinforcing layers is found to increase considerably torsional strength at inconsiderable decrease of tensile and compression strength. Results of layer-by-layer failure analysis agree well with experimental data. 12 refs.

  3. Mechanical and dielectric characterization of hemp fibre reinforced polypropylene (HFRPP by dry impregnation process

    Directory of Open Access Journals (Sweden)

    2010-03-01

    Full Text Available Natural fibres such as jute, coir, sisal, bamboo and pineapple are known to have high specific strength and can be effectively used in composites in various applications. The use of hemp fibres to reinforce the polymer aroused great interest and expectations amongst scientists and materials engineers. In this paper, composites with isotactic polypropylene (iPP matrix and hemp fibres were studied. These materials were manufactured via the patented FIBROLINE process based on the principle of the dry impregnation of a fibre assembly with a thermoplastic powder (iPP, using an alternating electric field. The aim of this paper is to show the influence of fibre/matrix interfaces on dielectric properties coupled with mechanical behaviours. Fibres or more probably the fibre/matrix interfaces allow the diffusion of electric charges and delocalise the polarisation energy. In this way, damages are limited during mechanical loading and the mechanical properties of the composites increase. The structure of composite samples was investigated by X-ray and FTIR analysis. The mechanical properties were analysed by quasistatic and dynamic tests. The dielectric investigations were carried out using the SEMME (Scanning Electron Microscope Mirror Effect method coupled with the measurement of the induced current (ICM.

  4. Properties of Recycled Aggregate Concrete Reinforced with Polypropylene Fibre

    Directory of Open Access Journals (Sweden)

    Wan Mohammad Wan Nur Syazwani

    2016-01-01

    Full Text Available This research work is aimed to investigate how the addition of various proportion of polypropylene fibre affects the mechanical strength and permeability characteristics of recycled aggregate concrete (RAC which has been produced with treated coarse recycled concrete aggregate (RCA. Further research on RAC properties and their applications is of great importance as the scarcity of virgin aggregate sources in close proximity to major urban centers is becoming a worldwide problem. In this study, the hardened RAC properties at the curing age of 7 and 28 days such as compressive strength, flexural strength, ultrasonic pulse velocity (UPV, water absorption and total porosity were evaluated and compare with control specimens. Experimental result indicates that although the inclusion of the treated coarse RCA can enhance the mechanical strength and permeability properties of RAC, Further modification by addition of polypropylene fibre can optimize the results.

  5. Effects of glass fiber modified with calcium silicate hydrate (C-S-H(I)) reinforced cement

    Science.gov (United States)

    Xin, M.; Zhang, L.; Ge, S.; Cheng, X.

    2017-03-01

    In this paper, calcium silicate hydrate (C-S-H(I)) and glass fiber modified with C-S-H(I) (SiF) at ambient temperature were synthesized. SiF and untreated fiber (OF) were incorporated into cement paste. Phase composition of C-S-H(I), SiF and OF was characterized by XRD. The surface morphologies were characterized by SEM. Flexural performance of fiber reinforced cement (FRC) at different curing ages was investigated. Results indicated that both SiF and OF could reinforce cement paste. SiF had a more positive effect on improving the flexural performance of FRC than OF. The strength of SiF reinforced cement was 11.48MPa after 28 days curing when fiber volume was 1.0%, 12.55% higher than that of OF reinforced cement. The flexural strength increased with the addition of fiber volume. However, the large dosage of fiber might cause a decrease in flexural strength of FRC.

  6. Monitoring ageing of alkali resistant glass fiber reinforced cement (GRC) using guided ultrasonic waves

    Science.gov (United States)

    Eiras, J. N.; Amjad, U.; Mahmoudabadi, E.; Payá, J.; Bonilla, M.; Kundu, T.

    2013-04-01

    Glass fiber reinforced cement (GRC) is a Portland cement based composite with alkali resistant (AR) glass fibers. The main drawback of this material is the ageing of the reinforcing fibers with time and especially in presence of humidity in the environment. Until now only destructive methods have been used to evaluate the durability of GRC. In this study ultrasonic guided wave inspection of plate shaped specimens has been carried out. The results obtained here show that acoustic signatures are capable of discerning ageing in GRC. Therefore, the ultrasonic guided wave based inspection technique is a promising method for the nondestructive evaluation of the durability of the GRC.

  7. Utilizing wood wastes as reinforcement in wood cement composite bricks

    Directory of Open Access Journals (Sweden)

    Nusirat Aderinsola Sadiku

    2015-07-01

    Full Text Available This paper presents the research work undertaken to study the properties of Wood Cement Composite Bricks (WCCB from different wood wastes and cement / wood content. The WCBBs with nominal density of 1200 kg m-3 were produced from three tropical wood species and at varying cement and wood content of 2:1, 2.5:1 and 3:1 on a weight to weight basis. The properties evaluated were compressive strength, Ultra Pulse Velocity (UPV, water absorption (WA and thickness swelling (TS. The Compressive strength values ranged from 0.25 to 1.13 N mm-2 and UPV values ranged from 18753 to 49992 m s-1. The mean values of WA after 672 hours (28 days of water soaking of the WCCBs ranged from 9.50% to 47.13% where there were no noticeable change in the TS of the bricks. The observed density (OD ranged from 627 to 1159 kg m-3. A. zygia from the three wood/cement content were more dimensionally stable and better in compressive strength than the other two species where T. scleroxylon had the best performance in terms of UPV. All the properties improved with increasing cement content. WCCBs at 3.0:1 cement/wood content are suitable for structural application such as panelling, ceiling and partitioning

  8. Investigations on d.c. conductivity behaviour of milled carbon fibre reinforced epoxy graded composites

    Indian Academy of Sciences (India)

    Navin Chand; Archana Nigrawal

    2008-08-01

    This paper reports the d.c. conductivity behaviour of milled carbon fibre reinforced polysulphide modified epoxy gradient composites. Milled carbon fibre reinforced composites having 3 vol. % of milled carbon fibre and poly sulphide modified epoxy resin have been developed. D.C. conductivity measurements are conducted on the graded composites by using an Electrometer in the temperature range from 26°C to 150°C. D.C. conductivity increases with the increase of distance in the direction of centrifugal force, which shows the formation of graded structure with the composites. D.C. conductivity increases on increase of milled carbon fibre content from 0.45 to 1.66 vol.%. At 50°C, d.c. conductivity values were 1.85 × 10-11, 1.08 × 10-11 and 2.16 × 10-12 for samples 1, 2 and 3, respectively. The activation energy values for different composite samples 1, 2 and 3 are 0.489, 0.565 and 0.654 eV, respectively which shows decrease in activation energy with increase of fibre content.

  9. Hybrid filler composition optimization for tensile strength of jute fibre-reinforced polymer composite

    Indian Academy of Sciences (India)

    ANURAG GUPTA; HARI SINGH; R SWALIA

    2016-09-01

    In present research work, pultrusion process is used to develop jute fibre-reinforced polyester (GFRP) composite and experiments have been performed on an indigenously developed pultrusion experimental setup. The developed composite consists of natural jute fibre as reinforcement and unsaturated polyester resin as matrix with hybrid filler containing bagasse fibre, carbon black and calcium carbonate (CaCO$_3$). The effect of weight content of bagasse fibre, carbon black and calcium carbonate on tensile strength of pultruded GFRP composite is evaluated and the optimum hybrid filler composition for maximizing the tensile strength is determined. Different compositions of hybrid filler are prepared by mixing three fillers using Taguchi L$_9$ orthogonal array. Fifteen percent of hybrid filler of different composition by weight was mixed in the unsaturated polyester resin matrix. Taguchi L$_9$ orthogonal array (OA) has been used to plan the experiments and ANOVA is used for analysing tensile strength. A regression model has also been proposed to evaluate the tensile strength of the composite within 7% error by varying the abovefillers weight. A confirmation experiment was performed which gives 73.14 MPa tensile strength of pultruded jute fibre polymer composite at the optimum composition of hybrid filler.

  10. The Influence of Nanofillers on the Mechanical Properties of Carbon Fibre Reinforced Methyl Methacrylate Composite

    Directory of Open Access Journals (Sweden)

    Tomas ŽUKAS

    2012-09-01

    Full Text Available The influence of different types of nanofillers – carbon nanotubes (CNT and organically modified nanoclay – on the flexural properties and nail penetration resistance of carbon fiber reinforced methyl methacrylate (MMA composite have been investigated. An ultrasonic mixing was used to distribute various content of nanofillers (0.7 wt.% – 3.0 wt.% in MMA resin. Scanning electron microscopy and X-ray diffraction analyses confirmed formation of intercalated MMA clay nanocomposites. Two different stacking sequences, [0/90]3 or [0/90/45]2, and two types of carbon fibre, with or without epoxy binder, were used for composites preparation. The composites with stacking sequence of [0/90]3 show higher resistance to the mechanical loading. Epoxy binder increases fibre adhesion interaction with MMA resin, however, almost does not influences on the fibre reinforced composite strength properties. The results demonstrated that only low content (up to 1 wt.% of organically modified nanoclay Cloisite 10A increases the carbon fibre reinforced composites resistance to flexure and nail penetration. The low content of CNT also increases flexural stress and modulus, but decreases resistance to the nail penetration.DOI: http://dx.doi.org/10.5755/j01.ms.18.3.2434

  11. Synthesis, characterization and antibacterial activity of biodegradable starch/PVA composite films reinforced with cellulosic fibre.

    Science.gov (United States)

    Priya, Bhanu; Gupta, Vinod Kumar; Pathania, Deepak; Singha, Amar Singh

    2014-08-30

    Cellulosic fibres reinforced composite blend films of starch/poly(vinyl alcohol) (PVA) were prepared by using citric acid as plasticizer and glutaraldehyde as the cross-linker. The mechanical properties of cellulosic fibres reinforced composite blend were compared with starch/PVA crossed linked blend films. The increase in the tensile strength, elongation percentage, degree of swelling and biodegradability of blend films was evaluated as compared to starch/PVA crosslinked blend films. The value of different evaluated parameters such as citric acid, glutaraldehyde and reinforced fibre to starch/PVA (5:5) was found to be 25 wt.%, 0.100 wt.% and 20 wt.%, respectively. The blend films were characterized using Fourier transform-infrared spectrophotometry (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA/DTA/DTG). Scanning electron microscopy illustrated a good adhesion between starch/PVA blend and fibres. The blend films were also explored for antimicrobial activities against pathogenic bacteria like Staphylococcus aureus and Escherichia coli. The results confirmed that the blended films may be used as exceptional material for food packaging. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Fibre reinforcement in a structurally compromised endodontically treated molar: a case report

    Science.gov (United States)

    de Ataide, Ida de Noronha; Fernandes, Marina; Lambor, Rajan

    2016-01-01

    The reconstruction of structurally compromised posterior teeth is a rather challenging procedure. The tendency of endodontically treated teeth (ETT) to fracture is considerably higher than vital teeth. Although posts and core build-ups followed by conventional crowns have been generally employed for the purpose of reconstruction, this procedure entails sacrificing a considerable amount of residual sound enamel and dentin. This has drawn the attention of researchers to fibre reinforcement. Fibre-reinforced composite (FRC), designed to replace dentin, enables the biomimetic restoration of teeth. Besides improving the strength of the restoration, the incorporation of glass fibres into composite resins leads to favorable fracture patterns because the fibre layer acts as a stress breaker and stops crack propagation. The following case report presents a technique for reinforcing a badly broken-down ETT with biomimetic materials and FRC. The proper utilization of FRC in structurally compromised teeth can be considered to be an economical and practical measure that may obviate the use of extensive prosthetic treatment. PMID:27200283

  13. Embedded Fibre Bragg Grating Sensor Response Model: Crack Growing Detection in Fibre Reinforced Plastic Materials

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira; Mikkelsen, Lars Pilgaard; McGugan, Malcolm

    2015-01-01

    This article presents a novel method to simulate the sensor output response of a Fibre Bragg Grating (FBG) sensor when embedded in a host material (Composite material or adhesive), during a crack growing/damage event. A finite element model of the crack growth mechanisms was developed, and differ...

  14. Potential of Carbon Nanotube Reinforced Cement Composites as Concrete Repair Material

    Directory of Open Access Journals (Sweden)

    Tanvir Manzur

    2016-01-01

    Full Text Available Carbon nanotubes (CNTs are a virtually ideal reinforcing agent due to extremely high aspect ratios and ultra high strengths. It is evident from contemporary research that utilization of CNT in producing new cement-based composite materials has a great potential. Consequently, possible practical application of CNT reinforced cementitious composites has immense prospect in the field of applied nanotechnology within construction industry. Several repair, retrofit, and strengthening techniques are currently available to enhance the integrity and durability of concrete structures with cracks and spalling, but applicability and/or reliability is/are often limited. Therefore, there is always a need for innovative high performing concrete repair materials with good mechanical, rheological, and durability properties. Considering the mechanical properties of carbon nanotubes (CNTs and the test results of CNT reinforced cement composites, it is apparent that such composites could be used conveniently as concrete repair material. With this end in view, the applicability of multiwalled carbon nanotube (MWNT reinforced cement composites as concrete repair material has been evaluated in this study in terms of setting time, bleeding, and bonding strength (slant shear tests. It has been found that MWNT reinforced cement mortar has good prospective as concrete repair material since such composites exhibited desirable behavior in setting time, bleeding, and slant shear.

  15. Short Fibre and Particulate-reinforced Rubber Composites

    Directory of Open Access Journals (Sweden)

    Kavita Agarwal

    2002-07-01

    Full Text Available Particulate fillers (carbon black and silica and short fibre (aromatic polyamide, Kevlar have been utilised to produce rubber composites based on acrylonitrile-co-butadiene rubber (NBR. Mechanical properties of these composites have been determined and compared with unfilled rubber vulcanisate. The effect of surface treatment on the improvement of strength, in case of Kevlar, has also been considered. The influence of elevated temperature on tear strength, an important failure criterion, has been evaluated. Scanning electron microscopy has been used as a tool to correlate the topographical features associated with changes in the tear strength of the composites.

  16. Effect of fibre content and alkali treatment on mechanical properties of Roystonea regia-reinforced epoxy partially biodegradable composites

    Indian Academy of Sciences (India)

    Govardhan Goud; R N Rao

    2011-12-01

    The present paper investigates the effect of fibre content and alkali treatment on tensile, flexural and impact properties of unidirectional Roystonea regia natural-fibre-reinforced epoxy composites which are partially biodegradable. The reinforcement Roystonea regia (royal palm) fibre was collected from the foliage of locally available royal palm tree through the process of water retting and mechanical extraction. The poor adhesion between fibre and matrix is commonly encountered problem in natural-fibre-reinforced composites. To overcome this problem, specific physical and chemical treatments were suggested for surface modification of fibres by investigators. Alkali treatment is one of the simple and effective surface modification techniques which is widely used in natural fibre composites. In the present study both untreated and alkali-treated fibres were used as reinforcement in Roystonea regia epoxy composites and the tensile, flexural and impact properties were determined at different fibre contents. The alkali treatment found to be effective in improving the tensile and flexural properties while the impact strength decreased.

  17. The Dependance of Damage Accumulation in Carbon Fibre Reinforced Epoxy Composites on Matrix Properties.

    Science.gov (United States)

    1985-12-01

    Diguuibutiofl Unlimited 0- Contract U.S. AIR FORCE/ARMINES- Centre des Matdriaux No A.F.O.S.R. 84-0397 - Final Report December 1985 THE DEPENDANCE OF DAMAGE...61102F 2301 D1 185 11 TITLE (include Security Classification) THE DEPENDANCE OF DAMAGE ACCUMULATION IN CARBON FIBRE REINFORCED EPOXY COMPOSITES ON...ATN OF: LTS/Autovon 235-4299 26 March 1986 SUBJECT: EOARD-TR-86-04, Final Scientific Report, "The Dependance of Damage Accumu- lation in Carbon Fibre

  18. Single Fibre Pullout from Hybrid Fiber Reinforced Concrete

    NARCIS (Netherlands)

    Markovich, I.; Van Mier, J.G.M.; Walraven, J.C.

    2001-01-01

    Hybrid fiber reinforcement can be very efficient for improving the tensile response of the composite. In such materials, fibers of different geometries can act as bridging mechanisms over cracks of different widths. The fiber bridging efficiency depends on the interface properties, which makes inter

  19. Mechanical performance of oil palm empty fruit bunches/jute fibres reinforced epoxy hybrid composites

    Energy Technology Data Exchange (ETDEWEB)

    Jawaid, M. [School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia); Abdul Khalil, H.P.S., E-mail: akhalilhps@gmail.com [School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia); Abu Bakar, A. [School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)

    2010-11-15

    Research highlights: {yields} Hybrid composites constituents of natural fibres show good mechanical performances. {yields} Hybridization with 20% jute fibre gives rise to sufficient modulus to composites. {yields} Outer or core material affect mechanical performance of hybrid composites. {yields} Impact strength of pure EFB composite is higher than hybrid composites. - Abstract: Oil palm empty fruit bunches (EFB)/jute fibre reinforced epoxy hybrid composites with different sequence of fibre mat arrangement such as EFB/jute/EFB and jute/EFB/jute were fabricated by hand lay-up method. The effect of layering patterns on the mechanical performance of the composites was studied. The hybrid composites are intended for engineering applications as an alternative to synthetic fibre composites. Mechanical performance of hybrid composites were evaluated and compared with the pure EFB, pure jute composites and neat epoxy using flexural and impact testing. The flexural properties of hybrid composite is higher than that of pure EFB composite with respect to the weight fraction of fibre, where as the impact strength of pure EFB composite is much higher than those of hybrid composites. The flexural results were interpreted using sandwich theory. The fracture surface morphology of the impact testing samples of the hybrid composites was performed by scanning electron microscopy (SEM).

  20. Mechanical properties and fabrication of small boat using woven glass/sugar palm fibres reinforced unsaturated polyester hybrid composite

    Science.gov (United States)

    Misri, S.; Leman, Z.; Sapuan, S. M.; Ishak, M. R.

    2010-05-01

    In recent years, sugar palm fibre has been found to have great potential to be used as fibre reinforcement in polymer matrix composites. This research investigates the mechanical properties of woven glass/sugar palm fibres reinforced unsaturated polyester hybrid composite. The composite specimens made of different layer of fibres such as strand mat, natural and hand woven of sugar palm fibres. The composites were fabricated using a compression moulding technique. The tensile and impact test was carried out in accordance to ASTM 5083 and ASTM D256 standard. The fibre glass boat is a familiar material used in boat industry. A lot of research on fabrication process such as lay-up, vacuum infusion mould and resin transfer mould has been conducted. Hybrid material of sugar palm fibre and fibre glass was used in fabricating the boat. This research investigates the method selection for fabrication of small boat application of natural fibre composites. The composite specimens made of different layer of fibres; woven glass fibre, strand mat, natural and hand woven of woven sugar palm fibres were prepared. The small boat were fabricated using a compression moulding and lay up technique. The results of the experiment showed that the tensile strength, tensile modulus, elongation at break value and impact strength were higher than the natural woven sugar palm fibre. The best method for fabricating the small boat was compression moulding technique. As a general conclusion, the usage of glass fibre had improved the tensile properties sugar palm fibre composites and compression moulding technique is suitable to be used in making a small boat application of natural fibre composites.

  1. Use of Fiber-Reinforced Cements in Masonry Construction and Structural Rehabilitation

    Directory of Open Access Journals (Sweden)

    Ece Erdogmus

    2015-02-01

    Full Text Available The use of fiber reinforcement in traditional concrete mixes has been extensively studied and has been slowly finding its regular use in practice. In contrast, opportunities for the use of fibers in masonry applications and structural rehabilitation projects (masonry and concrete structures have not been as deeply investigated, where the base matrix may be a weaker cementitious mixture. This paper will summarize the findings of the author’s research over the past 10 years in these particular applications of fiber reinforced cements (FRC. For masonry, considering both mortar and mortar-unit bond characteristics, a 0.5% volume fraction of micro fibers in type N Portland cement lime mortar appear to be a viable recipe for most masonry joint applications both for clay and concrete units. In general, clay units perform better with high water content fiber reinforced mortar (FRM while concrete masonry units (CMUs perform better with drier mixtures, so 130% and 110% flow rates should be targeted, respectively. For earth block masonry applications, fibers’ benefits are observed in improving local damage and water pressure resistance. The FRC retrofit technique proposed for the rehabilitation of reinforced concrete two-way slabs has exceeded expectations in terms of capacity increase for a relatively low cost in comparison to the common but expensive fiber reinforced polymer applications. For all of these applications of fiber-reinforced cements, further research with larger data pools would lead to further optimization of fiber type, size, and amount.

  2. Experimentation and numerical simulation of steel fibre reinforced concrete pipes

    Directory of Open Access Journals (Sweden)

    de la Fuente, Albert

    2011-06-01

    Full Text Available The results concerning on an experimental and a numerical study related to SFRCP are presented. Eighteen pipes with an internal diameter of 600 mm and fibre dosages of 10, 20 and 40 kg/m3 were manufactured and tested. Some technological aspects were concluded. Likewise, a numerical parameterized model was implemented. With this model, the simulation of the resistant behaviour of SFRCP can be performed. In this sense, the results experimentally obtained were contrasted with those suggested by means MAP reaching very satisfactory correlations. Taking it into account, it could be said that the numerical model is a useful tool for the optimal design of the SFRCP fibre dosages, avoiding the need of the systematic employment of the test as an indirect design method. Consequently, the use of this model would reduce the overall cost of the pipes and would give fibres a boost as a solution for this structural typology.

    En este artículo se presentan los resultados principales de un estudio experimental y numérico del comportamiento de tubos hormigón reforzado con fibras de acero (THFA. Se fabricaron y ensayaron 18 tubos de 600 mm de diámetro con cuantías de 10, 20 y 40 kg/m3 de fibras, concluyéndose varios aspectos tecnológicos relacionados con la fabricación y el ensayo así como del comportamiento resistente. Por otra parte, se ha desarrollado el modelo numérico MAP que permite la simulación del comportamiento resistente de THFA sometidos al ensayo de aplastamiento. Los resultados han sido satisfactorios para cualquier régimen de carga, permitiendo concluir que el modelo es una herramienta útil para el diseño óptimo de este tipo de tubos. Se concluye que el uso del modelo conduce a una reducción del coste del armado y da un impulso al uso de fibras como elemento de refuerzo en esta tipología estructural.

  3. Development of high performance fiber reinforced cement composites (HPFRCC for application as a transition layer of reinforced beams

    Directory of Open Access Journals (Sweden)

    V. J. Ferrari

    Full Text Available This study presents the development and behavior analysis of high performance fiber reinforced cement composites (HPFRCC. The describedmaterials were specifically developed for application as a transition layer: a repair layer that constitutes the stressed chord of reinforcedconcrete beams strengthened in flexure with carbon fiber reinforced polymers (CFRP. Nineteen different composites were produced by thehybridization process, varying the conventional short steel fiber and steel microfiber (manufactured exclusively for this research contentsto modify the microstructure of the material, thus enhancing the stress transfer process from the cement matrix to the fibers. To analyze theresponse to flexural loading, the composites underwent three point bending tests in notched prism specimens. The response of the materialwas obtained considering strength and tenacity parameters (flexural and fracture. There was evidence of high performance by the composites with a pseudo-hardening behavior.

  4. Experimental investigation of the relation between damage at the concrete-steel interface and initiation of reinforcement corrosion in plain and fibre reinforced concrete

    DEFF Research Database (Denmark)

    Michel, Alexander; Solgaard, Anders Ole Stubbe; Pease, Bradley Justin;

    2013-01-01

    Cracks in covering concrete are known to hasten initiation of steel corrosion in reinforced concrete structures. To minimise the impact of cracks on the deterioration of reinforced concrete structures, current approaches in (inter)national design codes often limit the concrete surface crack width....... Recent investigations however, indicate that the concrete-reinforcement interfacial condition is a more fundamental criterion related to reinforcement corrosion. This work investigates the relation between macroscopic damage at the concrete-steel interface and corrosion initiation of reinforcement...... embedded in plain and fibre reinforced concrete. Comparisons of experimental and numerical results indicate a strong correlation between corrosion initiation and interfacial condition....

  5. Behaviour of -glass fibre reinforced vinylester resin composites under impact fatigue

    Indian Academy of Sciences (India)

    Rita Roy; B K Sarkar; N R Bose

    2001-04-01

    An impact fatigue study has been made for the first time on 63.5% glass fibre reinforced vinylester resin notched composites. The study was conducted in a pendulum type repeated impact apparatus especially designed and fabricated for determining single and repeated impact strengths. A well-defined impact fatigue (S–N) behaviour, having a progressive endurance below the threshold single cycle impact fracture stress with decreasing applied stress has been demonstrated. Fractographic analysis revealed fracture by primary debonding having fibre breakage and pullout at the tensile zone, but a shear fracture of fibre bundles at the compressive zone of the specimen. The residual strength, modulus and toughness showed retention of the properties at high impact stress levels up to 1000 impacts followed by a sharp drop. Cumulative residual stresses with each number of impacts not withstanding the static fatigue failure at long endurances have been ascribed for the composite failures under the repeated impact stresses.

  6. Characterization of short-fibre reinforced thermoplastics for fracture fixation devices.

    Science.gov (United States)

    Brown, S A; Hastings, R S; Mason, J J; Moet, A

    1990-10-01

    This study focuses on determining the effects of clinically relevant procedures on the flexural and fracture toughness properties of three short-fibre thermoplastic composites for potential application as fracture fixation devices. The procedures included sterilization, heat contouring and saline soaking. The three materials tested were polysulphone, polybutylene terephthalate and polyetheretherketone, all reinforced with 30% short carbon fibres. The polysulphone composite showed significant degradation in mechanical properties due to saline soaking. The polybutylene terephthalate exhibited significant degradation of mechanical properties following both contouring and saline soaking. The polyetheretherketone composite, however, exhibited no degradation in mechanical properties. The results demonstrated that flexion and fracture toughness testing were effective for determining the response of the composites to different applied conditions and demonstrated the stability of polyetheretherketone subjected to these treatments. Scanning electron microscopy demonstrated the most effective fibre-matrix bonding to be in the polyetheretherketone.

  7. Finite element investigations on the microstructure of fibre-reinforced composites

    Directory of Open Access Journals (Sweden)

    2008-09-01

    Full Text Available The effect of residual stress due to the curing process on damage evolution in unidirectional (UD fibre-reinforced polymer-matrix composites under longitudinal and transverse loading has been investigated using a three-dimensional micromechanical representative volume element (RVE model with a hexagonal packing geometry and the finite element method. Residual stress has been determined by considering two contributions: volume shrinkage of matrix resin from the crosslink polymerization during isothermal curing and thermal contraction of both resin and fibre as a result of cooling from the curing temperature to room temperature. To examine the effect of residual stress on failure, a study based on different failure criteria and a stiffness degradation technique has been used for damage analysis of the RVE subjected to mechanical loading after curing for a range of fibre volume fractions. Predicted damage initiation and evolution are clearly influenced by the presence of residual stress.

  8. Nonlocal plasticity effects on fibre debonding in a whisker-reinforced metal

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Tvergaard, Viggo

    2002-01-01

    , in the form of fibre sizes and the length associated with the debonding process, so the nonlocal plasticity model brings in an additional material length. The analyses for metal reinforced by aligned short fibres are used to obtain an understanding of the interaction of the different length scales......Numerical cell-model analyses for the matrix-fibre debonding in a metal matrix composite are used to study the effect of a characteristic material length in the plasticity description of the matrix material deformations. Characteristic material lengths are already present in the model problem...... in the problem. The nonlocal plasticity effect tends to increase the stress level at a given overall strain, which clearly tends to promote the onset of debonding....

  9. Tensile and Flexural Properties of Cement Composites Reinforced with Flax Nonwoven Fabrics

    Directory of Open Access Journals (Sweden)

    Josep Claramunt

    2017-02-01

    Full Text Available The aim of this study is to develop a process to produce high-performance cement-based composites reinforced with flax nonwoven fabrics, analyzing the influence of the fabric structure—thickness and entanglement—on mechanical behavior under flexural and tensile loadings. For this purpose, composite with flax nonwoven fabrics with different thicknesses were first prepared and their cement infiltration was evaluated with backscattered electron (BSE images. The nonwoven fabrics with the optimized thickness were then subjected to a water treatment to improve their stability to humid environments and the fiber-matrix adhesion. For a fixed thickness, the effect of the nonwoven entanglement on the mechanical behavior was evaluated under flexural and direct tension tests. The obtained results indicate that the flax nonwoven fabric reinforcement leads to cement composites with substantial enhancement of ductility.

  10. Tensile and Flexural Properties of Cement Composites Reinforced with Flax Nonwoven Fabrics

    Science.gov (United States)

    Claramunt, Josep; Ventura, Heura; Fernández-Carrasco, Lucía J; Ardanuy, Mònica

    2017-01-01

    The aim of this study is to develop a process to produce high-performance cement-based composites reinforced with flax nonwoven fabrics, analyzing the influence of the fabric structure—thickness and entanglement—on mechanical behavior under flexural and tensile loadings. For this purpose, composite with flax nonwoven fabrics with different thicknesses were first prepared and their cement infiltration was evaluated with backscattered electron (BSE) images. The nonwoven fabrics with the optimized thickness were then subjected to a water treatment to improve their stability to humid environments and the fiber-matrix adhesion. For a fixed thickness, the effect of the nonwoven entanglement on the mechanical behavior was evaluated under flexural and direct tension tests. The obtained results indicate that the flax nonwoven fabric reinforcement leads to cement composites with substantial enhancement of ductility. PMID:28772573

  11. The effect of ion implantation on the tribomechanical properties of carbon fibre reinforced polymers

    Energy Technology Data Exchange (ETDEWEB)

    Mistica, R.; Sood, D.K. [Royal Melbourne Inst. of Tech., VIC (Australia); Janardhana, M.N. [Deakin University, Geelong, VIC (Australia). School of Engineering and Technology

    1993-12-31

    Graphite fibre reinforced epoxy composite material (GFRP) is used extensively in the aerospace and other industries for structural application. The trend is to address the 20 to 30 year life endurance of this material in service. Mechanical joints in air crafts are exposed to dynamic loads during service and wear may be experienced by the composite material joint. Generally it has been shown that graphite fibre reinforced polymers have superior wear and friction properties as compared with the unfilled polymers. In the described experiment, ion implantation was used as a novel surface treatment. Wear and friction of a polymer composite material (GFRP) was studied and ion implantation was used in order to observe the effect on the tribomechanical properties of the material. It was found that ion implantation of C on GFRP sliding against Ti changes the tribological properties of the system, and in particular decreases the coefficient of friction and wear. 4 refs., 2 figs.

  12. Modelling the nonlinear response of fibre-reinforced bending fluidic actuators

    Science.gov (United States)

    Cacucciolo, Vito; Renda, Federico; Poccia, Ernesto; Laschi, Cecilia; Cianchetti, Matteo

    2016-10-01

    Soft actuators are receiving increasing attention from the engineering community, not only in research but even for industrial applications. Among soft actuators, fibre-reinforced bending fluidic actuators (BFAs) became very popular thanks to features such as robustness and easy design and fabrication. However, an accurate modelling of these smart structures, taking into account all the nonlinearities involved, is a challenging task. In this effort, we propose an analytical mechanical model to capture the quasi-static response of fibre-reinforced BFAs. The model is fully 3D and for the first time includes the effect of the pressure on the lateral surface of the chamber as well as the non-constant torque produced by the pressure at the tip. The presented model can be used for design and control, while providing information about the mechanics of these complex actuators.

  13. Surface topography of machined fibre reinforced plastics obtained by stylus instruments and optical profilometers

    DEFF Research Database (Denmark)

    Eriksen, Else; Hansen, Hans Nørgaard

    1998-01-01

    introduced. They use another working principle to obtain the same parameters, but the settings of most of the measuring variables are not standardized. The present study has investigated aspects that have to be taken into account when the roughness of short fibre reinforced thermoplastics is measured...... identical values, whereas significantly higher roughnesses were measured with one of the two optical instruments. The optical instruments were identical but with different settings of the control parameters, which resulted in large deviations between the values measured. Some of the differences between...... by stylus instruments and by optical profilometers. The measurements were performed on machined surfaces with three distinct different roughness levels. The materials were two thermoplastics, polyoxymethylene and polypropylene, reinforced with short glass fibres. The two stylus instruments gave almost...

  14. Fibre-reinforced composite (FRC) bridge--a minimally destructive approach.

    Science.gov (United States)

    Van Rensburg, J J Jansen

    2015-05-01

    Replacing missing teeth is an integral part of the clinical services of the dental practitioner. The fibre-reinforced composite (FRC) bridge is a relatively new method for replacing missing teeth. This article will explain and discuss this alternative treatment option. Practical instructions on how to construct a FRC bridge will be given, by means of a clinical case. Different technique options will be illustrated to provide the reader with a good understanding of the most practical way to use the FRC strips. The fibre-reinforced composite provides a non-destructive, aesthetically pleasing and cost-effective way to restore missing teeth. Clinical Relevance: Minimally invasive options should always be considered and destruction of healthy enamel and dentine during the preparation phase of a replacement treatment should be avoided as much as possible.

  15. Modelling of ultrasound tomography technique for Glass Fibre Reinforced Epoxy (GFRE) composites liquid transportation pipeline

    Science.gov (United States)

    Siow, L. T.; Rahiman, M. H. F.; Majid, M. S. Abdul; Rahim, R. A.; Zakaria, Z.; Thomas W. K., T.; Ang, Vernoon

    2017-03-01

    The purpose of this paper is to model the ultrasonic tomography on the E-glass fibre reinforced epoxy composite pipe for process monitoring and control. Finite element software and mathematical estimation were applied to model and study the ultrasound wave propagation, especially the reflection and transmission coefficient. While there is a significant result achieved between mathematical estimation and finite element analysis with maximum percentage distinctly in 2.33.

  16. Hypodontia, ankylosis and infraocclusion: report of a case restored with a fibre-reinforced ceromeric bridge.

    Science.gov (United States)

    Sidhu, H K; Ali, A

    2001-12-08

    Retained primary molars without permanent successors often undergo progressive infra-occlusion, without predictable exfoliation. Early prophylactic removal, after assessment of root resorption and adjacent periodontal support loss as well as age of onset, is often indicated. This article describes the joint orthodontic-restorative care of such a case and describes an alternative method of restoration using a fibre-reinforced ceromeric bridge. As well as a conservative preparation and good aesthetics, an overlay restoration provided a fully functional occlusion.

  17. Application of steel fibre reinforced sprayed concrete to a deep tunnel in weak rocks

    Institute of Scientific and Technical Information of China (English)

    周宏伟; 彭瑞东; 李振东; 董正亮; 陈文伟; 王健

    2002-01-01

    Based on an engineering background of a deep tunneling in weak rocks, the numerical modeling is used to compare different support schemes of tunnel at great depth in this paper. Focused on the general behaviors of weak rocks at great depth, a tunneling scheme with rock bolting and steel fibre reinforced sprayed concrete is proposed. This scheme is practiced successfully at a deep tunnel in weak rocks in Coal Mine No.10 of Hebi Coal Mining Administration.

  18. FTIR and Thermal Studies on Nylon-66 and 30% Glass Fibre Reinforced Nylon-66

    OpenAIRE

    Julie Charles; Ramkumaar, G. R.; Azhagiri, S.; Gunasekaran, S.

    2009-01-01

    The present study deals with the characterization of the polymeric materials viz., nylon-66 and 30% glass fibre reinforced nylon-66 (GF Nylon-66) by employing FTIR and thermal measurements. The complete vibrational band assignment made available for nylon-66 and GF nylon-66 using FTIR spectra confirm their chemical structure. FTIR spectroscopy provides detailed information on polymer structure through the characteristic vibrational energies of the various groups present in the molecule. The t...

  19. Morphology and Properties of Geopolymer Coatings on Glass Fibre-Reinforced Epoxy (GRE) pipe

    OpenAIRE

    2016-01-01

    Geopolymer coatings were coated on glass fibre-reinforced epoxy (GRE) pipe by using kaolin, white clay and silica sand as source materials and sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) as alkaline solution. The microstructure and mechanical property of geopolymer coating on GRE pipe were methodically investigated through morphology analysis, and flexural strength test. The result indicates the microstructure and interfacial layer between geopolymer coating and GRE pipe significant...

  20. Coupling of plasticity and damage in glass fibre reinforced polymer composites

    Directory of Open Access Journals (Sweden)

    Osnes H.

    2012-08-01

    Full Text Available This study addresses the nonlinear stress-strain response in glass fibre reinforced polymer composite laminates. Loading and unloading of these laminates indicate that the nonlinear response is caused by both damage and plasticity. A user defined material model is implemented in the finite element code LS-DYNA. The damage evolution is based on the Puck failure criterion [1], and the plastic behaviour is based on the quadratic Hill yield criterion for anisotropic materials [2].

  1. Pore pressure development in hybrid fibre-reinforced high strength concrete at elevated temperatures

    OpenAIRE

    Bangi, Mugume Rodgers; HORIGUCHI, Takashi

    2011-01-01

    The present experimental work investigates the build-up of pore pressure at different depths of High Strength Concrete (HSC) and Hybrid-Fibre-Reinforced High Strength Concrete (HFRHSC) when exposed to different heating rates. First, the effect of the measurement technique on maximum pore pressures measured was evaluated. The pressure measurement technique which utilized a sintered metal and silicon oil was found to be the most effective technique for pore pressure measurement. Pore pressure m...

  2. Embedded Fibre Bragg Grating Sensor Response Model: Crack Growing Detection in Fibre Reinforced Plastic Materials

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira; Mikkelsen, Lars Pilgaard; McGugan, Malcolm

    2015-01-01

    This article presents a novel method to simulate the sensor output response of a Fibre Bragg Grating (FBG) sensor when embedded in a host material (Composite material or adhesive), during a crack growing/damage event. A finite element model of the crack growth mechanisms was developed...... the crack or non-uniform strain, and then identify the presence of such damage in the structure. Experimental tests were conducted in order to validate this concept and support the model. The FBG sensor response model was applied in a delamination of a Wind Turbine trailing edge, to demonstrate...

  3. Tensile & impact behaviour of natural fibre-reinforced composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Tobias, B.C. [Victoria Univ. of Technology, Footscray (Australia). Dept. of Mechanical Engineering

    1993-12-31

    Short abaca fiber reinforced composite materials are fabricated and investigated for short term performance. Abaca plants which grow in abundance in Asia contain fibers that are inexpensive but underutilized. This study attempts to utilize the abaca fibers for composite material structure as a possible alternative to timber products in building applications. The composite material is fabricated using the hand lay-up method under varying fiber length and fiber volume fraction. The fibers are impregnated with a mixture of resins which cures at room temperature. A fabricating facility is designed to accommodate fabrication of lamina. Tensile and impact properties are determined in relation to the length and volume fraction of the fiber. For a given fiber length, the tensile and impact strength increase as the volume fraction increases up to a limiting value. And for a given fiber volume fraction, the tensile strength increases but the impact strength decreases as the fiber length increases. This behavior of abaca fiber-reinforced composite lamina will help in optimizing the design parameter in random composite panels.

  4. es on Strength Characteristics of Pond Ash Replaced Fibre Reinforced Pavement Quality Concrete

    Directory of Open Access Journals (Sweden)

    Anand G Patil

    2015-08-01

    Full Text Available Energy consumption and generation is increasing day by day due to rapid industrialization & urbanization. A major portion of the energy is generated by Thermal Power Plants. Pond ash (PA and other by-products from these plants are disposed in large quantities. Pond ash utilization helps to reduce the consumption of natural resources. Hence there is scope for using Pond ash as Fine Aggregate (FA. Use of alternative material in concrete such as industrial by-products like Coal Ash (Fly Ash and Pond Ash is eco-friendly. This study reports the results of experimental studies carried out on the use of Pond ash as Fine Aggregate (FA in concrete with and without fibre reinforcement. The properties of Pond Ash were compared to the standard sand. The pond ash added by weight is 10%,20%,30%,40%,50% and 60% respectively as replacement of FA in concrete and 2% low tensile steel fibre was used for reinforcement. Experiments carried out indicate that Pond ash as partial replacement of sand has beneficial effect on the mechanical properties. The strength properties are determined for various percentages (10-60% of replacement of Fine Aggregate with Pond ash with and without fibre reinforcement. The test results indicate that the optimum PA replacement is 20% for both the cases.

  5. Improving Impact Strength Recovery of Fractured and Healed Rice Husks Fibre Reinforced Polypropylene Composites.

    Directory of Open Access Journals (Sweden)

    Odhong, O.V.E

    2016-10-01

    Full Text Available Rice husks fibre reinforced polypropylene composite (rhfrpc is a natural plant fibre reinforced polymer composite having advantages of high strength, light weight and affordability. They are commonly used for light load structural and non structural applications. They are mainly used as particle boards, for fencing post, roofing tiles, for interiors of car and aircrafts among other usages. This material once cracked by impact forces cannot be repaired using traditional repair methods for engineering materials such as metals or other composites that can be repaired by welding or by patch repair methods respectively, thus a method of repair of rice husks fibre reinforced polypropylene composites by refilling the damaged volume by injection of various healing agents has been investigated. The composite coupons were produced by injection moulding, cooled sufficiently and prepared for charpy impact tests. Test results for pristine coupons were a maximum of 48 J/mm2 . The destroyed coupons were then subjected to healing in a fabricated healing fixture. Healing agents such as epoxy resin, ethyl cyanoacrylate, and tannin gum have been investigated for their use as possible healing agents to fill the damaged volume and perform healing action at the fractured surfaces. The impact test results were recorded and compared with those of unhealed pristine coupons. The recovered strengths were a maximum of 60 J/mm2 translating into a 125% impact strength recovery, and this is good enough for the healed composites to be recommended for reuse in their second lives of their respective original functions.

  6. Processing of microencapsulated dyes for the visual inspection of fibre reinforced plastics

    Energy Technology Data Exchange (ETDEWEB)

    Hopmann, Ch., E-mail: kerschbaum@ikv.rwth-aachen.de; Kerschbaum, M., E-mail: kerschbaum@ikv.rwth-aachen.de; Küsters, K., E-mail: kerschbaum@ikv.rwth-aachen.de [Institute of Plastics Processing at RWTH Aachen University (IKV), Pontstrasse 49, 52064 Aachen (Germany)

    2014-05-15

    The evaluation of damages caused during processing, assembly or usage of fibre reinforced plastics is still a challenge. The use of inspection technology like ultrasonic scanning enables a detailed damage analysis but requires high investments and trained staff. Therefore, the visual inspection method is widely used. A drawback of this method is the difficult identification of barely visible damages, which can already be detrimental for the structural integrity. Therefore an approach is undertaken to integrate microencapsulated dyes into the laminates of fibre reinforced plastic parts to highlight damages on the surface. In case of a damage, the microcapsules rupture which leads to a release of the dye and a visible bruise on the part surface. To enable a wide application spectrum for this technology the microcapsules must be processable without rupturing with established manufacturing processes for fibre reinforced plastics. Therefore the incorporation of microcapsules in the filament winding, prepreg autoclave and resin transfer moulding (RTM) process is investigated. The results show that the use of a carrier medium is a feasible way to incorporate the microcapsules into the laminate for all investigated manufacturing processes. Impact testing of these laminates shows a bruise formation on the specimen surface which correlates with the impact energy level. This indicates a microcapsule survival during processing and shows the potential of this technology for damage detection and characterization.

  7. Processing of microencapsulated dyes for the visual inspection of fibre reinforced plastics

    Science.gov (United States)

    Hopmann, Ch.; Kerschbaum, M.; Küsters, K.

    2014-05-01

    The evaluation of damages caused during processing, assembly or usage of fibre reinforced plastics is still a challenge. The use of inspection technology like ultrasonic scanning enables a detailed damage analysis but requires high investments and trained staff. Therefore, the visual inspection method is widely used. A drawback of this method is the difficult identification of barely visible damages, which can already be detrimental for the structural integrity. Therefore an approach is undertaken to integrate microencapsulated dyes into the laminates of fibre reinforced plastic parts to highlight damages on the surface. In case of a damage, the microcapsules rupture which leads to a release of the dye and a visible bruise on the part surface. To enable a wide application spectrum for this technology the microcapsules must be processable without rupturing with established manufacturing processes for fibre reinforced plastics. Therefore the incorporation of microcapsules in the filament winding, prepreg autoclave and resin transfer moulding (RTM) process is investigated. The results show that the use of a carrier medium is a feasible way to incorporate the microcapsules into the laminate for all investigated manufacturing processes. Impact testing of these laminates shows a bruise formation on the specimen surface which correlates with the impact energy level. This indicates a microcapsule survival during processing and shows the potential of this technology for damage detection and characterization.

  8. The effect of CNTs reinforcement on thermal and electrical properties of cement-based materials

    Science.gov (United States)

    Exarchos, D. A.; Dalla, P. T.; Tragazikis, I. K.; Matikas, T. E.

    2015-03-01

    This research aims to investigate the influence of the nano-reinforcement on the thermal properties of cement mortar. Nano-modified cement mortar with carbon nanotubes (CNTs) leading to the development of innovative materials possessing multi-functionality and smartness. Such multifunctional properties include enhanced mechanical behavior, electrical and thermal conductivity, and piezo-electric characteristics. The assessment of the thermal behavior was evaluated using IR Thermography. Two different thermographic techniques are used to monitor the influence of the nano-reinforcement. To eliminate any extrinsic effects (e.g. humidity) the specimens were dried in an oven before testing. The electrical resistivity was measured with a contact test method using a custom made apparatus and applying a known D.C. voltage. This study indicate that the CNTs nano-reinforcement enhance the thermal and electrical properties and demonstrate them useful as sensors in a wide variety of applications.

  9. Impact fatigue behaviour of carbon fibre-reinforced vinylester resin composites

    Indian Academy of Sciences (India)

    Rita Roy; B K Sarkar; A K Rana; N R Bose

    2001-02-01

    Two types of unidirectional carbon fibre, one of high strength (DHMS) and another of medium strength (VLMS) reinforced vinylester resin composites have been examined for their impact fatigue behaviour over 104 impact cycles for the first time. The study was conducted using a pendulum type repeated impact apparatus specially designed and constructed for the purpose. A well-defined impact fatigue behaviour (S–N type curve) curve has been demonstrated. It showed a plateau region of 10–102 cycles immediately below the single cycle impact strength, followed by progressive endurance with decreasing impact loads, culminating in an endurance limit at about 71% and 85% of the single impact strength for DHMS-48 and VLMS-48, respectively. Analysis of the fractured surfaces revealed primary debonding, fibre breakage and pull-out at the tensile zone of the samples and a shear mode of fracture with breakage of fibre bundles at the compressive zone of the samples. The occurrence of a few major macrocracks in the matrix with fibre breakage at the high load–low endurance region and development of multiple microcracks in the matrix, coalescing and fibre breakage at the low-load–high endurance region have been inferred to explain the fatigue behaviour of the composites examined.

  10. Mechanical properties of sisal fibre reinforced urea-formaldehyde resin composites

    Directory of Open Access Journals (Sweden)

    2007-10-01

    Full Text Available Alkali-treated sisal fibres were used as novel reinforcement to obtain composites with self-synthesized ureaformaldehyde resin as matrix phase. The composites were prepared by means of compression molding, and then the effects of sisal loading on mechanical properties such as impact strength, flexural strength, and wear resistance were investigated. In addition, water uptake was studied and structural features were revealed by the scanning electron microscopy (SEM. The composite with 30 wt% sisal fibres gives excellent flexural strength, water absorption, and especially the wear resistance showing that it has the most superior bonding and adhesion of all the composites. In particular, the highest value 9.42 kJ/m2 of charpy impact strength is observed in the composite with 50 wt% sisal fibre. SEM micrographs of impact fractured and worn surfaces clearly demonstrate the interfacial adhesion between fibre and matrix. This work shows the potential of sisal fibre (SF to improve the composite wear resistance and to be used in fibreboard.

  11. A Study on the Mechanical Properties of Oil Palm Mesocarp Fibre-Reinforced Thermoplastic

    Directory of Open Access Journals (Sweden)

    Olusola Femi Olusunmade

    2016-01-01

    Full Text Available Oil palm mesocarp fibre obtained from a palm oil processing mill was washed with detergent and water to remove the oil and sun-dried to enhance good adhesion to Linear Low Density Polyethylene (LLDPE. The fibre was pulverized and filtered through a sieve of pore size 300 microns. The Oil Palm Mesocarp Fibre Reinforced Thermoplastic (OPMFRT was produced with a form of hand lay-up method and varying fibres weight ratio in the matrix from 5 wt% to 25 wt% in steps of 5 wt%. Tensile test was carried out to determine the tensile strength, tensile modulus, and elongation at break of the material. The hardness and impact strength of the composite were also determined. The results showed that tensile modulus and hardness of the OPMFRT increased by 50% and 24.56%, respectively, while tensile strength, impact strength, and percentage elongation of the OPMFRT decreased by 36.78%, 39.07%, and 95.98%, respectively, as fibre loading increased from 5 wt% to 25 wt%. The study concluded that the application of the OPMFRT developed should be restricted to areas demanding high rigidity and wear resistance.

  12. Recovery of carbon fibres and production of high quality fuel gas from the chemical recycling of carbon fibre reinforced plastic wastes

    OpenAIRE

    Yildirir, E; Onwudili, JA; Williams, PT

    2014-01-01

    A solvolysis process to depolymerize the resin fraction of carbon fibre reinforced plastic waste to recover carbon fibre, followed by hydrothermal gasification of the liquid residual product to produce fuel gas was investigated using batch reactors. The depolymerisation reactions were carried out in ethylene glycol and ethylene glycol/water mixtures at near-critical conditions of the two solvents. With ethylene glycol alone the highest resin removal of 92.1% was achieved at 400 °C. The additi...

  13. Investigation of Creep Rupture Phenomenon in Glass Fibre Reinforced Polymer (GFRP) Stirrups

    Science.gov (United States)

    Johal, Kanwardeep Singh

    Glass Fibre-Reinforced Polymer (GFRP) bars offer a feasible alternative to typical steel reinforcement in concrete structures where there are concerns of corrosion or magnetic interference. In order to design safe structures for a service life of 50 to 100 years, the long-term material properties of GFRP must be understood. Thirty GFRP stirrups of three types were tested under sustained loading to investigate creep rupture and modulus degradation behaviour. The time to failure under varying sustained loads was used to extrapolate the safe design load for typical service lives. It was found that shear critical beams with shear reinforcement designed in accordance with CSA-S806 and ACI-440 provisions may be at risk of premature failure under sustained design loads. Analysis was based on finite element modelling and previously tested beams. Additionally, no moduli degradation was observed in this study. A cumulative weakening model was developed to potentially take into account fatigue loading.

  14. Shape memory performance of asymmetrically reinforced epoxy/carbon fibre fabric composites in flexure

    Directory of Open Access Journals (Sweden)

    M. Fejos

    2013-06-01

    Full Text Available In this study asymmetrically reinforced epoxy (EP/carbon fibre (CF fabric composites were prepared and their shape memory properties were quantified in both unconstrained and fully constrained flexural tests performed in a dynamic mechanical analyser (DMA. Asymmetric layering was achieved by incorporating two and four CF fabric layers whereby setting a resin- and reinforcement-rich layer ratio of 1/4 and 1/2, respectively. The recovery stress was markedly increased with increasing CF content. The related stress was always higher when the CF-rich layer experienced tension load locally. Specimens with CF-rich layers on the tension side yielded better shape fixity ratio, than those with reinforcement layering on the compression side. Cyclic unconstrained shape memory tests were also run up to five cycles on specimens having the CF-rich layer under local tension. This resulted in marginal changes in the shape fixity and recovery ratios.

  15. Prestressing effect of cold-drawn short NiTi SMA fibres in steel reinforced mortar beams

    Science.gov (United States)

    Choi, Eunsoo; Kim, Dong Joo; Hwang, Jin-Ha; Kim, Woo Jin

    2016-08-01

    This study investigated the prestressing effect of cold-drawn short NiTi shape memory alloy (SMA) fibres in steel reinforced mortar beams. The SMA fibres were mixed with 1.5% volume content in a mortar matrix with the compressive strength of 50 MPa. The SMA fibres had an average length of 34 mm, and they were manufactured with a dog-bone shape: the diameters of the end- and middle-parts were 1.024 and 1.0 mm, respectively. Twenty mortar beams with the dimensions of 40 mm × 40 mm × 160 mm (B × H × L) were prepared. Two types of tests were conducted. One was to investigate the prestressing effect of the SMA fibres, and the beams with the SMA fibres were heated at the bottom. The other was to assess the bending behaviour of the beams prestressed by the SMA fibres. The SMA fibres induced upward deflection and cracking at the top surface by heating at the bottom; thus, they achieved an obvious prestressing effect. The beams that were prestressed by the SMA fibres did not show a significant difference in bending behaviour from that of the SMA fibre reinforced beams that were not subjected to heating. Stress analysis of the beams indicated that the prestressing effect decreased in relation to the cooling temperature.

  16. Bioresorbable screws reinforced with phosphate glass fibre: manufacturing and mechanical property characterisation.

    Science.gov (United States)

    Felfel, R M; Ahmed, I; Parsons, A J; Rudd, C D

    2013-01-01

    Use of bioresorbable screws could eliminate disadvantages associated with metals such as removal operations, corrosion, MRI interference and stress shielding. Mechanical properties of bioresorbable polymers alone are insufficient for load bearing applications application as screws. Thus, reinforcement is necessary to try and match or surpass the mechanical properties of cortical bone. Phosphate based glass fibres were used to reinforce polylactic acid (PLA) in order to produce unidirectionally aligned (UD) and unidirectionally plus randomly distributed (UD/RM) composite screws (P40 UD and P40 UD/RM). The maximum flexural and push-out properties for the composite screws (P40 UD and P40 UD/RM) increased by almost 100% in comparison with the PLA screws. While the pull-out strength and stiffness of the headless composite screws were ∼80% (strength) and ∼130% (stiffness) higher than for PLA, those with heads exhibited properties lower than those for PLA alone as a result of failure at the heads. An increase in the maximum shear load and stiffness for the composite screws (∼30% and ∼40%) in comparison to the PLA screws was also seen. Maximum torque for the PLA screws was ∼1000 mN m, while that for the composite screws were slightly lower. The SEM micrographs for P40 UD and P40 UD/RM screws revealed small gaps around the fibres, which were suggested to be due to buckling of the UD fibres during the manufacturing process.

  17. Analysis of mechanical properties anisotropy of nanomodified carbon fibre-reinforced woven composites

    Science.gov (United States)

    Ruslantsev, A. N.; Portnova, Ya M.; Tairova, L. P.; Dumansky, A. M.

    2016-10-01

    The polymer binder cracking problem arises while designing and maintaining polymer composite-based aircraft load-bearing members. Some technological methods are used to solve this problem. In particular the injection of nanoagents can block the initiation and growth of microscopic cracks. Crack propagation can also be blocked if the strain energy release is not related with fracturing. One of the possible ways for such energy release is creep. Testing of the anisotropy of the woven carbon fibre reinforced plastic elastic characteristics and creep have been conducted. The samples with different layouts have been made of woven carbon fibre laminate BMI-3/3692 with nanomodified bismaleimide matrix. This matrix has a higher glass transition temperature and improved mechanical properties. The deformation regularities have been analyzed, layer elastic characteristics have been determined. The constitutive equations describing composite material creep have been obtained and its parameters have been defined. Experimental and calculated creep curves have been plotted. It was found that the effects of rheology arise as the direction of load does not match the direction of reinforcing fibres of the material.

  18. Tannin-based flax fibre reinforced composites for structural applications in vehicles

    Science.gov (United States)

    Zhu, J.; Abhyankar, H.; Nassiopoulos, E.; Njuguna, J.

    2012-09-01

    Innovation is often driven by changes in government policies regulating the industries, especially true in case of the automotive. Except weight savings, the strict EU regulation of 95% recyclable material-made vehicles drives the manufactures and scientists to seek new 'green materials' for structural applications. With handing at two major drawbacks (production cost and safety), ECHOSHELL is supported by EU to develop and optimise structural solutions for superlight electric vehicles by using bio-composites made of high-performance natural fibres and resins, providing enhanced strength and bio-degradability characteristics. Flax reinforced tannin-based composite is selected as one of the candidates and were firstly investigated with different fabric lay-up angles (non-woven flax mat, UD, [0, 90°]4 and [0, +45°, 90°, -45°]2) through authors' work. Some of the obtained results, such as tensile properties and SEM micrographs were shown in this conference paper. The UD flax reinforced composite exhibits the best tensile performance, with tensile strength and modulus of 150 MPa and 9.6 MPa, respectively. It was observed that during tension the oriented-fabric composites showed some delamination process, which are expected to be eliminated through surface treatment (alkali treatment etc.) and nanotechnology, such as the use of nano-fibrils. Failure mechanism of the tested samples were identified through SEM results, indicating that the combination of fibre pull-out, fibre breakage and brittle resins failure mainly contribute to the fracture failure of composites.

  19. Durability of cracked fibre reinforced concrete exposed to freeze-thaw and deicing salt

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    1998-01-01

    -thaw and deicing salt. The concrete has a water-powder ratio of 0.38 including both fly ash and silica fume. Both steel fibres (ZP, 0.4 vol%) and polypropylene fibres (PP, 1 vol%) are used as well as main reinforcement. The freeze-thaw test emphasizes the need for a critical evaluation of the mix design and mixing......Durability studies are carried out by subjecting FRC-beams to combined mechanical and environmental load. Mechanical load is obtained by subjecting beams to 4-point bending until a predefined crack width is reached. Specimens sawn from the beams after unloading are exposed to freeze...... methods when designing FRC-structures. The scaling is increased by a factor 5 to 10 when adding fibres to the concrete while the air content is below 4% by volume. The variation of the scaling increases when adding fibres. Capillary water uptake in uncracked specimens of FRC was 20-30% higher at 1°C than...

  20. Comparative Investigation of Tungsten Fibre Nets Reinforced Tungsten Composite Fabricated by Three Different Methods

    Directory of Open Access Journals (Sweden)

    Linhui Zhang

    2017-07-01

    Full Text Available Tungsten fibre nets reinforced tungsten composites (Wf/W containing four net layers were fabricated by spark plasma sintering (SPS, hot pressing (HP and cold rolling after HP (HPCR, with the weight fraction of fibres being 17.4%, 10.5% and 10.5%, respectively. The relative density of the HPCRed samples is the highest (99.8% while that of the HPed composites is the lowest (95.1%. Optical and scanning electron microscopy and electron back scattering diffraction were exploited to characterize the microstructure, while tensile and hardness tests were used to evaluate the mechanical properties of the samples. It was found that partial recrystallization of fibres occurred after the sintering at 1800 °C. The SPSed and HPed Wf/W composites begin to exhibit plastic deformation at 600 °C with tensile strength (TS of 536 and 425 MPa and total elongation at break (TE of 11.6% and 23.0%, respectively, while the HPCRed Wf/W composites exhibit plastic deformation at around 400 °C. The TS and TE of the HPCRed Wf/W composites at 400 °C are 784 MPa and 8.4%, respectively. The enhanced mechanical performance of the Wf/W composites over the pure tungsten can be attributed to the necking, cracking, and debonding of the tungsten fibres.

  1. In-plane mechanics of soft architectured fibre-reinforced silicone rubber membranes.

    Science.gov (United States)

    Bailly, L; Toungara, M; Orgéas, L; Bertrand, E; Deplano, V; Geindreau, C

    2014-12-01

    Silicone rubber membranes reinforced with architectured fibre networks were processed with a dedicated apparatus, allowing a control of the fibre content and orientation. The membranes were subjected to tensile loadings combined with continuous and discrete kinematical field measurements (DIC and particle tracking). These tests show that the mechanical behaviour of the membranes is hyperelastic at the first order. They highlight the influence of the fibre content and orientation on both the membrane in-plane deformation and stress levels. They also prove that for the considered fibrous architectures and mechanical loadings, the motion and deformation of fibres is an affine function of the macroscale transformation. These trends are fairly well described by the micromechanical model proposed recently in Bailly et al. (JMBBM, 2012). This result proves that these materials are very good candidates for new biomimetic membranes, e.g. to improve aortic analogues used for in vitro experiments, or existing textiles used for vascular (endo)prostheses. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Effect of silane activation on shear bond strength of fiber-reinforced composite post to resin cement

    OpenAIRE

    Kim, Hyun-Dong; Lee, Joo-Hee; Ahn, Kang-Min; Kim, Hee-Sun; Cha, Hyun-Suk

    2013-01-01

    PURPOSE Among the surface treatment methods suggested to enhance the adhesion of resin cement to fiber-reinforced composite posts, conflicting results have been obtained with silanization. In this study, the effects of silanization, heat activation after silanization, on the bond strength between fiber-reinforced composite post and resin cement were determined. MATERIALS AND METHODS Six groups (n=7) were established to evaluate two types of fiber post (FRC Postec Plus, D.T. Light Post) and th...

  3. Mechanical response of a fibre reinforced earthen material under static and impact loadings

    Science.gov (United States)

    Aymerich, Francesco; Fenu, Luigi; Francesconi, Luca; Meloni, Paola

    2015-09-01

    This study examines the improvements provided by the insertion of hemp fibres with different weight fractions and lengths in an earthen material. The structural response of the materials was investigated by means of static and impact bending tests carried out on notched samples. The main focus of the analyses was in the characterization of the structural properties of the materials in terms of fracture resistance, post-cracking performance and energy absorption capability. The results of the study show that hemp fibres improve significantly the mechanical and fracture properties of the earthen material under both static and dynamic bending. It was also found that the structural properties of unreinforced and reinforced earthen materials are highly sensitive to the stress-rate, with higher strength and fracture resistance under impact loading than under static loading.

  4. Assessment of the exit defects in carbon fibre-reinforced plastic plates caused by drilling

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Houjiang; Zhang Liangchi [Sydney Univ. (Australia). Dept. of Mechanical and Mechatronic Engineering; Chen Wuyi; Chen Dingchang [Beijing Univ. of Aeronautics and Astronautics, BJ (China). Dept. of Manufacturing Engineering

    2001-07-01

    This paper investigates the formation of the exit defects in carbon fibre-reinforced plates and characterizes their features in terms of drilling conditions. It was found that spalling and fuzzing are the major mechanisms of exit defects. The spalling, consisting of a main region and a secondary region, is caused by chisel and cutting edge actions, in which the former plays a key role. The fuzzing, however, exists in the cutting region where the included angle between the fibre direction of the surface layer and that of the cutting speed is acute. A severer spalling damage corresponds to a high spindle speed, a large feed rate and a great thrust force. Some empirical relationships, including a dimensionless formula, were developed for assessing the characteristic dimension of the spalling damage based on the known drilling conditions. (orig.)

  5. Stiffness Characteristics of Fibre-reinforced Composite Shaft Embedded with Shape Memory Alloy Wires

    Directory of Open Access Journals (Sweden)

    K. Gupta

    2003-04-01

    Full Text Available Frequent coast up/coast down operations of rotating shafts in the power and aerospace industry expose the flexible rotors to the risk of fatigue failures. Resonant vibrations during passage through critical speeds induce large stresses that may lead to failures. In this paper, the use of nitinol [shape memory alloy (SMA] wires in the fibre-reinforced composite shaft, for the purpose ofmodifying shaft stiffness properties to avoid such failures, is discussed. A setup has been developed to fabricate the composite shaft (made of fibre glass and epoxy resin embedded with pre-stressed SMA wires. Experiments have been carried out on the shaft to estimate the changes in the natural frequency of the composite shaft due to activation and deactivation ofSMA wires. The comparisonofthe experimental results with the established analytical results indicates feasibility ofvibration control using the special properties of SMA wires.

  6. Optimization of woven jute/glass fibre-reinforced polyester hybrid composite solar parabolic trough collector

    Science.gov (United States)

    Reddy, K. S.; Singla, Hitesh

    2017-07-01

    In the present work, structural analysis of 5.77m × 4m woven jute (J)/glass (G) fibre-reinforced polyester hybrid composite solar parabolic trough is carried out based on trough parameters to obtain the minimum RMS local slope deviation, termed as SDx value under gravity loading. The optimization is done by varying parameters viz. direction and size of reinforced conduits, stacking number and sequence of hybrid trough laminate at fibre orientation of Δθ=45° and Δθ=60° amongst the layers at 0° collector angle. The analysis revealed that the configuration in which the conduits are placed in both X and Y directions is preferred over other configurations to scale down the effect of wind loads. Furthermore it has been observed that laminate of the order [0°G/45°G/-45°J/90°J]s undergoes minimum surface deformation amongst all the other configurations at conduit reinforcement in both X and Y directions for a conduit thickness of 0.75 mm and radius of 10 mm and obtains the overall SDx value of 1.3492 mrad. The results shows that proposed trough model is very promising and evolves a cost effective system.

  7. Electrical resistance stability of high content carbon fiber reinforced cement composite

    Institute of Scientific and Technical Information of China (English)

    YANG Zai-fu; TANG Zu-quan; LI Zhuo-qiu; QIAN Jue-shi

    2005-01-01

    The influences of curing time, the content of free evaporable water in cement paste, environmental temperature, and alternative heating and cooling on the electrical resistance of high content carbon fiber reinforced cement (CFRC) paste are studied by experiments with specimens of Portland cement 42.5 with 10 mm PAN-based carbon fiber and methylcellulose. Experimental results indicate that the electrical resistance of CFRC increases relatively by 24% within a hydration time of 90 d and almost keeps constant after 14 d, changes hardly with the mass loss of free evaporable water in the concrete dried at 50℃C, increases relatively by 4% when ambient temperature decreases from 15℃ to-20℃, and decreases relatively by 13% with temperature increasing by 88℃. It is suggested that the electric resistance of the CFRC is stable, which is testified by the stable power output obtained by electrifying the CFRC slab with a given voltage. This implies that such kind of high content carbon fiber reinforced cement composite is potentially a desirable electrothermal material for airfield runways and road surfaces deicing.

  8. Influence of Fabric Parameters on Microstructure, Mechanical Properties and Failure Mechanisms in Carbon-Fibre Reinforced Composites

    Institute of Scientific and Technical Information of China (English)

    B.Wielage; D.Richter; H.Mucha; Th.Lampke

    2008-01-01

    The effects of fibre/matrix bonding,fabric density,fibre volume fraction and bundle size on microstructure,mechanical properties and failure mechanisms in carbon fibre reinforced composites (plastic and carbon matrix) have been investigated.The microstructure of unloaded and cracked samples was studied by optical microscopy and scanning electron microscopy (SEM),respectively whereas the mechanical behaviour was examined by 3-point bending experiments.Exclusively one type of experimental resole type phenolic resin was applied.A strong fibre/matrix bonding,which is needed for high strength of carbon fibre reinforced plastic (CFRP) materials leads to severe composite damages during the pyrolysis resulting in low strength,brittle failure and a very low utilisation of the fibres strain to failure in C/C composites.Inherent fabric parameters such as an increasing fabric density or bundle size or a reduced fibre volume fraction introduce inhomogenities to the CFRP's microstructure.Results are lower strength and stiffness whereas the strain to failure increases or remains unchanged.Toughness is almost not affected.In C/C composites inhomogenities due to a reduced bundle size reduce strain to failure,strength,stiffness and toughness.Vice versa a declining fibre volume fraction leads to exactly the opposite behaviour.Increasing the fabric density (weight per unit area) causes similar effects as in CFRPs.

  9. Morphology and Properties of Geopolymer Coatings on Glass Fibre-Reinforced Epoxy (GRE pipe

    Directory of Open Access Journals (Sweden)

    Shahedan Noor Fifinatasha

    2016-01-01

    Full Text Available Geopolymer coatings were coated on glass fibre-reinforced epoxy (GRE pipe by using kaolin, white clay and silica sand as source materials and sodium hydroxide (NaOH and sodium silicate (Na2SiO3 as alkaline solution. The microstructure and mechanical property of geopolymer coating on GRE pipe were methodically investigated through morphology analysis, and flexural strength test. The result indicates the microstructure and interfacial layer between geopolymer coating and GRE pipe significantly influence the mechanical property of geopolymer coating. However, different source materials gave different microstructure and property in geopolymer coating.

  10. 50-Hz plasma treatment of glass fibre reinforced polyester at atmospheric pressure enhanced by ultrasonic irradiation

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Norrman, Kion; Singh, Shailendra Vikram

    2011-01-01

    Glass fibre reinforced polyester (GFRP) plates are treated using a 50-Hz dielectric barrier discharge at peak-to-peak voltage of 30 kV in helium at atmospheric pressure with and without ultrasonic irradiation to study adhesion improvement. The ultrasonic waves at the fundamental frequency of around...... approximately from 20 mJ m-2 up to 80 mJ m-2 with ultrasonic irradiation. The plasma treatment with ultrasonic irradiation also introduced oxygen and nitrogen containing functional groups at the GFRP surface. These changes would improve the adhesion properties of the GFRP plates....

  11. Effect of nanoparticles on tensile, impact and fatigue properties of fibre reinforced plastics

    Indian Academy of Sciences (India)

    R Nagalingam; S Sundaram; B Stanly Jones Retnam

    2010-10-01

    Advanced composite, fibre-reinforced polymer (FRP), has been favoured for certain aerospace, military, marine and automotive applications. Polymer nanocomposites containing layered silicates have attracted much attention. These exhibit increased modulus, decreased thermal expansion coefficient, increased solvent resistance and enhanced ionic conductivity when compared to the polymer alone. Here we have developed eight different combinations of composites FRP with nanoclay (montmorillonite) by layered manufacturing techniques (LM) and measured the mechanical properties. The measurement showed that the tensile strength, impact strength and fatigue life are greatly increased. A plausible explanation for high increase of properties has also been discussed.

  12. 50-Hz plasma treatment of glass fibre reinforced polyester at atmospheric pressure enhanced by ultrasonic irradiation

    OpenAIRE

    Kusano, Yukihiro; Norrman, Kion; Singh, Shailendra Vikram; Leipold, Frank; Morgen, P.; Bardenshtein, A.; Krebs, N.

    2011-01-01

    Glass fibre reinforced polyester (GFRP) plates are treated using a 50-Hz dielectric barrier discharge at peak-to-peak voltage of 30 kV in helium at atmospheric pressure with and without ultrasonicirradiation to study adhesion improvement. The ultrasonic waves at the fundamental frequency of around 30 kHz with the sound pressure level of approximately 155 dB were introduced vertically to the GFRP surface through a cylindrical waveguide. The polar component of the surface energy was almost unch...

  13. Adhesion improvement of glass-fibre-reinforced polyester composites by gliding arc discharge treatment

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Sørensen, Bent F.; Løgstrup Andersen, Tom

    2013-01-01

    A gliding arc is a plasma that can be operated at atmospheric pressure and applied for plasma surface treatment for adhesion improvement. In the present work, glass-fibre-reinforced polyester plates were treated using an atmospheric pressure gliding arc discharge with an air flow to improve...... adhesion with a vinylester adhesive. The treatment improved wettability and increased the polar component of the surface energy and the density of oxygen-containing polar functional groups at the surfaces. Double cantilever beam specimens were prepared for fracture mechanics characterisation (fracture...

  14. Application of WST-method fore fracture testing of fibre-reinforced concrete

    DEFF Research Database (Denmark)

    Löfgren, Ingemar; Olesen, John Forbes; Flansbjer, Mathias

    ). The test results from each lab were analysed and a study of the variation was performed. From the study of the intra-lab variations, it is evident that the variations of the steel fibre-reinforced concrete properties are significant. The coefficient of variance for the splitting load was found to vary...... between 20 to 40%. The investigation of the inter-lab variation, based on an analysis of variance (ANOVA) indicated that there is no inter-lab variation. The test result can be said to be independent of the testing location and the equipment used (with or without CMOD-control). The conclusions that can...

  15. An engineering analysis of penetration of metal ball into fibre-reinforced composite targets

    Institute of Scientific and Technical Information of China (English)

    Yong-chi LI; Zhi-hai WANG; Xiao-jun WANG; Xiu-zhang HU

    2009-01-01

    An engineering analysis of computing the penetration problem of a steel ball penetrating into fibre-reinforced composite targets is presented. Assume the metal ball is a rigid body, and the composite target is a transversely isotropic elasto-plastic material. In the analysis, a spherical cavity dilatation model is incorporated in the cylindrical cavity penetration method. Simulation results based on the modified model are in good agreement with the results for 3-D Kevlar woven (3DKW) composite anti-penetration experiments. Effects of the target material parameters and impact parameters on the penetration problem are also studied.

  16. Application of WST-method fore fracture testing of fibre-reinforced concrete

    DEFF Research Database (Denmark)

    Löfgren, Ingemar; Olesen, John Forbes; Flansbjer, Mathias

    be drawn from this study are that: § the wedge-splitting test method is a suitable test method for assessment of fracture properties of steel fibre-reinforced concrete; § the test method is easy to handle and relatively fast to execute § the test can be run with CMOD-control or without, in a machine......To evaluate the reproducibility of the wedge-splitting test method and to provide guidelines, a round robin study was conducted in which three labs participated. The participating labs were: § DTU – the Technical University of Denmark, Department of Civil Engineering; § CTH – Chalmers University...

  17. Strengthening of reinforced concrete circular columns using glass fibre reinforced polymers

    Directory of Open Access Journals (Sweden)

    Manish kumar Tiwari

    2014-04-01

    Full Text Available Seismic retrofitting of reinforced concrete members vulnerable to strong earthquakes is a great problem. It has long been recognized that confinement to concrete compression members not only increase the strength but improve ductility significantly. The present study focuses on the behavior of reinforced concrete specimens strengthened using glass fiber reinforced polymer (GFRP subjected to axial compressive loading. In this study specimen of circular cross section having length to diameter ratio of 2.0 and 0.96% longitudinal reinforcement were prepared and tested for 28 days compressive strength. The specimens were wrapped with 0,2,4,6 and 8 layers of GFRP outside the surface of the specimens as confinement. The test results showed that there is a significant increase in the strength of specimen with the increase of confinement layers on the specimen. The 28 days compressive strength of specimen wrapped with 8 layers of GRRP was increased by 47% as compared to the strength of specimen without any confinement.

  18. The effect of fly ash and coconut fibre ash as cement replacement materials on cement paste strength

    Science.gov (United States)

    Bayuaji, R.; Kurniawan, R. W.; Yasin, A. K.; Fatoni, H. AT; Lutfi, F. M. A.

    2016-04-01

    Concrete is the backbone material in the construction field. The main concept of the concrete material is composed of a binder and filler. Cement, concrete main binder highlighted by environmentalists as one of the industry are not environmentally friendly because of the burning of cement raw materials in the kiln requires energy up to a temperature of 1450° C and the output air waste CO2. On the other hand, the compound content of cement that can be utilized in innovation is Calcium Hydroxide (CaOH), this compound will react with pozzolan material and produces additional strength and durability of concrete, Calcium Silicate Hydrates (CSH). The objective of this research is to explore coconut fibers ash and fly ash. This material was used as cement replacement materials on cement paste. Experimental method was used in this study. SNI-03-1974-1990 is standard used to clarify the compressive strength of cement paste at the age of 7 days. The result of this study that the optimum composition of coconut fiber ash and fly ash to substitute 30% of cement with 25% and 5% for coconut fibers ash and fly ash with similar strength if to be compared normal cement paste.

  19. Impact of chemical treatments on the mechanical and water absorption properties of coconut fibre (Cocos nucifera reinforced polypropylene composites

    Directory of Open Access Journals (Sweden)

    Isiaka O. OLADELE

    2016-07-01

    Full Text Available In this work, chemically treated coconut fibres were used to reinforce Homopolymer Polypropylene in order to ascertain the effect of the treatments on the mechanical and water absorption properties of the composites produced. Coconut fibre was first extracted from its husk by soaking it in water and was dried before it was cut into 10 mm lengths. It was then chemically treated in alkali solution of sodium hydroxide (NaOH and potassium hydroxide (KOH in a shaker water bath. The treated coconut fibres were used as reinforcements in polypropylene matrix to produce composites of varied fibre weight contents; 2, 4, 6, 8 and 10 wt.%. Tensile and flexural properties were investigated using universal testing machine while water absorption test was carried out on the samples for 7 days. It was observed from the results that, NaOH treated samples gave the best tensile properties while KOH treated samples gave the best flexural and water repellent properties.

  20. Use of steel fibres recovered from waste tyres as reinforcement in concrete: pull-out behaviour, compressive and flexural strength.

    Science.gov (United States)

    Aiello, M A; Leuzzi, F; Centonze, G; Maffezzoli, A

    2009-06-01

    The increasing amount of waste tyres worldwide makes the disposition of tyres a relevant problem to be solved. In the last years over three million tons of waste tyres were generated in the EU states [ETRA, 2006. Tyre Technology International - Trends in Tyre Recycling. http://www.etra-eu.org]; most of them were disposed into landfills. Since the European Union Landfill Directive (EU Landfill, 1999) aims to significantly reduce the landfill disposal of waste tyres, the development of new markets for the tyres becomes fundamental. Recently some research has been devoted to the use of granulated rubber and steel fibres recovered from waste tyres in concrete. In particular, the concrete obtained by adding recycled steel fibres evidenced a satisfactory improvement of the fragile matrix, mostly in terms of toughness and post-cracking behaviour. As a consequence RSFRC (recycled steel fibres reinforced concrete) appears a promising candidate for both structural and non-structural applications. Within this context a research project was undertaken at the University of Salento (Italy) aiming to investigate the mechanical behaviour of concrete reinforced with RSF (recycled steel fibres) recovered from waste tyres by a mechanical process. In the present paper results obtained by the experimental work performed up to now are reported. In order to evaluate the concrete-fibres bond characteristics and to determine the critical fibre length, pull-out tests were initially carried out. Furthermore compressive strength of concrete was evaluated for different volume ratios of added RSF and flexural tests were performed to analyze the post-cracking behaviour of RSFRC. For comparison purposes, samples reinforced with industrial steel fibres (ISF) were also considered. Satisfactory results were obtained regarding the bond between recycled steel fibres and concrete; on the other hand compressive strength of concrete seems unaffected by the presence of fibres despite their irregular

  1. Physico-Mechanical Properties of Cement-Bonded Particle Boards of Bambusa vulgaris and Gmelina arborea Fibres

    Directory of Open Access Journals (Sweden)

    D.N. Izekor

    2015-09-01

    Full Text Available This study investigated the effect of pre-treatment and particle geometry/stratification on the physical and mechanical properties of cement-bonded particle boards (CBPBs. 6 mm thick homogeneous cement-bonded particle boards were made from Gmelina arborea roxb. sawdust and bambusa vulgaris shard. fibres with type 1 Portland cement. The CBPBs were manufactured at four particle geometry/stratification levels and three pre-treatment levels. The CBPB was manufactured with a cement wood ratio of 3:1, board density of 1500 kg/m3, board size of 350×350×6 mm and a pressing pressure of 1.23 N/mm2. The CBPBs were tested for modulus of rupture (MOR, modulus of elasticity (MOE, thickness swelling (TS and water absorption (WA. The MOR obtained for each of the 12 factor combinations in this experiment ranged from 2.02 to 11.27 N/mm2 while MOE value ranged from 253.88 to 4942.60 N/mm2. The mean percentage for water absorption (WA values ranged from 8.78% to 35.66% while mean TS values ranged from 0.16% to 15.71%. Stronger and stiffer boards were produced using the sawdust/fibre/sawdust geometry stratification. Calcium chloride pre-treatment increased the mechanical properties of the boards, while Al2(SO43 improved their physical properties. There were significant differences between particle geometry and pre-treatment on both physical and mechanical properties of cement-bonded particle board (p<0.05.

  2. Influence of the physical structure of flax fibres on the mechanical properties of flax fibre reinforced polypropylene composites

    NARCIS (Netherlands)

    Oever, van den M.J.A.; Bos, H.L.; Kemenade, van M.J.J.M.

    2000-01-01

    This study investigates the influence of the physical structure of flax fibres on the mechanical properties of polypropylene (PP) composites. Due to their composite-like structure, flax fibres have relatively weak lateral bonds which are in particular present in flax fibres that are often used in na

  3. Design and evaluation of carbon fibre-reinforced launch packages with segmented, copper and molybdenum fibre armatures

    NARCIS (Netherlands)

    Koops, M.; Huijser, T.; Karthaus, W.

    1997-01-01

    Fibre armatures have been studied both dynamically and statically to gain insight in their electrothermal and mechanical behaviour. In the first part of this paper, the results of launch experiments with single and multi-segment copper and molybdenum fibre armatures integrated in carbon-fibre reinfo

  4. Mechanical Characterization and Water Absorption Behaviour of Interwoven Kenaf/PET Fibre Reinforced Epoxy Hybrid Composite

    Directory of Open Access Journals (Sweden)

    Yakubu Dan-mallam

    2015-01-01

    Full Text Available The development of interwoven fabric for composite production is a novel approach that can be adopted to address the challenges of balanced mechanical properties and water absorption behaviour of polymer composites. In this paper, kenaf and PET (polyethylene terephthalate fibre were selected as reinforcing materials to develop the woven fabric, and low viscosity epoxy resin was chosen as the matrix. Vacuum infusion process was adopted to produce the hybrid composite due to its superior advantages over hand lay-up technique. The weight percentage composition of the Epoxy/kenaf/PET hybrid composite was maintained at 70/15/15 and 60/20/20, respectively. A significant increase in tensile strength and elastic modulus of approximately 73% and 53% was recorded in relation to neat epoxy. Similarly, a substantial increase in flexural, impact, and interlaminar properties was also realized in relation to neat epoxy. This enhancement in mechanical properties may be attributed to the interlocking structure of the interwoven fabric, individual properties of kenaf and PET fibres, strong interfacial bonding, and resistance of the fibres to impact loading. The water absorption of the composites was studied by prolonged exposure in distilled water, and the moisture absorption pattern was found to follow Fickian behaviour.

  5. Strength and Toughness of Steel Fibre Reinforced Reactive Powder Concrete Under Blast Loading

    Institute of Scientific and Technical Information of China (English)

    KUZNETSOV Valerian A; REBENTROST Mark; WASCHL John

    2006-01-01

    The blast resistance of structures used in buildings needs to be investigated due to the increased threat of a terrorist attack.The damage done by Composition B or Powergel to steel fibre reinforced reactive powder concrete (SFRPC) panels and ordinary reinforced concrete (RC) panels of equivalent static flexural strength is compared.A 0.5 kg charge was detonated at a distance of 0.1 m from the 1.3 m × 1.0 m × 0.1 m (thick) panels,which were simply supported and spaning 1.3 m.Dynamic displacement measurements,high-speed video recording and visual examination of the panels for spall and breach were undertaken.The SFRPC panels withstood the bare charge blast better than the reinforced ordinary concrete panels.Neither type of panel was breached using a 0.5 kg charge.The RC panel exhibited more spalling when Composition B was used.Under successive Composition B loading conditions,the RC panel was breached.In comparison the SFRPC panel was not breached.Exposure to fragmenting charge loading conditions confirmed these performance differences between the SFRPC panel and the reinforced ordinary concrete panel.

  6. Synthesis and Characterization of Fibre Reinforced Silica Aerogel Blankets for Thermal Protection

    Directory of Open Access Journals (Sweden)

    S. Chakraborty

    2016-01-01

    Full Text Available Using tetraethoxysilane (TEOS as the source of silica, fibre reinforced silica aerogels were synthesized via fast ambient pressure drying using methanol (MeOH, trimethylchlorosilane (TMCS, ammonium fluoride (NH4F, and hexane. The molar ratio of TEOS/MeOH/(COOH2/NH4F was kept constant at 1 : 38 : 3.73 × 10−5 : 0.023 and the gel was allowed to form inside the highly porous meta-aramid fibrous batting. The wet gel surface was chemically modified (silylation process using various concentrations of TMCS in hexane in the range of 1 to 20% by volume. The fibre reinforced silica aerogel blanket was obtained subsequently through atmospheric pressure drying. The aerogel blanket samples were characterized by density, thermal conductivity, hydrophobicity (contact angle, and Scanning Electron Microscopy. The radiant heat resistance of the aerogel blankets was examined and compared with nonaerogel blankets. It has been observed that, compared to the ordinary nonaerogel blankets, the aerogel blankets showed a 58% increase in the estimated burn injury time and thus ensure a much better protection from heat and fire hazards. The effect of varying the concentration of TMCS on the estimated protection time has been examined. The improved thermal stability and the superior thermal insulation of the flexible aerogel blankets lead to applications being used for occupations that involve exposure to hazards of thermal radiation.

  7. Fibre-reinforced ceramics for industrial applications; Faserverstaerkte Keramik in industriellen Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Leuchs, M.; Spoerer, J.; Zechmeister, H. [MAN Technologie AG, Karlsfeld (Germany)

    1998-05-01

    High-performance composites now include also materials with a ceramic matrix. By means of the long-fibre reinforcement of ceramics, using carbon (C) or silicium carbide (SiC) fibres embedded in SiC matrix material, a breakthrough has been achieved regarding enhanced embrittlement behaviour of ceramics. The basic mechanism of the reinforcement, as well as different fabrication methods which are now ready for transfer to market, are described. Exemplary results of applications are reported, which demonstrate the high fracture toughness, thermo-shock resistance and tribological stress tolerance of the ceramic composite. (orig.) [Deutsch] Zu den Hochleistungsverbundwerkstoffen gehoeren inzwischen auch die Werkstoffe mit keramischer Matrix. Mit der Langfaserverstaerkung von Keramik ist unter Verwendung von Kohlenstoff (C)- oder Siliciumcarbid (SiC)-Fasern, die in SiC-Matrixmaterial eingebettet werden, ein Durchbruch bei der Verbesserung des Sproedbruchverhaltens keramischer Werkstoffe gelungen. Der Grundmechanismus der Verstaerkung und verschiedene, inzwischen anwendungsreife Herstellverfahren werden beschrieben. Beispielhafte Ergebnisse von Anwendungsentwicklungen werden vorgestellt, in denen die hohe Bruchzaehigkeit, Thermoschockbestaendigkeit und tribologische Belastbarkeit von Verbundkeramik demonstriert wird. (orig.)

  8. Machinability Study of Hybrid Nanoclay-Glass Fibre Reinforced Polyester Composites

    Directory of Open Access Journals (Sweden)

    P. Prabhu

    2013-01-01

    Full Text Available Glass fibre reinforced polyester composites (GRP and hybrid nanoclay and glass fibre reinforced polyester nanocomposites (CGRP are fabricated by vacuum assisted resin infusion technique. The optimum mechanical properties are obtained for CGRP with 3 wt.% nanoclay. Three types of drills (carbide twist drill D 5407060, HSS twist drill BS-328, and HSS end mill (4 flutes “N”-type end mill RH-helical flute of 6 mm diameters are used to drill holes on GRP and CGRP. Three different speeds (600, 852, and 1260 rpm and two different feeds (0.045, 0.1 mm/rev are selected as process parameters. The effect of process parameter on thrust force and delamination during drilling CGRP is analyzed for optimizing the machining parameters. The delamination factor is low for the optimum process parameter (feed = 0.1 mm/rev and speed 852 rpm. Microstructural analysis confirms that at higher feeds, delamination is low for CGRP drilled with carbide tools. In order to analyze the effect of nanoclay in CGRP on tool wear, 200 holes were drilled on CGRP samples with 3 wt.% nanoclay, and the tool wear is analyzed under optimized parametric condition. Tool wear is high in HSS twist drill compared with carbide drill. The presence of nanoclay also accelerates the tool wear.

  9. Strengthening of 230KV wood transmission structures with glass fibre reinforced polymer (GFRP) wraps

    Energy Technology Data Exchange (ETDEWEB)

    Shahi, A.; West, J.S.; Pandey, M.D. [Waterloo Univ., ON (Canada). Dept. of Civil Engineering

    2007-07-01

    In northern Canada, an unexpected structural failure resulting from wood deterioration has been determined to pose a risk to the safety of the 230 kV wood transmission lines. Because of the remote location of the transmission structures and the need to keep the transmission lines in continuous service, replacement of deteriorated elements can be very expensive. One potential alternative is to install a lightweight strengthening system while the old structure is being serviced. One of the most common structural repair systems are fibre reinforced polymer (FRP) materials. Limited research has explored the feasibility of this strengthening system on wood beams. This paper presented a pilot experimental research program to study the feasibility of using Glass Fibre Reinforced Polymer (GFRP) fabrics as a lightweight, reliable, and effective strengthening system for deteriorated circular cross-arms of the Gulfport transmission structures. The paper discussed previous research on FRP materials, the research strategy of this study, the experimental program, and experimental results and analysis. This included measured moisture content, failure mode, relationship between stiffness and failure load, effect of wrapping on strength, and the effect of wrapping on stiffness. The results of the experimental program suggested a strong correlation between the failure load and the stiffness of the specimens and that the proposed strengthening system could result in more consistent strengths. 9 refs., 2 tabs., 8 figs.

  10. Particulate Filled Composite Plastic Materials from Recycled Glass Fibre Reinforced Plastics

    Directory of Open Access Journals (Sweden)

    Aare ARUNIIT

    2011-09-01

    Full Text Available Glass fibre reinforced plastic (GFRP scrap consisted of acrylic plastic with glass fibre reinforcement in polyester resin matrix was used in our experiments. The multi-functional DS-series disintegrator mills were used for mechanical processing of GFRP scrap. Preceding from the results characterization of the milled powder particles size, shape and other properties the numerical algorithm for modelling of the density of the new filler material was developed. The main goal of the current study is to develop new particulate filled composite plastic material from recycled GFRP scrap. With recovered plastic powder material the higher filler content in polyester resin matrix can be achieved. The new composite is modelled on basis of the properties of new material. Such an approach requires tests of the new material. The considered target characteristics of the new material are the tensile strength, elongation at break and the cost. The multicriteria optimization problem has been formulated and solved by use of physical programming techniques and Pareto optimality concept. The designed new composites were manufactured in different mixing ratios of powder and binder agent. The strength and stiffness properties of new composite material were tested. http://dx.doi.org/10.5755/j01.ms.17.3.593

  11. Preparation And Properties Of Bionanocomposite Films Reinforced With Nanocellulose Isolated From Moroccan Alfa Fibres

    Directory of Open Access Journals (Sweden)

    Youssef Benyoussif

    2015-09-01

    Full Text Available Nanocellulose (NC were extracted from the Moroccan Alfa plant (Stipa tenacissima L. and characterised. These Alfa cellulosic nanoparticles were used as reinforcing phase to prepare bionanocomposite films using carboxymethyl cellulose as matrix. These films were obtained by the casting/evaporation method. The crystallinity of NC was analysed by X-ray diffraction, the dimension of NC by atomic force microscopy, molecular interactions due to incorporation of NC in carboxymethyl cellulose (CMC matrix were supported by Fourier transforms infrared (FTIR spectroscopy. The properties of the ensuing bionanocomposite films were investigated using tensile tests, water vapour permeability (WVP study and thermogravimetric analysis. With the progress of purification treatment of cellulose, the crystallinity is improved compared to the untreated fibres; this can be explained by the disappearance of the amorphous areas in cellulose chain of the plant. Consequently, the tensile modulus and tensile strength of CMC film increased by 60 and 47%, respectively, in the bionanocomposite films with 10 wt% of NC, and decrease by 8.6% for WVP with the same content of NC. The NC obtained from the Moroccan Alfa fibres can be used as a reinforcing agent for the preparation of bionanocomposites, and they have a high potential for the development of completely biodegradable food packaging materials.

  12. Exposure Assessment of Particulate Matter from Abrasive Treatment of Carbon and Glass Fibre-Reinforced Epoxy-Composites

    DEFF Research Database (Denmark)

    Jensen, Alexander C. Ø.; Levin, Marcus; Koivisto, Antti J.

    2015-01-01

    The use of composites is ever increasing due to their important structural and chemical features. The composite component production often involves high energy grinding and sanding processes to which emissions workers are potentially exposed. In this study we investigated the machining of carbon...... and glass fibre-reinforced epoxy composite materials at two facilities. We measured particle number concentrations and size distributions of the released material in near field and far field during sanding of glass-and carbon fibre-reinforced composites. We assessed the means of reducing exposure during...

  13. Shrinkage modeling of concrete reinforced by palm fibres in hot dry environments

    Science.gov (United States)

    Akchiche, Hamida; Kriker, Abdelouahed

    2017-02-01

    The cement materials, such as concrete and conventional mortar present very little resistance to traction and cracking, these hydraulic materials which induces large withdrawals on materials and cracks in structures. The hot dry environments such as: the Saharan regions of Algeria, Indeed, concrete structures in these regions are very fragile, and present high shrinkage. Strengthening of these materials by fibers can provide technical solutions for improving the mechanical performance. The aim of this study is firstly, to reduce the shrinkage of conventional concrete with its reinforcement with date palm fibers. In fact, Algeria has an extraordinary resources in natural fibers (from Palm, Abaca, Hemp) but without valorization in practical areas, especially in building materials. Secondly, to model the shrinkage behavior of concrete was reinforced by date palm fibers. In the literature, several models for still fiber concrete were founded but few are offers for natural fiber concretes. To do so, a still fiber concretes model of YOUNG - CHERN was used. According to the results, a reduction of shrinkage with reinforcement by date palm fibers was showed. A good ability of molding of shrinkage of date palm reinforced concrete with YOUNG - CHERN Modified model was obtained. In fact, a good correlation between experimental data and the model data was recorded.

  14. Effect of fibre-reinforced composite on the fracture resistance of endodontically treated teeth.

    Science.gov (United States)

    Ozsevik, Abdul Semih; Yildirim, Cihan; Aydin, Ugur; Culha, Emre; Surmelioglu, Derya

    2016-08-01

    The aim of this study is to evaluate the fracture resistance of root-filled teeth restored with fibre-reinforced composite (everX posterior). Fifty mandibular molars were divided into five groups (n = 10). Group 1: no treatment was applied (intact teeth). Group 2-5: canals were prepared and root filled. Group 2: no coronal restoration was placed. Group 3: teeth were coronally restored with composite. Group 4: composite restorations were performed following polyethylene fibre insertion at the cavity base. Group 5: composite resin placed over everX posterior. After thermocycling (5-55°C, 5000×), fracture resistance was measured. Mean force load for each sample was recorded in Newtons (N). Results were statistically analysed with one-way analysis of variance and post hoc Tukey's tests. The mean force required to fracture samples and standard deviations are as follows: group 1: 2859.5 ± 551.27 N, group 2: 318.97 ± 108.67 N, group 3: 1489.5 ± 505.04 N, group 4: 1958.3 ± 362.94 N, group 5: 2550.7 ± 586.1 N. everX posterior (group 5) was higher than groups 2, 3 and 4 (P  0.05). Placing fibre-reinforced composite under composite increased the fracture strength of root-filled teeth to the level of intact teeth.

  15. Comparison of traditional field retting and Phlebia radiata Cel 26 retting of hemp fibres for fibre-reinforced composites.

    Science.gov (United States)

    Liu, Ming; Ale, Marcel T; Kołaczkowski, Bartłomiej; Fernando, Dinesh; Daniel, Geoffrey; Meyer, Anne S; Thygesen, Anders

    2017-12-01

    Classical field retting and controlled fungal retting of hemp using Phlebia radiata Cel 26 (a mutant with low cellulose degrading ability) were compared with pure pectinase treatment with regard to mechanical properties of the produced fibre/epoxy composites. For field retting a classification of the microbial evolution (by gene sequencing) and enzyme profiles were conducted. By phylogenetic frequency mapping, different types of fungi, many belonging to the Ascomycota phylum were found on the fibres during the first 2 weeks of field retting, and thereafter, different types of bacteria, notably Proteobacteria, also proliferated on the field retted fibres. Extracts from field retted fibres exhibited high glucanase activities, while extracts from P. radiata Cel 26 retted fibres showed high polygalacturonase and laccase activities. As a result, fungal retting gave a significantly higher glucan content in the fibres than field retting (77 vs. 67%) and caused a higher removal of pectin as indicated by lower galacturonan content of fibres (1.6%) after fibres were retted for 20 days with P. radiata Cel 26 compared to a galacturonan content of 3.6% for field retted fibres. Effective fibre stiffness increased slightly after retting with P. radiata Cel 26 from 65 to 67 GPa, while it decreased after field retting to 52 GPa. Effective fibre strength could not be determined similarly due to variations in fibre fracture strain and fibre-matrix adhesion. A maximum composite strength with 50 vol% fibres of 307 MPa was obtained using P. radiata Cel 26 compared to 248 MPa with field retting.

  16. Microstructure and Mechanical Properties of CaCO3 Whisker-reinforced Cement

    Institute of Scientific and Technical Information of China (English)

    CAO Mingli; WEI Jianqiang

    2011-01-01

    Composite Portland cement (PC) played an important role in various kinds of construction engineering owing to low hydration heat,low-cost,and application of solid industrial waste,but its brittleness and low strength limited its use in stress-bearing locations.The aim of this study is to improve the toughness and fracture resistance by incorporating CaCO3 whisker in cement matrix.Effect of different content of calcium carbonate whiskers on the mechanical properties of PC was investigated.The results showed that the flexural strength,impact strength and split tensile strength were increased by 39.7%,39.25% and 36.34% at maximum,respectively.Microstructure and elements of the whiskers in hardened cement were observed and analyzed by SEM/EDS.The mechanisms of the reinforcement of CaCO3 whisker on cement were also discussed,and the conclusion was that the improvement could be correlated to energy-dissipating processes owing to crack bridging,crack deflection,and whisker pull-out at the crack tips.

  17. Vegetable fibres from agricultural residues as thermo-mechanical reinforcement in recycled polypropylene-based green foams.

    Science.gov (United States)

    Ardanuy, Mònica; Antunes, Marcelo; Velasco, José Ignacio

    2012-02-01

    Novel lightweight composite foams based on recycled polypropylene reinforced with cellulosic fibres obtained from agricultural residues were prepared and characterized. These composites, initially prepared by melt-mixing recycled polypropylene with variable fibre concentrations (10-25 wt.%), were foamed by high-pressure CO(2) dissolution, a clean process which avoids the use of chemical blowing agents. With the aim of studying the influence of the fibre characteristics on the resultant foams, two chemical treatments were applied to the barley straw in order to increase the α-cellulose content of the fibres. The chemical composition, morphology and thermal stability of the fibres and composites were analyzed. Results indicate that fibre chemical treatment and later foaming of the composites resulted in foams with characteristic closed-cell microcellular structures, their specific storage modulus significantly increasing due to the higher stiffness of the fibres. The addition of the fibres also resulted in an increase in the glass transition temperature of PP in both the solid composites and more significantly in the foams.

  18. Piezoresistive properties of cement composites reinforced by functionalized carbon nanotubes using photo-assisted Fenton

    Science.gov (United States)

    Jianlin, Luo; Kwok L, Chung; Qiuyi, Li; Shunjian, Chen; Lu, Li; Dongshuai, Hou; Chunwei, Zhang

    2017-03-01

    A combined chemical technique for surface functionalization of carbon nanotubes (CNTs) is presented in this paper. The functionalized CNTs (f-CNTs) were employed to reinforce both the mechanical and electromechanical properties of cementitious composites for the purpose of developing intrinsic self-sensing sensors. With moderate functionalization, the f-CNTs were found to easily disperse in an aqueous system while just aiding with low fraction of dispersants: (a) polyethylene oxide (MPEG), (b) Trition X-100 (Tx-100). Both the FTIR and DSC results show that the oxidation effect of this combined technique were not as strong as those when using conventional strong oxidation methods. As a result, the integrity of electronic structure inside the f-CNT reinforced cement matrixes can be effectively maintained. This paper is aimed at exploring the electrical resistivity and piezoresistive properties of the f-CNT reinforced cement composites (f-CNT-RCCs). Both the monoaxial and cyclic compression tests were undertaken on the specimens with different f-CNT doping levels of 0.1%, 0.2% and 0.3%. Experimental results indicated that excellent piezoresistive properties were achieved at the doping level of 0.3%, wherein high strain sensitivity were recorded as 254.9 and 286.6 for the cases of adding small amounts of surfactants, MPEG and combination of MPEG and Tx100, respectively.

  19. Electrical Resistance and Microstructure of Latex Modified Carbon Fiber Reinforced Cement Composites

    Institute of Scientific and Technical Information of China (English)

    WEI Jian; CHENG Feng; YUAN Hudie

    2012-01-01

    The electrical resistance,flexural strength,and microstructure of carbon fiber reinforced cement composites (CFRC) were improved greatly by adding water-redispersible latex powder.The electrical resistance of CFRC was investigated by two-probe method.The input range of CFRC based strain sensors was therefore increased,whereas electrical resistance was increased and remained in the perfect range of CFRC sensors.The analysis of scanning electron microscopy indicated that elastic latex bridges and a latex layer existed among the interspaces of the adjacent cement hydration products which were responsible for the enhancement of the flexural strength and electrical resistance.The formation mechanism of the elastic latex bridges was also discussed in detail.The continuous moving of two opposite interfaces of the latex solution-air along the interspaces of the adjacent hydrated crystals or colloids was attributed to the formation of the elastic latex bridges.

  20. Influence of Fabric Geometrical Structure on Bonding of the Fabric Reinforced Cement Composites

    Institute of Scientific and Technical Information of China (English)

    YU Qiao-zhen

    2007-01-01

    Influence of fabric geometrical parameters,including the number of filling yams per 10 cm, yarntwist and fiber type, on bonding of the fabric reinforcedcement composites is studied by fabric pull-out test andSEM microstructure analysis. The results show that thebonding strength increase with the increase of the numberof filling yams per 10 cm in the range of this study. Butthe influence of fabric count on the interfacial bonding isdual and there is a critical value. The twist of yarns hasa little effect on the bending strength and interfacialbonding behaves of nylon fabric reinforced cementcomposites. There is an optimum twist range. Withinthis range, the bonding strength increase slowly with theincrease of yarn twist. Beyond this range, it is versus.The bonding strength is strongly affected by the fabriccharacter. The bonding between the nylon fiber fabricand cement is good; that of between glass fiber fabric andcement is moderate and that of between the carbon fiberfabric and cement is poor.

  1. A Fibre-Reinforced Poroviscoelastic Model Accurately Describes the Biomechanical Behaviour of the Rat Achilles Tendon

    Science.gov (United States)

    Heuijerjans, Ashley; Matikainen, Marko K.; Julkunen, Petro; Eliasson, Pernilla; Aspenberg, Per; Isaksson, Hanna

    2015-01-01

    Background Computational models of Achilles tendons can help understanding how healthy tendons are affected by repetitive loading and how the different tissue constituents contribute to the tendon’s biomechanical response. However, available models of Achilles tendon are limited in their description of the hierarchical multi-structural composition of the tissue. This study hypothesised that a poroviscoelastic fibre-reinforced model, previously successful in capturing cartilage biomechanical behaviour, can depict the biomechanical behaviour of the rat Achilles tendon found experimentally. Materials and Methods We developed a new material model of the Achilles tendon, which considers the tendon’s main constituents namely: water, proteoglycan matrix and collagen fibres. A hyperelastic formulation of the proteoglycan matrix enabled computations of large deformations of the tendon, and collagen fibres were modelled as viscoelastic. Specimen-specific finite element models were created of 9 rat Achilles tendons from an animal experiment and simulations were carried out following a repetitive tensile loading protocol. The material model parameters were calibrated against data from the rats by minimising the root mean squared error (RMS) between experimental force data and model output. Results and Conclusions All specimen models were successfully fitted to experimental data with high accuracy (RMS 0.42-1.02). Additional simulations predicted more compliant and soft tendon behaviour at reduced strain-rates compared to higher strain-rates that produce a stiff and brittle tendon response. Stress-relaxation simulations exhibited strain-dependent stress-relaxation behaviour where larger strains produced slower relaxation rates compared to smaller strain levels. Our simulations showed that the collagen fibres in the Achilles tendon are the main load-bearing component during tensile loading, where the orientation of the collagen fibres plays an important role for the tendon

  2. Water-cooled non-thermal gliding arc for adhesion improvement of glass-fibre-reinforced polyester

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Sørensen, Bent F.; Løgstrup Andersen, Tom;

    2013-01-01

    -fibre-reinforced polyester plates were treated using an atmospheric pressure gliding-arc discharge with air flow to improve adhesion with a vinylester adhesive. The electrodes were water-cooled so as to operate the gliding arc continually. The treatment improved wettability and increased the density of oxygen...

  3. Go with the flow: conservation of a floating sculpture from 1961 made from glass fibre-reinforced polyester resin

    NARCIS (Netherlands)

    Beerkens, L.; Stigter, S.; van Oosten, T.; van Keulen, H.; Keneghan, B.; Egan, L.

    2008-01-01

    Marta Pan’s Sculpture flottante, Otterlo was commissioned by the Kröller-Müller Museum for a pond at the entrance of the new sculpture garden that opened in June 1961. The floating sculpture is made from glass fibre-reinforced polyester resin and is now coated with white paint layers. The top is c

  4. Go with the flow: conservation of a floating sculpture from 1961 made from glass fibre-reinforced polyester resin

    NARCIS (Netherlands)

    Beerkens, L.; Stigter, S.; van Oosten, T.; van Keulen, H.; Keneghan, B.; Egan, L.

    2008-01-01

    Marta Pan’s Sculpture flottante, Otterlo was commissioned by the Kröller-Müller Museum for a pond at the entrance of the new sculpture garden that opened in June 1961. The floating sculpture is made from glass fibre-reinforced polyester resin and is now coated with white paint layers. The top is

  5. Effect of water absorption on the mechanical properties of nanoclay filled recycled cellulose fibre reinforced epoxy hybrid nanocomposites

    KAUST Repository

    Alamri, H.

    2013-01-01

    Recycled cellulose fibre (RCF) reinforced epoxy/clay nanocomposites were successfully synthesized with different weight percentages (0%, 1%, 3% and 5%) of organoclay platelets (30B). The objective of this study was to investigate the effect of water absorption on the physical and mechanical properties of the RCF reinforced epoxy/clay nanocomposites. TEM images indicated a well-intercalated structure of nanoclay/epoxy matrix with some exfoliated regions. Water absorption was found to decrease as the clay content increased. The flexural strength, flexural modulus and fracture toughness significantly decreased as a result of water absorption. However, the properties of impact strength and impact toughness were found to increase after exposing to water. The addition of nanoclay slightly minimized the effect of moisture on the mechanical properties. SEM images showed that water absorption severely damaged the cellulose fibres and the bonding at fibres-matrix interfaces in wet composites. © 2012 Elsevier Ltd. All rights reserved.

  6. Fabrication of metallic reinforcement fibres for metal matrix composites by in-rotating-liquid spinning. Herstellung metallischer Verstaerkungsfasern fuer Metallmatrixverbundwerkstoffe durch Schmelzspinnen in eine rotierende Fluessigkeit

    Energy Technology Data Exchange (ETDEWEB)

    Heyder, B.; Frommeyer, G. (Max-Planck-Institut fuer Eisenforschung GmbH, Duesseldorf (Germany). Abt. Werkstofftechnik)

    1992-02-01

    The application of reinforced metal matrix composites reinforced by continuous fibres are in particular limited by the lack of inexpensive and high-strength reinforcement fibres. Starting-points for a solution offer new methods of rapid solidification technology such as the in-rotating-liquid spinning that is suitable for a broad acceptance by industry. Fundamental investigations of the influence factors and the process parameters showed the aptitude of this method. (orig.).

  7. Assessment of microcapsule—catalyst particles healing system in high performance fibre reinforced polymer composite

    Science.gov (United States)

    Bolimowski, P. A.; Wass, D. F.; Bond, I. P.

    2016-08-01

    Autonomous self-healing in carbon fibre reinforced polymer (CFRP) is demonstrated using epoxy resin filled microcapsules and a solid-state catalyst. Microcapsules filled with oligomeric epoxy resin (20-450 μm) and particles of Sc(OTf)3 are embedded in an interleave region of a unidirectional CFRP laminate and tested under mode I loading. Double cantilever beam (DCB) test specimens containing variable concentrations of microcapsules and catalyst were prepared, tested and compared to those healed by manual injection with corresponding healing resin formulation. The healing efficiency was evaluated by comparing the maximum peak load recorded on load-displacement curves for pristine and healed specimens. A 44% maximum recovery was observed for specimens containing 10 wt% of solid phase catalyst and 11 wt% of epoxy microcapsules. However, a significant (80%) decrease in initial strain energy release rate (G IC) was observed for specimens with the embedded healing chemistries.

  8. Repeated self-healing of microvascular carbon fibre reinforced polymer composites

    Science.gov (United States)

    Coope, T. S.; Wass, D. F.; Trask, R. S.; Bond, I. P.

    2014-11-01

    A self-healing, high performance, carbon fibre reinforced polymer (CFRP) composite is demonstrated by embedding a Lewis-acid catalytic curing agent within a laminate, manufactured using out of autoclave (OOA) composite manufacturing methods. Two configurations of healing agent delivery, pre-mixed and autonomous mixing, are investigated via injection of a healing agent through bio-inspired microvascular channels exposed on Mode I fractured crack planes. Healing is effected when an epoxy resin-solvent healing agent mixture reaches the boundary of embedded solid-state scandium(III) triflate (Sc(OTf)3) catalyst, located on the crack plane, to initiate the ring-opening polymerisation (ROP) of epoxides. Tailored self-healing agents confer high healing efficiency values after multiple healing cycles (69-108%) to successfully mitigate against crack propagation within the composite microstructure.

  9. High-power picosecond laser drilling/machining of carbon fibre-reinforced polymer (CFRP) composites

    Science.gov (United States)

    Salama, A.; Li, L.; Mativenga, P.; Sabli, A.

    2016-02-01

    The large differences in physical and thermal properties of the carbon fibre-reinforced polymer (CFRP) composite constituents make laser machining of this material challenging. An extended heat-affected zone (HAZ) often occurs. The availability of ultrashort laser pulse sources such as picosecond lasers makes it possible to improve the laser machining quality of these materials. This paper reports an investigation on the drilling and machining of CFRP composites using a state-of-the-art 400 W picosecond laser system. Small HAZs (drilled on sample of 6 mm thickness, whereas no HAZ was seen below the top surface on the cut surfaces. Multiple ring material removal strategy was used. Furthermore, the effect of laser processing parameters such as laser power, scanning speed and repetition rate on HAZ sizes and ablation depth was investigated.

  10. Study on Sound Absorption Properties of Coconut Coir Fibre Reinforced Composite with Added Recycled Rubber

    Directory of Open Access Journals (Sweden)

    S. Mahzan

    2010-06-01

    Full Text Available Sound pollutions have become worsen and creating concerns for many peoples. Conventionally, expensive sound absorption materials are employed to control noise disturbances. However, recent developments on natural fibres have created interest for researchers especially for acoustics application purposes. This paper investigates the viability of coconut coir added with recycled rubber to be implemented as sound absorption panel. The composite is constructed at prescribed percentages of fillers and polyurethane as resin. The two-microphone method was applied to obtain the acoustic properties of the samples. The samples were also tested for physical properties such as density and porosity, as well as the microstructures. The results demonstrate good acoustics performances and highlight the potential of the coconut coir reinforced with recycled rubber as the sound absorption panel.

  11. Theoretical & Experimental Studies on Vibration & Damping of Fibre-Reinforced Cantilever Laminates.

    Directory of Open Access Journals (Sweden)

    M. Ganapathi

    2000-07-01

    Full Text Available In this paper, vibration and damping analyses  of glass fibre-reinforced laminated composite cantilever beams and plates are studied using C1 finite element using shear deformation theory and alsothrough experiments. The formulation in the theoretical model includes in-plane and rotary inertiaterms. The governing equations for the complex eigenvalue problem based on complex elastic moduliare formulated. The solutions are obtained using QR algorithm. Parametric study is carried out tohighlight; the effects of lay-up and ply-angle of the laminates. A limited number of experimentalinvestigafions on cantilever laminates are conducted for obtaining the natural frequenciqs, dampingfactor and frequency responses. The comparison between the theoretical and the experimfntal resultsshows good agreement.

  12. Dual energy CT inspection of a carbon fibre reinforced plastic composite combined with metal components

    Directory of Open Access Journals (Sweden)

    Daniel Vavrik

    2016-11-01

    Full Text Available This work is focused on the inspection of carbon fibre reinforced plastic composites (CFRP combined with metal components. It is well known that the high absorption of metallic parts degrades the quality of radiographic measurements (contrast and causes typical metal artefacts in X-ray computed tomography (CT reconstruction. It will be shown that these problems can be successfully solved utilizing the dual energy CT method (DECT, which is typically used for the material decomposition of complex objects. In other words, DECT can help differentiate object components with a similar overall attenuation or visualise low attenuation components that are next to high attenuation ones. The application of DECT to analyse honeycomb sandwich panels and CFRP parts joined with metal fasteners will be presented in the article.

  13. Strengthening of steel–concrete composite girders using carbon fibre reinforced polymer (CFRP) plates

    Indian Academy of Sciences (India)

    S M Mosavi; A Sadeghi Nik

    2015-02-01

    Applying composites in order to strengthen and renew the infrastructures has globally been accepted. Traditional methods to strengthen the out-of-standard structures are costly, time consuming and requires a lot of labour. Today, new techniques are hired using light and strong substances which also resist against corrosion, known as Carbon Fibre Reinforced Polymer (CFRP) plates. Regarding the high tensile strength and proper module of elasticity, CFRP plates are considered as a suitable alternative to strengthen girders. The behaviour of steel–concrete composite girders being statically loaded and strengthened by CFRP plates in this study. The CFRP plates used in this study have been stuck, with epoxy adhesive, under the tensile sections of three steel girders. The results accompanied with analytical study of moment–curvature and numerical analysis done with ANSYS, show that CFRP plates with epoxy adhesive increases the ultimate loading capacity of steel–concrete composite girder. Plastic stiffness of the girders was also increased.

  14. Development of a slim window frame made of glass fibre reinforced polyester

    DEFF Research Database (Denmark)

    Appelfeld, David; Hansen, Christian Skodborg; Svendsen, Svend

    2010-01-01

    This paper presents the development of an energy efficient window frame made of a glass fibre reinforced polyester (GFRP) material. Three frame proposals were considered. The energy and structural performances of the frames were calculated and compared with wooden and aluminium reference frames....... In order to estimate performances, detailed thermal calculations were performed in four successive steps including solar energy and light transmittance in addition to heat loss and supplemented with a simplified structural calculation of frame load capacity and deflection. Based on these calculations, we...... carried out an analysis of the potential energy savings of the frame. The calculations for a reference office building showed that the heating demand was considerably lower with a window made of GFRP than with the reference frames. It was found that GFRP is suitable for window frames, and windows made...

  15. Gliding arc surface treatment of glass fibre reinforced polyester enhanced by ultrasonic irradiation

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Singh, Shailendra Vikram; Bardenshtein, Alexander

    2010-01-01

    of approximately 150 dB were introduced vertically to the GFRP surface through a cylindrical waveguide. The water contact angle of the GFRP surface dropped markedly with no ultrasonic irradiation, and tended to decrease furthermore at higher power. Ultrasonic irradiation during the plasma treatment consistently...... onto the surface. In the present work glass fibre reinforced polyester (GFRP) plates are treated using an atmospheric pressure gliding arc discharge with and without ultrasonic irradiation to study adhesion improvement. The gliding arc was generated between divergent electrodes by utilizing...... improved the wettability. The polar component of the surface energy changed from 12 mJ m-2 to approximately 66 - 74 mJ m-2 after the gliding arc treatment, and increased by up to approximately 10 mJ m-2 with ultrasonic irradiation, but showed no significant change at different arc powers. It is seen...

  16. Effect of filler addition on the compressive and impact properties of glass fibre reinforced epoxy

    Indian Academy of Sciences (India)

    Nikhil Gupta; Balraj Singh Brar; Eyassu Woldesenbet

    2001-04-01

    Flyash is incorporated in glass fibre reinforced epoxies to study their response to the filler addition. Low cost of flyash can reduce the overall cost of the component. Only very low volume fractions of filler are investigated in the present study. To obtain further clarification of the observed phenomenon, another abundantly available low cost material, calcium carbonate is incorporated in one set of the specimens. Compressive strength of the material is found to decrease, whereas steep increase in impact strength is observed by introduction of very small quantity of fillers. Specimens containing calcium carbonate are tested for impact properties only. Effect of specimen aspect ratio on the compressive strength values is also studied by testing specimens of three different aspect ratios. Scanning electron microscopic observations are taken to develop a better understanding of the phenomena taking place in the material system at microscopic level.

  17. International RILEM Workshop on Creep Behaviour in Cracked Sections of Fibre Reinforced Concrete

    CERN Document Server

    Llano-Torre, Aitor; Cavalaro, Sergio

    2017-01-01

    This is the first publication ever focusing strictly on the creep behaviour in cracked sections of Fibre Reinforced Concrete (FRC). These proceedings contain the latest scientific papers about new testing methodologies, results and conclusions of multiple experimental campaigns and recommendations about significant factors of long-term behaviour, experiences from more than ten years of creep testing and some reflections about future perspectives on this topic. This book is an essential reference for all researchers of creep behaviour on FRC. This volume is the result of the efforts of the RILEM TC 261-CCF, that has been working since 2014 to develop standardized methodologies and guidelines to compare results from different laboratories and get a better understanding of the significant parameters related to creep of FRC.

  18. Resistance welding of carbon fibre reinforced polyetheretherketone composites using metal mesh and PEI film

    Institute of Scientific and Technical Information of China (English)

    闫久春; 王晓林; 秦明; 赵新英; 杨士勤

    2004-01-01

    Weldability of polyetheretherketone(PEEK) with polyetherimide(PEI) is tested. And carbon fiber reinforced PEEK laminates are resistance welded using stainless steel mesh heating element. The effects of the welding time and welding pressure on the lap shear strength of joints are investigated. Results show that PEEK can heal with PEI well in welding condition and the lap shear strength of PEEK/CF(carbon fibre) joint increases linearly with welding time, but reaches a maximum value when welding pressure ranging from 0.3MPa to 0.5MPa with constant welding time. The fracture characteristics of surface are analyzed by SEM techniques, and four types of fracture modes of lap shear joints are suggested.

  19. Effect of High Velocity Ballistic Impact on Pretensioned Carbon Fibre Reinforced Plastic (CFRP) Plates

    Science.gov (United States)

    Azhar KAMARUDIN, Kamarul; HAMID, Iskandar ABDUL

    2017-01-01

    This work describes an experimental investigation of the pretensioned thin plates made of Carbon Fibre Reinforced Plastic (CFRP) struck by hemispherical and blunt projectiles at various impact velocities. The experiments were done using a gas gun with combination of pretension equipment positioned at the end of gun barrel near the nozzle. Measurements of the initial and residual velocities were taken, and the ballistic limit velocity were calculated for each procedures. The pretension target results in reduction of ballistic limit compared to non-pretension target for both flat and hemispherical projectiles. Target impacted by hemispherical projectile experience split at earlier impact velocity compared to target by flat projectile. C-Scan images analysis technique was used to show target impact damaged by hemispherical and flat projectiles. The damage area was shown biggest at ballistic limit velocity and target splitting occurred most for pretention plate.

  20. Mechanical behaviour of glass fibre reinforced composite at varying strain rates

    Science.gov (United States)

    Acharya, Saikat; Mondal, D. K.; Ghosh, K. S.; Mukhopadhyay, A. K.

    2017-03-01

    Here we report the results of compressive split Hopkinson pressure bar experiments (SHPB) conducted on unidirectional glass fibre reinforced polymer (GFRP) in the strain rate regime 5  ×  102–1.3  ×  103 s‑1. The maximum compressive strength of GFRP was found to increase by as much as 55% with increase in strain rate. However, the corresponding relative strain to failure response was measured to increase only marginally with increase in strain rates. Based on the experimental results and photomicrographs obtained from FE-SEM based post mortem examinations, the failure phenomena are suggested to be associated with increase in absorption of energy from low to high strain rates. Attempts have been made to explain these observations in terms of changes in deformation mechanisms primarily as a function of strain rates.

  1. Linear and Non-linear Analysis of Fibre Reinforced Plastic Bridge Deck due to Vehicle Loads

    Science.gov (United States)

    Ray, Chaitali; Mandal, Bibekananda

    2015-06-01

    The present work deals with linear and nonlinear static analysis of fibre reinforced plastics composite bridge deck structures using the finite element method. The nonlinear static analysis has been carried out considering geometric nonlinearity. The analysis of bridge deck has been carried out under vehicle load as specified by IRC Class B wheel load classification. The formulation has been carried out using the finite element software package ANSYS 14.0 and the SHELL281 element is used to model the bridge deck. The bridge deck has also been modeled as a plate stiffened with closely spaced hollow box sections and a computer code is developed based on this formulation. The results obtained from the present formulation are compared with those available in the published literature. A parametric study on the stiffened bridge deck has also been carried out with varying dimensions of the stiffeners under vehicle loads.

  2. Mechanical, thermal and microstructural characteristics of cellulose fibre reinforced epoxy/organoclay nanocomposites

    KAUST Repository

    Alamri, H.

    2012-10-01

    Epoxy nanocomposites reinforced with recycled cellulose fibres (RCFs) and organoclay platelets (30B) have been fabricated and investigated in terms of WAXS, TEM, mechanical properties and TGA. Results indicated that mechanical properties generally increased as a result of the addition of nanoclay into the epoxy matrix. The presence of RCF significantly enhanced flexural strength, fracture toughness, impact strength and impact toughness of the composites. However, the inclusion of 1 wt.% clay into RCF/epoxy composites considerably increased the impact strength and toughness. The presence of either nanoclay or RCF accelerated the thermal degradation of neat epoxy, but at high temperature, thermal stability was enhanced with increased char residue over neat resin. The failure micromechanisms and energy dissipative processes in these nanocomposites were discussed in terms of microstructural observations. © 2012 Published by Elsevier Ltd. All rights reserved.

  3. CARBON-FIBRE-REINFORCED POLYMER PARTS EFFECT ON SPACECRAFT OPTOELECTRONIC MODULE LENS SCATTERING

    Directory of Open Access Journals (Sweden)

    S. S. Kolasha

    2016-01-01

    Full Text Available Spacecraft optoelectronic modules traditionally have aluminum alloy or titanium alloy casing which substantial weight increases fuel consumption required to put them into orbit and, consequently, total cost of the project. Carbon fiber reinforced polymer based composite constructive materials is an efficient solution that allows reducing weight and dimensions of large optoelectronic modules 1,5–3 times and the coefficient of linear thermal expansion 15–20 times if compared with metals. Optical characteristic is a crucial feature of carbon-fibre-reinforced polymer that determines composite material interaction with electromagnetic emission within the optical range. This work was intended to develop a method to evaluate Carbon fiber reinforced polymer optoelectronic modules casing effect on lens scattering by computer simulation with Zemax application software package. Degrees of scattered, reflected and absorbed radiant flux effect on imaging quality are described here. The work included experimental study in order to determine bidirectional reflectance distribution function by goniometric method for LUP-0.1 carbon fabric check test pieces of EDT-69U epoxy binder with EPOFLEX-0.4 glue layer and 5056-3.5-23-A aluminium honeycomb filler. The scattered emission was registered within a hemisphere above the check test piece surface. Optical detection direction was determined with zenith (0º < θ < 90º and azimuth (0º < φ < 180º angles with 10° increment. The check test piece surface was proved to scatter emission within a narrow angle range (approximately 20° with clear directivity. Carbon fiber reinforced polymers was found to feature integrated reflectance coefficient 3 to 4 times greater than special coatings do. 

  4. Batch experiments of Cs, Co and Eu sorption onto cement with dissolved fibre mass UP2 in the liquid phase

    Energy Technology Data Exchange (ETDEWEB)

    Holgersson, Stellan; Dubois, Isabelle; Boerstell, Lisa (Department of Chemical and Biochemical Engineering, Nuclear Chemistry, Chalmers University of Technology (Sweden))

    2011-05-15

    The potential effects of alkaline degradation products of the fibre mass UP2 on metal sorption onto fresh and degraded cement have been investigated. For this purpose, crushed cement have been leached to support material for the subsequent batch sorption experiments. Alkaline leaching of UP2 were also made, which gave leaching solutions of 30 ppm DOC after 300 days. These solutions were used in the batch experiments. Continued leaching shows that even higher concentrations can be expected: 45 ppm DOC in the leaching with a low-alkaline (pH 12.5) artificial cement pore-water and 150 ppm DOC with a high alkaline (pH 13.3) artificial pore-water. Batch sorption experiments with 134Cs and 60Co show no effects on metal sorption onto leached or fresh cement when the 30 ppm DOC leaching solutions of UP2 were used as liquid phase. The measured R{sub d} values were 10-3 m3/kg for Cs and in the range of 0.03-0.1 m3/kg for Co. Separate experiments with other organics ligands were also made: EDTA, ISA and citric acid with maximum concentrations of 500, 300 and 300 ppm DOC, respectively. Also here no effects on Cs and Co sorption onto leached and fresh cement were established. Batch experiments of 152Eu were not successful since results were above detection level of about 2-3 m3/kg. The addition of the aforementioned 30 ppm UP2 leaching solution or the other organic ligands did not affect the detection level. Measurements of background concentrations of total Eu show a peculiar result of Eu apparently increasing in batch experiments with cement to final values of about 5-10 nM. The underlying reason for this effect, whether real or artificial, could not be established. Background concentrations of Th were about 1 nM in both cement and blank samples. Background concentrations of Zr were about 100-700 nM in both cement and blank samples, the high values were measured acidic blanks, which suggests either acidic leaching from tube walls or contamination from the acid itself. No

  5. Characterization and analysis of carbon fibre-reinforced polymer composite laminates with embedded circular vasculature.

    Science.gov (United States)

    Huang, C-Y; Trask, R S; Bond, I P

    2010-08-06

    A study of the influence of embedded circular hollow vascules on structural performance of a fibre-reinforced polymer (FRP) composite laminate is presented. Incorporating such vascules will lead to multi-functional composites by bestowing functions such as self-healing and active thermal management. However, the presence of off-axis vascules leads to localized disruption to the fibre architecture, i.e. resin-rich pockets, which are regarded as internal defects and may cause stress concentrations within the structure. Engineering approaches for creating these simple vascule geometries in conventional FRP laminates are proposed and demonstrated. This study includes development of a manufacturing method for forming vascules, microscopic characterization of their effect on the laminate, finite element (FE) analysis of crack initiation and failure under load, and validation of the FE results via mechanical testing observed using high-speed photography. The failure behaviour predicted by FE modelling is in good agreement with experimental results. The reduction in compressive strength owing to the embedding of circular vascules ranges from 13 to 70 per cent, which correlates with vascule dimension.

  6. Toughening and healing of continuous fibre reinforced composites with bis-maleimide based pre-pregs

    Science.gov (United States)

    Kostopoulos, V.; Kotrotsos, A.; Tsantzalis, S.; Tsokanas, P.; Christopoulos, A. C.; Loutas, T.

    2016-08-01

    Unidirectional (UD) pre-pregs containing self-healing materials based on Diels-Alder reaction bis-maleimide (BMI) polymers were successfully incorporated on the mid-plane of UD carbon fibre reinforced polymers. The fracture toughness of these composites and the introduced healing capability were measured under mode I loading. The interlaminar fracture toughness was enhanced considerably, since the maximum load (P max) of the modified composite increased approximately 1.5 times and the mode I fracture energy (G IC) displayed a significant increase of almost 3.5 times when compared to the reference composites. Furthermore the modified composites displayed a healing efficiency (HE) value of about 30% for P max and 20% for G IC after the first healing, appearing to be an almost stable behaviour after the third healing cycle. The HE displayed a decrease of 20% and 15% for P max and G IC values, respectively, after the fifth healing cycle. During the tests, the monitored acoustic emission (AE) activity of the samples showed that there is no significant difference due to the presence of BMI polymer in terms of AE hits. Moreover, optical microscopy not only showed that the epoxy matrix at the interface is partly infiltrated by the BMI polymer, but it also revealed the presence of pulled out fibres at the fractured surface, indicating ductile behaviour.

  7. Ultrasonic, Molecular and Mechanical Testing Diagnostics in Natural Fibre Reinforced, Polymer-Stabilized Earth Blocks

    Directory of Open Access Journals (Sweden)

    C. Galán-Marín

    2013-01-01

    Full Text Available The aim of this research study was to evaluate the influence of utilising natural polymers as a form of soil stabilization, in order to assess their potential for use in building applications. Mixtures were stabilized with a natural polymer (alginate and reinforced with wool fibres in order to improve the overall compressive and flexural strength of a series of composite materials. Ultrasonic pulse velocity (UPV and mechanical strength testing techniques were then used to measure the porous properties of the manufactured natural polymer-soil composites, which were formed into earth blocks. Mechanical tests were carried out for three different clays which showed that the polymer increased the mechanical resistance of the samples to varying degrees, depending on the plasticity index of each soil. Variation in soil grain size distributions and Atterberg limits were assessed and chemical compositions were studied and compared. X-ray diffraction (XRD, X-ray fluorescence spectroscopy (XRF, and energy dispersive X-ray fluorescence (EDXRF techniques were all used in conjunction with qualitative identification of the aggregates. Ultrasonic wave propagation was found to be a useful technique for assisting in the determination of soil shrinkage characteristics and fibre-soil adherence capacity and UPV results correlated well with the measured mechanical properties.

  8. Mechanical and thermal characterisation of poly (l-lactide) composites reinforced with hemp fibres

    Science.gov (United States)

    Shakoor, A.; Muhammad, R.; Thomas, N. L.; Silberschmidt, V. V.

    2013-07-01

    Polylactic acid (PLA) is the most promising in the bio-derived polymer's family. But its use can be constrained by its poor mechanical properties, poor thermal stability and processing difficulties. The objective of this research is to investigate and improve mechanical and dynamic thermal properties of PLA by developing PLA composites reinforced with natural fibres (hemp). Composites were prepared by melt blending of PLA with hemp fibres. Their properties were investigated using mechanical and dynamic thermal analysis. The elastic modulus increased significantly - from 4.1 ± 0.74 to 9.32 ± 0.86 (GPA) - when the weight fraction of hemp increased from 0 to 30(wt %). The storage modulus obtained by dynamic mechanical analysis increased from 2.20 to 4.58 (GPA) for the same change in the volume fraction of hemp. FE simulation of tensile testing and DMA were carried out to investigate the effect of strain rate and temperature on the observed properties respectively. The model was developed in the commercially available code MSC Marc mentate. The model validated all experimental results.

  9. Recycling and Fibre Reinforcement of Thermoplastic Wastes to Produce Composites for Construction Works

    Directory of Open Access Journals (Sweden)

    P.M. Wambua

    2012-04-01

    Full Text Available Thermoplastics are among polymers that biodegrades very slowly over a very long period and can be regarded as nonbiodegradable despite their rapid accumulation in the environment. The use of plant natural fibres as reinforcement for thermoplastics to produce composites is an important area for research. In this study, composites of high density polyethylene wastes reinforced with wood flour, rice husks and bagasse fibers were prepared. The fibers were heated to reduce their moisture content and improve their compatibilities with heated high density polyethylene wastes so as to increase adhesion at the interface. Binders were used to improve interfacial strength of the composite. Composites were prepared by extrusion. From preliminary laboratory test results based on Fratios using ANOVA, optimal coupon was found to be wood flour mixed with high density polyethylene and polyurethane resin (X 17 heated to 210ºC and extruded at 140ºC. The final test results for mechanical properties for optimal wood flour, rice husks and bagasse composites respectively were: Tensile strength; 83.87, 74, and 62.73 MPa. Flexural strength; 26.73, 39and 15.22 MPa. Compressive; 225, 190.5 and 140 MPa and Impact; 78, 81 and 66 J/mm2. The use of binders significantly improved impact strengths and widely expanded the usage of such product to include light load structural applications thus offering alternative source of construction materials to supplement timber and hence save forests. The technology can create employment to thermoplastic waste collectors, fibre collectors and composite producers.

  10. Assessing the Environmental Impact of Flax Fibre Reinforced Polymer Composite from a Consequential Life Cycle Assessment Perspective

    Directory of Open Access Journals (Sweden)

    Yelin Deng

    2015-08-01

    Full Text Available The study implements the consequential life cycle assessment (CLCA to provide a market based perspective on how overall environmental impact will change when shifting glass fibres to flax fibres as reinforcements in composite fabrication. With certain assumptions, the marginal flax fibre supply is identified to be a combination of Chinese flax fibre (70% and French flax fibre (30%. Due to inferior cultivars and coal-fired electricity in Chinese flax cultivation, the CLCA study reveals that flax mat-PP has 0.8–2 times higher environmental impact values than the glass mat-PP in most environmental impact categories over the production and end-of-life (EoL phases. For purpose of providing potential trajectories of marginal flax fibre supply, additional scenarios: the “all French fibre”, and “all Chinese fibre” are evaluated formulating the lower and upper boundaries in terms of environmental impact change, respectively. A “the attributional fibre supply mix” scenario is supplied as well. All of these scenarios are useful for policy analysis.

  11. Multifunctional Cement Composites Strain and Damage Sensors Applied on Reinforced Concrete (RC Structural Elements

    Directory of Open Access Journals (Sweden)

    Pedro Garcés

    2013-03-01

    Full Text Available In this research, strain-sensing and damage-sensing functional properties of cement composites have been studied on a conventional reinforced concrete (RC beam. Carbon nanofiber (CNFCC and fiber (CFCC cement composites were used as sensors on a 4 m long RC beam. Different casting conditions (in situ or attached, service location (under tension or compression and electrical contacts (embedded or superficial were compared. Both CNFCC and CFCC were suitable as strain sensors in reversible (elastic sensing condition testing. CNFCC showed higher sensitivities (gage factor up to 191.8, while CFCC only reached gage factors values of 178.9 (tension or 49.5 (compression. Furthermore, damage-sensing tests were run, increasing the applied load progressively up to the RC beam failure. In these conditions, CNFCC sensors were also strain sensitive, but no damage sensing mechanism was detected for the strain levels achieved during the tests. Hence, these cement composites could act as strain sensors, even for severe damaged structures near to their collapse.

  12. Experimental Study of Cement Mortar-Steel Fiber Reinforced Rammed Earth Wall

    Directory of Open Access Journals (Sweden)

    Shuai Yang

    2012-10-01

    Full Text Available Rammed earth construction is an ancient technique which has recently attracted renewed interest throughout the world. Although rammed earth is currently regarded as a promising material in the construction industry in the context of sustainable development, it is difficult to quantify its bearing capacity, mechanical performance, as well as retrofitting approach, which discourages people from large-scale application in architectural engineering. This paper is devoted to the study of these problems based on rammed earth wall model experimentation. Three different models are studied considering different material components as well as structural configurations. By measuring the strain and deformation of the rammed earth wall models subjected to uniformly-distributed vertical loading, their ultimate bearing capacities are tested based on experimental investigation. Then the method of cement mortar-steel fiber reinforcement (CMSF is carried out to study the ultimate bearing capacity enhancement of the wall models. Results show that the method of cement mortar-steel fiber reinforcement can increase the ultimate bearing capacity of the rammed earth wall models significantly, which is of relevant engineering significance in practical application.

  13. The reinforcement effect of polyethylene fibre and composite impregnated glass fibre on fracture resistance of endodontically treated teeth: An in vitro study

    Directory of Open Access Journals (Sweden)

    Archana Luthria

    2012-01-01

    Full Text Available Aim: The aim of this study was to evaluate the fracture resistance of endodontically treated maxillary premolars with wide mesio-occluso-distal (MOD cavities restored with either composite resin, or composite resin reinforced with different types of fibres. Materials and Methods: Fifty human maxillary premolars were selected. Five intact teeth served as positive controls. Endodontic therapy was carried out in the remaining forty-five teeth. Standardized MOD cavities were prepared in all the teeth. The teeth were restored with a nanocomposite using an incremental technique. These forty five teeth were randomly divided into three experimental groups (Group A, B and C (n = 15. The teeth in Group A did not undergo any further procedures. The teeth in Group B and C were reinforced with composite impregnated glass fibre and polyethylene fibre, respectively. Fracture resistance was measured in Newtons (N. Results: The positive controls showed the highest mean fracture resistance (811.90 N, followed by Group B (600.49N, Group A (516.96N and Group C (514.64N, respectively. One Way analysis of variance (ANOVA test revealed a statistically significant difference between all the groups (P = 0.001. Post-hoc Tukey test revealed a moderately significant difference (P = 0.034 between Control and Group B, and a strongly significant difference between Control and Group A (P = 0.002, and Control and Group C (P = 0.001. Conclusions: Endodontic therapy and MOD cavity preparation significantly reduced the fracture resistance of endodontically treated maxillary premolars (P = 0.001. No statistically significant difference was found between the experimental groups (Group A, B and C (P > 0.1. However, the fracture resistance of the composite impregnated glass fibre reinforced group was much higher than the others.

  14. Qualitative and quantitative evaluation of chrysotile and crocidolite fibres with infrared spectrophotometry: application to asbestos-cement products.

    Science.gov (United States)

    Valerio, F; Balducci, D

    1989-01-01

    Infrared (IR) spectrophotometry allows simple and rapid qualitative and quantitative evaluations of different types of asbestos, as well as of other inorganic particles. In particular, chrysotile and crocidolite have characteristic IR spectra, and optical density measurements in the 2710 nm band for chrysotile and the 12820 nm band for crocidolite permit the quantitative evaluation of each fibre either alone or in mixtures. IR spectra also provide information on changes in fibre structure and in chemical composition as the result, for example, of thermal treatment or acid leaching. The analytical method that we have developed can detect amounts as small as 0.1 mg of fibre in a 300-mg disk of potassium bromide using a low-cost IR spectrophotometer. The use of a Fourier transform IR spectrophotometer dramatically improves the sensitivity and selectivity. Computer-assisted analysis of spectra offers the possibility of reducing matrix interference and of comparing different spectra. The application of the IR technique to asbestos-cement products and insulating materials is described.

  15. Sustained release of small molecules from carbon nanotube-reinforced monetite calcium phosphate cement.

    Science.gov (United States)

    Lin, Boren; Zhou, Huan; Leaman, Douglas W; Goel, Vijay K; Agarwal, Anand K; Bhaduri, Sarit B

    2014-10-01

    The interest in developing calcium phosphate cement (CPC) as a drug delivery system has risen because of its capability to achieve local and controlled treatment to the site of the bone disease. The purpose of this study was to investigate the release pattern of drug-carrying carboxylic acid-functionalized multi-walled carbon nanotube (MWCNT)-reinforced monetite (DCPA, CaHPO4)-based CPC. Z-Leu-Leu-Leu-al (MG132), a small peptide molecule inhibiting NF-κB-mediated osteoclastic resorption, was used as a model drug. MG132 was added into the cement during setting and released into the medium used to culture indicator cells. Significant cell death was observed in osteoblast MC3T3-E1 cells cultured in the medium incubated with MG132-loaded CPC; however, with the presence of MWCNTs in the cement, the toxic effect was not detectable. NF-κB activation was quantified using a NF-κB promoter-driving luciferase reporter in human embryonic kidney 293 cells. The medium collected after incubation with drug-incorporated CPC with or without MWCNT inhibited TNFα-induced NF-κB activation indicating that the effective amount of MG132 was released. CPC/drug complex showed a rapid release within 24h whereas incorporation of MWCNTs attenuated this burst release effect. In addition, suppression of TNFα-induced osteoclast differentiation in RAW 264.7 cell culture also confirmed the sustained release of MWCNT/CPC/drug. Our data demonstrated the drug delivery capability of this cement composite, which can potentially be used to carry therapeutic molecules to improve bone regeneration in conjunction with its fracture stabilizing function. Furthermore, it suggested a novel approach to lessen the burst release effect of the CPC-based drug delivery system by incorporating functionalized MWCNTs.

  16. Composite Strain Hardening Properties of High Performance Hybrid Fibre Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Vikram Jothi Jayakumar

    2014-01-01

    Full Text Available Hybrid fibres addition in concrete proved to be a promising method to improve the composite mechanical properties of the cementitious system. Fibre combinations involving different fibre lengths and moduli were added in high strength slag based concrete to evaluate the strain hardening properties. Influence of hybrid fibres consisting of steel and polypropylene fibres added in slag based cementitious system (50% CRL was explored. Effects of hybrid fibre addition at optimum volume fraction of 2% of steel fibres and 0.5% of PP fibres (long and short steel fibre combinations were observed in improving the postcrack strength properties of concrete. Test results also indicated that the hybrid steel fibre additions in slag based concrete consisting of short steel and polypropylene (PP fibres exhibited a the highest compressive strength of 48.56 MPa. Comparative analysis on the performance of monofibre concrete consisting of steel and PP fibres had shown lower residual strength compared to hybrid fibre combinations. Hybrid fibres consisting of long steel-PP fibres potentially improved the absolute and residual toughness properties of concrete composite up to a maximum of 94.38% compared to monofibre concrete. In addition, the relative performance levels of different hybrid fibres in improving the matrix strain hardening, postcrack toughness, and residual strength capacity of slag based concretes were evaluated systematically.

  17. Recycling solid residues recovered from glass fibre-reinforced composites – A review applied to wind turbine blade materials

    DEFF Research Database (Denmark)

    Beauson, Justine; Lilholt, Hans; Brøndsted, Povl

    2014-01-01

    to face large amount of future wind turbine (WT) blades coming to EoL. Among the EoL solutions available for WT blades, i.e. reuse, remanufacturing, recycling, incineration or disposal, this literature review focuses on recycling and particularly the recycling of shredded composite (SC) materials...... and recovered glass fibre (GF) into new polymer composite. WT blades are mainly made of glass fibre reinforced polymer (GFRP) using thermosetting resins. Shredding this material and recovering GF are possible recycling solutions for WT blade. Based on a detailed literature review, the formulations of new...

  18. Enhanced toughness and stable crack propagation in a novel tungsten fibre-reinforced tungsten composite produced by chemical vapour infiltration

    Science.gov (United States)

    Riesch, J.; Höschen, T.; Linsmeier, Ch; Wurster, S.; You, J.-H.

    2014-04-01

    Tungsten is a promising candidate for the plasma-facing components of a future fusion reactor, but its use is strongly restricted by its inherent brittleness. An innovative concept to overcome this problem is tungsten fibre-reinforced tungsten composite. In this paper we present the first mechanical test of such a composite material using a sample containing multiple fibres. The in situ fracture experiment was performed in a scanning electron microscope for close observation of the propagating crack. Stable crack propagation accompanied with rising load bearing capacity is observed. The fracture toughness is estimated using the test results and the surface observation.

  19. Effect of inter-laminar fibre orientation on the tensile properties of sisal fibre reinforced polyester composites

    Science.gov (United States)

    Senthilkumar, K.; Siva, I.; Winowlin Jappes, J. T.; Amico, S. C.; Cardona, F.; Sultan, M. T. H.

    2016-10-01

    In this present work, effects of interlamina fibre orientation on the tensile properties of composites were studied and the results were discussed. The varying types of fibre oriented composites were prepared using the compression moulding technique at a pressure of 17 MPa. The different types of oriented composites investigated were 90°/0 ° /90 °, 0 ° /90 ° /0 °, 90 ° /0 ° /0 ° /90 °, 0 ° /45 ° /0 °, 0 ° /90 ° /45 ° /45 ° /90 ° /0 °, 0 ° /45 ° /90 ° /90 ° /45 ° /0 ° and these composites were subjected to tensile testing according to ASTM: D3039-08. The sisal fibres were arranged in various angles with the help of specially designed mould. It was found that the tensile strength of sisal fibre composites improved when 0 ° oriented fibres were positioned at the extreme layers of the composites compared to 90 ° oriented fibres. The highest tensile strength among the types of composites was observed for 0 ° /90 ° /0 °. The scanning electron microscopy (SEM) analysis was performed to understand the interphase adhesion mechanism.

  20. Chopped basalt fibres: A new perspective in reinforcing poly(lactic acid to produce injection moulded engineering composites from renewable and natural resources

    Directory of Open Access Journals (Sweden)

    P. Tamas

    2013-02-01

    Full Text Available This paper focuses on the reinforcing of Poly(lactic acid with chopped basalt fibres by using silane treated and untreated basalt fibres. Composite materials with 5–10–15–20–30–40 wt% basalt fibre contents were prepared from silane sized basalt fibres using extrusion, and injection moulding, while composites with 5–10–15 wt% basalt fibre contents were also prepared by using untreated basalt fibres as control. The properties of the injection moulded composites were extensively examined by using quasi-static (tensile, three-point bending and dynamic mechanical tests (notched and unnotched Charpy impact tests, dynamic mechanical analysis (DMA, differential scanning calorimetry (DSC, heat deflection temperature (HDT analysis, dimensional stability test, as well as melt flow index (MFI analysis and scanning electron microscopic (SEM observations. It was found that silane treated chopped basalt fibres are much more effective in reinforcing Poly(lactic acid than natural fibres; although basalt fibres are not biodegradable but they are still considered as natural (can be found in nature in the form of volcanic rocks and biologically inert. It is demonstrated in this paper that by using basalt fibre reinforcement, a renewable and natural resource based composite can be produced by injection moulding with excellent mechanical properties suitable even for engineering applications. Finally it was shown that by using adequate drying of the materials, composites with higher mechanical properties can be achieved compared to literature data.

  1. Cytocompatibility and Mechanical Properties of Short Phosphate Glass Fibre Reinforced Polylactic Acid (PLA Composites: Effect of Coupling Agent Mediated Interface

    Directory of Open Access Journals (Sweden)

    Gavin Walker

    2012-10-01

    Full Text Available In this study three chemical agents Amino-propyl-triethoxy-silane (APS, sorbitol ended PLA oligomer (SPLA and Hexamethylene diisocyanate (HDI were identified to be used as coupling agents to react with the phosphate glass fibre (PGF reinforcement and the polylactic acid (PLA polymer matrix of the composite. Composites were prepared with short chopped strand fibres (l = 20 mm, ϕ = 20 µm in a random arrangement within PLA matrix. Improved, initial composite flexural strength (~20 MPa was observed for APS treated fibres, which was suggested to be due to enhanced bonding between the fibres and polymer matrix. Both APS and HDI treated fibres were suggested to be covalently linked with the PLA matrix. The hydrophobicity induced by these coupling agents (HDI, APS helped to resist hydrolysis of the interface and thus retained their mechanical properties for an extended period of time as compared to non-treated control. Approximately 70% of initial strength and 65% of initial modulus was retained by HDI treated fibre composites in contrast to the control, where only ~50% of strength and modulus was retained after 28 days of immersion in PBS at 37 °C. All coupling agent treated and control composites demonstrated good cytocompatibility which was comparable to the tissue culture polystyrene (TCP control, supporting the use of these materials as coupling agent’s within medical implant devices.

  2. Microtensile bond strength of a resin cement to glass infiltrated zirconia-reinforced ceramic: The effect of surface conditioning

    NARCIS (Netherlands)

    Amaral, R.; Ozcan, M.; Bottino, M.A.; Valandro, L.F.

    2006-01-01

    Objectives. This study evaluated the effect of three surface conditioning methods on the microtensile bond strength of resin cement to a glass-infiltrated zirconia-reinforced alumina-based core ceramic. Methods. Thirty blocks (5 x 5 x 4 mm) of In-Ceram Zirconia ceramics (In-Ceram Zirconia-INC-ZR, VI

  3. Microtensile bond strength of a resin cement to glass infiltrated zirconia-reinforced ceramic : The effect of surface conditioning

    NARCIS (Netherlands)

    Amaral, R; Ozcan, M; Bottino, MA; Valandro, LF

    2006-01-01

    Objectives. This study evaluated the effect of three surface conditioning methods on the microtensile bond strength of resin cement to a glass-infiltrated zirconia-reinforced alumina-based core ceramic. Methods. Thirty blocks (5 x 5 x 4 mm) of In-Ceram Zirconia ceramics (In-Ceram Zirconia-INC-ZR, VI

  4. Bond strength of a resin cement to high-alumina and zirconia-reinforced ceramics : The effect of surface conditioning

    NARCIS (Netherlands)

    Felipe Valandro, Luiz; Ozcan, Mutlu; Bottino, Marco Cicero; Bottino, Marco Antonio; Scotti, Roberto; Della Bona, Alvaro

    2006-01-01

    Purpose: The aim of this study was to evaluate the effect of two surface conditioning methods on the microtensile bond strength of a resin cement to three high-strength core ceramics: high alumina-based (In-Ceram Alumina, Procera AllCeram) and zirconia-reinforced alumina-based (in-Ceram Zirconia) ce

  5. Bond strength of a resin cement to high-alumina and zirconia-reinforced ceramics: The effect of surface conditioning

    NARCIS (Netherlands)

    Valandro, L.F.; Ozcan, M.; Bottino, M.C.; Bottino, M.A.; Scotti, R.; Della Bona, A.

    2006-01-01

    Purpose: The aim of this study was to evaluate the effect of two surface conditioning methods on the microtensile bond strength of a resin cement to three high-strength core ceramics: high alumina-based (In-Ceram Alumina, Procera AllCeram) and zirconia-reinforced alumina-based (in-Ceram Zirconia) ce

  6. A non-destructive test method to monitor corrosion products and corrosion-induced cracking in reinforced cement based materials

    DEFF Research Database (Denmark)

    Michel, Alexander; Pease, Bradley Justin; Peterova, Adela;

    2011-01-01

    ) was conducted to describe the impact of water-to-cement ratio and corrosion current density (i.e., corrosion rate) on the reinforcement corrosion process. Focus was placed, in particular on the determination of the corrosion accommodating region (CAR) and time to corrosion-induced cracking. Experimental results...

  7. Microtensile bond strength of a resin cement to glass infiltrated zirconia-reinforced ceramic : The effect of surface conditioning

    NARCIS (Netherlands)

    Amaral, R; Ozcan, M; Bottino, MA; Valandro, LF

    Objectives. This study evaluated the effect of three surface conditioning methods on the microtensile bond strength of resin cement to a glass-infiltrated zirconia-reinforced alumina-based core ceramic. Methods. Thirty blocks (5 x 5 x 4 mm) of In-Ceram Zirconia ceramics (In-Ceram Zirconia-INC-ZR,

  8. Microtensile bond strength of a resin cement to glass infiltrated zirconia-reinforced ceramic: The effect of surface conditioning

    NARCIS (Netherlands)

    Amaral, R.; Ozcan, M.; Bottino, M.A.; Valandro, L.F.

    2006-01-01

    Objectives. This study evaluated the effect of three surface conditioning methods on the microtensile bond strength of resin cement to a glass-infiltrated zirconia-reinforced alumina-based core ceramic. Methods. Thirty blocks (5 x 5 x 4 mm) of In-Ceram Zirconia ceramics (In-Ceram Zirconia-INC-ZR,

  9. Bond strength of a resin cement to high-alumina and zirconia-reinforced ceramics: The effect of surface conditioning

    NARCIS (Netherlands)

    Valandro, L.F.; Ozcan, M.; Bottino, M.C.; Bottino, M.A.; Scotti, R.; Della Bona, A.

    2006-01-01

    Purpose: The aim of this study was to evaluate the effect of two surface conditioning methods on the microtensile bond strength of a resin cement to three high-strength core ceramics: high alumina-based (In-Ceram Alumina, Procera AllCeram) and zirconia-reinforced alumina-based (in-Ceram Zirconia)

  10. Enhanced mechanical properties of a novel, injectable, fiber-reinforced brushite cement.

    Science.gov (United States)

    Maenz, Stefan; Kunisch, Elke; Mühlstädt, Mike; Böhm, Anne; Kopsch, Victoria; Bossert, Jörg; Kinne, Raimund W; Jandt, Klaus D

    2014-11-01

    Injectable, brushite-forming calcium phosphate cements (CPCs) have great potential as bone replacement materials due to enhanced degradability and long-term inclusion in bone remodeling. However, the use of such brushite-forming CPCs in load-bearing areas is limited by their low mechanical strength. One approach to overcome this limitation is the use of reinforcing fibers. Thus, an injectable, biodegradable, brushite-forming CPC based on beta-tricalcium phosphate/phosphoric acid with fiber reinforcement was developed for minimally invasive surgery. The fibers (diameter 25 µm; length 0.25, 1 or 2mm) were extruded from poly(l-lactide-co-glycolide) acid (PLGA) and added to the CPC (2.5, 5 or 7.5% (w/w)). Independent of the fiber content, injectability of the CPC was retained up to a fiber length of 1mm. The addition of all PLGA fiber types increased diametral tensile strength, biaxial flexural strength, and flexural strength by up to 25% (p ≤ 0.05 for the diametral tensile strength for the CPC with 5% (w/w) 1mm fibers and the biaxial flexural strength of the CPC with 5% (w/w) 0.25 mm fibers). In contrast, the work of fracture strongly and significantly increased (pfiber content, the mechanical properties of the fiber-reinforced CPC were mostly augmented with increasing fiber length. Also, the addition of PLGA fibers to the brushite-forming CPC (up to 7.5% (w/w)) only transiently delayed cell growth and did not decrease cell viability. Fiber reinforcement of CPCs thus augments their mechanical strength while preserving the injectability and biocompatibility required for their application in modern surgery.

  11. Vibration strength of squeeze cast aluminium components with and without fibre reinforcement. Pt. 1. Schwingfestigkeit von fluessiggepressten Aluminiumbauteilen mit und ohne Faserverstaerkung. T. 1

    Energy Technology Data Exchange (ETDEWEB)

    Heuler, P. (Industrieanlagen-Betriebsgesellschaft mbH (IABG), Ottobrunn (Germany))

    1992-05-01

    The essentials of squeeze casting and spects of light metal reinforcement with ceramic fibres are described. A vehicle chassis component and disks cast separately for material sampling are used to discuss strength properties of squeeze cast components with and without fibre reinforcement. It was shown that for technological reasons it is not possible to assume that strength properties of a material sample apply to the component as well. (orig.).

  12. SH-Wave at a Plane Interface between Homogeneous and Inhomogeneous Fibre-Reinforced Elastic Half-Spaces

    Directory of Open Access Journals (Sweden)

    C. Zorammuana

    2015-01-01

    Full Text Available The problem of reflection and refraction of SH-waves at a plane interface between the homogeneous and inhomogeneous fibre-reinforced elastic half-spaces has been investigated. Amplitude and energy ratios corresponding to the reflected and refracted SH-waves are derived using appropriate boundary conditions. These ratios are computed numerically for a particular model and the results are depicted graphically.

  13. Effect of pMDI isocyanate additive on mechanical and thermal properties of Kenaf fibre reinforced thermoplastic polyurethane composites

    Indian Academy of Sciences (India)

    Y A El-Shekeil; S M Sapuan; K Abdan; E S Zainudin; O M Al-Shuja’a

    2012-12-01

    The effect of polymeric methylene diphenyl diisocyanate (pMDI) on mechanical and thermal properties of Kenaf fibre (KF) reinforced thermoplastic polyurethane (TPU) composites was studied. Various percentages viz. 2%, 4% and 6%, were studied. The composites were characterized by using tensile testing, thermogravimetric analysis (TG), differential scanning calorimetry (DSC) and fourier transform infrared spectroscopy (FTIR). It was noticed that the addition of pMDI 2%, 4%and 6% did not induce a better tensile nor thermal properties.

  14. Adsorption of dyes by ACs prepared from waste tyre reinforcing fibre. Effect of texture, surface chemistry and pH.

    Science.gov (United States)

    Acevedo, Beatriz; Rocha, Raquel P; Pereira, Manuel F R; Figueiredo, José L; Barriocanal, Carmen

    2015-12-01

    This paper compares the importance of the texture and surface chemistry of waste tyre activated carbons in the adsorption of commercial dyes. The adsorption of two commercial dyes, Basic Astrazon Yellow 7GLL and Reactive Rifafix Red 3BN on activated carbons made up of reinforcing fibres from tyre waste and low-rank bituminous coal was studied. The surface chemistry of activated carbons was modified by means of HCl-HNO3 treatment in order to increase the number of functional groups. Moreover, the influence of the pH on the process was also studied, this factor being of great importance due to the amphoteric characteristics of activated carbons. The activated carbons made with reinforcing fibre and coal had the highest SBET, but the reinforcing fibre activated carbon samples had the highest mesopore volume. The texture of the activated carbons was not modified upon acid oxidation treatment, unlike their surface chemistry which underwent considerable modification. The activated carbons made with a mixture of reinforcing fibre and coal experienced the largest degree of oxidation, and so had more acid surface groups. The adsorption of reactive dye was governed by the mesoporous volume, whilst surface chemistry played only a secondary role. However, the surface chemistry of the activated carbons and dispersive interactions played a key role in the adsorption of the basic dye. The adsorption of the reactive dye was more favored in a solution of pH 2, whereas the basic dye was adsorbed more easily in a solution of pH 12. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Effects of Rotation and Gravity Field on Surface Waves in Fibre-Reinforced Thermoelastic Media under Four Theories

    Directory of Open Access Journals (Sweden)

    A. M. Abd-Alla

    2013-01-01

    Full Text Available Estimation is done to investigate the gravitational and rotational parameters effects on surface waves in fibre-reinforced thermoelastic media. The theory of generalized surface waves has been firstly developed and then it has been employed to investigate particular cases of waves, namely, Stoneley waves, Rayleigh waves, and Love waves. The analytical expressions for surface waves velocity and attenuation coefficient are obtained in the physical domain by using the harmonic vibrations and four thermoelastic theories. The wave velocity equations have been obtained in different cases. The numerical results are given for equation of coupled thermoelastic theory (C-T, Lord-Shulman theory (L-S, Green-Lindsay theory (G-L, and the linearized (G-N theory of type II. Comparison was made with the results obtained in the presence and absence of gravity, rotation, and parameters for fibre-reinforced of the material media. The results obtained are displayed by graphs to clear the phenomena physical meaning. The results indicate that the effect of gravity, rotation, relaxation times, and parameters of fibre-reinforced of the material medium is very pronounced.

  16. Mechanical properties and fire retardancy of bidirectional reinforced composite based on biodegradable starch resin and basalt fibres

    Directory of Open Access Journals (Sweden)

    2008-11-01

    Full Text Available Environmental problems caused by extensive use of polymeric materials arise mainly due to lack of landfill space and depletion of finite natural resources of fossil raw materials, such as petroleum or natural gas. The substitution of synthetic petroleum-based resins with natural biodegradable resins appears to be one appropriate measure to remedy the above-mentioned situation. This study presents the development of a composite that uses environmentally degradable starch-based resin as matrix and basalt fibre plain fabric as reinforcement. Prepreg sheets were manufactured by means of a modified doctor blade system and a hot power press. The sheets were used to manufacture bidirectional-reinforced specimens with fibre volume contents ranging from 33 to 61%. Specimens were tested for tensile and flexural strength, and exhibited values of up to 373 and 122 MPa, respectively. Through application of silane coupling agents to the reinforcement fibres, the flexural composite properties were subsequently improved by as much as 38%. Finally, in order to enhance the fire retardancy and hence the applicability of the composite, fire retardants were applied to the resin, and their effectiveness was tested by means of flame rating (according to UL 94 and thermogravimetric analysis (TGA, respectively.

  17. Comparison of traditional field retting and Phlebia radiata Cel 26 retting of hemp fibres for fibre-reinforced composites

    DEFF Research Database (Denmark)

    Liu, Ming; Ale, Marcel Tutor; Kołaczkowski, Bartłomiej

    2017-01-01

    Classical field retting and controlled fungal retting of hemp using Phlebia radiata Cel 26 (a mutant with low cellulose degrading ability) were compared with pure pectinase treatment with regard to mechanical properties of the produced fibre/epoxy composites. For field retting a classification...... was obtained using P. radiata Cel 26 compared to 248 MPa with field retting....

  18. Average Frequency – RA Value for Reinforced Concrete Beam Strengthened with Carbon Fibre Sheet

    Directory of Open Access Journals (Sweden)

    Mohamad M. Z.

    2016-01-01

    Full Text Available Acoustic Emission (AE is one of the tools that can be used to detect the crack and to classify the type of the crack of reinforced concrete (RC structure. Dislocation or movement of the material inside the RC may release the transient elastic wave. In this situation, AE plays important role whereby it can be used to capture the transient elastic wave and convert it into AE parameters such as amplitude, count, rise time and duration. Certain parameter can be used directly to evaluate the crack behavior. But in certain cases, the AE parameter needs to add and calculate by using related formula in order to observe the behavior of the crack. Using analysis of average frequency and RA value, the crack can be classified into tensile or shear cracks. In this study, seven phases of increasing static load were used to observe the crack behavior. The beams were tested in two conditions. For the first condition, the beams were tested in original stated without strengthened with carbon fibre sheet (CFS at the bottom of the beam or called as tension part of the beam. For the second condition, the beams were strengthened with CFS at the tension part of the beam. It was found that, beam wrapped with CFS enhanced the strength of the beams in term of maximum ultimate load. Based on the relationship between average frequency (AF and RA value, the cracks of the beams can be classified.

  19. Thermo-Mechanical Behaviour of Flax-Fibre Reinforced Epoxy Laminates for Industrial Applications

    Directory of Open Access Journals (Sweden)

    Giuseppe Pitarresi

    2015-11-01

    Full Text Available The present work describes the experimental mechanical characterisation of a natural flax fibre reinforced epoxy polymer composite. A commercial plain woven quasi-unidirectional flax fabric with spun-twisted yarns is employed in particular, as well as unidirectional composite panels manufactured with three techniques: hand-lay-up, vacuum bagging and resin infusion. The stiffness and strength behaviours are investigated under both monotonic and low-cycle fatigue loadings. The analysed material has, in particular, shown a typical bilinear behaviour under pure traction, with a knee yield point occurring at a rather low stress value, after which the material tensile stiffness is significantly reduced. In the present work, such a mechanism is investigated by a phenomenological approach, performing periodical loading/unloading cycles, and repeating tensile tests on previously “yielded” samples to assess the evolution of stiffness behaviour. Infrared thermography is also employed to measure the temperature of specimens during monotonic and cyclic loading. In the first case, the thermal signal is monitored to correlate departures from the thermoelastic behaviour with the onset of energy loss mechanisms. In the case of cyclic loading, the thermoelastic signal and the second harmonic component are both determined in order to investigate the extent of elastic behaviour of the material.

  20. Flame Retardancy of Carbon Fibre Reinforced Sorbitol Based Bioepoxy Composites with Phosphorus-Containing Additives

    Directory of Open Access Journals (Sweden)

    Andrea Toldy

    2017-04-01

    Full Text Available Carbon fibre reinforced flame-retarded bioepoxy composites were prepared from commercially available sorbitol polyglycidyl ether (SPE cured with cycloaliphatic amine hardener. Samples containing 1, 2, and 3% phosphorus (P were prepared using additive type flame retardants (FRs resorcinol bis(diphenyl phosphate (RDP, ammonium polyphosphate (APP, and their combinations. The fire performance of the composites was investigated by limiting oxygen index (LOI, UL-94 tests, and mass loss calorimetry. The effect of FRs on the glass transition temperature, and storage modulus was evaluated by dynamic mechanical analysis (DMA, while the mechanical performance was investigated by tensile, bending, and interlaminar shear measurements, as well as by Charpy impact test. In formulations containing both FRs, the presence of RDP, acting mainly in gas phase, ensured balanced gas and solid-phase mechanism leading to best overall fire performance. APP advantageously compensated the plasticizing (storage modulus and glass transition temperature decreasing effect of RDP in combined formulations; furthermore, it led to increased tensile strength and Charpy impact energy.

  1. A composite-appropriate integration method of thick functional components in fibre-reinforced plastics

    Science.gov (United States)

    Filippatos, A.; Höhne, R.; Kliem, M.; Gude, M.

    2016-03-01

    The use of integrated structural health monitoring systems for critical composite parts, such as wind turbine blades, fuselage and wing parts, is an promising approach to guarantee a safe and efficient operational lifetime of such components. Therefore, the integration of thick functional components like sensors, actuators and electronic components is often necessary. An optimal integration of such components should be ensured without material imperfections in the composite structure, i.e. voids and resin rich areas, and failure of the functional components. In this paper, first investigations were undertaken for a basic understanding of the mechanical performance of a fibre reinforced plastic component with integrated functional elements. The influence of different materials and treatment methods for the encapsulation of electronic components was experimentally investigated under static and dynamic loading tests. By means of a parametric finite element model, the effects of an encapsulation and various parameters such as the shape and orientation of the electronic components were examined. Several encapsulation variants were investigated in order to minimise the chance of failure initiations. Based both on experimental and numerical results, a preferred composite integration concept was selected for an electronic board and some first recommendations for an optimal integration were derived.

  2. Graphite Nanoplatelet Modified Epoxy Resin for Carbon Fibre Reinforced Plastics with Enhanced Properties

    Directory of Open Access Journals (Sweden)

    Yan Li

    2017-01-01

    Full Text Available A simple approach to deliver graphene or graphite nanoplatelets (GNPs into carbon fibre reinforced plastic (CFRPs to enhance the multifunctional properties of carbon/epoxy laminates was demonstrated. GNPs improved the typically low interlaminar mechanical, thermal, and electrical properties of CFRPs after direct vacuum infusion of GNP doped resin obtained via in situ exfoliation by three-roll milling (TRM. Compared to high shear mixing or probe ultrasonication, TRM produces higher shear rates and stresses to exfoliate and finely disperse GNP particles within an epoxy matrix. This environmentally friendly and industrial scalable process does not require the use of solvents, additives, or chemical treatments. The flexural modulus and interlaminar shear strength (ILSS of CFRPs was increased by 15% and by 18%, respectively, with the addition of 5 wt.% in situ exfoliated GNP in the doped epoxy resin. Out-of-plane electrical and thermal conductivity, at the same filler content, were, respectively, improved by nearly two orders of magnitude and 50%.

  3. Asset Management Business Model for Design, Realization, and Maintenance of Fibre Reinforced Polymer Bridges

    Directory of Open Access Journals (Sweden)

    Rizal Sebastian

    2013-01-01

    Full Text Available This paper particularly addresses the market implementation of Fibre Reinforced Polymer (FRP for bridges. It presents the concept of demand and supply chain innovation as being investigated within two ongoing European collaborative research projects (FP7 titled Trans-IND and PANTURA. FRP has emerged as a real alternative structural material based on various sustainability considerations, among others the reduced life-cycle cost due to less maintenance needs, longer lifetime, and easiness to repair, replace, or recycle the components. The Trans-IND research project aims to develop and demonstrate new industrialized processes to use FRP for civil infrastructure projects at a large scale. In order to be cost effective, a new value-chain strategy for the design, realization, and maintenance of FRP bridges is required to replace the fragmented supply chain and the one-off approach to a construction project. This paper focuses on the development of new business models based on asset management strategy, which covers the entire demand and supply chains. Research on new business models is supported by the insight into the market and regulatory frameworks in different EU countries. This is based on field surveys across the EU that have been carried out as a part of the Trans-IND and PANTURA collaborative research projects.

  4. FLOAT - development of new flexible UHPC. Final report. [Ultra High Performance Fibre Reinforced Concrete

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    The current project is a preliminary study intended to clarify the background and give a better basis for an evaluation of the risks and possible rewards of funding a full project with the overall purpose of developing and testing a new concept for wave energy floaters, made of Ultra High Performance Fibre Reinforced Concrete (UHPC), as an enabling technology for the establishment of competitive wave energy production (FLOAT). As an initial step for this preliminary study of FLOAT an investigation has been undertaken in relation to preliminary design of 2 types of floaters, essential properties of UHPFRC - and identification of necessary developments, compilation of existing data from off shore applications and analysis of effect on Cost Of Energy. Preliminary float design and economical considerations - is a theoretical and numerical study including preliminary float designs and cost estimates. It aims at making a first comparison between the different materials options for DEXA and Wave Star floats and giving a first judgement about the suitability of CRC concrete. This is done through a qualitative assessment of pros and cons of different materials for both types of floats and a design study of the Dexa Wave float. It is concluded that the requirements for the Dexa Wave float are so that CRC is not able to compete with conventional concrete for the best and most cost effective solution. The good durability (leading to low maintenance costs), the mechanical properties and the ductility of CRC are not important enough to offset the increased cost for this float. For Wave Star on the other hand, there are significant advantages in using CRC as the only other option in this case is fibre glass, which is a much more expensive product. An investigation was made of methods of optimizing the properties of CRC - customizing them for particular applications in WEC's. The method of optimization has been to change the types of fibres in the mix, and it is demonstrated

  5. Assessment of thermal shock induced damage in silicon carbide fibre reinforced glass matrix composites

    Directory of Open Access Journals (Sweden)

    Boccaccini, A. R.

    1998-09-01

    Full Text Available The development of microstructural damage in silicon carbide fibre (Nicalon™ reinforced glass matrix composite samples subjected to thermal shock was investigated by using a nondestructive forced resonance technique and fibre push out indentation tests. Thermal shock testing involved quenching samples in a water bath maintained at room temperature from a high temperature (650ºC. Changes in the Young's modulus and internal friction of the samples with increasing number of shocks were measured accurately by the forced resonance technique. Fibre push-out tests showed no significant changes in the properties of the fibre-matrix interface, indicating that damage in the composite was concentrated mainly in the development of matrix microcracking. It was also shown that the internal friction is a very sensitive parameter by which to detect the onset and development of such microcracking. A simple semi-empirical model is proposed to correlate the internal friction level with the microcracking density in the glass matrix. Finally, the relevance of detecting nondestructively the existence of microcracks in the glass matrix, before any significant interfacial degradation occurs, is emphasized, in conextion with the possibility of inducing a crack healing process by a thermal treatment (annealing, taking advantage of the viscous flow properties of the glass.

    El desarrollo de daño microestructural en materiales compuestos de matriz de vidrio reforzados con fibras de carburo de silicio (Nicalon™ sometidos a choque térmico fue investigado mediante la técnica no-destructiva de resonancia forzada y por mediciones de indentación "push-out" de fibras. Los ensayos de choque térmico involucraron el enfriamiento brusco en un baño de agua a temperatura ambiente de las piezas previamente calentadas a una temperatura elevada (650ºC. La técnica de resonancia forzada permitió medir cambios en el módulo de Young de elasticidad y en la fricci

  6. Effect of sewage wastes on the physico-mechanical properties of cement and reinforced steel

    Directory of Open Access Journals (Sweden)

    Magdy A. Abd El-Aziz

    2013-09-01

    Full Text Available The aggressive chemical attack due to salt water is one of many factors affecting the concrete deterioration. This effect includes corrosion of concrete and steel due to the exposure to the aggressive natural or artificial chemicals such as ammonia and ammonium salts. Ammonia is one of the compounds substantially in each of the remnants of sanitation plants, industrial or service of some units within building industrial waste. This work aims to study the effect of different concentrations of ammonia in the popular image on the physical, chemical and mechanical properties of different types of cement such as SRC; OPC and HSC. The electrochemical measurement (linear polarization systems as well as infrared spectroscopy (IR were used in this study. The behaviour of reinforced steel embedded in SRC; OPC and HSC with (5 wt.% ammonium sulphate solution were determined. The results show that ammonia gets a harmful effect on OPC and SRC mortars but HSC shows high resistivity. Also, the reinforced steel is greatly affected in the aggressive medium containing ammonium solution.

  7. Structure and properties of a pulp fibre-reinforced composite with regenerated cellulose matrix

    Science.gov (United States)

    Gindl, W.; Schöberl, T.; Keckes, J.

    2006-04-01

    Fully bio-based cellulose cellulose composites were produced by partly dissolving beech pulp fibres in lithium chloride/dimethylacetamide (LiCl/DMAc) and subsequent regeneration of matrix cellulose in the presence of undissolved fibres. Compared to cellulose epoxy composites produced from the same fibres, a two-fold increase in tensile strength and elastic modulus was observed for cellulose cellulose composites. From scanning electron microscopy and nanoindentation it is concluded that changes in the fibre cell wall during LiCl/DMAc treatment, improved matrix properties of regenerated cellulose compared to epoxy, and improved fibre matrix adhesion are responsible for the superior properties of cellulose cellulose composites.

  8. The reinforcement and healing of asphalt mastic mixtures by rejuvenator encapsulation in alginate compartmented fibres

    Science.gov (United States)

    Tabaković, A.; Post, W.; Cantero, D.; Copuroglu, O.; Garcia, S. J.; Schlangen, E.

    2016-08-01

    This paper explores the potential use of compartmented alginate fibres as a new method of incorporating rejuvenators into asphalt pavement mixtures. The compartmented fibres are employed to locally distribute the rejuvenator and to overcome the problems associated with spherical capsules and hollow fibres. The work presents proof of concept of the encapsulation process which involved embedding the fibres into the asphalt mastic mixture and the survival rate of fibres in the asphalt mixture. To prove the effectiveness of the alginate as a rejuvenator encapsulating material and to demonstrate its ability survive asphalt production process, the fibres containing the rejuvenator were prepared and subjected to thermogravimetric analysis and uniaxial tensile test. The test results demonstrated that fibres have suitable thermal and mechanical strength to survive the asphalt mixing and compaction process. The CT scan of an asphalt mortar mix containing fibres demonstrated that fibres are present in the mix in their full length, undamaged, providing confirmation that the fibres survived the asphalt production process. In order to investigate the fibres physiological properties and ability to release the rejuvenator into cracks in the asphalt mastic, the environmental scanning electron microscope and optical microscope analysis were employed. To prove its success as an asphalt healing system, compartmented alginate fibres containing rejuvenator were embedded in asphalt mastic mix. The three point bend tests were performed on the asphalt mastic test samples and the degree to which the samples began to self-heal in response was measured and quantified. The research findings indicate that alginate fibres present a promising new approach for the development of self-healing asphalt pavement systems.

  9. Silicon ceramic reinforced by endless fibres on liquid matrix precursor (with commercial C and SiC fibres); Endlosfaser-verstaerkte Siliciumkeramik aus fluessigem Matrixprecursor (mit kommerziellen C- und SiC-Fasern)

    Energy Technology Data Exchange (ETDEWEB)

    Nieder, D.

    1991-12-13

    In this work, the possibilities of manufacture of very strong or non-brittle fracturing silicon carbide/nitride compound bodies were examined using endless ceramic fibres and liquid silazane as matrix precursor. The experiments for the selection of the different reinforcement fibres showed the good suitability of high strength C fibres HT-7 (Toho). The high module fibres HM-12 (Sigri) and the intermediate fibre T800 (Toray) were used for comparison, without reaching the same values for the compound body properties as with the high strength fibre HT-7. However, typical differences were clearly shown in the reinforcement behaviour of the high strength and high module fibres, althoug the individual types of fibres originated from different manufacturing firms. (orig.) [Deutsch] In der Arbeit wurden Herstellungsmoeglichkeiten fuer hochfeste, bzw. nicht sproedbrechende Siliciumcarbid/-nitrid-Verbundkoerper unter Verwendung keramischer Endlos-Fasern sowie fluessiger Silazane als Matrix-Precursor untersucht. Die Versuche zur Auswahl der verschiedenen Verstaerkungsfasern ergaben eine gute Eignung der Hochfest-C-Faser HT-7 (Toho). Die Hochmodulfaser HM-12 (Sigri) und die Intermediatefaser T800 (Toray) wurden fuer Vergleichszwecke eingesetzt, ohne dass mit diesen die Werte fuer die Verbundkoerpereigenschaften wie mit der Hochfestfaser HT-7 erreicht wurden. Es kamen jedoch die typischen Unterschiede im Verstaerkungsverhalten der Hochfest- und Hochmodul-Fasern deutlich zum Ausdruck, obwohl die einzelnen Fasertypen von unterschiedlichen Herstellerfirmen stammten. (orig.)

  10. Dental glass ionomer cement reinforced by cellulose microfibers and cellulose nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Rafael M. [Departamento de Odontologia, Universidade Federal do Vale do Jequitinhonha e Mucuri, UFVJM, Diamantina CEP: 39100-000, MG (Brazil); Centro Avançado de Avaliação e Desenvolvimento de Biomateriais, BioMat, Universidade Federal do Vale do Jequitinhonha e Mucuri, UFVJM, Diamantina CEP: 39100-000, MG (Brazil); Pereira, Fabiano V., E-mail: fabianovp@ufmg.br [Departamento de Química, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte CEP: 31270-901, MG (Brazil); Mota, Felipe A.P. [Centro Avançado de Avaliação e Desenvolvimento de Biomateriais, BioMat, Universidade Federal do Vale do Jequitinhonha e Mucuri, UFVJM, Diamantina CEP: 39100-000, MG (Brazil); Watanabe, Evandro [Departamento de Odontologia Restauradora, Faculdade de Odontologia de Ribeirão Preto, USP, Ribeirão Preto CEP: 14040-904, SP (Brazil); Soares, Suelleng M.C.S. [Departamento de Odontologia, Universidade Federal do Vale do Jequitinhonha e Mucuri, UFVJM, Diamantina CEP: 39100-000, MG (Brazil); Santos, Maria Helena [Departamento de Odontologia, Universidade Federal do Vale do Jequitinhonha e Mucuri, UFVJM, Diamantina CEP: 39100-000, MG (Brazil); Centro Avançado de Avaliação e Desenvolvimento de Biomateriais, BioMat, Universidade Federal do Vale do Jequitinhonha e Mucuri, UFVJM, Diamantina CEP: 39100-000, MG (Brazil)

    2016-01-01

    The aim of this work was to evaluate if the addition of cellulose microfibers (CmF) or cellulose nanocrystals (CNC) would improve the mechanical properties of a commercial dental glass ionomer cement (GIC). Different amounts of CmF and CNC were previously prepared and then added to reinforce the GIC matrix while it was being manipulated. Test specimens with various concentrations of CmF or CNC in their total masses were fabricated and submitted to mechanical tests (to evaluate their compressive and diametral tensile strength, modulus, surface microhardness and wear resistance) and characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). The incorporation of CmF in the GIC matrix did not greatly improve the mechanical properties of GIC. However, the addition of a small amount of CNC in the GIC led to significant improvements in all of the mechanical properties evaluated: compressive strength (increased up to 110% compared with the control group), elastic modulus increased by 161%, diametral tensile strength increased by 53%, and the mass loss decreased from 10.95 to 3.87%. Because the composites presented a considerable increase in mechanical properties, the modification of the conventional GIC with CNC can represent a new and promising dental restorative material. - Highlights: • Cellulose microfibers (CmF) and cellulose nanocrystals (CNC) were prepared. • The CmF and CNC were incorporated in commercial dental glass ionomer cement (GIC). • Small amount of CNC improved significantly all the mechanical properties evaluated. • Modified GIC with CNC can represent a new and promising dental restorative material.

  11. An experimental study of non-destructive testing on glass fibre reinforced polymer composites after high velocity impact event

    Science.gov (United States)

    Razali, N.; Sultan, M. T. H.; Cardona, F.

    2016-10-01

    A non-destructive testing method on Glass Fibre Reinforced Polymer (GFRP) after high velocity impact event using single stage gas gun (SSGG) is presented. Specimens of C- type and E-type fibreglass reinforcement, which were fabricated with 6mm, 8mm, 10mm and 12mm thicknesses and size 100 mm x 100 mm, were subjected to a high velocity impact with three types of bullets: conical, hemispherical and blunt at various gas gun pressure levels from 6 bar to 60 bar. Visual observation techniques using a lab microscope were used to determine the infringed damage by looking at the crack zone. Dye penetrants were used to inspect the area of damage, and to evaluate internal and external damages on the specimens after impact. The results from visual analysis of the impacted test laminates were discussed and presented. It was found that the impact damage started with induced delamination, fibre cracking and then failure, simultaneously with matrix cracking and breakage, and finally followed by the fibres pulled out. C-type experienced more damaged areas compared to E-type of GFRP.

  12. Mechanical and thermal properties of water glass coated sisal fibre-reinforced polypropylene composite

    CSIR Research Space (South Africa)

    Phiri, G

    2012-10-01

    Full Text Available ?C). Figure 1 shows the processing steps followed to produce composite samples. Up to 15% fibre loading could be achieved and the sisal fibres were coated with water glass to improve fire resistance. In order to improve the adhesion between sisal... preparation process: (A) WG coated fibre, (B) High speed granulator, (C) Composite granules, (D) Single screw extruder, (E) Injection moulder and (F) Composite samples (dumbbells) Mechanical and thermal properties of water glass coated sisal fi bre...

  13. Self-healing of damage in fibre-reinforced polymer-matrix composites.

    Science.gov (United States)

    Hayes, S A; Zhang, W; Branthwaite, M; Jones, F R

    2007-04-22

    Self-healing resin systems have been discussed for over a decade and four different technologies had been proposed. However, little work on their application as composite matrices has been published although this was one of the stated aims of the earliest work in the field. This paper reports on the optimization of a solid-state self-healing resin system and its subsequent use as a matrix for high volume fraction glass fibre-reinforced composites. The resin system was optimized using Charpy impact testing and repeated healing, while the efficiency of healing in composites was determined by analysing the growth of delaminations following repeated impacts with or without a healing cycle. To act as a reference, a non-healing resin system was subjected to the same treatments and the results are compared with the healable system. The optimized resin system displays a healing efficiency of 65% after the first healing cycle, dropping to 35 and 30% after the second and third healing cycles, respectively. Correction for any healability due to further curing showed that approximately 50% healing efficiency could be achieved with the bisphenol A-based epoxy resin containing 7.5% of polybisphenol-A-co-epichlorohydrin. The composite, on the other hand, displays a healing efficiency of approximately 30%. It is therefore clear that the solid-state self-healing system is capable of healing transverse cracks and delaminations in a composite, but that more work is needed to optimize matrix healing within a composite and to develop a methodology for assessing recovery in performance.

  14. Short fibre-reinforced composite for extensive direct restorations: a laboratory and computational assessment.

    Science.gov (United States)

    Barreto, Bruno Castro Ferreira; Van Ende, Annelies; Lise, Diogo Pedrollo; Noritomi, Pedro Yoshito; Jaecques, Siegfried; Sloten, Jos Vander; De Munck, Jan; Van Meerbeek, Bart

    2016-06-01

    The objective of the study was to evaluate the effectiveness of a short fibre-reinforced composite (FRC) applied in combination with a conventional filler composite (CFC) on the fatigue resistance, fracture strength, failure mode and stress distribution, for restorations of premolars under two loading angles. Thirty-two inferior premolars received extensive cavities with removal of the lingual cusp. Teeth were restored directly using 'FRC (EverX Posterior, GC) + CFC (G-aenial, GC)' or 'CFC only' and received two fatigue/fracture loadings at two different angles (0°/45°) (n = 8). Data were submitted to two-way ANOVA (α = 5 %) and Tukey test. Failure mode was analysed using SEM. Four 3D finite element (FE) models were constructed and static, linear and elastic analyses were performed. Maximum principal and von Mises stresses were evaluated. All specimens survived the mechanical fatigue simulation. No statistical difference in fracture resistance was recorded between FRC + CFC and CFC only, considering both loading angles (p = 0.115). However, the 0° loading showed a statistical significant higher strength than the 45° loading (p = 0.000). Failure mode analysis revealed more repairable fractures upon 0° loading, versus more root fractures (unrepairable) upon 45° loading. FE revealed a higher amount of stress upon 45° loading, with tensile stress being imposed to the lingual cervical area. The fracture strength was not increased using the FRC. Loading at a 45° decreased significantly the fracture resistance. The restoration of extensive cavities in posterior tooth is a challenge for the clinicians and the choice of the material that increases the fracture strength of tooth-restoration complex is required.

  15. Concrete laterally confined with fibre-reinforced polymers (FRP: experimental study and theoretical model

    Directory of Open Access Journals (Sweden)

    Casas, J. R.

    2010-02-01

    Full Text Available This paper presents the findings of an experimental and analytical study of concrete cylinder behaviour when wrapped in fibreglass or carbon fibre-reinforced polymers (FRP. Compression testing was conducted on normal (30 MPa and high (70 MPa strength confined and unconfined concrete cylinders measuring 150 x 300 mm. The stress-strain relationship was evaluated in both cases. The findings showed that strength and ductility rose with FRP confinement. The experimental findings were used to develop an analytical model for predicting the stress-strain behaviour of FRP-confined concrete. A comparison of the experimental and analytical results revealed that the model can satisfactorily predict the stress-strain behaviour and ultimate compressive strength of the concretes studied.

    Este trabajo presenta los resultados de un estudio experimental y analítico del comportamiento de elementos de hormigón confinados con polímeros reforzados con fibras (FRP de vidrio y carbono. El programa experimental consistió en ensayar cilindros de hormigón de 150 x 300 mm (confinados y sin confinar bajo compresión axial en dos niveles de resistencia: normal (30 MPa y alta resistencia (70 MPa. En ambos casos, se evaluó el comportamiento tensión-deformación. Los resultados muestran que la resistencia y ductilidad se incrementan con el confinamiento con FRP. A partir de los resultados experimentales, se desarrolló un modelo analítico para predecir el comportamiento tensión-deformación del hormigón confinado con FRP. La comparación de los resultados experimentales y analíticos muestra que el modelo es aplicable a los hormigones estudiados, proporcionando predicciones satisfactorias del comportamiento tensión-deformación y de la resistencia a compresión última.

  16. PMMA-based composite materials with reactive ceramic fillers: part III: radiopacifying particle-reinforced bone cements.

    Science.gov (United States)

    Abboud, M; Vol, S; Duguet, E; Fontanille, M

    2000-05-01

    New acrylic bone cements were prepared from alumina particles previously treated by 3-(trimethoxysilyl)propylmethacrylate (gamma-MPS), able to act both as radiopacifying and reinforcing agents. The present study deals with the handling characteristics and the compressive behavior of such cements. The influence of the particles morphology, their surface-modification by gamma-MPS bonding agent, their concentration in the cement, the powder-to-liquid ratio and the benzoyl peroxide concentration are reported. The role of grafted gamma-MPS molecules as coupling agent was confirmed. For several formulations, compressive strength and modulus reached 150 MPa and 3400 MPa respectively. Limitations in the use of such formulations are also comprehensively discussed.

  17. A facile method for processing lignin reinforced chitosan biopolymer microfibres: optimising the fibre mechanical properties through lignin type and concentration

    Science.gov (United States)

    Wang, K.; Loo, L. S.; Goh, K. L.

    2016-03-01

    A chitosan biopolymer microfibre—reinforced by lignin—has been processed by a wet-spinning method. To optimise the fibre mechanical and structural properties two types of lignin, with molecular weights 28 000 g mol-1 and 60 000 g mol-1, were examined and the chitosan fibre was blended with the respective lignin type at 1, 3, 5, 7 and 8 wt% lignin concentrations. The main effects of lignin type and concentration, as well as the interaction between the two parameters, on the fibre tensile stiffness, extensibility, strength and toughness were evaluated using the two-factor analysis of variance. Significant variations in the respective mechanical properties were observed with varying lignin concentrations (P results were related to the dispersion of lignin in the fibre and the nature of the bonds between lignin and chitosan, based on findings from scanning electron microscopy and Fourier transform infrared spectroscopy. This new method for the fabrication of chitosan biopolymer microfibre is inexpensive and versatile and could lend itself to the production of high performance biocomposite structures.

  18. The effect of silica fume and metakaolin on glass-fibre reinforced concrete (GRC ageing

    Directory of Open Access Journals (Sweden)

    Enfedaque Díaz, A.

    2010-12-01

    Full Text Available The deterioration of the mechanical properties of glassfibre reinforced concrete (GRC over time rules out the use of this material in load-bearing structures. While one possible solution to this problem is the addition of pozzolans or metakaolin to the cement mortar, the amounts needed to ensure GRC integrity raise its price to non-competitive levels. Experimental research has been conducted to analyze whether the addition of small amounts of silica fume or metakaolin can prevent or mitigate the ageing issue. Unfortunately, the findings indicate that the addition of small proportions of metakaolin or silica fume to GRC are ineffective in improving its long-term performance.

    Para el uso del mortero de cemento reforzado con fibras de vidrio (GRC en estructuras portantes se han de solucionar los problemas de reducción de las propiedades mecánicas que aparecen con el paso del tiempo. Estos problemas pueden ser solucionados mediante la adición de puzolanas o de metacaolín, a la pasta de mortero de cemento. Sin embargo, la cantidad de metacaolín que ha de ser añadida es elevada y el precio del GRC fabricado está fuera del mercado. Se ha realizado una campaña experimental que analiza si la adición de humo de sílice o de metacaolín en proporciones reducidas consigue evitar o paliar el problema del envejecimiento, que supone un freno al uso del GRC en elementos estructurales. Desgraciadamente, los resultados experimentales muestran que proporciones bajas de metacaolín o de humo de sílice no son efectivas para reducir el problema de pérdida de propiedades mecánicas.

  19. Glass Fibre-Reinforced Composite Post and Core Used in Decayed Primary Anterior Teeth: A Case Report

    Directory of Open Access Journals (Sweden)

    Leena Verma

    2011-01-01

    Full Text Available Aesthetic requirement of severely mutilated primary anterior teeth in the case of early childhood caries has been a challenge to pediatric dentist. Among restorative treatment options, prefabricated crown and biological and resin composite restoration either by means of direct or indirect technique are mentioned in the literature. This paper presents the clinical sequence of rehabilitation of maxillary anterior primary teeth. Endodontic treatment was followed by the placement of a glass fibre-reinforced composite resin post. The crown reconstruction was done with composite restoration. Resin glass fibre post has best properties in elasticity, translucency, adaptability, tenaciousness, and resistance to traction and to impact. Along with ease of application, fiber can be used as an alternative to traditionally used materials in the management of early childhood caries.

  20. Internal-Notched Flexure Test for Measurement of Mode II Delamination Resistance of Fibre-Reinforced Polymers

    Directory of Open Access Journals (Sweden)

    Chengye Fan

    2013-01-01

    Full Text Available This paper introduces a new test, method, named internal-notched flexure (INF test, that is designed to measure the critical energy release rate of fibre-reinforced polymers for delamination growth in shear mode (mode II. The INF test generates stable delamination growth, with a monotonic increase of load and displacement in a nearly linear fashion. Values of the mode II delamination toughness were deduced using experimental compliance fitting method. Good repeatability of the results was obtained. Compared with the end-notched flexure (ENF test using the same material, the INF test yielded higher delamination resistance, possibly due to the bridging fibres found between fracture surfaces of the INF test specimens.

  1. Magnetism and rotation effect on surface waves in fibre-reinforced anisotropic general viscoelastic media of higher order

    Energy Technology Data Exchange (ETDEWEB)

    Abo-Dahab, S. M. [Taif University, Taif (Saudi Arabia); Abd-Alla, A. M. [SVU, Qena (Egypt); Khan, Aftab [Sohag University, Sohag (Egypt)

    2015-08-15

    The aim of this paper is to study the propagation of surface waves in a rotating fibre-reinforced viscoelastic media of higher order under the influence of magnetic field. The general surface wave speeds derived to study the effects of rotation and magnetic field on surface waves. Particular cases for Stoneley, Love and Rayleigh waves are also discussed and dispersion relation for the waves has been deduced. The results obtained in this investigation are more general in the sense that some earlier published results are obtained from our result as special cases. For order zero our results are well agreement to fibre-reinforced materials. Also by neglecting the reinforced elastic parameters, the results reduce to well known isotropic medium. It is observed that in a rotating medium the surface waves are dispersive. Also magnetic effects play a significant roll. It is observed that Love wave remain unaffected in a rotating medium but remain under the influence of magnetic field. Rayleigh waves are affected by rotation and magnetic field whereas Stoneley waves are independent of Maxwell stresses. It is also observed that, surface waves cannot propagate in a fast rotating medium or in the presence of magnetic field of high intensity. Numerical results for particular materials are given and illustrated graphically. The results indicate that the effect of rotation and magnetic field are very pronounced.

  2. Benefits of crimped and prestressed CFRP's over noncrimped fibres as reinforcement in machine elements

    Science.gov (United States)

    Kanellopoulos, Ioannis; Vasileiou, Ioannis; Kitsos, Ioannis

    2014-10-01

    In this paper, a representative volume element consisted of a single wavy carbon fibre engulfed in a thermoplastic rectangular matrix is studied in order to examine the effect ofnon-crimped carbon fibre, and specifically its waviness, at the mechanical behavior. In order to quantify these influences and their nonlinear elastic behavior, a plane strain analysis of this model was simulated with finite elements.

  3. Screening life cycle assessment study of a sisal fibre reinforced micro-concrete structural insulated panel

    CSIR Research Space (South Africa)

    Ampofo-Anti, N

    2013-12-01

    Full Text Available requirements of fibre processing are two weak points in the cradle-to-gate life cycle of sisal. Further research should focus on sisal farming on non-arable; development of sisal cultivars which will maximise the sisal fibre yield per hectare; and conversion...

  4. Effect of Chemical Treatments on Flax Fibre Reinforced Polypropylene Composites on Tensile and Dome Forming Behaviour

    Directory of Open Access Journals (Sweden)

    Wentian Wang

    2015-03-01

    Full Text Available Tensile tests were performed on two different natural fibre composites (same constituent material, similar fibre fraction and thickness but different weave structure to determine changes in mechanical properties caused by various aqueous chemical treatments and whether any permanent changes remain on drying. Scanning electronic microscopic examinations suggested that flax fibres and the flax/polypropylene interface were affected by the treatments resulting in tensile property variations. The ductility of natural fibre composites was improved significantly under wet condition and mechanical properties (elongation-to-failure, stiffness and strength can almost retain back to pre-treated levels when dried from wet condition. Preheating is usually required to improve the formability of material in rapid forming, and the chemical treatments performed in this study were far more effective than preheating. The major breakthrough in improving the formability of natural fibre composites can aid in rapid forming of this class of material system.

  5. Studies on Mechanical, Thermal, and Morphological Properties of Glass Fibre Reinforced Polyoxymethylene Nanocomposite

    Directory of Open Access Journals (Sweden)

    K. Mohan Babu

    2014-01-01

    Full Text Available Polyoxymethylene is a material which has excellent mechanical properties similar to Nylon-6 filled with 30% GF. 75% POM and 25% glass fibre (POMGF were blended with nanoclay to increase the tensile and flexural properties. Samples were extruded in twin screw extruder to blend POMGF and (1%, 3%, and 5% Cloisite 25A nanoclay and specimens were prepared by injection moulding process. The tensile properties, flexural properties, impact strength, and hardness were investigated for the nanocomposites. The fibre pull-outs, fibre matrix adhesion, and cracks in composites were investigated by using scanning electron microscopy. 1% POMGF nanocomposite has low water absorption property. Addition of nanoclay improves the mechanical properties and thermal properties marginally. Improper blending of glass fibre and nanoclay gives low tensile strength and impact strength. SEM image shows the mixing of glass fibre and nanoclay among which 1% POMGF nanocomposite shows better properties compared to others. The thermal stability decreased marginally only with the addition of nanoclay.

  6. Dental glass ionomer cement reinforced by cellulose microfibers and cellulose nanocrystals.

    Science.gov (United States)

    Silva, Rafael M; Pereira, Fabiano V; Mota, Felipe A P; Watanabe, Evandro; Soares, Suelleng M C S; Santos, Maria Helena

    2016-01-01

    The aim of this work was to evaluate if the addition of cellulose microfibers (CmF) or cellulose nanocrystals (CNC) would improve the mechanical properties of a commercial dental glass ionomer cement (GIC). Different amounts of CmF and CNC were previously prepared and then added to reinforce the GIC matrix while it was being manipulated. Test specimens with various concentrations of CmF or CNC in their total masses were fabricated and submitted to mechanical tests (to evaluate their compressive and diametral tensile strength,modulus, surface microhardness and wear resistance) and characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). The incorporation of CmF in the GIC matrix did not greatly improve the mechanical properties of GIC. However, the addition of a small amount of CNC in the GIC led to significant improvements in all of the mechanical properties evaluated: compressive strength (increased up to 110% compared with the control group), elastic modulus increased by 161%, diametral tensile strength increased by 53%, and the mass loss decreased from 10.95 to 3.87%. Because the composites presented a considerable increase in mechanical properties, the modification of the conventional GIC with CNC can represent a new and promising dental restorative material.

  7. 浅述玻璃钢制品质量控制%Research on the Quality Control of Fibre Reinforced Plastic Product

    Institute of Scientific and Technical Information of China (English)

    陈瑛卿

    2012-01-01

      Fibre-reinforced plastic (FRP) (also fibre-reinforced polymer) is a composite material made of a polymer matrix reinforced with fibres, which with light quality and high intensity. At present, the integrated quality control system of fibre reinforced plastic technics still not been established in China, to insure the product quality of fibre reinforced plastic, some measures must be taken from the technical training of perspnnel, quality control of raw materials, process control of manufacturing and quality control of final product.%  玻璃钢是一种高性能的纤维增强树脂基复合材料,轻质高强。目前我国的玻璃钢工业尚未建立起完整的质量控制体系,为了确保玻璃钢产品的质量,必须从人员的技术培训、原材料的质量把关,制造过程的工艺控制和成品控制等几方面入手。

  8. Computertomographic investigation of steel fibre reinforced sprayed concrete using multi-dimensional transfer functions [Computertomografische Untersuchung von Stahlfaserspritzbeton mit mehrdimensionalen Transferfunktionen

    KAUST Repository

    Pittino, Gerhard

    2011-06-01

    The composite material steel fibre reinforced concrete or steel fibre reinforced sprayed concrete (SFRS) is widely used in geotechnics. For the modelling of the mechanical behaviour the knowledge of the distribution and orientation of the fibres in the concrete is of particular importance. For a bachelor thesis the steel fibres in drill cores were investigated by computed tomography (CT) at the Austrian Foundry Research Institute (ÖGI). The orientation of each fibre was calculated using a STL-interface and further software tools. The results were statistically evaluated and graphically represented using Schmidt\\'s net. This time consuming (expensive) method was automated by a post-processing of VRVis. With that tool the steel fibres in the sample can be explored, classified and visually examined in real-time regarding their orientation in two angles. Different possibilities of statistical evaluation can be implemented. A real-time direction sphere histogram (DSH), comparable to Schmidt\\'s net in 3D allows the user to recognise the distribution of orientations of the selected fibres at a glance. The colour-coding of the different orientations is also used for the 3D-volume-view of the fibres, to easily identify the spatial distribution of orientations in the SFRS sample. © 2011 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.

  9. Safety against formation of through cracks of profiled fibre-reinforced cement sheets for roofing

    DEFF Research Database (Denmark)

    Hansen, Klavs Feilberg; Stang, Birgitte Friis Dela

    2009-01-01

      Loads due to wind, snow or traffic on a roof determine the requirements to the strength and stiffness properties of profiled sheets for roofing. Apart from these loads, locked-in stresses can occur due to differences in temperature and moisture strains in the profiled sheets and the wooden lath...

  10. Micromechanical Models of Mechanical Response of High Performance Fibre Reinforced Cement Composites

    DEFF Research Database (Denmark)

    Li, V. C.; Mihashi, H.; Alwan, J.;

    1996-01-01

    generation of FRC with high performance and economical viability, is in sight. However, utilization of micromechanical models for a more comprehensive set of important HPFRCC properties awaits further investigations into fundamental mechanisms governing composite properties, as well as intergrative efforts......The state-of-the-art in micromechanical modeling of the mechanical response of HPFRCC is reviewed. Much advances in modeling has been made over the last decade to the point that certain properties of composites can be carefully designed using the models as analytic tools. As a result, a new...

  11. Short and long term behaviour of externally bonded fibre reinforced polymer laminates with bio-based resins for flexural strengthening of concrete beams

    Science.gov (United States)

    McSwiggan, Ciaran

    The use of bio-based resins in composites for construction is emerging as a way to reduce of embodied energy produced by a structural system. In this study, two types of bio-based resins were explored: an epoxidized pine oil resin blend (EP) and a furfuryl alcohol resin (FA) derived from corn cobs and sugar cane. Nine large-scale reinforced concrete beams strengthened using externally bonded carbon and glass fibre reinforced bio-based polymer (CFRP and GFRP) sheets were tested. The EP resin resulted in a comparable bond strength to conventional epoxy (E) when used in wet layup, with a 7% higher strength for CFRP. The FA resin, on the other hand, resulted in a very weak bond, likely due to concrete alkalinity affecting curing. However, when FA resin was used to produce prefabricated cured CFRP plates which were then bonded to concrete using conventional epoxy paste, it showed an excellent bond strength. The beams achieved an increase in peak load ranging from 18-54% and a 9-46% increase in yielding load, depending on the number of FRP layers and type of fibres and resin. Additionally, 137 concrete prisms with a mid-span half-depth saw cut were used to test CFRP bond durability, and 195 CFRP coupons were used to examine tensile strength durability. Specimens were conditioned in a 3.5% saline solution at 23, 40 or 50°C, for up to 240 days. Reductions in bond strength did not exceed 15%. Bond failure of EP was adhesive with traces of cement paste on CFRP, whereas that of FA was cohesive with a thicker layer of concrete on CFRP, suggesting that the bond between FA and epoxy paste is excellent. EP tension coupons had similar strength and modulus to E resin, whereas FA coupons had a 9% lower strength and 14% higher modulus. After 240 days of exposure, maximum reductions in tensile strength were 8, 19 and 10% for EP, FA and E resins, respectively. Analysis of Variance (ANOVA) was also performed to assess the significance of the reductions observed. High degrees of

  12. Analysis, design and development of a carbon fibre reinforced plastic knee-ankle-foot orthosis prototype for myopathic patients.

    Science.gov (United States)

    Granata, C; De Lollis, A; Campo, G; Piancastelli, L; Merlini, L

    1990-01-01

    A traditional knee-ankle-foot orthosis (KAFO) for myopathic patients has been studied for the assessment of loads and fatigue resistance. Starting from this basis a thermoplastic matrix carbon fibre reinforced plastic composite (CFRP) KAFO has been developed in order to reduce the weight. A finite-element simulation programme for deformation analysis was used to compare the behaviour of conventional and CFRP orthosis. There were no breakages either of the prototype or of its parts. The CFRP orthosis allows a weight reduction of more than 40 per cent.

  13. Effect of Grinding Process Parameters on Surface Area Roughness of Glass fibre Reinforced Composite Laminate under Dry and Coolant Environment

    Directory of Open Access Journals (Sweden)

    P. Chockalingam

    2016-04-01

    Full Text Available This paper presents a comparative study on dry and wet grinding of chopped strand mat glass fibre reinforced polymer laminates using an alumina wheel. Investigations were performed to study the impact of the grinding parameters, namely feed, speed, and depth of cut on grinding force ratio and surface area roughness. Effective grinding parameters were sought in this study to maximize grinding force ratio and minimize surface area roughness. Test results show that coolant helped to decrease surface area roughness, but inevitably reduced the grinding force ratio in some cases. These findings lead to economic machining solution for optimum grinding conditions in grinding composite laminates.

  14. MECHANICAL BEHAVIOUR OF ABACA-GLASS-BANANA FIBRE REINFORCED HYBRID COMPOSITES

    Directory of Open Access Journals (Sweden)

    H. VENKATASUBRAMANIAN

    2015-08-01

    Full Text Available Hybrid composites comprising of natural and synthetic fibres with phenolic resin is one of the present composite manufacturing techniques for achieving enhanced mechanical properties. In this study Abaca-banana-glass composites has been fabricated and its mechanical properties were analysed. Tensile, flexural and impact strength were investigated in the process of mechanical characterisation. Matrix material used is a phenolic resin of Ortho-Phthalic acid. The manufacture of the composite is done by hand layup technique where the fibre content is varied through volume fraction of 0.4 to 0.5. Setup is arranged in such a way that glass fibre is arranged on the top and bottom layers of the laminate which adds up strength and produces a better surface finish, where in the natural fibre is sandwiched in intermediate layers within the glass fibre. Fibre orientation and the detailed internal structure of matrix were studied by using SEM photography. The results showed that Abaca-banana-glass hybrid composite has better tensile property, Banana-glass composite has the best flexural property and Abaca-glass composite has the best impact property. The results obtained show a substantial increase in mechanical properties and hence these hybrid composites can be used as an effective alternative for synthetic fibres and can be used as an alternate for different industrial application.

  15. CFRP materials reinforced with LCP fibres for applications in vehicle and aircraft engineering. Final report; Faserverbundkunststoffe mit einer LCP-Faserverstaerkung fuer Anwendungen im Fahrzeug- und Flugzeugbau. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-11

    CFRP materials reinforced with liquid crystalline polyester (LCP) fibres were produced and characterized with regard to their physical and mechanical characteristics. Compared with non-reinforced plastics, polypropylene/LCP fibre-UD laminates produced by filmstacking, epoxy resin/LCP fibre-UD laminates produced by spooling and epoxy resin composites with internal LCP fibre fleece had significantly higher strength and stiffness as well as high thermoforming resistance and waterproofness. [Deutsch] In diesem Forschungsvorhaben wurden Faserverbundkunststoffe mit einer Verstaerkungsfaser auf Basis eines thermotropen fluessigkristallinen Polyester [Liquid Crystalline Polyester, abgekuerzt LCP] hergestellt und bezueglich der physikalisch-mechanischen Eigenschaften charakterisiert. Die im `filmstacking`-Verfahren hergestellte Polypropylen/LCP-Faser-UD-Laminate und mittels Bewicklung gewonnene Epoxidharz/LCP-Faser-UD-Laminate sowie Epoxidharzverbunde mit eingearbeiteten LCP-Faservlies zeigen gegenueber den unverstaerkten Kunststoffmaterialien einen betraechtlichen Anstieg von Festigkeit und Steifigkeit. Die Faserverbunde weisen ausserdem eine hohe Waermeformbestaendigkeit und Wassersperrwirkung auf. (orig.)

  16. Steel Fibre Reinforcing Characteristics on the Size Reduction of Fly Ash Based Concrete

    OpenAIRE

    2014-01-01

    The behavior of glued steel fibres in high strength concrete with size reduction properties of concrete has been attempted. Glued steel fibres with both ends hooked having length to diameter ratio of 70 was added at a dosage level of 0.5% to 1.5% by volume fraction. The study was carried out to analyze the effects of fibre addition on the thickness reduction of concrete element. A high strength concrete mixture was designed and various thicknesses of concrete prisms were casted for different ...

  17. Characteristics of Impact Damage and Post-Impact Strength in Glass-Fibre-Reinforced Plastics with Different Reinforcement Architecture

    Directory of Open Access Journals (Sweden)

    Michał BARCIKOWSKI

    2013-12-01

    Full Text Available Fiber-reinforced plastics (FRP are nowadays used commonly for constructions subjected to impacts of different energies and velocities; therefore, the problem of impact resistance is crucial. This paper presents the results of high-velocity impact tests and post-impact evaluation of damage in glass-fiber-reinforced plastics, depending on the architecture of reinforcing material (different woven fabrics, mat. Composites reinforced with continuous-filament mat, woven roving, roving fabric and twisted-yarn fabric were prepared and subjected to intermediate- and high-velocity impact. After the ballistic impact, damage extent and residual strength, as well as water leakage through the composites, were evaluated. The damage was also investigated under a microscope. The damage extent was confirmed to be linearly dependent on impact energy. The addition of rubber was found to decrease damage extent and increase post-impact residual strength, as well as decrease water leakage rate.

  18. Comparative Environmental Sustainability Assessment of Bio-Based Fibre Reinforcement Materials for Wind Turbine Blades

    DEFF Research Database (Denmark)

    Corona, Andrea; Markussen, Christen Malte; Birkved, Morten;

    2015-01-01

    and flax/carbon, flax/glass mixed fibres) are compared in terms of environmental sustainability. Applying one of the most recent life cycle impact assessment methods, we demonstrate that the environmental sustainability of natural fibre based composite materials is similar or even lower, within certain......Over the recent decades biomaterials have been marketed successfully supported by the common perception that biomaterials and environmental sustainability de facto represents two sides of the same coin. The development of sustainable composite materials for wind turbine blades for small-scale wind...... turbines have therefore partially been focused on substitution of conventional fibre materials with bio-fibres assuming that this substitution was in the better for the environment and human health. The major question is if this material substitution, taking into account a multitude of environmental impact...

  19. Comparative Environmental Sustainability Assessment of Bio-Based Fibre Reinforcement Materials for Wind Turbine Blades

    DEFF Research Database (Denmark)

    Corona, Andrea; Markussen, Christen Malte; Birkved, Morten

    2015-01-01

    Over the recent decades biomaterials have been marketed successfully supported by the common perception that biomaterials and environmental sustainability de facto represents two sides of the same coin. The development of sustainable composite materials for wind turbine blades for small-scale wind...... categories, not only climate change, actually is supporting sustainable development or if the development of sustainable composite materials is more complex and perhaps even contra-intuitive due to complex trade-offs. Based on a case study 4 different types of fibres and fibre mixtures (flax, carbon, glass...... and flax/carbon, flax/glass mixed fibres) are compared in terms of environmental sustainability. Applying one of the most recent life cycle impact assessment methods, we demonstrate that the environmental sustainability of natural fibre based composite materials is similar or even lower, within certain...

  20. Efficient evaluation of the material response of tissues reinforced by statistically oriented fibres

    Science.gov (United States)

    Hashlamoun, Kotaybah; Grillo, Alfio; Federico, Salvatore

    2016-10-01

    For several classes of soft biological tissues, modelling complexity is in part due to the arrangement of the collagen fibres. In general, the arrangement of the fibres can be described by defining, at each point in the tissue, the structure tensor (i.e. the tensor product of the unit vector of the local fibre arrangement by itself) and a probability distribution of orientation. In this approach, assuming that the fibres do not interact with each other, the overall contribution of the collagen fibres to a given mechanical property of the tissue can be estimated by means of an averaging integral of the constitutive function describing the mechanical property at study over the set of all possible directions in space. Except for the particular case of fibre constitutive functions that are polynomial in the transversely isotropic invariants of the deformation, the averaging integral cannot be evaluated directly, in a single calculation because, in general, the integrand depends both on deformation and on fibre orientation in a non-separable way. The problem is thus, in a sense, analogous to that of solving the integral of a function of two variables, which cannot be split up into the product of two functions, each depending only on one of the variables. Although numerical schemes can be used to evaluate the integral at each deformation increment, this is computationally expensive. With the purpose of containing computational costs, this work proposes approximation methods that are based on the direct integrability of polynomial functions and that do not require the step-by-step evaluation of the averaging integrals. Three different methods are proposed: (a) a Taylor expansion of the fibre constitutive function in the transversely isotropic invariants of the deformation; (b) a Taylor expansion of the fibre constitutive function in the structure tensor; (c) for the case of a fibre constitutive function having a polynomial argument, an approximation in which the

  1. A methodology for the control of the residual lifetimes of carbon fibre reinforced composite pressure vessels

    OpenAIRE

    Bunsell, Anthony R.; Blassiau, Sébastien; Thionnet, Alain

    2005-01-01

    International audience; Pressure vessels must be periodically proof tested. Traditional techniques for metal vessels are inapplicable for composite vessels as the latter do not break by crack propagation so that the reasoning behind the traditional testing procedures is not appropriate. Damage accumulation leading to the degradation of a composite vessel is by fibre failure. Fibres show a wide distribution in strengths and loading a composite inevitably breaks some. The method which has been ...

  2. Flexural behaviour of reinforced concrete beams with discrete steel – polypropylene fibres

    Directory of Open Access Journals (Sweden)

    Amizah Wan Jusoh Wan

    2017-01-01

    Full Text Available This paper discusses the experimental results on the flexural test of concrete containing different proportions of steel fibre (SF and polypropylene fibre (PPF. The flexural test was carried out under 4-point bending load and followed the relevant standards to FRC. Hooked-end deformed SF fibre with 60 mm length and fibrillated virgin PPF fibre with 19 mm length were used in this study. Meanwhile, the concrete was designed for high strength concrete of C60. The mixture included both single SF and PPF, and also the combination of both fibres; Control beam (PC, beam with 75%SF, beam with 75%SF + 25%PPF and beam with 25%PPF. The total fibre volume fraction (Vf was fixed at 1.5%. The experimental results show that the percentage proportion of combined SF-PPF at 75-25% had the best performance for its flexural capacity. Mixture with single PPF was also found not effective in delaying the onset of tension cracks and to increase the tensile strength of the concrete. Experimental result also shows beam with 75%SF +25%PPF had their structural stiffness improved the most as compared with the others. For the compressive strength, beam with 75%SF + 25%PPF also revealed comparable performance with the control for high strength composite concrete.

  3. Fibre-reinforced glasses and SiC matrices. Analysis and properties; Faserverstaerkte Glaeser und SiC-Matrices. Analyse und Eigenschaften

    Energy Technology Data Exchange (ETDEWEB)

    Meier, B.

    1992-08-01

    The dissertation investigates ceramic fibres, from single-fibre model composites to multi-fibre materials on a glass or SiC matrix. The glass matrices used were `Duran` and `Supremax`, the reinforcing materials SiC fibres (Niacalon, SCS-6) and carbon fibres (T300). The mechanical properties and the structure of the composite materials were investigated by different methods. (MM) [Deutsch] Der Bogen dieser Doktorarbeit spannt sich von der Untersuchung keramischer Fasern ueber Einzelfaserverbundmodellproben bis hin zu den Vielfaserverbundwerkstoffen mit Glas- und SiC-Matrix. Als Glasmatrizes wurden `Duran` und `Supremax` und als Verstaerkungsmaterialien SiC-Fasern (Niacalon, SCS-6) und Kohlenstoffasern (T300) eingesetzt. Mit Hilfe verschiedener Methoden wurden die mechanischen Eigenschaften und das Gefuege dieser Verbundwerkstoffe untersucht. (MM)

  4. Effect of monomer composition of polymer matrix on flexural properties of glass fibre-reinforced orthodontic archwire.

    Science.gov (United States)

    Ohtonen, J; Vallittu, P K; Lassila, L V J

    2013-02-01

    To compare force levels obtained from glass fibre-reinforced composite (FRC) archwires. Specifically, FRC wires were compared with polymer matrices having different dimethacrylate monomer compositions. FRC material (E-glass provided by Stick Tech Ltd, Turku, Finland) with continuous unidirectional glass fibres and four different types of dimethacrylate monomer compositions for the resin matrix were tested. Cross-sectionally round FRC archwires fitting into the 0.3 mm slot of a bracket were divided into 16 groups with six specimens in each group. Glass fibres were impregnated by the manufacturer, and they were initially light-cured by hand light-curing unit or additionally post-cured in light-curing oven. The FRC archwire specimens were tested at 37°C according to a three-point bending test in dry and wet conditions using a span length of 10 mm and a crosshead speed of 1.0 mm/minute. The wires were loaded until final failure. The data were statistically analysed using analysis of variance (ANOVA). The dry FRC archwire specimens revealed higher load values than water stored ones, regardless of the polymer matrix. A majority of the FRC archwires showed higher load values after being post-cured. ANOVA revealed that the polymer matrix, curing method, and water storage had a significant effect (P composition, curing method, and water storage affected the flexural properties and thus, force level and working range which could be obtained from the FRC archwire.

  5. Effect of Expansive Admixtures on the Shrinkage and Mechanical Properties of High-Performance Fiber-Reinforced Cement Composites

    Directory of Open Access Journals (Sweden)

    Won-Chang Choi

    2013-01-01

    Full Text Available High-performance fiber-reinforced cement composites (HPFRCCs are characterized by strain-hardening and multiple cracking during the inelastic deformation process, but they also develop high shrinkage strain. This study investigates the effects of replacing Portland cement with calcium sulfoaluminate-based expansive admixtures (CSA EXAs to compensate for the shrinkage and associated mechanical behavior of HPFRCCs. Two types of CSA EXA (CSA-K and CSA-J, each with a different chemical composition, are used in this study. Various replacement ratios (0%, 8%, 10%, 12%, and 14% by weight of cement of CSA EXA are considered for the design of HPFRCC mixtures reinforced with 1.5% polyethylene (PE fibers by volume. Mechanical properties, such as shrinkage compensation, compressive strength, flexural strength, and direct tensile strength, of the HPFRCC mixtures are examined. Also, crack width and development are investigated to determine the effects of the EXAs on the performance of the HPFRCC mixtures, and a performance index is used to quantify the performance of mixture. The results indicate that replacements of 10% CSA-K (Type 1 and 8% CSA-J (Type 2 considerably enhance the mechanical properties and reduce shrinkage of HPFRCCs.

  6. Effect of Corrugation and Reinforcement on the Dispersion of SH-wave Propagation in Corrugated Poroelastic Layer Lying over a Fibre-reinforced Half-space

    Science.gov (United States)

    Singh, Abhishek Kumar; Das, Amrita; Lakshman, Anirban; Chattopadhyay, Amares

    2016-10-01

    The presence of porosity and reinforcement in a medium is an important factor affecting seismic wave propagation and plays vital role in many geophysical prospects. Also, the presence of salt and ore deposits, mountains, basins, mountain roots, etc. is responsible for the existence of corrugated boundary surfaces of constituent layers. Such facts brought motivation for the present paper which deals with the propagation of SH-wave in a heterogeneous fluid-saturated poroelastic layer with corrugated boundaries lying over an initially stressed fibre-reinforced elastic halfspace. Closed form of dispersion relation has been obtained and is found in well agreement to classical Love wave equation for isotropic case. The effect of corrugation, wave number, undulation, position parameter, horizontal compressive/tensile initial stress and heterogeneity on phase velocity has been analysed through numerical computation and graphical illustration. Moreover, comparative study exploring the effect of presence and absence of reinforcement in half-space on dispersion curve is the major highlight of the current study.

  7. Effect of Corrugation and Reinforcement on the Dispersion of SH-wave Propagation in Corrugated Poroelastic Layer Lying over a Fibre-reinforced Half-space

    Directory of Open Access Journals (Sweden)

    Singh Abhishek Kumar

    2016-10-01

    Full Text Available The presence of porosity and reinforcement in a medium is an important factor affecting seismic wave propagation and plays vital role in many geophysical prospects. Also, the presence of salt and ore deposits, mountains, basins, mountain roots, etc. is responsible for the existence of corrugated boundary surfaces of constituent layers. Such facts brought motivation for the present paper which deals with the propagation of SH-wave in a heterogeneous fluid-saturated poroelastic layer with corrugated boundaries lying over an initially stressed fibre-reinforced elastic halfspace. Closed form of dispersion relation has been obtained and is found in well agreement to classical Love wave equation for isotropic case. The effect of corrugation, wave number, undulation, position parameter, horizontal compressive/tensile initial stress and heterogeneity on phase velocity has been analysed through numerical computation and graphical illustration. Moreover, comparative study exploring the effect of presence and absence of reinforcement in half-space on dispersion curve is the major highlight of the current study.

  8. Preparation and properties of unidirectional boron nitride fibre reinforced boron nitride matrix composites via precursor infiltration and pyrolysis route

    Energy Technology Data Exchange (ETDEWEB)

    Li Duan, E-mail: whataboutduan@gmail.com [State Key Laboratory of Advanced Ceramic Fibres and Composites, College of Aerospace and Materials Engineering, National University of Defense Technology, Changsha 410073 (China); Zhang Changrui; Li Bin; Cao Feng; Wang Siqing; Li Junsheng [State Key Laboratory of Advanced Ceramic Fibres and Composites, College of Aerospace and Materials Engineering, National University of Defense Technology, Changsha 410073 (China)

    2011-10-25

    Highlights: {yields} BN fibres degrade little when exposed at elevated temperatures. {yields} Precursor infiltration and pyrolysis route is useful to prepare BNf/BN composites. {yields} Few reports have related to the preparation and properties of BNf/BN composites. {yields} BNf/BN composites have desirable high-temperature mechanical properties. {yields} BNf/BN composites have excellent dielectric properties at 2-18 GHz. - Abstract: The unidirectional boron nitride fibre reinforced boron nitride matrix (BN{sub f}/BN) composites were prepared via the precursor infiltration and pyrolysis (PIP) route, and the structure, composition, mechanical and dielectric properties were studied. The composites have a high content and fine crystallinity of BN. The density is 1.60 g cm{sup -3} with a low open porosity of 4.66%. The composites display good mechanical properties with the average flexural strength, elastic modulus and fracture toughness being 53.8 MPa, 20.8 GPa and 6.88 MPa m{sup 1/2}, respectively. Lots of long fibres pull-out from the fracture surface, suggesting a good fibre/matrix interface. As temperature increases, both of the flexural strength and elastic modulus exhibit a decreasing trend, with the lowest values being 36.2 MPa and 8.6 GPa at 1000 deg. C, respectively. The desirable residual ratios of the flexural strength and elastic modulus at 1000 deg. C are 67.3% and 41.3%, respectively. The composites have excellent dielectric properties, with the average dielectric constant and loss tangent being 3.07 and 0.0044 at 2-18 GHz, respectively.

  9. Development of multi-walled carbon nanotubes reinforced monetite bionanocomposite cements for orthopedic applications

    Energy Technology Data Exchange (ETDEWEB)

    Boroujeni, Nariman Mansoori [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Zhou, Huan, E-mail: Huan.Zhou@Rockets.utoledo.edu [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Luchini, Timothy J.F. [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Bhaduri, Sarit B. [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Division of Dentistry, The University of Toledo, Toledo, OH (United States)

    2013-10-15

    In this study, we present results of our research on biodegradable monetite (DCPA, CaHPO{sub 4}) cement with surface-modified multi-walled carbon nanotubes (mMWCNTs) as potential bone defect repair material. The cement pastes showed desirable handling properties and possessed a suitable setting time for use in surgical setting. The incorporation of mMWCNTs shortened the setting time of DCPA and increased the compressive strength of DCPA cement from 11.09 ± 1.85 MPa to 21.56 ± 2.47 MPa. The cytocompatibility of the materials was investigated in vitro using the preosteoblast cell line MC3T3-E1. An increase of cell numbers was observed on both DCPA and DCPA-mMWCNTs. Scanning electron microscopy (SEM) results also revealed an obvious cell growth on the surface of the cements. Based on these results, DCPA-mMWCNTs composite cements can be considered as potential bone defect repair materials. - Highlights: • A monetite bone cement for orthopedic applications is reported. • Incorporation of MWCNTs into monetite bone cement is discussed. • Surface functionalized MWCNTs can improve the mechanical strength of monetite cement. • MWCNTs have no impacts on the cytocompatibility of monetite cements.

  10. Steel Fibre Reinforcing Characteristics on the Size Reduction of Fly Ash Based Concrete

    Directory of Open Access Journals (Sweden)

    Sounthararajan Vallarasu Manoharan

    2014-01-01

    Full Text Available The behavior of glued steel fibres in high strength concrete with size reduction properties of concrete has been attempted. Glued steel fibres with both ends hooked having length to diameter ratio of 70 was added at a dosage level of 0.5% to 1.5% by volume fraction. The study was carried out to analyze the effects of fibre addition on the thickness reduction of concrete element. A high strength concrete mixture was designed and various thicknesses of concrete prisms were casted for different volume fraction of steel fibres. The hardened concrete properties were determined based on the mix constituents such as water to binder ratio 0.3 (w/b, superplasticizer dosage, fine to coarse aggregate ratio 0.6 (F/c, and fly ash replacement level at 25% and 50% by weight of binder content. The experimental test results showed that the flexural strength varies with respect to the depth of concrete specimen. It can be observed that the reduction in size up to 10% size containing 25% fly ash with 1.5% steel fibres showed better strength enhancement of 4.70 MPa and 6.69 MPa for 7 days and 28 days, respectively. Also, the addition of steel fibres at higher percentage of fly ash containing 50% showed better improvement in the flexural strength for the size reduction at 5%, when compared to plain concrete beam which exhibited higher stress carrying capacity of 6.08 MPa at 28 days and showed an increase of 7.99%.

  11. Effect of fine to coarse aggregate ratio on the rheology and fracture energy of steel fibre reinforced self-compacting concretes

    Indian Academy of Sciences (India)

    Mert Yücel Yardimci; Bülent Baradan; Mehmet Alı Taşdemır

    2014-12-01

    In this study, the influence of aggregate grading and steel fibre properties on the flow properties and fracture energy of steel fibre reinforced self-compacting concrete (SFRSCC) has been investigated. Two types of hooked-end steel fibres at three different dosages (20, 40 and 60 kg/m3) were incorporated into self-compacting mixtures having similar paste contents but different fine to coarse aggregate (FA/CA) ratios (0.94, 1.72 and 2.50 by weight). Besides the flowability and passing ability of fresh concrete, the mechanical properties of hardened concrete including the fracture energy have also been investigated. The relations between flexural parameters and fibre orientation were established by image analysis technique. Test results showed that hooked-end steel fibre inclusion into the plain self-compacting concrete negatively affects the flowability and passing ability of themixture. Increasing FA/CA ratio enhances these rheological parameters and provides better fibre orientation. On the other hand, increasing FA/CA ratio decreases the fracture energy of plain SCC mixtures and the fibre incorporated series which were less affected from fibre inclusion follow the same trend with the plain SCC. The proper FA/CA ratio for the best rheological and mechanical performance depends on the fibre content, aspect ratio and their influence on the flowability of the mixture. In order to obtain better fibre orientation and hence higher fracture energy, relatively higher FA/CA ratios should be used when the fibre content and aspect ratio are relatively high.

  12. A rapid cyclic voltammetric method for studying cement factors affecting the corrosion of reinforced concrete

    Energy Technology Data Exchange (ETDEWEB)

    Foulkes, F.R.; McGrath, P. (Univ. of Toronto, Ontario (Canada))

    1999-06-01

    A rapid cyclic voltammetric method for studying the influence of cement factors on the corrosion of embedded iron and steel in hardened cement paste is described. The technique employs a cement electrode'' consisting of an iron or steel wire embedded in a miniature cylinder of hardened cement paste. The rapid cyclic voltammetric method is fast, reproducible, and provides information on the corrosiveness of the pore solution environment surrounding the embedded metal. The usefulness of the method is demonstrated by showing how it can be used to evaluate the threshold chloride content of hardened ordinary portland cement paste at which corrosion begins and by using it to evaluate the relative efficacy of several admixed corrosion inhibitors.

  13. Development of multi-walled carbon nanotubes reinforced monetite bionanocomposite cements for orthopedic applications.

    Science.gov (United States)

    Boroujeni, Nariman Mansoori; Zhou, Huan; Luchini, Timothy J F; Bhaduri, Sarit B

    2013-10-01

    In this study, we present results of our research on biodegradable monetite (DCPA, CaHPO4) cement with surface-modified multi-walled carbon nanotubes (mMWCNTs) as potential bone defect repair material. The cement pastes showed desirable handling properties and possessed a suitable setting time for use in surgical setting. The incorporation of mMWCNTs shortened the setting time of DCPA and increased the compressive strength of DCPA cement from 11.09±1.85 MPa to 21.56±2.47 MPa. The cytocompatibility of the materials was investigated in vitro using the preosteoblast cell line MC3T3-E1. An increase of cell numbers was observed on both DCPA and DCPA-mMWCNTs. Scanning electron microscopy (SEM) results also revealed an obvious cell growth on the surface of the cements. Based on these results, DCPA-mMWCNTs composite cements can be considered as potential bone defect repair materials.

  14. Solutions to intra-ply shear locking in finite element analyses of fibre reinforced materials

    NARCIS (Netherlands)

    ten Thije, R.H.W.; Akkerman, Remko

    2008-01-01

    Intra-ply shear locking results in unrealistic fibre stresses and spurious wrinkling in composite forming simulations. Three remedies were investigated: aligning the mesh, applying reduced integration and using multi-field elements. Several triangular and quadrilateral elements were tested on their

  15. Behaviour of fibre reinforced concrete using steel slag coarse aggregate produced in Qatar

    Directory of Open Access Journals (Sweden)

    Alnahhal Wael

    2017-01-01

    Full Text Available The state of Qatar suffers from the shortage of natural resources needed for concrete production. Therefore, it is essential to investigate the feasibility of using by-product recycled materials as aggregates to maintain the concrete construction industry. Several types of recyclable materials are currently used in concrete. One of the potential resources of recycled concrete is steel slag. Knowing that Steel slag is the most significant solid waste generated by Qatar Steel Company in Qatar, replacing of natural coarse aggregate with steel slag aggregate will have a significant environmental and economic impact to the state of Qatar. This paper presents the compression and flexural test results of different concrete mixes made of steel slag coarse aggregate combined with a newly developed basalt chopped fibres. The parameters investigated included the volume fraction of the fibre used and the type of coarse aggregates (natural aggregates “Gabbro” and steel slag aggregates. Plain concrete specimens containing natural coarse aggregates and steel slag aggregates with no fibres added were also tested to serve as control. Test results showed that adding the basalt chopped fibres to the concrete mixes enhanced their flexural tensile strengths at different percentages. In addition, the compressive strength of concrete made with steel slag aggregate was higher than that made with natural gabbro aggregate. Test results clearly showed that steel slag aggregates can be used as sustainable and eco-friendly alternative materials in concrete structures.

  16. Effect of water absorption on mechanical properties of flax fibre reinforced composites

    CSIR Research Space (South Africa)

    Guduri, BBR

    2007-01-01

    Full Text Available flax fibre composites were prepared by compounding, extrusion and injection moulding techniques. Polypropylene-graft-Maleic anhydride (PP-g-MA, Grade: G-3015) and Polyethylene-graft-Maleic anhydride (PE-g-MA, Grade: G-2608) were used as compatibilizer...

  17. Development of epoxidized soybean oil and soy fibre composites with Polyhedral Oligomeric Silsesquioxane (POSS) nano reinforcement

    Science.gov (United States)

    de Boer, Ryan Sietze

    Soy fibre and soybean oil were utilized to produce a bio-composite targeted as a substitute for conventional petroleum-based materials. The study was divided into two parts; the first was the development of a bio-epoxy that consisted of conventional epoxy, epoxidized soybean oil, and two types of functionalized POSS. The second part of the study involved blending of the bio-epoxy with titanate treated soy fibre. Combined incorporation of epoxide and amine functionalized POSS in the bio-epoxy matrix resulted in a 29% impact strength improvement compared to the petroleum-based epoxy. Incorporation of the epoxide functionalized POSS resulted in improvements in tensile strength by 8%, tensile modulus by 2%, and an increase in the glass transition temperature by 4% compared to the petroleum-based epoxy and epoxidized soybean oil hybrid. The coupling of titanate to soy fibre in comparison to the soy fibre without titanate treatment resulted in an impact strength improvement of 37%. Furthermore, the coupling of titanate increased the tensile strength and tensile modulus by 24% and 22% respectively, and reduced the water absorption by 70%.

  18. The use of an interphase to improve the transverse properties of unidirectional glass fibre reinforced polymer composites

    Science.gov (United States)

    Ellis, Keith

    The aim of the project was to improve the transverse mechanical properties of unidirectional glass fibre reinforced plastics (G.R.P.)* In addition it was intended that the longitudinal mechanical properties should not be Significantly a result of the transverse improvement The scientific and commercial literature were consulted to determine the most feasible means of improving the transverse properties. Four possible methods were identified, the most promising of which was interfacial modification. Interfacial modification involves the introduction of a third material ("the interphase" ) at the interface between the fibre and the matrix. For this project the interphase material was selected to be compliant or rubbery in nature. The Kies model for predicting the magnification of strain in the resin between fibres was extended to include an interphase. The model was developed for two modes of applied stress. The first was pure tension acting transverse to the fibre axis. The second was shear in the plane transverse to the fibre axis. A novel apparatus was constructed to manufacture composites with a compliant interphase. The apparatus combined a self-regulating coating technique with filament winding to give a continuous production facility. A range of mechanical tests were performed on composites both with and without an interphase. Presence of an interphase improved the following properties: transverse flexural strength, interlaminar and intralaminar shear strength , and transverse fiexural fracture energy. No improvement was noted for pure transverse tension. These results indicated that the interphase acted beneficially only when the composite was stressed in a predominantly shear mode. Conclusions from mechanical test results were supported by S.E.M. fractography. Considerable deformation of the interphase was found in composite tested in shear. This deformation was absent in composite tested in tension. It was postulated that these differences between behaviour

  19. Determination of the minimum size of a statistical representative volume element from a fibre-reinforced composite based on point pattern statistics

    DEFF Research Database (Denmark)

    Hansen, Jens Zangenberg; Brøndsted, Povl

    2013-01-01

    In a previous study, Trias et al. [1] determined the minimum size of a statistical representative volume element (SRVE) of a unidirectional fibre-reinforced composite primarily based on numerical analyses of the stress/strain field. In continuation of this, the present study determines the minimum...

  20. The Use of Fibre Reinforced Composites (Frcs in Periodontal Splinting & the Natural Tooth Pontic (NTP in the Management of Advanced Periodontal Disease

    Directory of Open Access Journals (Sweden)

    Ian Kerr

    2013-12-01

    Full Text Available This article uses a series of case studies to examine the use of fibre reinforced composite splints in the management of advanced gum disease that has led to mobility and imminent exfoliation of teeth. The case studies show the various techniques for producing a durable aesthetic splint and how to use these principles in the production of a natural tooth pontic.