Using ESEM to analyze the microscopic property of basalt fiber reinforced asphalt concrete

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Chunmei Gao

2018-07-01

Full Text Available The basalt fiber staggered distribution in the asphalt concrete matrix and the bonding situation between asphalt are analyzed by images collected using field emission environmental scanning electron microscope (ESEM test equipment. The results show that bonding of the fiber and the asphalt binder is very good and there is a strong binding force of chemical bonding connections between the two; the lipophilicity of basalt fiber is very good, the wrapped cover ability of asphalt for fiber is very strong; basalt fiber forms the local space network structure in the asphalt concrete matrix, effectively overcome the relative slip between the particles, connect the damaged parts into a whole; basalt fiber across internal micropores, and the internal defects in material can be remedied. At the same time, crack resistance mechanism of the fiber to internal micro cracks is qualitatively explained according to the magnitude of the stress intensity factor Kf. Keywords: Road engineering, Asphalt concrete, Basalt fiber, Microscopic analysis

SYSTEM FOR CONTROLLING ELECTRIC DRIVE OF ASPHALT CONCRETE MIXING PLANT

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A. S. Surmak

2005-01-01

Full Text Available It is proposed to evaluate quality of asphalt concrete mixture through definition of current component variable of a drive motor and measurement of its derivative sign. In order to carry out final determination of mixture uniformity a transducer on the basis of a nuclear magnetic resonance is applied. Block diagram of the system is presented and algorithm of its operation is given in the paper. In addition to improvement of the finished product quality the application of the system makes it possible to reduce bitumen consumption used for production of asphalt concrete.

Asphalt Concrete Mixtures: Requirements with regard to Life Cycle Assessment

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Jan Mikolaj

2015-01-01

Full Text Available Design of asphalt concrete, required properties of constituent materials and their mixing ratios, is of tremendous significance and should be implemented with consideration given to the whole life cycle of those materials and the final construction. Conformity with requirements for long term performance of embedded materials is the general objective of the Life Cycle Assessment (LCA. Therefore, within the assessment, material properties need to be evaluated with consideration given to the whole service life—from the point of embedding in the construction until their disposal or recycling. The evaluation focuses on verification of conformity with criteria set for these materials and should guarantee serviceability and performance during their whole service life. Recycling and reuse of asphalt concrete should be preferred over disposal of the material. This paper presents methodology for LCA of asphalt concrete. It was created to ensure not only applicability of the materials in the initial stage, at the point of their embedding, but their suitability in terms of normatively prescribed service performance of the final construction. Methods described and results are presented in a case study for asphalt mixture AC 11; I design.

INFLUENCE OF POLYMERIC-DISPERSED REINFORCEMENT ADDITIVES ON THE PERFORMANCE CHARACTERISTICS OF ASPHALT CONCRETE

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Chernov Sergey Anatolevych

2017-07-01

Full Text Available The technique and results of the studies of the influence of a polymeric-dispersed reinforcement additive on the performance characteristics of road hot asphalt concrete, namely, its resistance to fatigue failures, rutting and development of residual deformation are described. It is shown that the proposed method of modification of asphalt-concrete mixtures ensures an increase in the durability of layers of pavement road surface.

Concrete manufactured with crushed asphalt as partial replacement of natural aggregates

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L. Coppola

2016-09-01

Full Text Available The paper focuses on the reuse of crushed asphalt (GA as a partial replacement (up to 20% of natural aggregates for concrete manufacture. Addition of GA aggregates produced a positive effect on workability loss. The GA mixes, however, showed a significant tendency to bleed and segregate at the highest replacement percentage applied. GA led to a decrease of compressive strength in concrete (with respect to that of the reference concrete up to 50% due to the weakness of the cement paste / recycled aggregate interface. To compensate for this negative effect, a reduction of w/c for the GA concretes was necessary. A decrease of w/c allowed the GA concretes to show drying shrinkage values substantially similar to those of reference concrete with the same cement factor. The experimental results confirmed the possibility of partial substitution (max. 15% of natural aggregates with crushed asphalt for making concrete.

Interfacial debonding of ice-asphalt concrete

Energy Technology Data Exchange (ETDEWEB)

Tazawa, E.; Mizoue, Y. (Hiroshima Univ., Hiroshima (Japan)); Kojima, T. (Hitachi Chemical Co. Ltd., Tokyo (Japan))

1992-09-20

Series of experimental investigations were carried out to clarify the bonding mechanism between ice and asphalt and to develop a new technique to reduce bonding resistance. The surface bonding resistance was measured by three methods and the main variables taken into consideration have been surface energy, surface roughness and stiffness of asphalt. Surface energy was varied by using various water repellents and the stiffness of the concrete was varied by mixing rubber particles. Correlations of the three variables were studied and the following results have been obtained. Decreasing of surface energy and increasing of deformability of asphalt concrete has been the effective method to decrease the bonding between ice and asphalt. For the case of water repellent coated surface, shear debonding strength has been linearly related to the energy required for debonding by dynamic tension and the shear debonding strength has decreased with the decrease in roughness of pavement. In the case of surface without using repellent, shear debonding strength has not been influenced by surface energy and roughness of pavement. 6 refs., 16 figs., 7 tabs.

Laboratory investigation of the performances of cement and fly ash modified asphalt concrete mixtures

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Suched Likitlersuang

2016-09-01

Full Text Available The influence of filler materials on volumetric and mechanical performances of asphalt concrete was investigated in this study. The AC60/70 asphalt binder incorporating with cement and fly ash as filler materials was mixed with limestone following the Marshall mix design method. The filler contents of cement and/or fly ash were varied. The non-filler asphalt concrete mixtures of the AC60/70 and the polymer modified asphalt were prepared for the purpose of comparison. The investigation programme includes the indirect tensile test, the resilient modulus test and the dynamic creep test. The tests are conducted under the humid temperate environments. All tests were then carried out under standard temperature (25 °C and high temperature (55 °C by using a controlled temperature chamber via the universal testing machine. The wet-conditioned samples were prepared to investigate the moisture susceptibility. Results show that cement and/or fly ash were beneficial in terms of improved strength, stiffness and stripping resistance of asphalt mixture. In addition, the combined use of cement and fly ash can enhance rutting resistance at wet and high temperature conditions. The results indicate that the strength, stiffness and moisture susceptibility performances of the asphalt concrete mixtures improved by filler are comparable to the performance of the polymer modified asphalt mixture. Keywords: Asphalt concrete, Filler, Resilient modulus, Dynamic creep test, Moisture susceptibility

Modeling of Cyclic Strength for the Asphalt Concrete Considering Damage Accumulation

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Alibai Iskakbayev

2017-12-01

Full Text Available The expression is obtained for determination of cyclic tensile strength for asphalt concrete, which considers damage accumulation and history of loading, using the long-term strength curve for asphalt concrete obtained according to the test results of more than 110 samples to failure at stresses from 0.05 to 0.31 MPa and by introduction of damage kernel in this paper. Cyclic strength depends on the stress, parameters of long-term strength, frequency of loading, durations of loading and relax periods, and ratio of loading period to the long-term strength. Evaluation of accuracy for the obtained expression for the cyclic strength has been performed by comparison with the results of a series for experimental tests of asphalt concrete samples at a temperature of 22 °С and cyclic loading conditions. The stress is 0.31 MPa, and the durations of loading and relax periods are 5 and 60 s, respectively. Calculations performed with the obtained expressions at real road conditions (the stress is 0.31 MPa, and the durations of loading and relax periods are 0.1 and 9.9 s respectively showed the possibility of its use for the prediction of fatigue (multicyclic strength of an asphalt concrete pavement for a highway.

How to transform an asphalt concrete pavement into a solar turbine

International Nuclear Information System (INIS)

García, Alvaro; Partl, Manfred N.

2014-01-01

Highlights: • We create a system for harvesting energy from asphalt concrete. • We create an artificial porosity in the asphalt concrete. • We connect a chimney to this porosity. • Differences in temperature produce an air flow. • This air flow serves also for cooling down the pavement. - Abstract: Asphalt concrete can absorb a considerable amount of the incident solar radiation. For this reason asphalt roads could be used as solar collectors. There have been different attempts to achieve this goal. All of them have been done by integrating pipes conducting liquid, through the structure of the asphalt concrete. The problem of this system is that all pipes need to be interconnected: if one is broken, the liquid will come out and damage the asphalt concrete. To overcome these limitations, in this article, an alternative concept is proposed:parallel air conduits, where air can circulate will be integrated in the pavement structure. The idea is to connect these artificial pore volumes in the pavement to an updraft or to a downdraft chimney. Differences of temperature between the pavement and the environment can be used to create an air flow, which would allow wind turbines to produce an amount of energy and that would cool the pavement down in summer or even warm it up in winter. To demonstrate that this is possible, an asphalt concrete prototype has been created and basics calculations on the parameters affecting the system have been done. It has been found that different temperatures, volumes of air inside the asphalt and the difference of temperature between the asphalt concrete and the environment are critical to maximize the air flow through the pavement. Moreover, it has been found that this system can be also used to reduce the heat island effect

Influence of Temperature Upon Permanent Deformation Parameters of Asphalt Concrete Mixes

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Amjad Hamad Albayati

2017-07-01

Full Text Available The performance of asphalt concrete pavement has affected by many factors, the temperature is the most important environmental one which has a large effect on the structural behavior of flexible pavement materials. The main cause of premature failure of pavement is the rutting, Due to the viscoelastic nature of the asphalt cement, rutting is more pronounced in hot climate areas because the viscosity of the asphalt binder which is inversely related to rutting is significantly reduced with the increase in temperature resulting in a more rut susceptible paving mixtures. The objective of this study is to determine the effect of temperatures variations on the permanent deformation parameters (permanent strain (p, intercept (a, slope (b, Alpha and Mu as well as resilient strain (r and resilient modulus (Mr. To achieve this objective, one aggregate gradation with 12.5mm nominal maximum size, two grades of asphalt cements (40-50 and 60-70 brought form Al- Daurah refinery, limestone dust filler has been used to prepare the asphalt concrete mixtures. 30 Marshall specimens were prepared to determine the optimum asphalt cement content. Thereafter, 30 cylindrical asphalt concrete specimens (102mm in diameter and 203 mm in height are prepared in optimum asphalt cement and optimum ±0.5 percent. The prepared specimens were used in uniaxial repeated load test to evaluate the permanent deformation parameters of asphalt concrete mixes under the following testing temperature (5, 15, 25, 40 and 60c. The test result analyses appeared that Mr is decrease 51 percent when temperature increased from 5 c to 25 c and then decrease 22 percent with further increase in temperature from 25 c to 60 c. Also, the Alpha value decreases by a factor of 1.25 and 1.13 when temperature increases from 5 c to 25 c and 25 c to 60 c, espectively. Finally, statistical models were developed to predict the Alpha and Mu parameters of permanent deformation.

Mix Proportion Design of Asphalt Concrete

Science.gov (United States)

Wu, Xianhu; Gao, Lingling; Du, Shoujun

2017-12-01

Based on the gradation of AC and SMA, this paper designs a new type of anti slide mixture with two types of advantages. Chapter introduces the material selection, ratio of ore mixture ratio design calculation, and determine the optimal asphalt content test and proportioning design of asphalt concrete mix. This paper introduces the new technology of mix proportion.

Comparison of winter temperature profiles in asphalt and concrete pavements.

Science.gov (United States)

2014-06-01

The objectives of this research were to 1) determine which pavement type, asphalt or concrete, has : higher surface temperatures in winter and 2) compare the subsurface temperatures under asphalt and : concrete pavements to determine the pavement typ...

Characterization of Failure and Permanent Deformation Behaviour of Asphalt Concrete

NARCIS (Netherlands)

Wang, J.G.

2015-01-01

Asphalt concrete is a viscoelastic material consisting of aggregates, filler and bitumen. The response of asphalt concrete is highly dependent on temperature, loading rate and confining pressure. Permanent deformation is one of the most important distresses developing during the flexible pavement

Natural asphalt modified binders used for high stiffness modulus asphalt concrete

Science.gov (United States)

Bilski, Marcin; Słowik, Mieczysław

2018-05-01

This paper presents a set of test results supporting the possibility of replacing, in Polish climate conditions, hard road 20/30 penetration grade bitumen used in the binder course and/or base course made of high stiffness modulus asphalt concrete with binders comprising of 35/50 or 50/70 penetration grade bitumens and additives in the form of natural Gilsonite or Trinidad Epuré asphalts. For the purpose of comparing the properties of the discussed asphalt binders, values of the Performance Grade have been determined according to the American Superpave system criteria.

Characteristics and applications of high-performance fiber reinforced asphalt concrete

Science.gov (United States)

Park, Philip

Steel fiber reinforced asphalt concrete (SFRAC) is suggested in this research as a multifunctional high performance material that can potentially lead to a breakthrough in developing a sustainable transportation system. The innovative use of steel fibers in asphalt concrete is expected to improve mechanical performance and electrical conductivity of asphalt concrete that is used for paving 94% of U. S. roadways. In an effort to understand the fiber reinforcing mechanisms in SFRAC, the interaction between a single straight steel fiber and the surrounding asphalt matrix is investigated through single fiber pull-out tests and detailed numerical simulations. It is shown that pull-out failure modes can be classified into three types: matrix, interface, and mixed failure modes and that there is a critical shear stress, independent of temperature and loading rate, beyond which interfacial debonding will occur. The reinforcing effects of SFRAC with various fiber sizes and shapes are investigated through indirect tension tests at low temperature. Compared to unreinforced specimens, fiber reinforced specimens exhibit up to 62.5% increase in indirect tensile strength and 895% improvements in toughness. The documented improvements are the highest attributed to fiber reinforcement in asphalt concrete to date. The use of steel fibers and other conductive additives provides an opportunity to make asphalt pavement electrically conductive, which opens up the possibility for multifunctional applications. Various asphalt mixtures and mastics are tested and the results indicate that the electrical resistivity of asphaltic materials can be manipulated over a wide range by replacing a part of traditional fillers with a specific type of graphite powder. Another important achievement of this study is development and validation of a three dimensional nonlinear viscoelastic constitutive model that is capable of simulating both linear and nonlinear viscoelasticity of asphaltic materials. The

Use of rubber crumb for preparation of asphalt-concrete mixtures

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Yerbol Tileuberdi

2012-03-01

Full Text Available In this article use of rubber crumb from spent tire for preparation of rubber-bitumen compounds is investigated. Then the rubber-bitumen compositions are used in composition of asphalt concrete mixes .

In-Place Recycling and Reclamation of Asphaltic Concrete Pavements in Kentucky

Science.gov (United States)

2017-11-01

Full-depth reclamation has been defined by the Asphalt Recycling and Reclaiming Association as a rehabilitation technique in which the full thickness of the asphalt pavement and a predetermined portion of the underlying material (base, subbase, an...

Characteristic Asphalt Concrete Wearing Course (ACWC) Using Variation Lime Filler

Science.gov (United States)

Permana, R. A.; Pramesti, F. P.; Setyawan, A.

2018-03-01

This research use of lime filler Sukaraja expected add durability layers of concrete pavement is asphalt damage caused by the weather and load traffic. This study attempts to know how much value characteristic Marshall on a mixture of concrete asphalt using lime filler. This research uses experimental methods that is with a pilot to get results, thus will look filler utilization lime on construction concrete asphalt variation in filler levels 2 %, 3 %, 4 %.The results showed that the use of lime filler will affect characteristic a mixture of concrete asphalt. The more filler chalk used to increase the value of stability. On the cretaceous filler 2 % value of stability is 1067,04 kg. When lime filler levels added to the levels of filler 4 %, the value of stability increased to 1213,92 kg. The flexibility increased the number of filler as levels lime 2 % to 4 % suggests that are conducted more stiff mix.

Effect of using fly ash as alternative filler in hot mix asphalt

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Raja Mistry

2016-09-01

Full Text Available This study investigates the effect of using fly ash (FA in asphalt mixture as replacement of common filler. In view of the same, samples were prepared for different bitumen content (3.5−6.5% at 0.5% increments by using 2% hydrated lime (HL in control mix as well as varying percentage of FA ranging from 2 to 8% as alternative filler in modified mixes. The optimum bitumen content (OBC was then determined for all the mix by Marshall mix design. Experimental results indicated higher stability value with lower OBC for the mixture having 4% FA as optimum filler content in comparison with conventional mix and standard specification. So this study discuss the feasibility of using FA as alternative filler instead of HL in asphalt concrete mix by satisfying the standard specification.

Effect of Natural Sand Percentages on Fatigue Life of Asphalt Concrete Mixture

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Nahla Yassub Ahmed

2016-03-01

Full Text Available The design of a flexible pavement requires the knowledge of the material properties which are characterized by stiffness and fatigue resistance. The fatigue resistance relates the number of load cycles to failure with the strain level applied to the asphalt mixture. The main objective of this research is the evaluation of the fatigue life of asphalt mixtures by using two types of fine aggregate having different percentages. In this study, two types of fine aggregate were used natural sand (desert sand and crushed sand. The crushed sand was replaced by natural sand (desert sand with different percentages (0%, 25%, 75% and 100% by the weight of the sand (passing sieve No.8 and retained on sieve No.200 and one type of binder (40/50 penetration from Al-Daurah refinery. The samples of beams were tested by four point bending beam fatigue test at the control strain mode (250, 500 and 750 microstrain while the loading frequency (5Hz and testing temperature (20oC according to (AASHTO T321. The experimental work showed that fatigue life (Nf and initial flexural stiffness increased when control strain decreased for asphalt mixtures. Acceptable fatigue life at 750 microstrain was obtained with asphalt concrete mixtures containing 100% crushed sand as well as asphalt concrete contained 25% natural sand. The asphalt concrete contained 100% and 75% of natural sand exhibited high fatigue life at low level of microstrain (250. The main conclusion of this study found that best proportion of natural sand to be added to an asphaltic concrete mixture is falling within the range (0% and 25% by weight of fraction (passing No.8 and retained on No.200 sieve .

Performance Evaluation of Stone Mastic Asphalt and Hot Mix Asphalt Mixtures Containing Recycled Concrete Aggregate

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Mohammad Saeed Pourtahmasb

2014-01-01

Full Text Available Environmental and economic considerations have encouraged civil engineers to find ways to reuse recycled materials in new constructions. The current paper presents an experimental research on the possibility of utilizing recycled concrete aggregates (RCA in stone mastic asphalt (SMA and hot mix asphalt (HMA mixtures. Three categories of RCA in various percentages were mixed with virgin granite aggregates to produce SMA and HMA specimens. The obtained results indicated that, regardless of the RCA particular sizes, the use of RCA to replace virgin aggregates increased the needed binder content in the asphalt mixtures. Moreover, it was found that even though the volumetric and mechanical properties of the asphalt mixtures are highly affected by the sizes and percentages of the RCA but, based on the demands of the project and traffic volume, utilizing specific amounts of RCA in both types of mixtures could easily satisfy the standard requirements.

The use of waste materials in asphalt concrete mixtures.

Science.gov (United States)

Tuncan, Mustafa; Tuncan, Ahmet; Cetin, Altan

2003-04-01

The purpose of this study was to investigate (a) the effects of rubber and plastic concentrations and rubber particle sizes on properties of asphalt cement, (b) on properties of asphalt concrete specimens and (c) the effects of fly ash, marble powder, rubber powder and petroleum contaminated soil as filler materials instead of stone powder in the asphalt concrete specimens. One type of limestone aggregate and one penetration-graded asphalt cement (75-100) were used. Three concentrations of rubber and plastic (i.e. 5%, 10% and 20% of the total weight of asphalt cement), three rubber particle sizes (i.e. No. 4 [4.75mm] - 20 [0.85 mm], No. 20 [0.85mm] - 200 [0.075mm] and No. 4 [4.75mm] - 200 [0.075mm]) and one plastic particle size (i.e. No. 4 [4.75mm] - 10 [2.00mm]) were also used. It was found that while the addition of plastic significantly increased the strength of specimens, the addition of rubber decreased it. No. 4 [4.75mm] - 200 [0.075mm] rubber particles showed the best results with respect to the indirect tensile test. The Marshall stability and indirect tensile strength properties of plastic modified specimens increased. Marble powder and fly ash could be used as filler materials instead of stone powder in the asphalt concrete pavement specimens.

Crack repair of asphalt concrete with induction energy

NARCIS (Netherlands)

García, A.; Schlangen, E.; Ven, M. van de; Vliet, D. van

2011-01-01

It is well known that the healing rates of asphalt courses increase with the temperature. A new method, induction heating, is used in this paper to increase the lifetime of asphalt concrete pavements. Mastic will be first made electrically conductive by the addition of conductive fibers. Then it

Value-added utilisation of recycled concrete in hot-mix asphalt.

Science.gov (United States)

Wong, Yiik Diew; Sun, Darren Delai; Lai, Dickson

2007-01-01

The feasibility of partial substitution of granite aggregate in hot-mix asphalt (HMA) with waste concrete aggregate was investigated. Three hybrid HMA mixes incorporating substitutions of granite fillers/fines with 6%, 45% untreated, and 45% heat-treated concrete were evaluated by the Marshall mix design method; the optimum binder contents were found to be 5.3%, 6.5% and 7.0% of grade Pen 60/70 bitumen, respectively. All three hybrid mixes satisfied the Marshall criteria of the Singapore Land Transport Authority (LTA) W3B wearing course specification. The hybrid mix with 6% concrete fillers gave comparable resilient modulus and creep resistance as the conventional W3B mix, while hybrid mixes with higher concrete substitutions achieved better performance. X-ray diffraction (XRD) showed the distinct presence of free lime in the heat-treated concrete, while the scanning electron microscope (SEM) provided an in-depth perspective of the concrete grains in the HMA matrix. The results suggest feasible use of waste concrete as partial aggregate substitution in HMA.

Design and Properties of Asphalt Concrete Mixtures Using Renewable Bioasphalt Binder

Science.gov (United States)

Setyawan, A.; Djumari; Irfansyah, P. A.; Shidiq, A. M.; Wibisono, I. S.; Fauzy, M. N.; Hadi, F. N.

2017-02-01

The needs of petroleum asphalt as materials for pavement is very large, while the petroleum classified as natural resources that cannot be renewable. As a result of petroleum dwindling and prices tend to be more expensive. So that requiring other alternative materials as a substitute for conventional asphalt derived from biomass or often called bioasphalt. This study aims to know the volumetric and Marshall characteristics on Asphalt Cement ( AC ) using the Damar asphalt modification to substitute 60/70 penetration asphalt as a binder. The volumetric and Marshall characteristic are porosity, density, flow, stability, and Marshall quotient. The characteristic of asphalt concrete at optimum bitumen content are compared to the conditions from highway agency 1987 and the general specification of asphalt concrete Bina Marga 2010 the third revision. The research uses experimental method in the laboratory with the samples made using the dasphalt modification as binder and incorporating the aggregate gradation no. VII SNI 03-1737-1989. The research is using 15 samples divided into 5 contents of damar asphalt, they are 5%, 5,5%, 6%, 6,5%, dan 7%. Tests carried out using Marshall test equipment to get the value of flow and stability and then be searched the value of optimum damar asphalt content. The result of asphalt concrete analysis using dasphalt modification as binder gives the value of optimum dasphalt content at 5,242%. The most characteristics already met the requirements and specifications.

Evaluation of Colemanite Waste as Aggregate Hot Mix Asphalt Concrete

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Nihat MOROVA

2015-09-01

Full Text Available In this study usability of waste colemanite which is obtained after cutting block colemanite for giving proper shape to blocks as an aggregate in hot mix asphalt. For this aim asphalt concrete samples were prepared with four different aggregate groups and optimum bitumen content was determined. First of all only limestone was used as an aggregate. After that, only colemanite aggregate was used with same aggregate gradation. Then, the next step of the study, Marshall samples were produced by changing coarse and fine aggregate gradation as limestone and colemanite and Marshall test were conducted. When evaluated the results samples which produced with only limestone aggregate gave the maximum Marshall Stability value. When handled other mixture groups (Only colemanite, colemanite as coarse aggregate-limestone as fine aggregate, colemanite as fine aggregate-limestone as coarse aggregate all groups were verified specification limits. As a result, especially in areas where there is widespread colemanite waste, if transportation costs did not exceed the cost of limestone, colemanite stone waste could be used instead of limestone in asphalt concrete mixtures as fine aggregate

A study on engineering characteristics of asphalt concrete using filler with recycled waste lime.

Science.gov (United States)

Sung Do, Hwang; Hee Mun, Park; Suk keun, Rhee

2008-01-01

This study focuses on determining the engineering characteristics of asphalt concrete using mineral fillers with recycled waste lime, which is a by-product of the production of soda ash (Na(2)CO(3)). The materials tested in this study were made using a 25%, 50%, 75%, and 100% mixing ratio based on the conventional mineral filler ratio to analyze the possibility of using recycled waste lime. The asphalt concretes, made of recycled waste lime, hydrated lime, and conventional asphalt concrete, were evaluated through their fundamental engineering properties such as Marshall stability, indirect tensile strength, resilient modulus, permanent deformation characteristics, moisture susceptibility, and fatigue resistance. The results indicate that the application of recycled waste lime as mineral filler improves the permanent deformation characteristics, stiffness and fatigue endurance of asphalt concrete at the wide range of temperatures. It was also determined that the mixtures with recycled waste lime showed higher resistance against stripping than conventional asphalt concrete. It was concluded from various test results that a waste lime can be used as mineral filler and, especially, can greatly improve the resistance of asphalt concrete to permanent deformation at high temperatures.

Asphalt concrete modified by rubber crumbs in transport construction.

Science.gov (United States)

Duhovny, G. S.; Karpenko, AV

2018-03-01

High-temperature and low-temperature characteristics of the rubber-bitumen binder and rubber asphalt concrete based on it are researched. The determination method of binder’s low-temperature characteristics is offered. The estimation of binder’s and pavement’s stability against technological and operational aging is evaluated. Estimation of environmental and economic aspects of using rubber crumbs is made. The possibility of using rubber crumbs as modifier of organic binder for production of asphalt concrete on its base is justified.

Investigating the Properties of Asphalt Concrete Containing Glass Fibers and Nanoclay

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Hasan Taherkhani

2016-06-01

Full Text Available The performance of asphaltic pavements during their service life is highly dependent on the mechanical properties of the asphaltic layers. Therefore, in order to extend their service life, scientists and engineers are constantly trying to improve the mechanical properties of the asphaltic mixtures. One common method of improving the performance of asphaltic mixtures is using different types of additives. This research investigated the effects of reinforcement by randomly distributed glass fibers and the simultaneous addition of nanoclayon some engineering properties of asphalt concrete have been investigated. The properties of a typical asphalt concrete reinforced by different percentages of glass fibers were compared with those containing both the fibers and nanoclay. Engineering properties, including Marshall stability, flow, Marshall quotient, volumetric properties and indirect tensile strength were studied. Glass fibers were used in different percentages of 0.2, 0.4 and 0.6% (by weight of total mixture, and nanoclay was used in 2, 4 and 6% (by the weight of bitumen. It was found that the addition of fibers proved to be more effective than the nanoclay in increasing the indirect tensile strength. However, nanoclay improved the resistance of the mixture against permanent deformation better than the glass fibers. The results also showed that the mixture reinforced by 0.2% of glass fiber and containing 6% nanoclay possessed the highest Marshall quotient, and the mixture containing 0.6% glass fibers and 2% nanoclay possessedthe highest indirect tensile strength.

Mechanical Properties of Hot Mix Crumb Rubber Modified Asphalt Concrete Using Waste Tire

Energy Technology Data Exchange (ETDEWEB)

Kim, Nak Seok; Lee, Woo Yeol [Kyonggi University, Suwon (Korea)

1998-06-30

Wheel tracking and ravelling tests were conducted on the hot mix crumb rubber modified asphalt concrete using waste tire to evaluate the mechanical properties in comparison with conventional asphalt concrete. According to the test results, the modified product was superior to the conventional one by 50% in the resistance of permanent deformation and by 15% in the resistance of durability. The experimental results should recommend that the waste tire is positively recycled for asphalt concrete. (author). 11 refs., 6 tabs., 2 figs.

Stress Regression Analysis of Asphalt Concrete Deck Pavement Based on Orthogonal Experimental Design and Interlayer Contact

Science.gov (United States)

Wang, Xuntao; Feng, Jianhu; Wang, Hu; Hong, Shidi; Zheng, Supei

2018-03-01

A three-dimensional finite element box girder bridge and its asphalt concrete deck pavement were established by ANSYS software, and the interlayer bonding condition of asphalt concrete deck pavement was assumed to be contact bonding condition. Orthogonal experimental design is used to arrange the testing plans of material parameters, and an evaluation of the effect of different material parameters in the mechanical response of asphalt concrete surface layer was conducted by multiple linear regression model and using the results from the finite element analysis. Results indicated that stress regression equations can well predict the stress of the asphalt concrete surface layer, and elastic modulus of waterproof layer has a significant influence on stress values of asphalt concrete surface layer.

Laboratory Study on the Fatigue Resistance of Asphaltic Concrete Containing Titanium Dioxide

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Buhari Rosnawati

2018-01-01

Full Text Available This study aims to evaluate the fatigue performance of modified asphalt mixture using Indirect Tensile Fatigue Test. Titanium Dioxide (TiO2 powder in a form of rutile was used for producing asphalt concrete with lower mixing and compaction temperature compared to conventional hot mix asphalt without reducing its physical and mechanical also resistance to fatigue. The characteristic of the asphalt and modified asphalt was evaluated using penetration test, softening test and rotational viscosity test. Titanium dioxide of 2%, 4%, 6%, 8% and 10% by weight of asphalt has been incorporated into unaged 80/100 asphalt mix in order to improvise its performance and to fulfill the objectives of this experimental study. As a result, TiO2 as an additive is potential to decrease the penetration and increasing the softening point of the asphalt. In terms of fatigue performance testing, addition TiO2 additive does help in improving the fatigue properties as it shows greater result than the control asphalt. In conclusion, TiO2 is great in improving fatigue properties.

Effect of water on the triaxial response under monotonic loading of asphalt concrete used in dams

Science.gov (United States)

Gaxiola Hernández, Alberto; Ossa López, Alexandra

2018-01-01

Embankment dams with asphalt concrete cores have been constructed on practically all continents with satisfactory results. Nowadays many advantages, such as the mechanical strength, are known that makes asphalt concrete a competitive alternative for the construction of the impervious elements of dams. However, the current available information does not describe the effect of prolonged contact between asphalt concrete and water on the structure of an embankment dam. In this research cylindrical asphalt concrete specimens with a void content similar to that used in impervious barriers of dams were fabricated and submerged in water for a prolonged period to simulate the conditions experienced by asphalt concrete placed inside an embankment dam as its core material. Subsequently, triaxial compression tests were conducted on the specimens. The results indicated that the asphalt concrete exhibited a reduction in strength because of the saturation process to which the material was subjected. However, no changes were observed in the mechanical response to prolonged contact with water for periods of up to 12 months.

Fracture resistance of asphalt concrete modified with crumb rubber at low temperatures

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A. Razmi

2018-05-01

Full Text Available The main objective of this study is to obtain fracture toughness of asphalt concrete modified by Crumb Rubber (CR and Sasobit at low temperatures. First, Bending Beam Rheometer (BBR test was performed on unmodified binder (binder 60/70, binder 60/70 + 3%Sasobit and 20%CR + 3%Sasobit modified asphalt binder to find how each modifier affect asphalt binder stiffness and relaxation rate at low temperatures. Mixed mode I/II fracture tests were conducted by cracked Semi-Circular Bending (SCB specimens and the critical stress intensity factors were calculated for pure mode I, mixed mode I/II and pure mode II conditions. Results of BBR tests indicated that 20%CR + 3%Sasobit reduces stiffness and the m-value increase at low temperatures. As a result, 20%CR + 3%Sasobit has positive effect on low temperatures performance by improving thermal cracking resistance. Also, according to the fracture toughness test results, the Warm Mix Asphalt (WMA mixture containing 20% CR, shows higher resistance against crack growth than WMA mixture. It was found that mixed mode I/II can be more detrimental than pure mode I and II conditions. Keywords: Crumb rubber, Asphalt concrete, Bending Beam Rheometer, Fracture resistance, Semi-circular bending test

Recommendations for Longitudinal Post-Tensioning in Full-Depth Precast Concrete Bridge Deck Panels

OpenAIRE

Bowers, Susan Elizabeth

2007-01-01

Full-depth precast concrete panels offer an efficient alternative to traditional cast-in-place concrete for replacement or new construction of bridge decks. Research has shown that longitudinal post-tensioning helps keep the precast bridge deck in compression and avoid problems such as leaking, cracking, spalling, and subsequent rusting on the beams at the transverse panel joints. Current design recommendations suggest levels of initial compression for precast concrete decks in a very limit...

Investigation of Properties of Asphalt Concrete Containing Boron Waste as Mineral Filler

Directory of Open Access Journals (Sweden)

Cahit GÜRER

2016-05-01

Full Text Available During the manufacture of compounds in the boron mining industry a large quantity of waste boron is produced which has detrimental effects on the environment. Large areas have to be allocated for the disposal of this waste. Today with an increase in infrastructure construction, more efficient use of the existing sources of raw materials has become an obligation and this involves the recycling of various waste materials. Road construction requires a significant amount of raw materials and it is possible that substantial amounts of boron-containing waste materials can be recycled in these applications. This study investigates the usability of boron wastes as filler in asphalt concrete. For this purpose, asphalt concrete samples were produced using mineral fillers containing 4%, 5%, 6%, 7% and 8% boron waste as well as a 6% limestone filler (6%L as the control sample. The Marshall Design, mechanical immersion and Marshall Stability test after a freeze-thaw cycle and indirect tensile stiffness modulus (ITSM test were performed for each of the series. The results of this experimental study showed that boron waste can be used in medium and low trafficked asphalt concrete pavements wearing courses as filler.

Development of high stability hot mix asphalt concrete with hybrid binder

Directory of Open Access Journals (Sweden)

Toshiaki Hirato

2014-12-01

Full Text Available Cost reduction of public works projects has been desired due to severe financial circumstances. Therefore, asphalt pavement has been requested to extend its life. Semi-flexible pavement or epoxy asphalt pavement, which has high rutting resistance and oil resistance, may be applied to the place where these performances ae demanded. However, special technique is required in manufacturing and construction. In addition, these materials have also raised a problem that they cannot be recycled. Meanwhile, conventional asphalt pavement has several drawbacks. It is vulnerable to rutting caused by traffic load and damage caused by petroleum oils such as gasoline or motor oil. The materials used in asphalt mixtures were studied for improving the durability of asphalt mixture. A high stability asphalt concrete was developed which has equal or superior performance to semi-flexible pavement and epoxy asphalt pavement. In this paper, the process of selecting the substance and the characteristics evaluation of the developed mixtures ae described. Furthermore, an inspection result as well as follow-up survey of the performance of the developed mixtures obtained from trial and actual construction is shown.

Performance of asphaltic concrete incorporating styrene butadiene rubber subjected to varying aging condition

Science.gov (United States)

Salah, Faisal Mohammed; Jaya, Ramadhansyah Putra; Mohamed, Azman; Hassan, Norhidayah Abdul; Rosni, Nurul Najihah Mad; Mohamed, Abdullahi Ali; Agussabti

2017-12-01

The influence of styrene butadiene rubber (SBR) on asphaltic concrete properties at different aging conditions was presented in this study. These aging conditions were named as un-aged, short-term, and long-term aging. The conventional asphalt binder of penetration grade 60/70 was used in this work. Four different levels of SBR addition were employed (i.e., 0 %, 1 %, 3 %, and 5 % by binder weight). Asphalt concrete mixes were prepared at selected optimum asphalt content (5 %). The performance was evaluated based on Marshall Stability, resilient modulus, and dynamic creep tests. Results indicated the improving stability and permanent deformation characteristics that the mixes modified with SBR polymer have under aging conditions. The result also showed that the stability, resilient modulus, and dynamic creep tests have the highest rates compared to the short-term aging and un-aged samples. Thus, the use of 5 % SBR can produce more durable asphalt concrete mixtures with better serviceability.

An investigation of waste foundry sand in asphalt concrete mixtures.

Science.gov (United States)

Bakis, Recep; Koyuncu, Hakan; Demirbas, Ayhan

2006-06-01

A laboratory study regarding the reuse of waste foundry sand in asphalt concrete production by replacing a certain portion of aggregate with WFS was undertaken. The results showed that replacement of 10% aggregates with waste foundry sand was found to be the most suitable for asphalt concrete mixtures. Furthermore, the chemical and physical properties of waste foundry sand were analysed in the laboratory to determine the potential effect on the environment. The results indicated that the investigated waste foundry sand did not significantly affect the environment around the deposition

Influence of Hydrated Lime on the Properties and Permanent Deformation of the Asphalt Concrete Layers in Pavement

Directory of Open Access Journals (Sweden)

Al-Tameemi Ahmed F.

2015-07-01

Full Text Available Flexible or asphalt concrete pavement is the paving system most widely adopted all over the world. It has been recognized that there are many different types of the factors affecting the performance and durability of asphalt concrete pavement, including the service conditions, such as: the variation of temperature from mild to extremes and the repeated excessive axle loading as well as the inadequate quality of the raw materials. All of these when combined together are going to accelerate the occurrence of distresses in flexible pavement such as permanent deformation and fatigue cracking. As the result, there has an urgent need to enhance the ability of asphalt concrete mixture to resist distresses happened in pavement. Use of additives is one of the techniques adopted to improve pavement properties. It has been found that hydrated lime might be one of the effective additives because it is widely available and relatively cheap compared to other modifiers like polymers. This paper presents an experimental study of the hydrated-lime modified asphalt concrete mixtures. Five different percentages of the hydrated lime additive were investigated, namely (1, 1.5, 2, 2.5 and 3 percent. The hydrated lime additive was used as partial replacement of limestone filler by total weight of the aggregate. The designed Hot Mix Asphalt (HMA concretes are for the application of three pavement courses, i.e. Surface, Leveling and Base. These mixtures are designed and tested following Marshall procedure and uniaxial repeated loading to evaluate permanent deformation at different temperatures of 20°C, 40°C and 60°C. The experimental results show that the addition of hydrated lime as a partial replacement of ordinary limestone mineral filler results a significant improvement on mechanical properties and the resistant to permanent deformation of the designed asphalt concrete mixtures.

Effect of tack coat on bonding characteristics at interface between asphalt concrete layers; Asphalt concrete no sokan fuchaku ni okeru tack concrete no koka

Energy Technology Data Exchange (ETDEWEB)

Hachiya, Y. [Port and Harbour Research Inst., Kanagawa (Japan); Umeno, S. [Ministry of Transport, Tokyo (Japan); Sato, K. [Nagaoka National College of Technology, Niigata (Japan)

1997-08-20

The effect of tack coat on bonding characteristics at the interface between surface and base layers was studied for airport asphalt pavement. In a fracture behavior, shear stress is first caused by horizontal loading at the interface between surface and base layers, resulting in peeling of the layers in the case of poor bonding. Further loading under the above condition results in fracture of asphalt concrete layers by bending or tensile actions. The bonding strength between layers decreases with an increase in interval of construction between surface and base layers, while the bonding strength between layers increases with sufficient curing of tack coat. Curing for 1 hour in the daytime and 6 hours or more in the nighttime is sufficient for evaporation of water content in asphalt emulsion. The use of conventional asphalt emulsion for the sandy interface as tack coat deduces the bonding strength in the case of poor curing. Asphalt emulsion containing high-penetration rubber can improve the bonding strength. 12 refs., 27 figs., 2 tabs.

Asphalt Concrete for Cold Regions, A Comparative Laboratory Study and Analysis of Mixtures Containing Soft and Hard Grades of Asphalt Cement,

Science.gov (United States)

1980-01-01

Justification January 1980 BY Distribution Availabilit CodesIAvail an~d/or Dist special Prepa red for DIRECTORATE OF MILITARY PROGRAMS OFFICE, CHIEF OF...of water on the resilient modulus of asphalt treated mixes. Proecedinfp 4. Asphalt concrete mixes using the Tilton aggregates Association of Asphalt

Aggregate Toughness/Abrasion Resistance and Durability/Soundness Tests Related to Asphalt Concrete Performance in Pavements

Science.gov (United States)

1998-03-01

The properties of aggregates used in asphalt concretes are very important to the performance of the pavements in which the asphalt concretes are used. Often pavement distress, such as stripping and rutting, can be traced directly to the aggregates us...

Extending the Lifespan of Porous Asphalt Concrete

NARCIS (Netherlands)

Zhang, Y.

2015-01-01

Porous Asphalt (PA) concrete is widely used as a surfacing layer on highways in the Netherlands. The service life of PA wearing courses is limited because of the fact that it is vulnerable to raveling. The possibilities of applying preventive maintenance to PA wearing courses by means of spraying

Effects of conductive fillers on temperature distribution of asphalt pavements

International Nuclear Information System (INIS)

Chen Mingyu; Wu Shaopeng; Zhang Yuan; Wang Hong

2010-01-01

The sun provides a cheap and abundant source of clean and renewable energy. Solar cells have been used to capture this energy and generate electricity. A more useful form of the solar cell would be asphalt pavements, which get heated up by solar radiation. Graphite powders are utilized as thermal conductive fillers to make an asphalt collector conductive so as to improve the efficiency of the asphalt collector. Accounting for the important application conditions and evaluating the effects of the heat conductive materials and the solar energy absorbability of the conductive asphalt collector, a finite element model has been developed to predict temperature distributions in the conductive asphalt solar collector. In this study, an experimental validation exercise was conducted using the measured data taken from full-depth asphalt slabs. Validation results showed that the model can satisfactorily predict the temperature distributions in asphalt concrete slabs. The optimal depth is 25-50 mm for placing pipes that serve as the heat exchanger. Meanwhile, the effect of the surroundings on the solar energy potential of the asphalt collector was noticeable.

Quality control of recycled asphaltic concrete : final report.

Science.gov (United States)

1982-07-01

This study examined the variations found in recycled asphaltic concrete mix based upon plant quality control data and verification testing. The data was collected from four recycled hot-mix projects constructed in 1981. All plant control and acceptan...

Use of rubber asphalt binder with graded aggregate for seal coats

Energy Technology Data Exchange (ETDEWEB)

1979-01-01

It has been known that incorporating rubber particles into asphalt can improve highway pavement performance. This paper describes a test program on pavement construction using asphalts containing recycled rubber. During the summer 1978, eight test sections were constructed in parts of the Saskatchewan road system to evaluate seal coats using rubber-asphalt as a binder membrane and a graded aggregate as protective cover. Test sections were chosen to represent typical road surface types and different states of repair for each type. These types included prime subgrade, cold-mix on subgrade, primed granular base course, asphaltic concrete on granular base, and full depth asphaltic concrete. Problems with construction materials, techniques, and equipment are discussed. Performance and economics were evaluated to determine whether low cost cold mix and current seal coat surfaces could be replaced successfully and economically by this method of construction. It was shown that use of reclaimed rubber for rubberized asphalt seal coats on Saskatechewan highways is a practical construction application. The economic justification for rubber asphalt seals will be determined after a full assessment of performance. Initial indications are that Saskatchewan graded aggregates are a suitable cover material for the rubberized asphalt membranes used in the trials. 8 refs., 16 figs., 7 tabs.

Modelling of Asphalt Concrete Stiffness in the Linear Viscoelastic Region

Science.gov (United States)

Mazurek, Grzegorz; Iwański, Marek

2017-10-01

Stiffness modulus is a fundamental parameter used in the modelling of the viscoelastic behaviour of bituminous mixtures. On the basis of the master curve in the linear viscoelasticity range, the mechanical properties of asphalt concrete at different loading times and temperatures can be predicted. This paper discusses the construction of master curves under rheological mathematical models i.e. the sigmoidal function model (MEPDG), the fractional model, and Bahia and co-workers’ model in comparison to the results from mechanistic rheological models i.e. the generalized Huet-Sayegh model, the generalized Maxwell model and the Burgers model. For the purposes of this analysis, the reference asphalt concrete mix (denoted as AC16W) intended for the binder coarse layer and for traffic category KR3 (5×105 controlled strain mode. The fixed strain level was set at 25με to guarantee that the stiffness modulus of the asphalt concrete would be tested in a linear viscoelasticity range. The master curve was formed using the time-temperature superposition principle (TTSP). The stiffness modulus of asphalt concrete was determined at temperatures 10°C, 20°C and 40°C and at loading times (frequency) of 0.1, 0.3, 1, 3, 10, 20 Hz. The model parameters were fitted to the rheological models using the original programs based on the nonlinear least squares sum method. All the rheological models under analysis were found to be capable of predicting changes in the stiffness modulus of the reference asphalt concrete to satisfactory accuracy. In the cases of the fractional model and the generalized Maxwell model, their accuracy depends on a number of elements in series. The best fit was registered for Bahia and co-workers model, generalized Maxwell model and fractional model. As for predicting the phase angle parameter, the largest discrepancies between experimental and modelled results were obtained using the fractional model. Except the Burgers model, the model matching quality was

Design Method and Cost-Benefit Analysis of Hybrid Fiber Used in Asphalt Concrete

Directory of Open Access Journals (Sweden)

Haiwei Zhang

2016-01-01

Full Text Available Fiber, as an additive, can improve the performance of asphalt concrete and be widely studied, but only a few works have been done for hybrid fiber. This paper presents a new and convenient method to design hybrid fiber and verifies hybrid fiber’s superiority in asphalt pavement engineering. Firstly, this paper expounds the design method used as its applied example with the hybrid fiber composed of lignin, polyester, and polypropylene fibers. In this method, a direct shear device (DSD is used to measure the shear damage energy density (SDED of hybrid fiber modified asphalts, and range and variance statistical analysis are applied to determine the composition proportion of hybrid fiber. Then, the engineering property of hybrid fiber reinforced asphalt concrete (AC-13 is investigated. Finally, a cost-benefit model is developed to analyze the advantage of hybrid fiber compared to single fibers. The results show that the design method employed in this paper can offer a beneficial reference. A combination of 1.8% of lignin fiber and 2.4% of polyester fiber plus 3.0% polypropylene fiber presented the best reinforcement of the hybrid fiber. The cost-benefit model verifies that the hybrid fiber can bring about comprehensive pavement performance and good economy.

Evaluation of recycled hot mix asphalt concrete on Route 220 : final report.

Science.gov (United States)

1985-01-01

This report describes the performance of an approximately 8-mi section of roadway on which the rod two layers of asphalt concrete were milled, recycled through a conventional asphalt batch plant, and relaid. The recycled mix consisted of about 40% re...

Evaluation of warm mix technologies for use in asphalt rubber - asphaltic concrete friction courses (AR\\0x2010ACFC) : final report.

Science.gov (United States)

2016-07-01

The objective of this research project was to determine whether warm mix asphalt (WMA) technologies can be : used by the Arizona Department of Transportation (ADOT) for the production of an asphalt rubberasphaltic : concrete friction course (AR...

Effects of crumb rubber content and curing time on the properties of asphalt concrete and stone mastic asphalt using dry process

Directory of Open Access Journals (Sweden)

H.T. Tai Nguyen

2018-05-01

Full Text Available Along with the rapid increase in the number of road vehicles, a large amount of waste tires have been created, causing negative effects to the environment. Many attempts have been made to effectively reduce this type of solid waste including the reuse of recycled rubber powder from waste tires as an additive for improving the performance of asphalt mixtures. In this work, the authors aim to study the effects of crumb rubber (CR on the mechanical properties, especially the rutting resistance, of CR modified asphalt concrete (AC and stone mastic asphalt (SMA by varying two factors-namely, the content of additive and the curing time. The dimension of used CR ranges from 0 to 2.36 mm, which is not too coarse for promoting the CR–bitumen interaction and not too fine for facilitating the production of CR. The content of CR was increased gradually from 0 to 3% to examine the effects of CR content on the engineering properties and determine the optimal content in the mixture. It was observed that the optimal content is 1.5–2%, while the optimal curing time that contributes to the maximal increase in the mechanical characteristics of both mixtures could not be determined. In the range of 0–5 h of curing time, the longer the asphalt mixture is maintained at a high temperature, the better the performance of mixture will be. Ageing was found to have influence on the performance of asphalt mixtures; however, its effects are not as important as those of CR modification. Keywords: Crumb rubber, Dry process, Asphalt concrete, SMA, Curing time

The shakeout scenario: Meeting the needs for construction aggregates, asphalt, and concrete

Science.gov (United States)

Langer, W.H.

2011-01-01

An Mw 7.8 earthquake as described in the ShakeOut Scenario would cause significantdamage to buildings and infrastructure. Over 6 million tons of newly mined aggregate would be used for emergency repairs and for reconstruction in the five years following the event. This aggregate would be applied mostly in the form of concrete for buildings and bridges, asphalt or concrete for pavement, and unbound gravel for applications such as base course that goes under highway pavement and backfilling for foundations and pipelines. There are over 450 aggregate, concrete, and asphalt plants in the affected area, some of which would be heavily damaged. Meeting the increased demand for construction materials would require readily available permitted reserves, functioning production facilities, a supply of cement and asphalt, a source of water, gas, and electricity, and a trained workforce. Prudent advance preparations would facilitate a timely emergency response and reconstruction following such an earthquake. ?? 2011, Earthquake Engineering Research Institute.

Nanosized carbon modifier used to control plastic deformations of asphalt concrete

Science.gov (United States)

Vysotskaya, M. A.; Shekhovtsova, S. Yu; Barkovsky, D. V.

2018-03-01

Aspects related to plastic track, the formation of which directly depends on the properties of the binder in the composition of asphalt concrete, are considered in this article. The effect of primary carbon nanomaterials on the quality of polymer and bitumen binder in comparison with the traditional binder including cross-linking agent is evaluated. The influence of binders on the resistance to the track formation of type B asphalt concrete is studied. To quantify the service life of surfacing, a calculation method based on the criteria for the resistance of surfacing material to plastic deformations is used.

Assessment of Quality of Asphalt Concrete used in Road ...

African Journals Online (AJOL)

OLUWASOGO

subjected to bitumen extraction and sieve analysis, hot mix Marshall Stability and flow tests, penetration and ... asphalt concrete as well as other structures of the flexible pavement. ... High-quality road networks are very important to the.

Assessment of Asphalt Concrete Reinforcement Grid in Flexible Pavements

Science.gov (United States)

2016-05-01

successfully used as interlayers include asphalt rubber and geotextiles, and the applica- tion of recycling techniques to rework the upper 2–4 in. of the...from a set of weights dropped from increasingly greater predetermined heights onto a rubber buffer system connected to a 12 in. diameter segmented...pavement temperature at depth, IR = the infrared pavement surface temperature (°C), D = the asphalt depth to estimate the temperature (mm), 1

Feasibility of reclaimed asphalt pavement as aggregate in portland cement concrete pavements.

Science.gov (United States)

2013-11-01

This research effort was focused on evaluating the feasibility of using minimally processed reclaimed : asphalt pavement (RAP) as aggregate replacement in concrete pavements. This research demonstrated : that concretes with up to 50 percent of the fi...

Basic Performance of Fibre Reinforced Asphalt Concrete with Reclaimed Asphalt Pavement Produced In Low Temperatures with Foamed Bitumen

Science.gov (United States)

Chomicz-Kowalska, Anna; Iwański, Mateusz M.; Mrugała, Justyna

2017-10-01

During the reconstruction of road pavements, the reclaimed asphalt pavement (RAP), which is obtained through milling of the worn out existing asphalt, is commonly used for producing new base courses in cold recycling processes. Two of these techniques are most popular: one using mineral-cement-emulsion mixes and one utilizing mineral cement mixes with foamed bitumen. Additionally, some amounts of RAP can be incorporated into traditional hot mix asphalt. The demand for energy efficient and environmentally friendly solutions however, results in a need for development of new techniques that would result in cheaper and more reliable solutions with smaller carbon footprint. The reduction of processing temperatures with simultaneous incorporation of reclaimed material is the most efficient way of obtaining these objectives, but it often results in the overall decrease of bituminous mix quality. The paper presents the possibility of using RAP for producing asphalt concrete in warm mix asphalt (WMA) production process by the use of foamed bitumen modified with Fischer-Tropsch synthetic wax and polymer-basalt fibers. Additionally, a series of reference mixtures were produced to investigate the effects of the additives and of the warm process. The carried out analyses and tests shown that the experimental warm mix asphalt produced with RAP and foamed bitumen returned satisfactory performance. The introduction of synthetic F-T wax in the warm foam bitumen mixes resulted in a significantly improved compaction levels and moisture and frost resistance and the addition of polymer-basalt fibers has further improved the permanent deformation resistance of the mixes. All of the designed and tested mixes have fulfilled the requirements for binding course asphalt concrete with medium traffic loads.

Experimental Study on Modification of Concrete with Asphalt Admixture

Science.gov (United States)

Bołtryk, Michał; Małaszkiewicz, Dorota; Pawluczuk, Edyta

2017-10-01

Durability of engineering structures made of cement concrete with high compressive strength is a very vital issue, especially when they are exposed to different aggressive environments and dynamic loads. Concrete resistance to weathering actions and chemical attack can be improved by combined chemical and mechanical modification of concrete microstructure. Asphalt admixture in the form of asphalt paste (AP) was used for chemical modification of cement composite microstructure. Concrete structure was formed using special technology of compaction. A stand for vibro-vibropressing with regulated vibrator force and pressing force was developed. The following properties of the modified concrete were tested: compressive strength, water absorption, freeze-thaw resistance, scaling resistance in the presence of de-icing agents, chloride migration, resistance to CO2 and corrosion in aggressive solutions. Corrosion resistance was tested alternately in 1.8% solutions of NH4Cl, MgSO4, (NH2)2CO and CaCl2, which were altered every 7 days; the experiment lasted 9.5 months. Optimum compaction parameters in semi-industrial conditions were determined: ratio between piston stress (Qp ) and external top vibrator force (Po ) in the range 0.4÷-0.5 external top vibrator force 4 kN. High strength concretes with compressive strength fcm = 60÷70 MPa, very low water absorption (barrier formed in pores of cement hydrates against dioxide and chloride ions. Concrete specimens containing AP 4% c.m. and consolidated by vibro-vibropressing method proved to be practically resistant to highly corrosive environment. Vibro-vibropressing compaction technology of concrete modified with AP can be applied in prefabrication plants to produce elements for road, bridge and hydraulic engineering constructions.

Steel slag in hot mix asphalt concrete : final report

Science.gov (United States)

2000-04-01

In September 1994, steel slag test and control sections were constructed in Oregon to evaluate the use of steel slag in hot mix asphalt concrete (HMAC). This report covers the construction and five-year performance of a pavement constructed with 30% ...

Determination of Stone-Mastic Asphalt Concrete Durability

Science.gov (United States)

Yastremsky, D. A.; Abaidullina, T. N.; Chepur, P. V.

2018-05-01

The paper is focused on determination of durability of the stone-mastic asphalt (SMA) concrete, containing various stabilizing additives: "Armidon" (authors’ development) and "Viatop". At the first stage of experiments, the APA method was used to determine the rutting in the SMA containing these additives. Strength test for only top layers of asphalt concrete surface is insufficient for the calculation of the pavement fatigue resistance limits. Due to this fact, a comprehensive approach was employed which incorporates the interaction of the surface and subgrade natural soil. To analyze the road surface stress-strain state and to determine the durability margin, a numerical model was used (describes the processes of fatigue life). The model was developed basing on the finite element method (FEM) in the ANSYS program. Conducted studies and numerical calculations allowed obtaining the minimum and maximum stress values in the structure affected zones and in the zones of plastic deformations occurrence in artificial and natural bases. It allows predicting deformation processes during repeated wheel loads caused by moving vehicles. In course of studies, the results of static stresses in the pavement were also obtained.

Evaluation of moisture damage in asphalt concrete with CRM motorcycle tire waste passing #50 sieve size

Science.gov (United States)

Siswanto, Henri; Supriyanto, Bambang; Pranoto, Pranoto; Chandra, Pria Rizky; Hakim, Arief Rahman

2017-09-01

The objective of this experimental research is to evaluate moisture damage in Asphalt Concrete (AC) with Crumb Rubber Modified (CRM) motorcycle tire waste passing #50 and retaining #100 sieve size. Two gradations were used in this research, the first gradation is usual for asphalt concrete base (ACB) and the second gradation is for asphalt concrete wearing course (ACWC). Marshall testing apparatus was used for testing the Marshall specimens. Seven levels of CRM content were used, namely 0%, 0.5%, 1%, 1.5%, 3%, 4.5% and 6% by weight of mixtures. Retained stability represent the level of moisture damage of AC pavement. The result indicates that addition CRM to the AC mixture increases their the stability to a maximum value and subsequent addition decrease the stability. The addition CRM to AC decreases their moisture damage susceptibility. AC with 1% CRM is the best asphalt-CRM mix.

Laboratory Study on the Fatigue Resistance of Asphaltic Concrete Containing Titanium Dioxide

Science.gov (United States)

Buhari, Rosnawati; Ezree Abdullah, Mohd; Khairul Ahmad, Mohd; Azhar Tajudin, Saiful; Khatijah Abu Bakar, Siti

2018-03-01

This study aims to evaluate the fatigue performance of modified asphalt mixture using Indirect Tensile Fatigue Test. Titanium Dioxide (TiO2) powder in a form of rutile was used for producing asphalt concrete with lower mixing and compaction temperature compared to conventional hot mix asphalt without reducing its physical and mechanical also resistance to fatigue. The characteristic of the asphalt and modified asphalt was evaluated using penetration test, softening test and rotational viscosity test. Titanium dioxide of 2%, 4%, 6%, 8% and 10% by weight of asphalt has been incorporated into unaged 80/100 asphalt mix in order to improvise its performance and to fulfill the objectives of this experimental study. As a result, TiO2 as an additive is potential to decrease the penetration and increasing the softening point of the asphalt. In terms of fatigue performance testing, addition TiO2 additive does help in improving the fatigue properties as it shows greater result than the control asphalt. In conclusion, TiO2 is great in improving fatigue properties.

Effect of Lime Addition Methods on Performance Related Properties of Asphalt Concrete Mixture

Directory of Open Access Journals (Sweden)

Amjad Hamd Khalil Albayati

2016-09-01

Full Text Available In the recent years, some of the newly constructed asphalt concrete pavements in Baghdad as well as other cities across Iraq showed premature failures with consequential negative impact on both roadway safety and economy. Frequently, load associated mode of failure (rutting and fatigue as well as, occasionally, moisture damage in some poorly drained sections are the main failure types found in those newly constructed road. In this research, hydrated lime was introduced into asphalt concrete mixtures of wearing course in two methods. The first one was the addition of dry lime on dry aggregate and the second one was the addition of dry lime on saturated surface dry aggregate moisturized by 2.0 to 3.0 percent of water. For each type of addition, five different percentages of lime as a partial replacement of ordinary limestone mineral filler were used; these were; 1.0, 1.5, 2.0, 2.5, and 3 percent by weight of aggregate besides a control mixture that did not contain lime. Marshall Mix design method was used and the performance properties of moisture damage, resilient modulus, permanent deformation and fatigue characteristics were evaluated using indirect tensile strength, uniaxial repeated loading and repeated flexural beam tests. Also, VESYS5W software was implemented to evaluate the pavements performance in terms of rut depth and fatigue area for a typical pavement structure. The main conclusion withdrawn from this research revealed that the use of 2.5 percent hydrated lime in dry addition method and wet addition method showed an improved fatigue and permanent deformation characteristics, lower moisture susceptibility and high resilient modulus.

Marshall properties of asphalt concrete using crumb rubber modified of motorcycle tire waste

Science.gov (United States)

Siswanto, Henri; Supriyanto, Bambang; Pranoto, Chandra, Pria Rizky; Hakim, Arief Rahman

2017-09-01

The aim of this study is to explain the effect of Crumb Rubber Modified (CRM) of motorcycle tire waste on Marshall properties of asphalt mix. Two types of aggregate gradation, asphalt concrete wearing course (ACWC) and asphalt concrete base (ACB), and CRM passing #50 sieve size were used. Seven levels of CRM content were investigated in this study, namely 0%, 0.5%, 1%, 1.5%, 3%, 4.5%, and 6% by weight of aggregate. Marshall test is conducted on Marshall specimens. The specimens are tested in their optimum binder content (OBC). The results indicate that CRM addition of motorcycle tire waste increases the Marshall stability of the both mix, ACWC and ACB. In addition, 1% CRM addition of motorcycle tire waste of the total mix weight is the best mix.

Density measurement verification for hot mix asphalt concrete pavement construction.

Science.gov (United States)

2010-06-01

Oregon Department of Transportation (ODOT) requires a minimum density for the construction of dense-graded hot mix asphalt concrete (HMAC) pavements to ensure the likelihood that the pavement will not experience distresses that reduce the expected se...

Density measurement verification for hot mixed asphalt concrete pavement construction.

Science.gov (United States)

2010-06-01

Oregon Department of Transportation (ODOT) requires a minimum density for the construction of dense-graded hot mix asphalt concrete (HMAC) pavements to ensure the likelihood that the pavement will not experience distresses that reduce the expected se...

Characterisation of Asphalt Concrete Using Nanoindentation.

Science.gov (United States)

Barbhuiya, Salim; Caracciolo, Benjamin

2017-07-18

In this study, nanoindentation was conducted to extract the load-displacement behaviour and the nanomechanical properties of asphalt concrete across the mastic, matrix, and aggregate phases. Further, the performance of hydrated lime as an additive was assessed across the three phases. The hydrated lime containing samples have greater resistance to deformation in the mastic and matrix phases, in particular, the mastic. There is strong evidence suggesting that hydrated lime has the most potent effect on the mastic phase, with significant increase in hardness and stiffness.

Specifications and Construction Methods for Asphalt Concrete and Other Plant-Mix Types, 3rd Edition.

Science.gov (United States)

Asphalt Inst., College Park, MD.

The purpose of this publication is to assist engineers in the analysis, design and control of paving projects that use asphalt concrete and other asphalt plant-mixes. The scope of this new third edition has been enlarged, and changes necessitated by advances in asphalt technology have been incorporated. Chapters I and II and Appendices A and B…

Calculation of the temperature of asphalt concrete at making the joints of multilane road pavement of non-rigid type

Directory of Open Access Journals (Sweden)

Giyasov Botir Iminzhonovich

2015-03-01

Full Text Available The construction quality of road surface of non-rigid type essentially depend on providing the temperature regimes in the process of laying and packing of hot asphalt concrete mixtures. In order to provide the required characteristics of asphalt concrete due to the surface width it is necessary to provide the temperature regimes of hot asphalt concrete mixture in the zones of lane connection. The hot mixture is promptly cooling right after laying within several minutes, which results, according to the construction technology and the specific conditions of work production, in temperature abuse of the mixture at joints of the lanes at packing. The authors present the analysis of the technology of arranging multilane road surface by one paver with the possibility of heating the surface lane edge with the temperature of the adjacent lane. The results of the studies of the production conditions effect on the temperature of edge heating of the previously laid lanes, and the time required to achieve the maximum heating temperature depending on the relative thickness of coating layers.

Absorption Characteristics of Cement Combination Concrete Containing Portland Cement, fly ash, and Metakaolin

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Folagbade S.O.

2016-03-01

Full Text Available The resistance to water penetration of cement combination concretes containing Portland cement (PC, fly ash (FA, and metakaolin (MK have been investigated at different water/cement (w/c ratios, 28-day strengths, and depths of water penetration using their material costs and embodied carbon-dioxide (eCO2 contents. Results revealed that, at equal w/c ratio, eCO2 content reduced with increasing content of FA and MK. MK contributed to the 28-day strengths more than FA. Compared with PC, FA reduced cost and increased the depth of water penetration, MK increased cost and reduced the depth of water penetration, and their ternary combinations become beneficial. At equal strengths and levels of resistance to water penetration, most of the cement combination concretes are more environmentally compatible and costlier than PC concrete. Only MK binary cement concretes with 10%MK content or more and ternary cement concretes at a total replacement level of 55% with 10%MK content or more have higher resistance to water penetration than PC concrete.

Thermal stability analysis under embankment with asphalt pavement and cement pavement in permafrost regions.

Science.gov (United States)

Junwei, Zhang; Jinping, Li; Xiaojuan, Quan

2013-01-01

The permafrost degradation is the fundamental cause generating embankment diseases and pavement diseases in permafrost region while the permafrost degradation is related with temperature. Based on the field monitoring results of ground temperature along G214 Highway in high temperature permafrost regions, both the ground temperatures in superficial layer and the annual average temperatures under the embankment were discussed, respectively, for concrete pavements and asphalt pavements. The maximum depth of temperature field under the embankment for concrete pavements and asphalt pavements was also studied by using the finite element method. The results of numerical analysis indicate that there were remarkable seasonal differences of the ground temperatures in superficial layer between asphalt pavement and concrete pavement. The maximum influencing depth of temperature field under the permafrost embankment for every pavement was under the depth of 8 m. The thawed cores under both embankments have close relation with the maximum thawed depth, the embankment height, and the service time. The effective measurements will be proposed to keep the thermal stabilities of highway embankment by the results.

Structural evaluation of asphalt pavements with full-depth reclaimed base.

Science.gov (United States)

2012-12-01

Currently, MnDOT pavement design recommends granular equivalency, GE = 1.0 for non-stabilized full-depth : reclamation (FDR) material, which is equivalent to class 5 material. For stabilized full-depth reclamation (SFDR), : there was no guideline for...

Recycling of asphalt concrete : Oregon's first hot mix project : interim report.

Science.gov (United States)

1977-11-01

The need to reduce fuel consumption and conserve natural resources have been items of ever-increasing importance during recent years. This report discusses a project in which almost 50,000 tons of asphalt concrete placed to carry detour traffic durin...

Performance of Hot Mix Asphalt Mixture Incorporating Kenaf Fibre

Science.gov (United States)

Hainin, M. R.; Idham, M. K.; Yaro, N. S. A.; Hussein, S. O. A. E.; Warid, M. N. M.; Mohamed, A.; Naqibah, S. N.; Ramadhansyah, P. J.

2018-04-01

Kenaf fibre has been recognised to increase the strength of concrete, but its application in asphalt concrete is still unanswered. This research investigated the performance of Hot Mix Asphalt (HMA) incorporated with different percentages of kenaf fibre (0.1 %, 0.2% and 0.3% by weight of dry aggregate) in term of resilient modulus, rutting performance using Asphalt Pavement analyser (APA) and moisture damage using the Modified Lottman test (AASHTO-T283). The fibre was interweaved to a diameter of about 5-10 mm and length of 30 mm which is three times the nominal maximum aggregate size used in the mix. Asphaltic mixtures of asphalt concrete (AC) 10 were prepared and compacted using Marshall compactor which were subsequently tested to evaluate the resilient modulus and moisture susceptibility. Twelve cylindrical specimens (150mm diameter) from AC10, two control samples with two modified ones for each percentage of kenaf fibres compacted using Gyratory compactor were used for rutting test using APA. The laboratory results reveal that the addition of kenaf fibres slightly reduce the resilient modulus of the mixes and that asphaltic mix with 0.3% kenaf fibre can mitigate both rutting and moisture damage which makes the pavement more sustain to the loads applied even in the presence of water. 0.3% kenaf fibre content is considered to be the optimal content which had the least rut depth and the highest TSR of 81.07%. Based on grid analysis, addition of 0.3% kenaf fibre in asphaltic concrete was recommended in modifying the samples.

Reducing the environmental impact of concrete and asphalt: a scenario approach

NARCIS (Netherlands)

Blankendaal, T.; Schuur, Peter; Voordijk, Johannes T.

2014-01-01

In this paper, measures are evaluated to reduce the environmental impact of concrete and asphalt. Several composition scenarios are designed for these materials and are evaluated based on their environmental performance using life-cycle assessment (LCA). The effect of low-energy production

Quality control analysis : part IV : field simulation of asphaltic concrete specifications.

Science.gov (United States)

1969-02-01

The report present some of the major findings, from a simulated study of statistical specifications, on three asphaltic concrete projects representing a total of approximately 30, 000 tons of hot mix. The major emphasis of the study has been on the a...

Recycling of polyethylene terephthalate (PET plastic bottle wastes in bituminous asphaltic concrete

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Adebayo Olatunbosun Sojobi

2016-12-01

Full Text Available This research sheds light on the concept of eco-friendly road construction which comprises eco-design, eco-extraction, eco-manufacturing, eco-construction, eco-rehabilitation, eco-maintenance, eco-demolition, and socioeconomic empowerment. It also revealed the challenges being faced in its adoption and the benefits derivable from its application. Furthermore, the effects of recycling PET plastic bottle wastes produced in North Central Nigeria in bituminous asphaltic concrete (BAC used in flexible pavement construction were also evaluated. The mix design consists of 60/70 penetration-grade asphaltic concrete (5%, 68% coarse aggregate, 6% fine aggregate, and 21% filler using the dry process at 170°C. The optimum bitumen content (OBC for conventional BAC was obtained as 4% by weight of total aggregates and filler. Polymer-coated aggregate (PCA-modified BAC seems preferable because it has the potential to utilize more plastic wastes with a higher optimum plastic content (OPC of 16.7% by weight of total aggregates and filler compared to that of 9% by weight of OBC achieved by PMB-BAC. For both PMB- and PCA-modified BAC, an increase in air void, void in mineral aggregate, and Marshall stability were observed. Eco-friendly road construction which recycles PET wastes should be encouraged by government considering its potential environmental and economic benefits.

Impact of Aggregate Gradation and Filler Type on Marshall Properties of Asphalt Concrete

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saad I. Sarsam

2015-09-01

Full Text Available As asphalt concrete wearing course (ACWC is the top layer in the pavement structure, the material should be able to sustain stresses caused by direct traffic loading. The objective of this study is to evaluate the influence of aggregate gradation and mineral filler type on Marshall Properties. A detailed laboratory study is carried out by preparing asphalt mixtures specimens using locally available materials including asphalt binder (40-50 penetration grade, two types of aggregate gradation representing SCRB and ROAD NOTE 31 specifications and two types of mineral filler including limestone dust and coal fly ash. Four types of mixtures were prepared and tested. The first type included SCRB specification and limestone dust, the second type included SCRB specification and coal fly ash, the third types included ROAD NOTE 31 specification and limestone dust and the fourth type included ROAD NOTE 31 specification and coal fly ash. The optimum asphalt content of each type of mixtures was determined using Marshall Method of mix design. 60 specimen were prepared and tested with dimension of 10.16 cm in diameter and 6.35 cm in height. Results of this study indicated that aggregate gradation and filler type have a significant effect on optimum asphalt content and Marshall Properties. From the experimental data, it was observed that the value of Marshall Stability is comparatively higher when using fly ash as filler as compared to limestone dust.

Feasibility of reclaimed asphalt pavement as aggregate in portland cement concrete pavement, phase II : field demonstration.

Science.gov (United States)

2015-10-01

This research was focused on evaluating the feasibility of using minimally processed reclaimed asphalt pavement (RAP) as : aggregate replacement in concrete pavements. An initial phase of research demonstrated that concretes with up to 50 percent : o...

Developing the elastic modulus measurement of asphalt concrete using the compressive strength test

Science.gov (United States)

Setiawan, Arief; Suparma, Latif Budi; Mulyono, Agus Taufik

2017-11-01

Elastic modulus is a fundamental property of an asphalt mixture. An analytical method of the elastic modulus is needed to determine the thickness of flexible pavement. It has a role as one of the input values on a stress-strain analysis in the finite element method. The aim of this study was to develop the measurement of the elastic modulus by using compressive strength testing. This research used a set of specimen mold tool and Delta Dimensi software to record strain changes occurring in the proving ring of compression machine and the specimens. The elastic modulus of the five types of aggregate gradation and 2 types of asphalt were measured at optimum asphalt content. Asphalt Cement 60/70 and Elastomer Modified Asphalt (EMA) were used as a binder. Manufacturing success indicators of the specimens used void-in-the-mix (VIM) 3-5 % criteria. The success rate of the specimen manufacturing was more than 76%. Thus, the procedure and the compressive strength test equipment could be used for the measurement of the elastic modulus. The aggregate gradation and asphalt types significantly affected the elastic modulus of the asphalt concrete.

Development of a stress-mode sensitive viscoelastic constitutive relationship for asphalt concrete: experimental and numerical modeling

Science.gov (United States)

Karimi, Mohammad M.; Tabatabaee, Nader; Jahanbakhsh, H.; Jahangiri, Behnam

2017-08-01

Asphalt binder is responsible for the thermo-viscoelastic mechanical behavior of asphalt concrete. Upon application of pure compressive stress to an asphalt concrete specimen, the stress is transferred by mechanisms such as aggregate interlock and the adhesion/cohesion properties of asphalt mastic. In the pure tensile stress mode, aggregate interlock plays a limited role in stress transfer, and the mastic phase plays the dominant role through its adhesive/cohesive and viscoelastic properties. Under actual combined loading patterns, any coordinate direction may experience different stress modes; therefore, the mechanical behavior is not the same in the different directions and the asphalt specimen behaves as an anisotropic material. The present study developed an anisotropic nonlinear viscoelastic constitutive relationship that is sensitive to the tension/compression stress mode by extending Schapery's nonlinear viscoelastic model. The proposed constitutive relationship was implemented in Abaqus using a user material (UMAT) subroutine in an implicit scheme. Uniaxial compression and indirect tension (IDT) testing were used to characterize the viscoelastic properties of the bituminous materials and to calibrate and validate the proposed constitutive relationship. Compressive and tensile creep compliances were calculated using uniaxial compression, as well as IDT test results, for different creep-recovery loading patterns at intermediate temperature. The results showed that both tensile creep compliance and its rate were greater than those of compression. The calculated deflections based on these IDT test simulations were compared with experimental measurements and were deemed acceptable. This suggests that the proposed viscoelastic constitutive relationship correctly demonstrates the viscoelastic response and is more accurate for analysis of asphalt concrete in the laboratory or in situ.

Full depth bituminous recycling of I-70, Thomas County, Kansas

Science.gov (United States)

2004-01-01

In 1990, 13 full depth asphalt pavement test sections were built on a portion of I-70 in Thomas County, Kansas. Various combinations of hot mix and cold recycle mixes with different additives were used to build the test sections. Two of the test sect...

Generation of urban road dust from anti-skid and asphalt concrete aggregates.

Science.gov (United States)

Tervahattu, Heikki; Kupiainen, Kaarle J; Räisänen, Mika; Mäkelä, Timo; Hillamo, Risto

2006-04-30

Road dust forms an important component of airborne particulate matter in urban areas. In many winter cities the use of anti-skid aggregates and studded tires enhance the generation of mineral particles. The abrasion particles dominate the PM10 during springtime when the material deposited in snow is resuspended. This paper summarizes the results from three test series performed in a test facility to assess the factors that affect the generation of abrasion components of road dust. Concentrations, mass size distribution and composition of the particles were studied. Over 90% of the particles were aluminosilicates from either anti-skid or asphalt concrete aggregates. Mineral particles were observed mainly in the PM10 fraction, the fine fraction being 12% and submicron size being 6% of PM10 mass. The PM10 concentrations increased as a function of the amount of anti-skid aggregate dispersed. The use of anti-skid aggregate increased substantially the amount of PM10 originated from the asphalt concrete. It was concluded that anti-skid aggregate grains contribute to pavement wear. The particle size distribution of the anti-skid aggregates had great impact on PM10 emissions which were additionally enhanced by studded tires, modal composition, and texture of anti-skid aggregates. The results emphasize the interaction of tires, anti-skid aggregate, and asphalt concrete pavement in the production of dust emissions. They all must be taken into account when measures to reduce road dust are considered. The winter maintenance and springtime cleaning must be performed properly with methods which are efficient in reducing PM10 dust.

Impact of the Superpave hot mix asphalt properties on its permanent deformation behavior

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Qasim Zahra

2018-01-01

Full Text Available In Iraq, the severity of rutting has increased in asphalt pavements possibly due to the increase in truck axle loads, tyre pressure, and high pavement temperature in summer. As of late, Superpave has been accounted as an enhanced system for performance based design, analysis of asphalt pavement performance prediction for asphalt concrete mixes. In this research the development of permanent deformation in asphalt concrete under repeated loadings was investigated, Wheel-Tracking apparatus has been used in a factorial testing program during which 44 slab samples were tested to simulate actual pavement. The objectives of the present research include; investigating the main factors affecting rutting in asphalt concrete mixture, quantifying the effect of SBS polymer and steel reinforcement on asphalt concrete mixtures in addition to studying the effect of variables on the asphalt concrete mixes against moisture sensitivity. It has been determined that that increasing of compaction temperature from 110 to 150°C will decrease the permanent deformation by 20.5 and 15.6 percent for coarse and fine gradation control asphalt mixtures, respectively. While the permanent deformation decreases by 21.3 percent when the compaction temperature is increased from 110 to 150°C for coarse gradation SBS modified asphalt mixtures.

Investigation of statistical relationship between dynamic modulus and thermal strength of asphalt concrete

International Nuclear Information System (INIS)

Qadir, A.; Gular, M.

2011-01-01

Dynamic modulus is a performance indicator for asphalt concrete and is used to qualify asphalt mixtures based on stress-strain characteristics under repeated loading. Moreover, the low temperature cracking of asphalt concrete mixes are measured in terms of fracture strength and fracture temperature. Dynamic modulus test was selected as one of the simple performance tests in the AASHTO 2002 guidelines to rate mixtures according to permanent deformation performance. However, AASHTO 2002 guidelines is silent in relating dynamic modulus values to low temperature cracking, probably because of weak correlations reported between these two properties. The present study investigates the relation between these two properties under the influence of aggregate type and mix gradation. Mixtures were prepared with two types of aggregate and gradations, while maintaining the binder type and air voids constant. The mixtures were later tested for dynamic modulus and fracture strength using thermal stress restrained specimen test (TSRST). Results indicate that there exists a fair correlation between the thermal fracture strength and stiffness at a selected test temperature and frequency level. These correlations are highly dependent upon the type of aggregate and mix gradation. (author)

Field investigation of skid resistance degradation of asphalt pavement during early service

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Yinghao Miao

2016-07-01

Full Text Available This paper documents a field investigation into the skid resistance degradation of asphalt pavement during early service. Field tests were conducted 7 times during more than 2 years. There are 2 highway sections included in the field tests, which cover 4 asphalt surface types, i.e., dense asphalt concrete (DAC, rubber asphalt concrete (RAC, stone matrix asphalt (SMA, and ultra-thin wearing course (UTWC. Macrotexture and friction data were collected using the sand patch method and the dynamic friction tester respectively. The degradation of the mean texture depth (MTD and the friction coefficient at slip speed of 60 km/h (DFT60 were analyzed. The international friction index (IFI was also calculated using the friction coefficient at slip speed of 20 km/h (DFT20 with MTD to evaluate the skid resistance degradation. The UTWC has relatively good skid resistance even after 7.4 × 106 standard vehicle passes. The SMA has very stable friction performance which maintains almost the same friction level after 4.61 × 106 standard vehicle passes. The DAC and RAC have relatively poor friction performance while the RAC has better macrotexture. The changing trends of skid resistance with traffic wear can be fitted by a logarithmic model for all surface types. The SMA and UTWC have relatively clear relationship between DFT20 and MTD, while the RAC and the DAC show more complex. Keywords: Asphalt pavement, Skid resistance, Degradation, International friction index

Quantify the energy and environmental effects of using recycled asphalt and recycled concrete for pavement construction phase I : final report.

Science.gov (United States)

2009-08-01

The objective of this study is to quantify the energy and environment impacts from using recycled materials : for highway construction. Specifically, when recycled asphalt pavement is re-used for producing hot mix : asphalt or when recycled concrete ...

Latex improvement of recycled asphalt pavement

Science.gov (United States)

Drennon, C.

1982-08-01

The performance of a single unmodified milled recycled asphalt concrete was compared to milled asphalt concrete modified by addition of three types of rubber latex. Latex was added at 2, 3, 5, and 8 percent latex by weight of asphalt in the asphalt concrete. Lattices used were a styrene butadiene (SBR), a natural rubber (NR), an acrylonitrile butadiene (NBR), and four varieties of out of specification SBR lattices. Marshall tests, while indecisive, showed a modest improvement in properties of SBR and NR added material at 3 and 5 percent latex. Addition of NBR latex caused deterioration in Marshall stability and flow over that of control. Repeated load tests were run using the indirect tensile test, analyzed by the VESYS program, which computes life of pavements. Repeated load tests showed improvement in asphalt concrete life when 3 and 5 percent SBR was added. Improvement was also shown by the out of specification SBR.

Improving of Water Resistance of Asphalt Concrete Wearing Course Using Latex-Bitumen Binder

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Siswanto Henri

2017-01-01

Full Text Available It is well known that presence of water in a bituminous mix is a critical factor which can lead to premature failure of flexible pavements. This requires solutions one of which is to formulate an asphalt mix that has a high resistance to moisture and one way to do this is to mix latex with the asphalt mix. The purpose of this experimental study was to investigate the effect of water on Marshall stability of asphalt concrete wearing course (ACWC made with a latex-bitumen binder. Latex-bitumen was mixed with aggregate and four levels of latex content were investigated in this study, namely, 0%, 2%, 4% and 6% respectively by weight of asphalt. Wet procces was used in the blending of mixtures. The procedure used to obtain the optimum binder contents conformed to the Marshall procedure (SNI 06-2489-1991. Six Marshall specimens at optimum binder content were prepared for each binder mix investigated. Three of six specimens from each group were tested under Marshall standards. The remaining specimens were tested by immersion in a bath at 60°C for 24 hours. The Marshall index of retained stability was used to evaluate the effect of water on the Marshall stability of ACWC. The results indicated that the addition of up to 4% latex to ACWC mix increased the retained Marshall stability, whereas the addition of latex above 4% decreased the retained stability of the mixture. The addition of 4% CRM significantly improved the retained stability of the mixture and was the best latex – ACWC mix.

Recycled Asphalt Pavement and Crushed Concrete Backfill: State-of-the-Art Review and Material Characterization

Science.gov (United States)

2001-10-01

This report describes research results from the first year of a three-year study focused on the use of recycled asphalt pavement (RAP) and crushed concrete (CC) as backfill for mechanically stabilized earth (MSE) walls.

Influence of DAD-TA temperature-reducing additive on physical and mechanical properties of bitumen and compaction of asphalt concrete.

Science.gov (United States)

Yadykina, V. V.; Akimov, A. E.; Trautvain, A. I.; Kholopov, V. S.

2018-03-01

The paper is devoted to the use of DAD-TA temperature-reducing additive for the preparation and pouring of asphalt concrete mixes at reduced temperatures. It also shows positive influence of the modified bitumen on the efficiency of organo-mineral composite compaction at reduced temperatures. Physical and mechanical properties of asphalt concrete with the use of bitumen modified by DAD-TA additive including indicators characterizing road surfacing life are presented. Arguments to use this material from the point of view of its production technology and environmental impact are given.

Investigating the Effects of Nanoclay and Nylon Fibers on the Mechanical Properties of Asphalt Concrete

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Hasan Taherkhani

2016-12-01

Full Text Available This paper describes the effects of reinforcement by randomly distributed nylon fibers and addition of nanoclay on some engineering properties of a typical asphalt concrete. The properties of asphalt concrete reinforced by different percentages of 25 mm nylon fibers have been compared with those of the mixtures containing different percentages of nanoclay and those in which both the fibers and nanoclay have been included. Engineering properties, including Marshall stability, resilient modulus, dynamic creep and fatigue life have been studied. Nylon fibers have been used in different percentages of 0.1, 0.2, 0.3 and 0.4% (by the weight of total mixture, and nanoclay has been used in 2, 4 and 7% (by the weight of bitumen. It is found that the addition of fibers is more effective than the nanoclay for increasing the resistance against fatigue cracking. However, nanoclay improves the resistance of the mixture against permanent deformation better than the nylon fibers. The results also show that the mixture reinforced by 0.4% of nylon fibers and containing 7% of nanoclay has the highest resilient modulus, Marshall stability and fatigue life. However, the mixture containing only 7% of nanoclay has the highest resistance against permanent deformation.

Environmental performance and mechanical analysis of concrete containing recycled asphalt pavement (RAP) and waste precast concrete as aggregate.

Science.gov (United States)

Erdem, Savaş; Blankson, Marva Angela

2014-01-15

The overall objective of this research project was to investigate the feasibility of incorporating 100% recycled aggregates, either waste precast concrete or waste asphalt planning, as replacements for virgin aggregates in structural concrete and to determine the mechanical and environmental performance of concrete containing these aggregates. Four different types of concrete mixtures were designed with the same total water cement ratio (w/c=0.74) either by using natural aggregate as reference or by totally replacing the natural aggregate with recycled material. Ground granulated blast furnace slag (GGBS) was used as a mineral addition (35%) in all mixtures. The test results showed that it is possible to obtain satisfactory performance for strength characteristics of concrete containing recycled aggregates, if these aggregates are sourced from old precast concrete. However, from the perspective of the mechanical properties, the test results indicated that concrete with RAP aggregate cannot be used for structural applications. In terms of leaching, the results also showed that the environmental behaviour of the recycled aggregate concrete is similar to that of the natural aggregate concrete. Copyright © 2013 Elsevier B.V. All rights reserved.

Induction Healing of Porous Asphalt Concrete

NARCIS (Netherlands)

Liu, Q.

2012-01-01

Porous asphalt shows excellent performance in both noise reduction and water drainage. Although porous asphalt has these great qualities, its service life is much shorter (sometimes only half) compared to dense graded asphalt roads. Ravelling, which is the loss of aggregate particles from the

Contributory Factors Related to Permanent Deformation of Hot Asphalt Mixtures

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Alaa Husein Abd

2017-03-01

Full Text Available Permanent deformation (Rutting of asphalt pavements which appears in many roads in Iraq, have caused a major impact on pavement performance by reducing the useful service life of pavement and creating services hazards for highway users. The main objective of this research is investigating the effect of some contributory factors related to permanent deformation of asphalt concrete mixture. To meet the objectives of this research, available local materials are used including asphalt binder, aggregates, mineral filler and modified asphalt binder. The Superpave mix design system was adopted with varying volumetric compositions. The Superpave Gyratory Compactor was used to compact 24 asphalt concrete cylindrical specimens. To collect the required data and investigate the development of permanent deformation in asphalt concrete under repeated loadings, Wheel-Tracking apparatus has been used in a factorial testing program during which 44 slab samples; with dimensions of 400×300×50 mm; were tested to simulate . actual pavement. Based on wheel-tracking test results, it has been concluded that increasing the compaction temperature from 110 to 150ºC caused a decreasing in permanent deformation by 20.5 and 15.6 percent for coarse and fine gradation control asphalt mixtures respectively. While the permanent deformation decreased about 21.3 percent when the compaction temperature is increased from 110 to 150ºC for coarse gradation asphalt mixtures modified with styrene butadiene styrene SBS with 3 percent by asphalt binder weight.

Performance of Recycled Porous Hot Mix Asphalt with Gilsonite Additive

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Ludfi Djakfar

2015-01-01

Full Text Available The objective of the study is to evaluate the performance of porous asphalt using waste recycled concrete material and explore the effect of adding Gilsonite to the mixture. As many as 90 Marshall specimens were prepared with varied asphalt content, percentage of Gilsonite as an additive, and proportioned recycled and virgin coarse aggregate. The test includes permeability capability and Marshall characteristics. The results showed that recycled concrete materials seem to have a potential use as aggregate in the hot mix asphalt, particularly on porous hot mix asphalt. Adding Gilsonite at ranges 8–10% improves the Marshall characteristic of the mix, particularly its stability, without decreasing significantly the permeability capability of the mix. The use of recycled materials tends to increase the asphalt content of the mix at about 1 to 2% higher. With stability reaching 750 kg, the hot mix recycled porous asphalt may be suitable for use in the local roads with medium vehicle load.

Assessment of The Asphalt Produced in Some Factories of Asphalt in Al-Hilla City

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Mohammed Karem Abd

2018-02-01

Full Text Available The purpose of this study is to present an evaluation of  the properties and characteristics of asphalt concrete of several hot mix asphalt (HMA from five factories in Al-Hilla city. The research is divided into two parts. The first part included the laboratory analysis of samples. The second part is evaluation of results according to standard specifications.      The test results included (Asphalt content percent, stability, creep compliance, voids ratio, density, flow, crushed aggregate percent, Loss Angless abrasion and SO3 percent.The results of laboratorial tests indicated that all properties of asphalt mixes were susceptible and possible to be used in the asphaltic roads. The mixes types prepared and tested according to Marshall method. The values of Marshall stability, creep and density are (9.4, 5.4, 9.8, 9, 8.6, (2.5, 2.7, 2.7, 2.6, 2.3 and (2.334, 2.336, 2.337, 2.333, 2.338 with asphalt content between (4.2 to 4.6 % for all asphalt mixes of different factories.

Experimental investigation of the fatigue behaviour of asphalt concrete mixtures containing waste iron powder

International Nuclear Information System (INIS)

Arabani, M.; Mirabdolazimi, S.M.

2011-01-01

Research highlights: → This paper presents the first model of the fatigue behaviour of iron-asphalt mixtures in the world. → This model is able to describe the fatigue behaviour of iron-asphalt under dynamic loading. → Coarse surface, high stiffness and angularity of iron powder lead to enhanced fatigue performance. → The model illustrates that the use of iron powder has a considerable effect on tensile strain of HMA. → The use of this type of waste material could be a helpful solution for less polluted environment. - Abstract: The use of additives and admixtures in the construction of asphalt concrete pavements to strengthen them against dynamic loads has increased considerably in recent years. Recent research has shown that employing desirable waste materials in hot mix asphalts (HMAs) improves their dynamic properties noticeably. The study of some special cases, such as the addition of blast furnace slag and metallic materials of waste electronic instruments to HMA, has led to a considerable increase in the ability of HMAs to tolerate fatigue phenomena and repeated loading. Based on experimental studies, a model is proposed to describe the fatigue behaviour of asphalt mixtures containing waste iron powder. The results of this research show an important increase in the strength of asphalt mixtures containing waste iron powder against fatigue phenomena in comparison to conventional HMAs.

Fatigue Life Prediction of High Modulus Asphalt Concrete Based on the Local Stress-Strain Method

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Mulian Zheng

2017-03-01

Full Text Available Previously published studies have proposed fatigue life prediction models for dense graded asphalt pavement based on flexural fatigue test. This study focused on the fatigue life prediction of High Modulus Asphalt Concrete (HMAC pavement using the local strain-stress method and direct tension fatigue test. First, the direct tension fatigue test at various strain levels was conducted on HMAC prism samples cut from plate specimens. Afterwards, their true stress-strain loop curves were obtained and modified to develop the strain-fatigue life equation. Then the nominal strain of HMAC course determined using finite element method was converted into local strain using the Neuber method. Finally, based on the established fatigue equation and converted local strain, a method to predict the pavement fatigue crack initiation life was proposed and the fatigue life of a typical HMAC overlay pavement which runs a risk of bottom-up cracking was predicted and validated. Results show that the proposed method was able to produce satisfactory crack initiation life.

The effects of coarse aggregate cleanliness and moisture content on asphalt concrete compactability and moisture susceptibility.

Science.gov (United States)

2011-12-31

Twelve field projects were studied where forty-four locations were evaluated to assess the cause or : causes of asphalt concrete that exhibits tender zone characteristics (i.e. instability during compaction) and to : investigate the tendency of...

Study of lime vs. no lime in cold in-place recycled asphalt concrete pavements : final report.

Science.gov (United States)

1991-09-01

The resilient characteristics of cold in-place recycled asphalt concrete with and without lime were examined. Six core samples were obtained from a site two months after construction; six months later, six additional core samples were obtained from t...

Utilization of recycled asphalt concrete with warm mix asphalt and cost-benefit analysis.

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Julide Oner

Full Text Available The asphalt paving industries are faced with two major problems. These two important challenges are generated with an increase in demand for environmentally friendly paving mixtures and the problem of rapidly rising raw materials. Recycling of reclaimed asphalt pavement (RAP is a critical necessity to save precious aggregates and reduce the use of costly bitumen. Warm Mix Asphalt (WMA technology provides not only the option of recycling asphalt pavement at a lower temperature than the temperature maintained in hot mixtures but also encourages the utilization of RAP and therefore saves energy and money. This paper describes the feasibility of utilizing three different WMA additives (organic, chemical and water containing at recommended contents with different percentages of RAP. The mechanical properties and cost-benefit analysis of WMA containing RAP have been performed and compared with WMA without RAP. The results indicated that, 30%, 10% and 20% can be accepted as an optimum RAP addition related to organic, chemical and water containing additives respectively and organic additive with 30% RAP content has an appreciable increase in tensile strength over the control mix. It was also concluded that the RAP with WMA technology is the ability to reduce final cost compared to HMA and WMA mixtures.

Application of Conductive Materials to Asphalt Pavement

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Hai Viet Vo

2017-01-01

Full Text Available Snow-melting pavement technique is an advanced preservation method, which can prevent the forming of snow or ice on the pavement surface by increasing the temperature using an embedded heating system. The main scope of this study is to evaluate the impact of conductive additives on the heating efficiency. The electrical resistivity and thermal conductivity were considered to investigate effects of conductive additives, graphite, and carbon fibers on the snow-melting ability of asphalt mixtures. Also, the distribution of the conductive additives within the asphalt concrete body was investigated by microstructural imaging. An actual test was applied to simulate realistic heating for an asphalt concrete mixture. Thermal testing indicated that graphite and carbon fibers improve the snow-melting ability of asphalt mixes and their combination is more effective than when used alone. As observed in the microstructural image, carbon fibers show a long-range connecting effect among graphite conductive clusters and gather in bundles when added excessively. According to the actual test, adding the conductive additives helps improve snow-melting efficiency by shortening processing time and raising the surface temperature.

Use of waste crushed glass for the production of hot-mix asphalt

CSIR Research Space (South Africa)

Anochie-Boateng, Joseph

2016-08-01

Full Text Available presents the development and evaluation of a new asphalt concrete mix that utilizes a sustainable crushed glass as a replacement material of a natural aggregate. The ultimate goal is to produce a cost-effective asphalt wearing course with comparative...

Behavior of sulfur mustard in sand, concrete, and asphalt matrices: Evaporation, degradation, and decontamination.

Science.gov (United States)

Jung, Hyunsook; Choi, Seungki

2017-10-15

The evaporation, degradation, and decontamination of sulfur mustard on environmental matrices including sand, concrete, and asphalt are described. A specially designed wind tunnel and thermal desorber in combination with gas chromatograph (GC) produced profiles of vapor concentration obtained from samples of the chemical agent deposited as a drop on the surfaces of the matrices. The matrices were exposed to the chemical agent at room temperature, and the degradation reactions were monitored and characterized. A vapor emission test was also performed after a decontamination process. The results showed that on sand, the drop of agent spread laterally while evaporating. On concrete, the drop of the agent was absorbed immediately into the matrix while spreading and evaporating. However, the asphalt surface conserved the agent and slowly released parts of the agent over an extended period of time. The degradation reactions of the agent followed pseudo first order behavior on the matrices. Trace amounts of the residual agent present at the surface were also released as vapor after decontamination, posing a threat to the exposed individual and environment.

Effect of moisture and freeze-thaw on mechanical properties of CRM asphalt mixture

Energy Technology Data Exchange (ETDEWEB)

Kim, Nak-Seok; Cho, Kee-Ju [Kyonggi University, Suwon(Korea)

2000-06-30

This paper presents the experimental test results on moisture and freeze-thaw resistance of hot mix crumb rubber modified (CRM) asphalt concrete mixture. To compare the differences in mechanical properties of conventional and CRM asphalt concretes, various tests were conducted under different moisture conditions and freeze-thaw cycles. Marshall mix design was also performed to determine the optimum asphalt contents for the both asphalt concrete mixtures. Test results revealed that the moisture and freeze-thaw resistance of CRM asphalt mixture was superior to the conventional asphalt concrete. As a result, it is considered that the utilization of waste tires in asphalt pavements has the potential of minimizing the damage due to the moisture and freeze-thaw. (author). 9 refs., 4 tabs., 8 figs.

Modification of asphaltic concrete with a mineral polymeric additive based on butadiene-styrene rubber and chemically precipitated calcium carbonate

Directory of Open Access Journals (Sweden)

S. I. Niftaliev

2016-01-01

Full Text Available Modification of asphaltic concrete with a mineral polymeric additive based on butadiene – styrene rubber and chemically precipitated calcium carbonate. This paper presents the results of the study of physical – mechanical and service properties of the asphaltic concrete modified with the mineral polymeric composition. Calcium carbonate is used both as a filler and a coagulant. The chalk was preliminarily ground and hydrophobizated by stearic acid. These operations contribute to even distribution of the filler and interfere with lump coagulation. As a result of the experiments, it was found that the best results were obtained by combining the operations of dispersion and hydrophobization. The optimal amount of stearic acid providing the finest grinding in a ball mill is a content from 3 to 5% by weight. The optimal grinding time of the filler was found (4–6 hours. With increasing dispersion time the particles form agglomerates. Filling the butadiene styrene latex with the hydrophobic fine-grained calcium carbonate was carried out in the laboratory mixer. As a result of the experimental works, it was found that the best distribution of the filler takes place with ratio of rubber: chalk – 100:400. The resulting modifier was subjected to the thermal analysis on the derivatograph to determine its application temperature interval. A marked reduction in weight of the mineral polymeric modifier begins at 350 °C. Thus, high temperature of the modifier destruction allows to use it at the temperature of the technological process of asphaltic concrete preparation (up to 170 °C. It was found that an increase in the amount of the carbonate filler in the rubber SKS 30АRК significantly increases its thermal resistance and connection of the polymer with the chalk in the composition.

Development of asphaltic mix with waste products use

Directory of Open Access Journals (Sweden)

Pugin Konstantin Georgievich

2014-07-01

Full Text Available The trend of high growth of the vehicle fleet in Russia along with the positive impact on the socio-economic development of the country has a number of adverse consequences, one of which is the high accident rate on the roads. The paper considers modern way to provide the safe vehicles flow with the use of colored asphalt, which is a kind of hot asphalt and can have a variety of colors, which consists of coloring pigments. The conventional method of coloring the asphalt mix is produced by adding color rubble or pigmenting additives. The task, which was put forward, was the establishment of such road concrete mix, from which, without the use of primary materials and without increasing the consumption of bitumen, asphalt concrete road surfaces of acceptable strength could be obtained. As a pigment the dust of gas purification system of electrical furnace DSP - 60 of «Kamastal» plant, Perm, was used. The composition of the dust waste from the furnace consists of metal oxides and silicates. Dust-gas-cleaning is a fine powder with a high specific surface (1.2…2.5 thousand cm /g and bulk density of 3.7…4.2 g/cm . The powder color is dark brown. The density of the ready colored asphalt samples is 2.47...2.49 g/cm , and water saturation is 3.50…3.55 %. As a result of the research the diagrams of the dependence of road concrete mix’s water saturation from dust percentage and a diagram of dependence of concrete mixes’ durability from dust percentage at t = 20° and 50° C were built. After analyzing the obtained curves it can be concluded that the increase of the percentage of dust leads to increase of water saturation of road concrete mix and reduced strength. Thus, the developed asphalt concrete mix allows visually separating the lanes on the road, it has the relevant regulatory requirements durability and water resistance. This mixture corresponds to the type B mark III and can be used in regions I, II, and partly III of road-climatic zones

Ultrasonic Measurement of Corrosion Depth Development in Concrete Exposed to Acidic Environment

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Fan Yingfang

2012-01-01

Full Text Available Corrosion depth of concrete can reflect the damage state of the load-carrying capacity and durability of the concrete structures servicing in severe environment. Ultrasonic technology was studied to evaluate the corrosion depth quantitatively. Three acidic environments with the pH level of 3.5, 2.5, and 1.5 were simulated by the mixture of sulfate and nitric acid solutions in the laboratory. 354 prism specimens with the dimension of 150 mm × 150 mm × 300 mm were prepared. The prepared specimens were first immersed in the acidic mixture for certain periods, followed by physical, mechanical, computerized tomography (CT and ultrasonic test. Damage depths of the concrete specimen under different corrosion states were obtained from both CT and ultrasonic test. Based on the ultrasonic test, a bilinear regression model is proposed to estimate the corrosion depth. It is shown that the results achieved by ultrasonic and CT test are in good agreement with each other. Relation between the corrosion depth of concrete specimen and the mechanical indices such as mass loss, compressive strength, and elastic modulus is discussed in detail. It can be drawn that the ultrasonic test is a reliable nondestructive way to measure the damage depth of concrete exposed to acidic environment.

Operational properties of nanomodified stone mastic asphalt

OpenAIRE

Inozemtsev Sergey Sergeevich; Korolev Evgeniy Valer’evich

2015-01-01

In order to prolong the lifetime and to improve the quality of pavements made of asphalt concrete it is necessary to apply innovative solutions in the process of design of such building materials. In order to solve the problem of low durability of asphalt concrete a modifier was proposed, which consists of diatomite, iron hydroxide sol (III) and silica sol. Application of the diatomite with nanoscale layer of nanomodifier allows getting a stone mastic asphalt, which has high values of physica...

Addressing Infrastructure Durability and Sustainability by Self Healing Mechanisms : Recent Advances in Self Healing Concrete and Asphalt

NARCIS (Netherlands)

Schlangen, H.E.J.G.; Sangadji, S.

2013-01-01

Infrastructures cover a very broad spectrum of different materials. This paper focuses on civil engineering structures, concrete and asphalt in particular. The public demand for such infrastructures is high level of service and performance, high durability and minimum negative ecological impact. New

Operational properties of nanomodified stone mastic asphalt

Directory of Open Access Journals (Sweden)

Inozemtsev Sergey Sergeevich

2015-03-01

Full Text Available In order to prolong the lifetime and to improve the quality of pavements made of asphalt concrete it is necessary to apply innovative solutions in the process of design of such building materials. In order to solve the problem of low durability of asphalt concrete a modifier was proposed, which consists of diatomite, iron hydroxide sol (III and silica sol. Application of the diatomite with nanoscale layer of nanomodifier allows getting a stone mastic asphalt, which has high values of physical and mechanical properties and allows refusing from expensive stabilizing additive. Mineral filler was replaced by diatomite, which has been modified by iron hydroxide sol (III and silica sol. Modified diatomite allows sorption of bitumen and increase the cohesive strength and resistance to shear at positive temperatures. The modified asphalt has higher resistance to rutting at high temperature, abrasion resistance at low temperature and impact of climatic factors: alternate freezing and thawing, wetting-drying, UV and IR radiations. It is achieved by formation of solid and dense bitumen film at the phase interface and controlling the content of light fractions of the bitumen. The modifier consists of sol of iron hydroxide, which blocks the oxidation and polymerization of bitumen during operation. The proposed material allows controlling the initial structure formation of stone mastic asphalt. It was shown that modern test methods allow assessing the durability of asphalt in the design phase compositions.

Design and evaluation of foamed asphalt base materials.

Science.gov (United States)

2013-05-01

Foamed asphalt stabilized base (FASB) combines reclaimed asphalt pavement (RAP), recycled : concrete (RC), and/or graded aggregate base (GAB) with a foamed asphalt binder to produce a : partially stabilized base material. The objectives of this study...

Evaluation and Study the Effect of Additives and Other Factors on Tensile Strength of Asphalt Paving Mixtures

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Hanaa Khaleel A. Al-Baiti

2012-03-01

Full Text Available The resistance of asphaltic concrete to cracking is dependent upon its tensile strength and flexibility characteristics. Also the low tensile strength has recognized as a major contributor to other performance problems. The fatigue life of mixtures decreases exponentially with decreasing of tensile strength. This trend is justified by the loss in stiffness and thereby initiating cracks and stripping. The main objective of this research is intended to study the effect of different variables related with the used materials and the external conditions on the tensile strength and predict a model of indirect tensile strength in asphalt concrete paving materials under the local prevailing conditions and investigate the effect of percent of additives of (Polyestrene resins and Hydrated Lime to enhance the resistance ability of asphalt concrete mixture against distresses. The main affected factors; soaking, asphalt content, compaction, aggregate maximum size and temperature, influence on the indirect tensile strength and presented through a statistics analysis model for tensile strength in asphalt mixture

Nanophase modified fly ash concrete with superior concrete properties, durability and biofouling resistance for seawater applications

International Nuclear Information System (INIS)

Vishwakarma, Vinita; Sudha, U.; Ramachandran, D.; George, R.P.; Kamachi Mudali, U.; Kalpana Kumari; Preetha, R.; Pillai, C.S.

2015-01-01

There are many concrete structures in the cooling water system of nuclear power plants that are exposed to seawater in the form of tanks, pillars and reservoirs. These structures come in contact with aggressive chlorides and acid producing microbes and deteriorate by chemical and biological factors. Recently fly ash (FA) concrete has emerged exhibiting excellent degradation resistance in seawater environments. However some disadvantages are reported like lesser early strength, higher carbonation and calcium leaching. This work attempted to modify FA concrete by adding nanoparticles of TiO 2 and CaCO 3 for increased strength and degradation resistance. Four types of concrete and mortar mix namely fly ash concrete (FA), FA with 2% TiO 2 nanoparticles (FAT), FA with 2% CaCO 3 nanoparticles and FA with 2% TiO 2 : CaCO 3 nanoparticles were cast and immersed in seawater for a year. Thermal analysis and Differential thermal analysis (TG-DTA) analysis was done before exposing in sea water to know the changes in the physical properties of the specimens at higher temperature. Strength and durability were evaluated using parameters like compressive strength, split tensile test, Rapid chloride permeability test (RCPT), carbonation test and pH degradation. Detailed biofilm characterizations were attempted using microbiological and molecular biology tools to study the antibacterial properties. Calcium leaching and sulfate attack studies were carried out by laboratory exposure studies. Using field emission scanning electron microscopy (FESEM) and X-ray diffraction technique (XRD), microstructural properties and chemical phases were identified. All the nanophase modified FA specimens showed superior properties compared to FA concrete with respect to strength, carbonation depth, calcium leaching and antibacterial activity. Results are discussed in detail in the paper. (author)

Advanced evaluation of asphalt mortar for induction healing purposes

NARCIS (Netherlands)

Apostolidis, P.; Liu, X.; Scarpas, Athanasios; Kasbergen, C.; van de Ven, M.F.C.

2016-01-01

Induction heating technique is an innovative asphalt pavement maintenance method that is applied to inductive asphalt concrete mixes in order to prevent the formation of macro-cracks by increasing locally the temperature of asphalt. The development of asphalt mixes with improved electrical and

Asphalt dust waste material as a paste volume in developing sustainable self compacting concrete (SCC)

Science.gov (United States)

Ismail, Isham; Shahidan, Shahiron; Bahari, Nur Amira Afiza Saiful

2017-12-01

Self-compacting concrete (SCC) mixtures are usually designed to have high workability during the fresh state through the influence of higher volumes of paste in concrete mixtures. Asphalt dust waste (ADW) is one of disposed materials obtained during the production of asphalt premix. These fine powder wastes contribute to environmental problems today. However, these waste materials can be utilized in the development of sustainable and economical SCC. This paper focuses on the preliminary evaluations of the fresh properties and compressive strength of developed SCC for 7 and 28 days only. 144 cube samples from 24 mixtures with varying water binder ratios (0.2, 0.3 and 0.4) and ADW volume (0% to 100%) were prepared. MD940 and MD950 showed a satisfactory performance for the slump flow, J-Ring, L-Box and V-Funnel tests at fresh state. The compressive strength after 28 days for MD940 and MD950 was 36.9 MPa and 28.0 MPa respectively. In conclusion, the use of ADW as paste volume should be limited and a higher water binder ratio will significantly reduce the compressive strength.

The crack growth mechanism in asphaltic mixes

NARCIS (Netherlands)

Jacobs, M.M.J.; Hopman, P.C.; Molenaar, A.A.A.

1995-01-01

The crack growth mechanism in asphalt concrete (Ac) mixes is studied. In cyclic tests on several asphaltic mixes crack growth is measured, both with crack foils and with cOD-gauges. It is found that crack growth in asphaltic mixes is described by three processes which are parallel in time: cohesive

Investigation on Tensile Strength Ratio (TSR Specimen to Predict Moisture Sensitivity of Asphalt Pavements Mixture and Using Polymer to Reduce Moisture Damage

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Mohammed Aziz Hameed Al-Shaybani

2017-05-01

Full Text Available Moisture damage of asphalt concrete is defined as losing the strength and Permanence caused by the active presence of moisture.The most common technique to reduce moisture damage is using modifiers with the asphalt binder or the aggregate.The goal of this study was to explore the effect of various modifiers of polymer on the moisture susceptibility mixture of asphaltic concrete pavement. Modifiers included in this research selected two kinds of polymers Crumb Rubber No 50 (CR No 50 and Methyl Methacrylates (MMA(which are available in the local markets in Iraq and have been used in three percentages for each type. These percentages are (5, 10 and 15% for (CR No 50 and (2.5, 5 and 7.5(% for (MMA.Each type of these polymers is blended with asphalt by wet process at constant blending times for a suitable range of temperatures. The experimental works showed that all polymers modified mixtures have indirect tensile strength higher than control asphalt mixtures, its about (2-15 %, dependent on different type of polymer and polymer concentration under predicted suitable blending time.Test results of indirect tensile strength indicated betterment in modifying the proprieties of mixture, the increased resistance mixture of asphalt concrete pavement versus moisture damage, and reduced the effect of water on asphalt concrete properties. The final result is the addition of (10% CR No 50 and (5% MMA to asphalt mixtures showed an improved mixture of asphalt concrete properties and produced strong mixtures for road construction.One model is predicted for tensile strength ratio [TSR]to estimate the effects of polymer modification on moisture susceptibility mixture of asphalt concrete.

Rubber modification of asphalt binders and mixes

Energy Technology Data Exchange (ETDEWEB)

Morrison, G.; Hesp, S.A.M. [Queen`s Univ., Kingston, ON (Canada). Dept. of Chemistry

1995-12-31

The physical properties of asphalt binders and concrete, modified with waste rubber tire, were examined. In an experiment designed to address the concern of waste disposal of scrap rubber, a control asphalt, devulcanized rubber modified asphalt and a crumb rubber modified asphalt were used to make asphalt concrete mixes. The three mixes were subjected to a thermal stress test to determine their low temperature fracture temperatures and strengths. Results were discussed in terms of the binder material used. At high service temperatures, the addition of 10% devulcanized rubber was found to have no beneficial effect, whereas the addition of 10% 80 mesh crumb rubber produced a modest improvement in performance. At low temperatures, the addition of devulcanized rubber produced increased resistance to cracking up to 90%. The addition of 10% 80 mesh crumb rubber increased fracture toughness by a factor of 3.3 times. 12 refs., 3 tabs.

Volumetric Analysis and Performance of Hot Mix Asphalt with Variable Rap Content

Directory of Open Access Journals (Sweden)

Arshad Ahmad Kamil

2017-01-01

Full Text Available Incorporating Reclaimed Asphalt Pavement (RAP to the asphalt concrete mixture for highway construction offer many benefits including energy consumption, conservation of natural resources and preservation of the environment to associated emissions. This paper presents a study on performance of Hot Mix Asphalt with variable RAP content. The study is carried out to evaluate the Marshall Properties and Performance of RAP-Asphalt mixes using conventional asphaltic concrete mix AC14. Marshall Mix Design Method was used to produce control mix (0% RAP and RAP-Asphalt mixes samples which consist of 15% RAP, 25% RAP and 35% RAP in accordance with Specifications for Road Works of Public Works Department, Malaysia. The Marshall Properties analysis was performed to ensure compliance with Marshall Requirements, The resilient modulus test was performed to measure the stiffness of the mixes while Modified Lottman test was conducted to evaluate the moisture susceptibility of these mixes. The results obtained showed that there were no substantial difference in Marshall Properties, moisture susceptibility and indirect tensile strength between RAP-Asphalt mixes with the control mix. The test results indicated that recycled mixes performed as good as the performance of conventional HMA in terms of moisture susceptibility and resilient modulus. It is recommended that further research be carried out for asphalt mixes containing more than 35% of RAP material.

Delamination detection in reinforced concrete using thermal inertia

International Nuclear Information System (INIS)

Del Grande, N K; Durbin, P F.

1998-01-01

We investigated the feasibility of thermal inertia mapping for bridge deck inspections. Using pulsed thermal imaging, we heat-stimulated surrogate delaminations in reinforced concrete and asphalt-concrete slabs. Using a dual-band infrared camera system, we measured thermal inertia responses of Styrofoam implants under 5 cm of asphalt, 5 cm of concrete, and 10 cm of asphalt and concrete. We compared thermal maps from solar-heated concrete and asphalt-concrete slabs with thermal inertia maps from flash-heated concrete and asphalt-concrete slabs. Thermal inertia mapping is a tool for visualizing and quantifying subsurface defects. Physically, thermal inertia is a measure of the resistance of the bridge deck to temperature change. Experimentally, it is determined from the inverse slope of the surface temperature versus the inverse square root of time. Mathematically, thermal inertia is the square root of the product of thermal conductivity, density, and heat capacity. Thermal inertia mapping distinguishes delaminated decks which have below-average thermal inertias from normal or shaded decks. Key Words: Pulsed Thermal Imaging, Thermal Inertia, Detection Of Concrete Bridgedeck Delaminations

Laboratorium Study of Asphalt Starbit E-55 Polymer Modified Application on Asphalt Concrete Wearing Course (Ac-Wc

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Damianus Kans Pangaraya

2015-09-01

Full Text Available The conventional asphalt road has almost been considered fail to serve the transportation needs. It is indicated by the occurrence of premature damage which is caused by vehicle load and climate. Starbit E-55, the polymer modified bitumen, is formulated to meet the requirement of transport development. Considering those needs, it is important to investigate the feasibility level of that modified bitumen as alternate asphalt instead of the conventional one. This research began with the measurement of the properties of hard layered AC-WC Starbit E-55, then comparing the result to 60/70 penetration of Pertamina asphalt. The next step is then, to determine the converted value so as to be close to that of Pertamina (60/70 penetration. This step is conducted by applying durability and ITS tests on the mixture. Result of the tests showed that hard layered AC-WC Starbit E-55 has better characteristic at 5.7% optimum level asphalt and 6.4% of Pertamina asphalt (60/70 penetration. Starbit E-55 converted level within hard-layered ACWC is 5.6%. The performance test result on immersion with variance of 1, 3, 5, 7 and 14 days shows that durability value of Starbit E-55 AC-WC has better performance. During the process, Starbit E-55 required 15.38% higher energy consumption.

Laboratory Performance Evaluation of High Modulus Asphalt Concrete Modified with Different Additives

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Peng Li

2017-01-01

Full Text Available The objective of this study is to evaluate comprehensive performance of high modulus asphalt concrete (HMAC and propose common values for establishing evaluation system. Three gradations with different modifiers were conducted to study the high and low temperature performance, shearing behavior, and water stability. The laboratory tests for HMAC included static and dynamic modulus tests, rutting test, uniaxial penetration test, bending test, and immersion Marshall test. Dynamic modulus test results showed that modifier can improve the static modulus and the improvements were remarkable at higher temperature. Moreover, modulus of HMAC-20 was better than those of HMAC-16 and HMAC-25. The results of performance test indicated that HMAC has good performance to resist high temperature rutting, and the resistances of the HMAC-20 and HMAC-25 against rutting were better than that of HMAC-16. Then, the common values of dynamic stability were recommended. Furthermore, common values of HMAC performance were established based on pavement performance tests.

Use of plastic waste (poly-ethylene terephthalate) in asphalt concrete mixture as aggregate replacement.

Science.gov (United States)

Hassani, Abolfazl; Ganjidoust, Hossein; Maghanaki, Amir Abedin

2005-08-01

One of the environmental issues in most regions of Iran is the large number of bottles made from poly-ethylene terephthalate (PET) deposited in domestic wastes and landfills. Due to the high volume of these bottles, more than 1 million m3 landfill space is needed for disposal every year. The purpose of this experimental study was to investigate the possibility of using PET waste in asphalt concrete mixes as aggregate replacement (Plastiphalt) to reduce the environmental effects of PET disposal. For this purpose the mechanical properties of plastiphalt mixes were compared with control samples. This study focused on the parameters of Marshall stability, flow, Marshall quotient (stability-to-flow ratio) and density. The waste PET used in this study was in the form of granules of about 3 mm diameter which would replace (by volume) a portion of the mineral coarse aggregates of an equal size (2.36-4.75 mm). In all prepared mixes the determined 6.6% optimum bitumen content was used. In this investigation, five different percentages of coarse aggregate replacement were used. The results showed that the aggregate replacement of 20% by volume with PET granules would result in a reduction of 2.8% in bulk compacted mix density. The value of flow in the plastiphalt mix was lower than that of the control samples. The results also showed that when PET was used as partial aggregate replacement, the corresponding Marshall stability and Marshall quotient were almost the same as for the control samples. According to most of specification requirement, these results introduce an asphalt mix that has properties that makes it suitable for practical use and furthermore, the recycling of PET for asphalt concrete roads helps alleviate an environmental problem and saves energy.

Determination of the heating temperature of potholes surface on road pavement in the process of repairs using hot asphalt concrete mixes

Directory of Open Access Journals (Sweden)

Giyasov Botir Iminzhonovich

2014-12-01

Full Text Available In the process of roads construction the necessary transport and operational characteristics should be achieved, which depend on the quality of the applied, material and technologies. Under the loads of transport means and the influence of weather conditions on the road pavement deformations and destructions occur, which lead to worsening of transport and operational characteristics, decrease of operational life of the road and they are often the reason of road accidents. According to the data of the Strategic Research Center of "Rosgosstrah" more than 20 % of road accidents in Russia occur due to bad quality of road pavement. One of the main directions in traffic security control and prolongation of operational life for road pavement of non-rigid type is road works, as a result of which defects of pavement are eliminated and in case of timely repairs of high quality the operational life of the road increases for several years. The most widely used material for non-rigid pavement repairs is hot road concrete mixes and in case of adherence to specifications they provide high quality of works. The authors investigate the problems of hot asphalt concrete mixes for repairs of road surfaces of non-rigid type. The results of the study hot asphalt concrete mix’s temperature regimes are offered in case of repair works considering the temperature delivered to the work site and the ambient temperature depending on the type of mix and class of bitumen.

Full surface inspection methods regarding reinforcement corrosion of concrete structures

International Nuclear Information System (INIS)

Reichling, K.; Raupach, M.; Broomfield, J.; Gulikers, J.; L'Hostis, Valerie

2013-01-01

For reinforced concrete structures a localisation of all significant critical areas can only be done by a full surface inspection. The economic advantages are obvious: uncritical areas have not to be repaired expensively.The first step of the assessment should always be a visual inspection. The range of deterioration causes can be limited and the degree of deterioration may be estimated roughly. The inspection program can be adjusted to the requirements. By means of a full surface potential mapping areas with a high risk for chloride induced reinforcement corrosion can be localised, although no deteriorations are visually detectable at the concrete surface. In combination with concrete cover depth and resistivity measurements areas with corrosion promoting exposure conditions can be localised even if the reinforcement is not yet de-passivated. The following publication gives an overview about the essential full surface investigation methods to localise critical areas regarding corrosion of steel in concrete. The selection of methods is based on the inspection procedure given in reference 2. (authors)

Application of waste tires to asphalt pavement. Improvement of adhesion of asphalt with rubber particles; Haitaiya no asphalt hoso eno tekiyo. Asphalt to gomu ryushi no fuchakusei no kairyo ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Nakaoka, I. [Kansai Electric Power Co. Inc., Osaka (Japan)

1994-10-10

With an objective to apply waste tires to asphalt pavement, an experiment was carried out to improve adhesion of asphalt with rubber particles by using polymers. The state of interface on rubber particle and asphalt mixture was observed by a scanning electron microscope. As a result, it was found that the surface of untreated rubber particles is not bonded with the asphalt, but polymer treated mixture was found to have the affinity of rubber particles with asphalt improved. Tensile bonding strength was tested on rubber plates and asphalt. The result revealed that the polymer-reformed mixture has two times as large tensile bonding strength as that of the untreated mixture. With regard to the characters of asphalt mixture mixed with rubber particles, the stability shows a decreasing trend as compared with the standard asphalt concrete, but presents an excellent performance in wear. The fluidity resistance value is inferior to the standard, but not as great as presenting a problem under normal using environment, where its applicability as a road paving material was verified. 4 figs., 2 tabs.

PECULIAR FEATURES OF HEAT-HUMIDITY MODE PERTAINING TO POROUS LAYERS OF ASPHALT CONCRETE PAVEMENTS

Directory of Open Access Journals (Sweden)

V. Verenko

2012-01-01

Full Text Available The paper presents results of experimental investigations and points out the fact that conventional approaches to design and calculations of road pavements that presuppose application of porous asphalt concrete on compact bedding can cause some deformations and destructions initiated due to humidity migration in large internal material pores and lead to material destruction during warm season of the year when water is characterized by high activity. Such processes result in bitumen washing-out, white spot occurrence on the pavement and quick destruction of the pavement.The paper proposes to reconsider existing approaches to design and calculation of road pavements, estimation of reliability and service-ability levels of the applied construction materials. In particular it is necessary to calculate a road pavement with respect to thermo-physical action while excluding condensate and humidity accumulation in porous materials. 

An Experimental Study on Mitigating Alkali Silica Reaction by Using Fly Ash (FA in Combination with Silica Fume and Expanded Perlite Powder (EPP

Directory of Open Access Journals (Sweden)

Isneini Mohd

2016-01-01

Full Text Available ASR suppression by FA, SF, EPP, FA in combination with SF and EPP were evaluated by both mortar bar and concrete prism test. Mortar bars were made based on JIS A 1146, meanwhile concrete prism bars were casted in accordance with Rilem AAR-3. Both specimens were stored in 40°C 100% R.H. controlled room. Mortar and concrete mixtures used reactive aggregate in pessimum proportion. The results indicated that FA in combination with SF and EPP showed smaller expansion compared to FA. The best of concrete mixtures in reducing expansion is combination of FA with SF (FA15SF10.

Effects of Test Conditions on APA Rutting and Prediction Modeling for Asphalt Mixtures

Directory of Open Access Journals (Sweden)

Hui Wang

2017-01-01

Full Text Available APA rutting tests were conducted for six kinds of asphalt mixtures under air-dry and immersing conditions. The influences of test conditions, including load, temperature, air voids, and moisture, on APA rutting depth were analyzed by using grey correlation method, and the APA rutting depth prediction model was established. Results show that the modified asphalt mixtures have bigger rutting depth ratios of air-dry to immersing conditions, indicating that the modified asphalt mixtures have better antirutting properties and water stability than the matrix asphalt mixtures. The grey correlation degrees of temperature, load, air void, and immersing conditions on APA rutting depth decrease successively, which means that temperature is the most significant influencing factor. The proposed indoor APA rutting prediction model has good prediction accuracy, and the correlation coefficient between the predicted and the measured rutting depths is 96.3%.

Variation of Shrinkage Strain within the Depth of Concrete Beams

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Jong-Hyun Jeong

2015-11-01

Full Text Available The variation of shrinkage strain within beam depth was examined through four series of time-dependent laboratory experiments on unreinforced concrete beam specimens. Two types of beam specimens, horizontally cast and vertically cast, were tested; shrinkage variation was observed in the horizontally cast specimens. This indicated that the shrinkage variation within the beam depth was due to water bleeding and tamping during the placement of the fresh concrete. Shrinkage strains were measured within the beam depth by two types of strain gages, surface-attached and embedded. The shrinkage strain distribution within the beam depth showed a consistent tendency for the two types of gages. The test beams were cut into four sections after completion of the test, and the cutting planes were divided into four equal sub-areas to measure the aggregate concentration for each sub-area of the cutting plane. The aggregate concentration increased towards the bottom of the beam. The shrinkage strain distribution was estimated by Hobbs’ equation, which accounts for the change of aggregate volume concentration.

Characteristics Buton Natural Asphalt-Rubber (BNA-R on the Performance Improvement of Warm Mix Asphalt Using Natural Zeolite

Directory of Open Access Journals (Sweden)

Wahjuningsih Nurul

2018-01-01

Full Text Available The decrease in the ability of service of pavement can be caused by the durability factor in the pavement layer in receiving heavy traffic load and the temperature of the pavement. Permanent deformation is one of the criteria of failure of asphalt mixture. Performance assessment of the asphalt mixture can be observed from the rheological properties of asphalt binder. The use of BNA-R in this study is intended to modify the characteristics of bitumen penetration grade 60 / 70 used in warm mix asphalt. Warm mix asphalt with lower temperatures of mixing and compaction than conventional asphalt mixtures was chosen because it is more environmentally friendly. To reduce the temperature in this warm asphalt technology is achieved by using natural zeolite. Both of these materials are local materials that are widely available in Indonesia. The rheology of asphalt 60/70 modified with BNA-R indicates that the addition of BNA-R in the base asphalt increase the complex modulus value and decrease the phase angle value. These values were related to the performance of mixture in the permanent deformation criteria. Reducing the temperature of mixing and compaction should be balanced with modifying the asphalt binder used. Rutting due to permanent deformation can resulted in inconvenience to the passengers and can lead to high costs of road maintenance. To determine the permanent deformation of asphalt mix with material combinations was performed through the wheel tracking test machine with 3,780 cycles for 3 hours. The results shows that after test track over 7 thousand passes have seen permanent deformation characteristics of asphalt concrete mixture with a variation of the characteristics of bitumen.

Performance assessment of warm mix asphalt (WMA) pavements.

Science.gov (United States)

2009-09-01

Warm Mix Asphalt (WMA) is a new technology that was introduced in Europe in 1995. WMA offers several advantages over : conventional asphalt concrete mixtures, including: reduced energy consumption, reduced emissions, improved or more uniform : binder...

Deformation behavior and load limits of asphaltic concrete under the conditions of cores in embankment dams; Deformationsverhalten und Belastungsgrenzen des Asphaltbetons unter den Bedingungen von Staudammkerndichtungen

Energy Technology Data Exchange (ETDEWEB)

Mueller, U.

1998-12-31

Based on the analysis of existing dams with asphaltic diaphragm and investigations in the three-phase-system of asphaltic concrete a recipe for the composition of asphaltic cores is recommended. For the construction, rest and operating period of an embankment dam the load and the reaction of the asphaltic concrete cores as well as the appearing stress and deformations are described. Extensive material testings have been performed and at 41 asphaltic concrete specimens triaxial stress controlled pressure and creeping tests have been carried out. The evaluation of the triaxial tests led to proportions of the main stress and deformation limits as criteria of breaking. Under application of the standard equation for nonlinear viscoelastic element-laws a rheonom element formulation was developed from the experiment data and transformed into its differential form. With this approach the stress and deformation behavior of watertight asphaltic diaphragm can be precalculated for a period up to 10 years. The applicability of this approach, which can be also used within FE-calculations as well, is illustrated in four examples. (orig.) [Deutsch] Nach der Analyse bestehender Staudaemme mit Asphaltbetonkerndichtung und Untersuchungen zum Dreiphasensystem Asphaltbeton wird eine Rezepturempfehlung fuer den Asphaltkerndichtungsbau aufgestellt. Fuer die Bau-, Ruhe- und Betriebsphase eines Staudammes werden die Beanspruchungen und Reaktionen der Asphaltbetonkerndichtung sowie die auftretenden Spannungen und Verformungen beschrieben. Nach umfangreichen Materialpruefungen sind an 41 Asphaltbetonpruefkoerpern triaxiale spannungsgesteuerte Druck-Kriechversuche durchgefuehrt worden. Die Auswertung der Triaxialversuche ergab ein Grenzhauptspannungsverhaeltnis und Deformationsgrenzen als Bruchkriterien. Unter Verwendung der Standarformulierung fuer nichtlineare viskoelastische Stoffgesetze wurde aus den Versuchsdaten ein rheonomer Stoffansatz entwickelt und in seine differentielle Form

Investigating the creep properties of asphaltic concrete containing ...

Indian Academy of Sciences (India)

Hasan Taherkhani

2018-03-10

Mar 10, 2018 ... A three-stage model, developed was fitted to the dynamic ... This indicates that the rutting resistance of such asphalt ... drug delivery [23]. .... Different mathematical ... viour of asphaltic materials and prediction of flow number. A.

Evaluation of canister weld flaw depth for concrete storage cask

Energy Technology Data Exchange (ETDEWEB)

Moon, Tae Chul; Cho, Chun Hyung [Korea Radioactive Waste Agency, Daejeon (Korea, Republic of); Jung, Sung Hun; Lee, Young Oh; Jung, In Su [Korea Nuclear Engineering and Service Corp, Daejeon (Korea, Republic of)

2017-03-15

Domestically developed concrete storage casks include an internal canister to maintain the confinement integrity of radioactive materials. In this study, we analyzed the depth of flaws caused by loads that propagate canister weld cracks under normal, off-normal and accident conditions, and evaluated the maximum allowable weld flaw depth needed to secure the structural integrity of the canister weld and to reduce the welding time of the internal canister lid of the concrete storage cask. Structural analyses for normal, off-normal and accident conditions were performed using the general-purpose finite element analysis program ABAQUS; the allowable flaw depth was assessed according to ASME B and PV Code Section XI. Evaluation results revealed an allowable canister weld flaw depth of 18.75 mm for the concrete storage cask, which satisfies the critical flaw depth recommended in NUREG-1536.

Application of Mastic Asphalt Waterproofing Layer in High-Speed Railway Track in Cold Regions

Directory of Open Access Journals (Sweden)

Song Liu

2018-04-01

Full Text Available Freeze-thaw damage is a typical distress incurred in road and railway engineering in cold regions. Concrete waterproofing layer is commonly used in high-speed railway tracks to prevent the penetration of surface water, however, it cracks easily under thermal stress, especially in cold regions. Recently solutions have been proposed to increase the waterproofing layer’s cracking resistance by using asphalt layers. Nonetheless, the use of emulsified asphalt as well as dense-graded asphalt mixture were not effective enough. To improve the effectiveness, in this study, mastic asphalt was designed for application as the waterproofing layer on the subgrade surface of high-speed railway tracks in cold regions. The overall performance of mastic asphalt was preliminarily evaluated by laboratory tests, then a 200-m test section was constructed for field validation in northeastern China as part of a new high-speed railway line, and water content sensors were placed inside the subgrade to monitor the performance of the mastic asphalt waterproofing layer (MAWL. The subsequent field investigation and monitoring data during the two years operation showed that MAWL dramatically outperformed the conventional concrete waterproofing layer in terms of waterproof performance. Plenty of serious cracks were found in the conventional concrete waterproofing layer, but only a limited number of local cracks were observed in MAWL. As a result, MAWL keeps the water content of subgrade at a stable level. In addition, MAWL showed relatively high stability during the two years investigation period, and no obvious deterioration was observed in the test section.

Spherical and cylindrical cavity expansion models based prediction of penetration depths of concrete targets.

Directory of Open Access Journals (Sweden)

Xiaochao Jin

Full Text Available The cavity expansion theory is most widely used to predict the depth of penetration of concrete targets. The main purpose of this work is to clarify the differences between the spherical and cylindrical cavity expansion models and their scope of application in predicting the penetration depths of concrete targets. The factors that influence the dynamic cavity expansion process of concrete materials were first examined. Based on numerical results, the relationship between expansion pressure and velocity was established. Then the parameters in the Forrestal's formula were fitted to have a convenient and effective prediction of the penetration depth. Results showed that both the spherical and cylindrical cavity expansion models can accurately predict the depth of penetration when the initial velocity is lower than 800 m/s. However, the prediction accuracy decreases with the increasing of the initial velocity and diameters of the projectiles. Based on our results, it can be concluded that when the initial velocity is higher than the critical velocity, the cylindrical cavity expansion model performs better than the spherical cavity expansion model in predicting the penetration depth, while when the initial velocity is lower than the critical velocity the conclusion is quite the contrary. This work provides a basic principle for selecting the spherical or cylindrical cavity expansion model to predict the penetration depth of concrete targets.

Evaluation of binder aging and its influence in aging of hot mix asphalt concrete : technical report.

Science.gov (United States)

2014-01-01

TxDOT Project 0-6009 was a comprehensive interdisciplinary research effort that has developed the ability : to predict asphalt oxidative hardening over time and pavement depth, and the impact of this hardening on : mixture durability. The many interr...

Laboratory evaluation of long-term anti-icing performance and moisture susceptibility of chloride-based asphalt mixture

Directory of Open Access Journals (Sweden)

Mulian Zheng

2016-03-01

Full Text Available The objective of this research is to investigate the long-term anti-icing performance and moisture susceptibility of chloride-based asphalt mixture. Two experiments (the natural and accelerated dissolving-out methods were conducted on the Marshall samples and their salt releasing amount were determined based on the density measurement of the aqueous solution with a hydrometer. In addition, the impact of anti-icing agents (MFL on the mixture water stability was also investigated. Results show that a similar tendency in both methods was observed and the salt dissolution history was generally divided into three phases. Most notably, compared with the natural dissolving-out experiment the accelerated test was more effective and time-saving. Moreover, asphalt concrete with MFL performed poorer water damage resistance than the conventional asphalt concrete and the residual stability of the former declined more dramatically than the later. Finally, based on the 60 °C dissolving-out experiment, a model to predict the effective working time of the anti-icing asphalt pavement was proposed subsequently. Keywords: Asphalt mixture, Chloride, Long-term anti-icing performance, Moisture susceptibility

Utilization of recycled asphalt concrete with warm mix asphalt and cost-benefit analysis.

Science.gov (United States)

Oner, Julide; Sengoz, Burak

2015-01-01

The asphalt paving industries are faced with two major problems. These two important challenges are generated with an increase in demand for environmentally friendly paving mixtures and the problem of rapidly rising raw materials. Recycling of reclaimed asphalt pavement (RAP) is a critical necessity to save precious aggregates and reduce the use of costly bitumen. Warm Mix Asphalt (WMA) technology provides not only the option of recycling asphalt pavement at a lower temperature than the temperature maintained in hot mixtures but also encourages the utilization of RAP and therefore saves energy and money. This paper describes the feasibility of utilizing three different WMA additives (organic, chemical and water containing) at recommended contents with different percentages of RAP. The mechanical properties and cost-benefit analysis of WMA containing RAP have been performed and compared with WMA without RAP. The results indicated that, 30%, 10% and 20% can be accepted as an optimum RAP addition related to organic, chemical and water containing additives respectively and organic additive with 30% RAP content has an appreciable increase in tensile strength over the control mix. It was also concluded that the RAP with WMA technology is the ability to reduce final cost compared to HMA and WMA mixtures.

Multiscale imaging and characterization of the effect of mixing temperature on asphalt concrete containing recycled components.

Science.gov (United States)

Cavalli, M C; Griffa, M; Bressi, S; Partl, M N; Tebaldi, G; Poulikakos, L D

2016-10-01

When producing asphalt concrete mixture with high amounts of reclaimed asphalt pavement (RAP), the mixing temperature plays a significant role in the resulting spatial distribution of the components as well as on the quality of the resulting mixture, in terms of workability during mixing and compaction as well as in service mechanical properties. Asphalt concrete containing 50% RAP was investigated at mixing temperatures of 140, 160 and 180°C, using a multiscale approach. At the microscale, using energy dispersive X-ray spectroscopy the RAP binder film thickness was visualized and measured. It was shown that at higher mixing temperatures this film thickness was reduced. The reduction in film thickness can be attributed to the loss of volatiles as well as the mixing of RAP binder with virgin binder at higher temperatures. X-ray computer tomography was used to characterize statistically the distribution of the RAP and virgin aggregates geometric features: volume, width and shape anisotropy. In addition using X-ray computer tomography, the packing and spatial distribution of the RAP and virgin aggregates was characterized using the nearest neighbour metric. It was shown that mixing temperature may have a positive effect on the spatial distribution of the aggregates but did not affect the packing. The study shows a tendency for the RAP aggregates to be more likely distributed in clusters at lower mixing temperatures. At higher temperatures, they were more homogeneously distributed. This indicates a higher degree of blending both at microscale (binder film) and macroscale (spatial distribution) between RAP and virgin aggregates as a result of increasing mixing temperatures and the ability to quantify this using various imaging techniques. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

Toxicity and environmental and economic performance of fly ash and recycled concrete aggregates use in concrete: A review

Directory of Open Access Journals (Sweden)

Rawaz Kurda

2018-04-01

Full Text Available This paper presents an overview of previous studies on the environmental impact (EI and toxicity of producing recycled concrete aggregates (RCA, fly ash (FA, cement, superplasticizer, and water as raw materials, and also on the effect of replacing cement and natural aggregates (NA with FA and RCA, respectively, on the mentioned aspects. EI and toxicity were analysed simultaneously because considering concrete with alternative materials as sustainable depends on whether their risk assessment is high. Therefore, this study mainly focuses on the cradle-to-gate EI of one cubic meter of concrete, namely abiotic depletion potential (ADP, global warming potential (GWP, ozone depletion potential (ODP, photochemical ozone creation (POCP, acidification potential (AP, eutrophication potential (EP, non-renewable energy (PE-NRe and renewable energy (PE-Re. In terms of toxicity, leachability (chemical and ecotoxicological characterization was considered. The results also include the economic performance of these materials, and show that the incorporation of FA in concrete significantly decreases the EI and cost of concrete. Thus, the simultaneous incorporation of FA and RCA decrease the EI, cost, use of landfill space and natural resources extraction. Nonetheless, the leaching metals of FA decrease when they are incorporated in concrete. Relative to FA, the incorporation of RCA does not significantly affect the EI and cost of concrete, but it significantly reduces the use of landfill space and the need of virgin materials. Keywords: Materials science, Environmental science, Industry, Economics, Safety engineering

Nondestructive estimation of depth of surface opening cracks in concrete beams

International Nuclear Information System (INIS)

Arne, Kevin; In, Chiwon; Kurtis, Kimberly; Kim, Jin-Yeon; Jacobs, Laurence J.

2014-01-01

Concrete is one of the most widely used construction materials and thus assessment of damage in concrete structures is of the utmost importance from both a safety point of view and a financial point of view. Of particular interest are surface opening cracks that extend through the concrete cover, as this can expose the steel reinforcement bars underneath and induce corrosion in them. This corrosion can lead to significant subsequent damage in concrete such as cracking and delamination of the cover concrete as well as rust staining on the surface of concrete. Concrete beams are designed and constructed in such a way to provide crack depths up to around 13 cm. Two different types of measurements are made in-situ to estimate depths of real surface cracks (as opposed to saw-cut notches) after unloading: one based on the impact-echo method and the other one based on the diffuse ultrasonic method. These measurements are compared to the crack depth visually observed on the sides of the beams. Discussions are given as to the advantages and disadvantages of each method

Carbon fiber reinforced asphalt concrete

International Nuclear Information System (INIS)

Jahromi, Saeed G.

2008-01-01

Fibers are often used in the manufacture of other materials. For many years, they have been utilized extensively in numerous applications in civil engineering. Fiber-reinforcement refers to incorporating materials with desired properties within some other materials lacking those properties. Use of fibers is not a new phenomenon, as the technique of fiber-reinforced bitumen began early as 1950. In all industrialized countries today, nearly all concretes used in construction are reinforced. A multitude of fibers and fiber materials are being introduced in the market regularly. The present paper presents characteristics and properties of carbon fiber-reinforced asphalt mixtures, which improve the performance of pavements. To evaluate the effect of fiber contents on bituminous mixtures, laboratory investigations were carried out on the samples with and without fibers. During the course of this study, various tests were undertaken, applying Marshall Test indirect tensile test, creep test and resistance to fatigue cracking by using repeated load indirect tensile test. Carbon fiber exhibited consistency in results and as such it was observed that the addition of fiber does affect the properties of bituminous mixtures, i.e. an increase in its stability and decrease in the flow value as well as an increase in voids in the mix. Results indicate that fibers have the potential to resist structural distress in pavement, in the wake of growing traffic loads and thus improve fatigue by increasing resistance to cracks or permanent deformation. On the whole, the results show that the addition of carbon fiber will improve some of the mechanical properties like fatigue and deformation in the flexible pavement. (author)

Utilizing Lab Tests to Predict Asphalt Concrete Overlay Performance

Science.gov (United States)

2017-12-01

A series of five experimental projects and three demonstration projects were constructed to better understand the performance of pavement overlays using various levels of asphalt binder replacement (ABR) from reclaimed asphalt pavement (RAP), recycle...

Strength characteristics of light weight concrete blocks using mineral admixtures

Science.gov (United States)

Bhuvaneshwari, P.; Priyadharshini, U.; Gurucharan, S.; Mithunram, B.

2017-07-01

This paper presents an experimental study to investigate the characteristics of light weight concrete blocks. Cement was partially replaced with mineral admixtures like Fly ash (FA), limestone powder waste (LPW), Rice husk ash (RHA), sugarcane fiber waste (SCW) and Chrysopogonzizanioides (CZ). The maximum replacement level achieved was 25% by weight of cement and sand. Total of 56 cubes (150 mm x 150 mm x150 mm) and 18 cylinders (100mmφ and 50mm depth) were cast. The specimens being (FA, RHA, SCW, LPW, CZ, (FA-RHA), (FA-LPW), (FA-CZ), (LPW-CZ), (FA-SCW), (RHA-SCW)).Among the different combination, FA,FA-SCW,CZ,FA-CZ showed enhanced strength and durability, apart from achieving less density.

The Concrete and Pavement Challenge

Science.gov (United States)

Roman, Harry T.

2012-01-01

The modern world is characterized by the extensive use of concrete and asphalt pavement. Periodically, these materials are replaced and the old materials disposed of. In this challenge, students will be asked to develop ways to reuse the old materials. It is important for students to understand how concrete and asphalt are made and applied, as…

Performance Modification of Asphalt Binders using Thermoplastic Polymers

Directory of Open Access Journals (Sweden)

H. I. Al-Abdul Wahhab

2004-12-01

Full Text Available There is a need to improve the performance of asphalt binders to minimize stress cracking that occurs at low temperatures and plastic deformation at high temperatures. Importation of used asphalt-polymers from abroad, leads to an increase in the total construction cost as compared to the cost if the used polymers were of local origin. The main objective of this research was to modify locally produced asphalt. Ten polymers were identified as potential asphalt modifiers based on their physical properties and chemical composition. After preliminary laboratory evaluation for the melting point of these polymers, five polymers were selected for local asphalt modification. In the initial stage, required mixing time was decided based on the relation between shear loss modulus and mixing time .The optimum polymer content was selected based on Superpave binder performance grade specifications.The suitability of improvement was verified through the evaluation of permanent deformation and fatigue behavior of laboratory prepared asphalt concrete mixes. The results indicated that the rheological properties of the modified binders improved significantly with sufficient polymer content (3%. The aging properties of the modified binders were found to be dependent on the type of polymer.The fatigue life and resistance to permanent deformation were significantly improved due to enhanced binder rheological properties.  Thus, local asphalts can be modified using thermoplastic polymers.

Prediction model for carbonation depth of concrete subjected to freezing-thawing cycles

Science.gov (United States)

Xiao, Qian Hui; Li, Qiang; Guan, Xiao; Xian Zou, Ying

2018-03-01

Through the indoor simulation test of the concrete durability under the coupling effect of freezing-thawing and carbonation, the variation regularity of concrete neutralization depth under freezing-thawing and carbonation was obtained. Based on concrete carbonation mechanism, the relationship between the air diffusion coefficient and porosity in concrete was analyzed and the calculation method of porosity in Portland cement concrete and fly ash cement concrete was investigated, considering the influence of the freezing-thawing damage on the concrete diffusion coefficient. Finally, a prediction model of carbonation depth of concrete under freezing-thawing circumstance was established. The results obtained using this prediction model agreed well with the experimental test results, and provided a theoretical reference and basis for the concrete durability analysis under multi-factor environments.

Impact of Aggregates Size and Fibers on basic Mechanical Properties of Asphalt Emulsion—Cement Concrete

Science.gov (United States)

Fu, Jun; Liu, Zhihong; Liu, Jie

2018-01-01

Asphalt Emulsion—Cement Concrete (AECC) is currently considered as a typical semi-flexibility material. One of the disadvantages of this material is brittle fracture and lacking ductility. This study aims at accelerating the basic mechanical properties of AECC using fibers and different aggregates size. The mix of AECC was introduced and the different content of fibers and aggregates size were studied. The results showed that the smaller aggregates size could improve the young’s modulus and compressive strength as well as fiber. The modulus-compressive strength ratio of fiber reinforced AECC is always below 500.

Assessment of dynamic modulus of high density polypropylene waste fiber reinforcement in asphalt concrete

Directory of Open Access Journals (Sweden)

Hassan S. OTUOZE

2015-12-01

Full Text Available Traditional asphalt tests like Hveem and Marshall tests are at best mere characterization than effective test of pavement field performance because of complex viscoelastic behavior of asphalt. Mechanical properties otherwise called simple performance tests (SPT are performance criteria of asphalt. Dynamic modulus among other SPT’s like permanent deformation, fatigue cracking, thermal cracking, moisture susceptibility, shear and friction properties; determines stress-strain to time-temperature relationships that imparts on strength, service life and durability. The test followed the recommendations of NCHRP 1-37a (2004 and mixes were prepared using 0, 0.5, 1.0 and 1.5% HDPP contents. The parameters tested for dynamic modulus, /E*/, are stiffness, recoverable strain (ε, and phase angle (ξ. Time – temperature superposition (TTS called master curve was fitted using sigmoidal curve to interpolate the parameters beyond measured data set so as to observe the viscoelastic behavior outside the physical properties. The performance of 0.5% HDPP asphalt is better enhanced than the conventional asphalt to improve upon strength, service and durability.

USE OF CRUMB RUBBER FROM USED CAR TIRES IN MINERAL ASPHALT MIXES

Directory of Open Access Journals (Sweden)

Andrzej Plewa

2014-11-01

Full Text Available With the development of the automotive industry the disposal of used tires is constantly growing problem. Storage of waste rubber is associated with a very long period of decomposition of rubber in the natural conditions. Simultaneously new technologies are developed every year, which in the future may significantly promote recycling of this type of materials. The crumb rubbery modification of the road bitumen is the one of the environmentally safe solutions of rubbery decomposition. Improvement of resistance of the crumb rubbery modification of the road asphalt mixtures is the very important ecological aspect of the future. The article presents the results of research on the fatigue life resistance of asphalt concretes AC16P and AC22P with asphalt-rubber binders. The above analyses have been based on the results of tests of fatigue life of mineral-rubber-asphalt mixes determined by the method of prismatic four-point bending (4PB-PR. Mineral-rubber -asphalt mixes have been diversified according to the amount of the additive of rubber fines in asphalt-rubber binder. On the basis of the test results have been proven improvements functional properties mineral-rubber-asphalt mixes compared with mineral-asphalt mixes with unmodified asphalt.

Estimation of Concrete Carbonation Depth Considering Multiple Influencing Factors on the Deterioration of Durability for Reinforced Concrete Structures

Directory of Open Access Journals (Sweden)

Hae-Chang Cho

2016-01-01

Full Text Available While the durability of concrete structures is greatly influenced by many factors, previous studies typically considered only a single durability deterioration factor. In addition, these studies mostly conducted their experiments inside the laboratory, and it is extremely hard to find any case in which data were obtained from field inspection. Accordingly, this study proposed an Adaptive Neurofuzzy Inference System (ANFIS algorithm that can estimate the carbonation depth of a reinforced concrete member, in which combined deterioration has been reflected based on the data obtained from field inspections of 9 buildings. The proposed ANFIS algorithm closely estimated the carbonation depths, and it is considered that, with further inspection data, a higher accuracy would be achieved. Thus, it is expected to be used very effectively for durability estimation of a building of which the inspection is performed periodically.

Drying of Concrete

DEFF Research Database (Denmark)

Hansen, Kurt Kielsgaard; Geiker, Mette Rica; Nygaard, Peter Vagn

2002-01-01

Estimated and measured relative humidity (RH) change during drying are compared for two concretes, 1: w/c=0.46 and 2: w/(c+0.5fa+2sf)=0.50. The estimations were undertaken by means of the Swedish program TorkaS 1.0. Measurements were performed by RH-sensors type Humi-Guard. Drying of 150 mm thick...... samples from sides at 60% RH and 22 °C took place from 4 to 56 days after casting. At the end of the drying period the measured RH was about 4% lower than the estimated RH at 1/5th depth from the exposed surface for both concretes. In the middle of the samples, the measured RH of concretes 1 and 2 were 2...

Use of rubber crumbs in cement concrete

Science.gov (United States)

Longvinenko, A. A.

2018-03-01

Rubber crumb obtained from worn out tires has been increasingly used over the last 15-20 years, especially in manufacture of asphalt and cement concrete mixtures. This review pays principal attention to application of the rubber crumb to cement concrete mixtures. Use of the rubber crumb in cement concrete is not as successful as in asphalt concrete mixtures, due to incompatibility problems linked to chemical composition and a significant difference in rigidity between the rubber crumb and concrete mixture aggregates. Different methods are proposed and studied to mitigate the adverse influence and increase the beneficial effects of the rubber crumb when added to cement concrete.

Utilization of Swedish fly ash from bio fuel fired power plants as a filler material in concrete; Anvaendning av svenska flygaskor som fillermaterial i betong

Energy Technology Data Exchange (ETDEWEB)

Sundblom, Hillevi [Vattenfall Utveckling AB, Aelvkarleby (Sweden)

2006-03-15

The tested Swedish fly ashes (FA) (FA from bio combustion) in this project proved to have good filler qualities such as improving the stability and the rheological behavior of the concrete. One of tested FA could directly replace the compared limestone filler in the concrete recipes in booth laboratory investigation and in full-scale demonstration. The other FA demanded more water. The recipes were modified in the laboratory investigation to get a functional recipe for full-scale demonstration. The process to investigate the Swedish FA has been following (this project is one part of several investigation): Basic characterization; Characterization as a filler material; Full-scale demonstration; Certification, regularly quality assurance; Continuous use of Swedish FA in the Swedish Concrete Industry. Three representatives Swedish FA have been investigated in step 1-3 according to the process above. There were two FA in a full-scale demonstration a FA from bio fuel/paper sludge fired circulated fluidized bed boiler (at a paper mill) and a FA from a peat fired pulverized boiler. The test made was basic chemical and physical characterization, investigation as a filler material and strength development of a crushed aggregate self-compacting concrete in laboratory and in a full-scale demonstration. The conclusion were following: FA from the paper mill CFB boiler changes in strength development depending on the combustion temperature. It seems the reason is in the way CaO is distribute into different chemical compounds. Higher compressive strength with higher free CaO (analyzed in XRD) Higher content of reactive SiO{sub 2} and free lime in the CFB FA comparing with the PF FA. The soundness of the FA have been tested in early research projects. The sieves curves demonstrated that the FA from the CFB boiler coarser than the other FA tested and the limestone filler compared. The coarser grain fraction could explain why the FA demanded more water in the laboratory and full

OPTIMIZATION OF PRESERVATIVE FOR PROTECTION OF CONCRETE PAVEMENT OF HIGHWAYS

Directory of Open Access Journals (Sweden)

M. K. Pshembaev

2018-01-01

Full Text Available Disadvantages of road concrete pavement quite well known professionals-standards. They were mainly low elasticity modulus asphaltic concrete, as well as a fairly rapid aging of asphalt concrete core component-bitumen. And, as a consequence, is relatively low durability of the coating, the need for frequent repair. To some extent, cement concrete cover signifi cantly outperform this index of asphalt, convinces experience roads of Germany, the United States and other countries. The correct structure of concrete, overall compliance technology laying concrete, comprehensive quality control production  work, sufficient technical personnel qualifications provide long defect-free work road re-coated. However, violations by manufacture of works or in the process of exploitation, particularly in the harsh conditions of freezing and thawing, saturation-drying, especially under the influence of salts-defrosting, cause defects, reduce its durability. There are two directions of increase of durability of the coating. Firstly, it is the primary protection is the creation of concrete with minimal possible on data components mixture water cement ratio that provides reception of concrete with minimum porosity and consequently with maximum durability. Secondly, the secondary protection, providing increased resistance already ready-mixed concrete cover external aggressive actions. In this case against the background of other ways quite promising looks impregnation of the surface concrete integrated structure. Composition must contain multiple components, primarily water repellents, preventing penetration of fluid into the body of the concrete, and finely dispersed silica sol in particular silica, providing reduction of the porosity of the surface layers of concrete by interacting with the free calcium hydroxide. The problem of optimization of impregnation structure and is dedicated to this work.

Performance Assessment of Warm Mix Asphalt (WMA) Pavements : Executive Summary Report

Science.gov (United States)

2009-09-01

Warm Mix Asphalt (WMA) is a new technology which was : introduced in 1995 in Europe. WMA is gaining attention all : over the world because it offers several advantages over : conventional asphalt concrete mixes. The benefits include: : (1) Reduced en...

On the representative volume element of asphalt concrete at low temperature

Science.gov (United States)

Marasteanu, Mihai; Cannone Falchetto, Augusto; Velasquez, Raul; Le, Jia-Liang

2016-08-01

The feasibility of characterizing asphalt mixtures' rheological and failure properties at low temperatures by means of the Bending Beam Rheometer (BBR) is investigated in this paper. The main issue is the use of thin beams of asphalt mixture in experimental procedures that may not capture the true behavior of the material used to construct an asphalt pavement.

Assessing Asphalt and Concrete Pavement Surface Texture in the Field

Directory of Open Access Journals (Sweden)

Saad I. Sarsam

2016-06-01

Full Text Available The incorporation of safety characteristics into the traditional pavement structural design or in the functional evaluation of pavement condition has not been established yet. The design has focused on the structural capacity of the roadway so that the pavement can withstand specific level of repetitive loading over the design life. On the other hand, the surface texture condition was neither included in the AASHTO design procedure nor in the present serviceability index measurements. The pavement surface course should provide adequate levels of friction and ride quality and maintain low levels of noise and roughness. Many transportation departments perform routine skid resistant testing, the type of equipment used for testing varies depending on the preference of each transportation department. It was felt that modeling of the surface texture condition using different methods of testing may assist in solving such problem. In this work, Macro texture and Micro texture of asphalt and cement concrete pavement surface have been investigated in the field using four different methods (The Sand Patch Method, Outflow Time Method, British Pendulum Tester and Photogrammetry Technique. Two different grain sizes of sand have been utilized in conducting the Sand Patch while the Micro texture was investigated using the British Pendulum tester method at wet pavement surface conditions. The test results of the four methods were correlated to the skid number. It was concluded that such modeling could provide instant data in the field for pavement condition which may help in pavement maintenance management.

Design of ultra-lightweight concrete: towards monolithic concrete structures

Directory of Open Access Journals (Sweden)

Yu Qing Liang

2014-04-01

Full Text Available This study addresses the development of ultra-lightweight concrete. A moderate strength and an excellent thermal conductivity of the lightweight concrete are set as the design targets. The designed lightweight aggregates concrete is targeted to be used in monolithic concrete façade structure, performing as both load bearing element and thermal insulator. The developed lightweight concrete shows excellent thermal properties, with a low thermal conductivity of about 0.12 W/(m·K; and moderate mechanical properties, with 28-day compressive strengths of about 10-12 N/mm . This combination of values exceeds, to the researchers’ knowledge, the performance of all other lightweight building materials. Furthermore, the developed lightweight concrete possesses excellent durability properties.

Linking asphalt binder fatigue to asphalt mixture fatigue performance using viscoelastic continuum damage modeling

Science.gov (United States)

Safaei, Farinaz; Castorena, Cassie; Kim, Y. Richard

2016-08-01

Fatigue cracking is a major form of distress in asphalt pavements. Asphalt binder is the weakest asphalt concrete constituent and, thus, plays a critical role in determining the fatigue resistance of pavements. Therefore, the ability to characterize and model the inherent fatigue performance of an asphalt binder is a necessary first step to design mixtures and pavements that are not susceptible to premature fatigue failure. The simplified viscoelastic continuum damage (S-VECD) model has been used successfully by researchers to predict the damage evolution in asphalt mixtures for various traffic and climatic conditions using limited uniaxial test data. In this study, the S-VECD model, developed for asphalt mixtures, is adapted for asphalt binders tested under cyclic torsion in a dynamic shear rheometer. Derivation of the model framework is presented. The model is verified by producing damage characteristic curves that are both temperature- and loading history-independent based on time sweep tests, given that the effects of plasticity and adhesion loss on the material behavior are minimal. The applicability of the S-VECD model to the accelerated loading that is inherent of the linear amplitude sweep test is demonstrated, which reveals reasonable performance predictions, but with some loss in accuracy compared to time sweep tests due to the confounding effects of nonlinearity imposed by the high strain amplitudes included in the test. The asphalt binder S-VECD model is validated through comparisons to asphalt mixture S-VECD model results derived from cyclic direct tension tests and Accelerated Loading Facility performance tests. The results demonstrate good agreement between the asphalt binder and mixture test results and pavement performance, indicating that the developed model framework is able to capture the asphalt binder's contribution to mixture fatigue and pavement fatigue cracking performance.

Modeling of Comparative Performance of Asphalt Concrete under Hammer, Gyratory, and Roller Compaction

Directory of Open Access Journals (Sweden)

Saad I. Sarsam

2016-11-01

Full Text Available The main objective of this study is to develop predictive models using SPSS software (version 18 for Marshall Test results of asphalt mixtures compacted by Hammer, Gyratory, and Roller compaction. Bulk density of (2.351 gm/cc, at OAC of (4.7 % was obtained as a benchmark after using Marshall Compactor as laboratory compactive effort with 75-blows. Same density was achieved by Roller and Gyratory Compactors using its mix designed methods. A total of (75 specimens, for Marshall, Gyratory, and Roller Compactors have been prepared, based on OAC of (4.7 % with an additional asphalt contents of more and less than (0.5 % from the optimum value. All specimens have been subjected to Marshall Test. Mathematical models obtained indicated that variation of Marshall Stiffness is based on the variation of air voids. All of these models depend on asphalt cement content too.

Determination of the neutralization depth of concrete under the aggressive environment influence

Science.gov (United States)

Morzhukhina, Anastasia; Nikitin, Stanislav; Akimova, Elena

2018-03-01

Aggressive environments have a significant impact on destruction of many reinforced concrete structures, such as high-rise constructions or chemical plants. For example, some high-rise constructions are equipped with a swimming pool, so they are exposed to chloride ions in the air. Penetration of aggressive chemical substances into the body of concrete contributes to acceleration of reinforced concrete structure corrosion that in turn leads to load bearing capacity loss and destruction of the building. The article considers and analyzes the main technologies for calculating penetration depth of various aggressive substances into the body of concrete. The calculation of corrosion depth was made for 50-year service life.

Effect of Waste Plastic as Bitumen Modified in Asphalt Mixture

Directory of Open Access Journals (Sweden)

Abdullah Mohd Ezree

2017-01-01

Full Text Available The objectives of this study are to investigate the engineering properties of the asphalt mixtures containing waste plastic at different percentages i.e. 4%, 6%, 8%, and 10% by weight of bitumen. The experimental tests performed in the study were stability, tensile strength, resilient modulus and dynamic creep test. Results showed that the mixture with 4% plastic has the highest stability (184kN. However, the stability slightly decreases with the increase of plastic additive. On the other hand, the highest tensile strength among the modified asphaltic concrete is 1049kPa (8% plastic added. The modified asphalt mixture with 8% plastic has the highest resilient modulus, which is 3422 MPa (25°C and 494Mpa (40°C. Where the highest creep modulus recorded is 73.30Mpa at 8% plastic added. It can be concluded that the addition of 8% plastic gave the highest value properties of asphalt mixture. Finally, it can be said that 8% plastic is the optimum value adding.

Pavement service life extension due to asphalt surface treatment interlayer : research project capsule.

Science.gov (United States)

2016-07-01

The Louisiana Department of Transportation and Development (DOTD) has been : using asphalt surface treatment (AST) interlayers over soil cement base courses : as a means to mitigate shrinkage cracks from reflecting through the asphaltic : concrete (A...

A review of asphalt and asphalt mixture aging

Directory of Open Access Journals (Sweden)

Wilmar Darío Fernández-Gómez

2013-01-01

Full Text Available This paper presents an extensive review of the pertinent literature regarding asphalt and asphalt mixture Aging. Aging affects flexible pavement performance and is produced by intrinsic and extrinsic variables as well as exposure time. Intrinsic variables include asphalt and aggregate properties, a mixture’s asphalt content, binder film thickness and air void content; extrinsic variables are associated with production (short-term aging and exposure to environmental field conditions (long-term aging. Taken together, both variables demonstrate that aging results from three distinct mechanisms: volatilisation, oxidation and steric hardening. Temperature, pressure and photo degradation treatments are used to simulate aging in the laboratory and empirical and semi-empirical models are created to represent and study aging. Aging increases asphalt complex modulus and decreases the phase angle. Mixtures become stiffer while fatigue life becomes reduced. Carbonyl and sulfoxide group formation in asphalt are often studied as such chemical changes show oxidation in aged asphalts. The prevailing models used to predict asphalt aging are discussed, though more comprehensive research into asphalt aging is still needed.

Mechanistic Evaluation of the Effect of Calcium Carbide Waste on Properties of Asphalt Mixes

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N. Isa

2018-03-01

Full Text Available Calcium Carbide Waste (CCW was used as an alternative to traditional Portland cement mineral filler in hot mix asphalt concrete to rid its disposal problem. Its effect on mechanical properties of hot mix asphalt was assessed using the Marshall method of mix design. Using the optimum bitumen content determined from Marshall Test, Portland cement used as mineral filler was partially replaced with 0, 10, 20, 30, 40 and 50% CCW by dry weight. Results of tests indicated an increase in stability, voids in mineral aggregates, Marshall Stiffness and reduction in flow, unit weight, voids filled with binder when the percentage of CCW increases. Based on results of tests, partial replacement of Portland cement with 40% CCW could be used in asphalt production. This will ensure economy in asphalt production and promote disposal of CCW which constitute environmental hazards.

Rutting Prediction in Asphalt Pavement Based on Viscoelastic Theory

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Nahi Mohammed Hadi

2016-01-01

Full Text Available Rutting is one of the most disturbing failures on the asphalt roads due to the interrupting it is caused to the drivers. Predicting of asphalt pavement rutting is essential tool leads to better asphalt mixture design. This work describes a method of predicting the behaviour of various asphalt pavement mixes and linking these to an accelerated performance testing. The objective of this study is to develop a finite element model based on viscoplastic theory for simulating the laboratory testing of asphalt mixes in Hamburg Wheel Rut Tester (HWRT for rutting. The creep parameters C1, C2 and C3 are developed from the triaxial repeated load creep test at 50°C and at a frequency of 1 Hz and the modulus of elasticity and Poisson’ s ratio determined at the same temperature. Viscoelastic model (creep model is adopted using a FE simulator (ANSYS in order to calculate the rutting for various mixes under a uniform loading pressure of 500 kPa. An eight-node with a three Degrees of Freedom (UX, UY, and UZ Element is used for the simulation. The creep model developed for HWRT tester was verified by comparing the predicted rut depths with the measured one and by comparing the rut depth with ABAQUS result from literature. Reasonable agreement can be obtained between the predicted rut depths and the measured one. Moreover, it is found that creep model parameter C1 and C3 have a strong relationship with rutting. It was clear that the parameter C1 strongly influences rutting than the parameter C3. Finally, it can be concluded that creep model based on finite element method can be used as an effective tool to analyse rutting of asphalt pavements.

20 CFR 654.409 - Heating.

Science.gov (United States)

2010-04-01

...) When a heating system has automatic controls, the controls shall be of the type which cut off the fuel... EMPLOYMENT SERVICE SYSTEM Housing for Agricultural Workers Housing Standards § 654.409 Heating. (a) All... concrete slab, insulated metal sheet, or other fireproof material on the floor under each stove, extending...

Assessment of asphalt concrete reinforcement grid in flexible pavements : final report.

Science.gov (United States)

2016-05-01

This report investigated the application of accepted methods of pavement structural evaluation to independently assess the potential structural benefit of asphalt geogrid reinforcement of an operational flexible highway pavement. The asphalt interlay...

Characteristics of permanent deformation rate of warm mix asphalt with additives variation (BNA-R and zeolite)

Science.gov (United States)

Wahjuningsih, Nurul; Hadiwardoyo, Sigit Pranowo; Sumabrata, R. Jachrizal

2017-06-01

Permanent deformation is one of the criteria of failure on asphalt concrete mixture. The nature of the bitumen melt at high temperatures, this condition causes the asphalt concrete mixture tends to soften due to an increase in temperature of the road surface. The increase in surface temperature and the load wheel that has repeated itself on the same trajectory causes deformation groove has formed. Conditions rutting due to permanent deformation has resulted in inconvenience to the passengers and can lead to high costs of road maintenance. On the road planning process required a prediction of the rate of the permanent deformation of asphalt concrete mixtures. It is important to know early on the road surface damage due to vehicle load and surface temperature during service life. Asphalt has been mixed with the additive BNA-R and Zeolite intended to make variations in the characteristics of bitumen in this study. This variation is further combined with variations in the composition of aggregate in order to obtain a combination of asphalt-aggregate mixture. This mixture using warm mix, and to determine the permanent deformation of asphalt mix with material combinations was performed through the wheel tracking test machine with 3,780 cycles or 7,560 tracks for 3 hours. Another analysis to determine the characteristics of asphalt concrete mixtures have also been carried out changes in the surface temperature at the time of the test track. From the results of the test track to nearly 8 thousand passes has seen permanent deformation characteristics of asphalt concrete mixture with a variation of the characteristics of bitumen and aggregate variation. Groove of deformation due to a wheel load from the initial until the last passes shows that there are influence of compaction temperature on the variation of bitumen and aggregate composition to the relationship of permanent deformation of the wheel groove, especially on the road surface temperature changes.

Performance of Asphalt Concrete Wearing Course (AC-WC) Utilizing Reclaimed Asphalt Pavement from Cold Milling Bound with 80/100 Pen Asphalt

Science.gov (United States)

Thanya, I. N. A.; Suweda, I. W.; Putra, G. K.

2018-03-01

Demands on natural aggregate materials for road pavement can be reduced by utilizing reclaimed asphalt pavement (RAP). This research was aimed at evaluating the performance of AC-WC mixture using RAP materials from cold milling, bound with 80/100 pen asphalt. The RAP aggregate gradation was adjusted by adding the required amount of natural aggregates to meet the specification in Indonesia. The RAP and added aggregates were hotmixed and compacted with Marshall hummer at 2×75 blows. The asphalt content were varied. It was found that the optimum asphalt content was 6.05 % with the following Marshall characteristics: stability 1237.08 kg; flow 3.36 mm; Marshall quotient 324,73kg/mm; void in mix (VIM) 3,360%; void in mineral aggregate (VMA) 15.103; and void filled with bitumen (VFB) 77.759% and residual stability 91.04; all met the Indonesian specification. The cantabro abration loss (CAL) at 30°C was 9,02%. The indirect tensile stiffness modulus (ITSM) at 20 °C was 7961.4 MPa; dynamic creep with 100 kPa pressure at 40°C gave slope 0.0112 microsstrain/pulse which is suitable for heavy load traffic. The fatigue test results was obtained at increased stress level, i.e. at 900, 1100, and 1300 kPa. Based on the equation derived from the fatigue strain and repeated loading relationship, at 100 microstrain (με) the repeated load was 434,661.58 times, and at one million (106) repeated loading, the samples could withstand strain of 92,38 microstrain. The performance of the samples were overall better than AC-WC mixture using virgin aggregates bound with 60/70 pen asphalt.

Investigation of asphalt core-plinth connection in embankment dams

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Weibiao Wang

2017-12-01

Full Text Available The asphalt core itself is a no-joint water barrier in embankment dams and is connected to the concrete plinth on the bottom of the core. A reliable asphalt core-plinth connection is crucial and must remain watertight when the core deforms due to deformations in the embankment and foundation and due to reservoir water pressure. A large number of tension tests were conducted to determine the best ratios, joint thickness and suitable additives for the sandy asphalt mastic (SAM mix used for the connection. With the ratios of bitumen to filler to sand of 20%:35%:45% and by adding 4% SBS in the bitumen, one got a very suitable composition for the asphalt core-plinth connection in tensile conditions. Model tests were conducted to study the connection behavior when subjected to large shear displacements and high water pressure. The joint model test results indicate that the plane-surface plinth, curved-surface plinth, and plinth with or without copper water-stop showed no significant difference for the connection in the joint shear behavior. However, plinth with copper water-stop is suggested to enhance its tensile and shear behavior.

Investigation of the use of recycled polymer-modified asphalt in asphaltic concrete pavements.

Science.gov (United States)

2004-06-30

This report presents issues associated with recycling polymer modified asphalt cements (PMACs), particularly blending aged PMAC with new PMAC. A styrene-butadiene-styrene (SBS) PMAC was selected and graded using the Superpave Performance Grading (PG)...

Three-dimensional modeling and simulation of asphalt concrete mixtures based on X-ray CT microstructure images

Directory of Open Access Journals (Sweden)

Hainian Wang

2014-02-01

Full Text Available X-ray CT (computed tomography was used to scan asphalt mixture specimen to obtain high resolution continuous cross-section images and the meso-structure. According to the theory of three-dimensional (3D reconstruction, the 3D reconstruction algorithm was investigated in this paper. The key to the reconstruction technique is the acquisition of the voxel positions and the relationship between the pixel element and node. Three-dimensional numerical model of asphalt mixture specimen was created by a self-developed program. A splitting test was conducted to predict the stress distributions of the asphalt mixture and verify the rationality of the 3D model.

Hanford protective barriers program: Status of asphalt barrier studies - FY 1989

International Nuclear Information System (INIS)

Freeman, H.D.; Gee, G.W.

1989-11-01

The Hanford Protective Barrier Program is evaluating alternate barriers to provide a means of meeting stringent water infiltration requirements. One type of alternate barrier being considered is an asphalt-based layer, 1.3 to 15 cm thick. Evaluations of these barriers were initiated in FY 1988, and, based on laboratory studies, two asphalt formulations were selected for further testing in small-tube lysimeters: a hot rubberized asphalt and an admixture of cationic asphalt emulsion and concrete sand containing 24 wt% residual asphalt. Eight lysimeters containing asphalt seals were installed as part of the Small Tube Lysimeter Test Facility on the Hanford Site. Two control lysimeters containing Hanford sand with a surface gravel treatment were also installed for comparison. 5 refs., 13 figs., 1 tab

Qualitative criteria and thresholds for low noise asphalt mixture design

Science.gov (United States)

Vaitkus, A.; Andriejauskas, T.; Gražulytė, J.; Šernas, O.; Vorobjovas, V.; Kleizienė, R.

2018-05-01

Low noise asphalt pavements are cost efficient and cost effective alternative for road traffic noise mitigation comparing with noise barriers, façade insulation and other known noise mitigation measures. However, design of low noise asphalt mixtures strongly depends on climate and traffic peculiarities of different regions. Severe climate regions face problems related with short durability of low noise asphalt mixtures in terms of considerable negative impact of harsh climate conditions (frost-thaw, large temperature fluctuations, hydrological behaviour, etc.) and traffic (traffic loads, traffic volumes, studded tyres, etc.). Thus there is a need to find balance between mechanical and acoustical durability as well as to ensure adequate pavement skid resistance for road safety purposes. Paper presents analysis of the qualitative criteria and design parameters thresholds of low noise asphalt mixtures. Different asphalt mixture composition materials (grading, aggregate, binder, additives, etc.) and relevant asphalt layer properties (air void content, texture, evenness, degree of compaction, etc.) were investigated and assessed according their suitability for durable and effective low noise pavements. Paper concluded with the overview of requirements, qualitative criteria and thresholds for low noise asphalt mixture design for severe climate regions.

Characteristics Buton Natural Asphalt-Rubber (BNA-R) on the Performance Improvement of Warm Mix Asphalt Using Natural Zeolite

Science.gov (United States)

Wahjuningsih, Nurul; Pranowo Hadiwardoyo, Sigit; Jachrizal Sumabrata, R.

2018-03-01

The decrease in the ability of service of pavement can be caused by the durability factor in the pavement layer in receiving heavy traffic load and the temperature of the pavement. Permanent deformation is one of the criteria of failure of asphalt mixture. Performance assessment of the asphalt mixture can be observed from the rheological properties of asphalt binder. The use of BNA-R in this study is intended to modify the characteristics of bitumen penetration grade 60 / 70 used in warm mix asphalt. Warm mix asphalt with lower temperatures of mixing and compaction than conventional asphalt mixtures was chosen because it is more environmentally friendly. To reduce the temperature in this warm asphalt technology is achieved by using natural zeolite. Both of these materials are local materials that are widely available in Indonesia. The rheology of asphalt 60/70 modified with BNA-R indicates that the addition of BNA-R in the base asphalt increase the complex modulus value and decrease the phase angle value. These values were related to the performance of mixture in the permanent deformation criteria. Reducing the temperature of mixing and compaction should be balanced with modifying the asphalt binder used. Rutting due to permanent deformation can resulted in inconvenience to the passengers and can lead to high costs of road maintenance. To determine the permanent deformation of asphalt mix with material combinations was performed through the wheel tracking test machine with 3,780 cycles for 3 hours. The results shows that after test track over 7 thousand passes have seen permanent deformation characteristics of asphalt concrete mixture with a variation of the characteristics of bitumen.

Significance of Fines in Hot Mix Asphalt Synthesis

Directory of Open Access Journals (Sweden)

Kalaitzaki Elvira

2017-07-01

Full Text Available According to their size, aggregates are classified in coarse grained, fine grained, and fines. The determination of fines content in aggregate materials is very simple and is performed through the aggregate washing during the sieving procedure to define the gradation curve. The very fine material consists of grains having a size lower than 63 μm. The presence of fines directly influences the composition and performance of concrete and asphalt mixtures (e.g. asphalt content, elasticity, fracture. The strength and load carrying capacity of hot mix asphalt (HMA results from the aggregate framework created through particle-particle contact and interlock. Fines or mineral filler have a role in HMA. The coarse aggregate framework is filled by the sand-sized material and finally by the mineral filler. At some point, the smallest particles lose contact becoming suspended in the binder not having the particle-particle contact that is created by the larger particles. The overall effect of mineral filler in hot mix asphalt specimens has been investigated through a series of laboratory tests. It is clear that a behaviour influenced by the adherence of fines to asphalt film has been developed. The optimum bitumen content requirement in case of stone filler is almost the same as that for fly ash. It has been found that the percentage of fly ash filler is crucial if it exceeds approximately a value of 4%.

Adjusting Asphalt Mixes for Increased Durability and Implementation of a Performance Tester to Evaluate Fatigue Cracking of Asphalt

Science.gov (United States)

2018-01-17

Cracking is a common failure mechanism in asphalt concrete pavement structures. It is one of the main reasons for large road maintenance and rehabilitation expenditures, as well as reduced user comfort and increased fuel consumption due to high road ...

Asphalt Pavement Aging and Temperature Dependent Properties Using Functionally Graded Viscoelastic Model

Science.gov (United States)

Dave, Eshan V.

2009-01-01

Asphalt concrete pavements are inherently graded viscoelastic structures. Oxidative aging of asphalt binder and temperature cycling due to climatic conditions being the major cause of non-homogeneity. Current pavement analysis and simulation procedures dwell on the use of layered approach to account for these non-homogeneities. The conventional…

Modelling absorption in porous asphalt concrete for oblique incident sound waves

NARCIS (Netherlands)

Bezemer-Krijnen, Marieke; Wijnant, Ysbrand H.; de Boer, Andries; Sas, P; Moens, D.; Denayer, H.

2014-01-01

A numerical model to predict the sound absorption of porous asphalt has been developed. The approach is a combination between a microstructural approach and a finite element approach. The model used to describe the viscothermal properties of the air inside the pores of the asphalt is the low reduced

An In-Depth Investigation into the Physicochemical, Thermal, Microstructural, and Rheological Properties of Petroleum and Natural Asphalts

Directory of Open Access Journals (Sweden)

Nader Nciri

2016-10-01

Full Text Available Over the last decade, unexpected and sudden pavement failures have occurred in several provinces in South Korea. Some of these failures remain unexplained, further illustrating the gaps in our knowledge about binder chemistry. To prevent premature pavement distress and enhance road performance, it is imperative to provide an adequate characterization of asphalt. For this purpose, the current research aims at inspecting the chemistry, microstructure, thermal, and physico-rheological properties of two types of asphalt, namely petroleum asphalt (PA and natural asphalt (NA. The binders were extensively investigated by using elemental analysis, thin-layer chromatography with flame ionization detection (TLC-FID, matrix-assisted laser desorption ionization time-of-fight mass spectroscopy (MALDI-TOF-MS, Fourier transform infrared spectroscopy (FT-IR, Raman spectroscopy (RS, Nuclear magnetic resonance spectroscopy (1H-NMR, ultraviolet and visible spectroscopy (UV-VIS, X-ray diffraction (XRD, scanning electron microscopy (SEM, thermogravimetric analysis (TGA, differential scanning calorimetry (DSC, penetration, softening point, ductility, and viscosity tests. The findings of this research have revealed the distinct variations between the chemical compositions, microstructures, and thermo-rheological properties of the two asphalts and provided valuable knowledge into the characteristics of the binders. Such insight has been effective in predicting the performance or distress of road pavement. This paper will, therefore, be of immediate interest to materials engineers in state highway agencies and asphalt industries.

Potential of utilizing asphalt dust waste as filler material in the production of sustainable self compacting concrete (SCC)

Science.gov (United States)

Ismail, Isham; Shahidan, Shahiron; Bahari, Nur Amira Afiza Saiful

2017-12-01

Waste materials from many industries are widely used in the production of sustainable green concrete. Utilizing asphalt dust waste (ADW) as a filler material in the development of self-compacting concrete (SCC) is one of the alternative solutions for reducing environmental waste. SCC is an innovative concrete that does not require vibration for placing and compaction. However, there is limited information on the effects of utilizing ADW in the development of SCC. Therefore, this research study examines the effects of various w/b ratios (0.2, 0.3 and 0.4) and differing amounts of ADW (0% to 50%) on the rheological properties of fresh state concrete. The compressive strength of the SCC was tested only for 7 and 28 days as preliminary studies. The results revealed that mixtures MD730, MD740 and MD750 showed satisfactory results for the slump flow, J-Ring, L-Box and V-Funnel test during the fresh state. The compressive strength values obtained after 28 days for MD730, MD740 and MD750 were 35.1 MPa, 36.8 MPa and 29.4 MPa respectively. In conclusion, the distribution of materials in mixtures has significant effect in achieving rheological properties and compressive strength of SCC.

A Factorial Design Approach to Analyse the Effect of Coarse Recycled Concrete Aggregates on the Properties of Hot Mix Asphalt

Science.gov (United States)

Tanty, Kiranbala; Mukharjee, Bibhuti Bhusan; Das, Sudhanshu Shekhar

2018-02-01

The present study investigates the effect of replacement of coarse fraction of natural aggregates by recycled concrete aggregates on the properties of hot mix asphalt (HMA) using general factorial design approach. For this two factors i.e. recycled coarse aggregates percentage [RCA (%)] and bitumen content percentage [BC (%)] are considered. Tests have been carried out on the HMA type bituminous concrete, prepared with varying RCA (%) and BC (%). Analysis of variance has been performed on the experimental data to determine the effect of the chosen factors on various parameters such as stability, flow, air void, void mineral aggregate, void filled with bitumen and bulk density. The study depicts that RCA (%) and BC (%) have significant effect on the selected responses as p value is less than the chosen significance level. In addition to above, the outcomes of the statistical analysis indicate that interaction between factors have significant effects on void mineral aggregate and bulk density of bituminous concrete.

A Factorial Design Approach to Analyse the Effect of Coarse Recycled Concrete Aggregates on the Properties of Hot Mix Asphalt

Science.gov (United States)

Tanty, Kiranbala; Mukharjee, Bibhuti Bhusan; Das, Sudhanshu Shekhar

2018-06-01

The present study investigates the effect of replacement of coarse fraction of natural aggregates by recycled concrete aggregates on the properties of hot mix asphalt (HMA) using general factorial design approach. For this two factors i.e. recycled coarse aggregates percentage [RCA (%)] and bitumen content percentage [BC (%)] are considered. Tests have been carried out on the HMA type bituminous concrete, prepared with varying RCA (%) and BC (%). Analysis of variance has been performed on the experimental data to determine the effect of the chosen factors on various parameters such as stability, flow, air void, void mineral aggregate, void filled with bitumen and bulk density. The study depicts that RCA (%) and BC (%) have significant effect on the selected responses as p value is less than the chosen significance level. In addition to above, the outcomes of the statistical analysis indicate that interaction between factors have significant effects on void mineral aggregate and bulk density of bituminous concrete.

Toxicity and environmental and economic performance of fly ash and recycled concrete aggregates use in concrete: A review.

Science.gov (United States)

Kurda, Rawaz; Silvestre, José D; de Brito, Jorge

2018-04-01

This paper presents an overview of previous studies on the environmental impact (EI) and toxicity of producing recycled concrete aggregates (RCA), fly ash (FA), cement, superplasticizer, and water as raw materials, and also on the effect of replacing cement and natural aggregates (NA) with FA and RCA, respectively, on the mentioned aspects. EI and toxicity were analysed simultaneously because considering concrete with alternative materials as sustainable depends on whether their risk assessment is high. Therefore, this study mainly focuses on the cradle-to-gate EI of one cubic meter of concrete, namely abiotic depletion potential (ADP), global warming potential (GWP), ozone depletion potential (ODP), photochemical ozone creation (POCP), acidification potential (AP), eutrophication potential (EP), non-renewable energy (PE-NRe) and renewable energy (PE-Re). In terms of toxicity, leachability (chemical and ecotoxicological characterization) was considered. The results also include the economic performance of these materials, and show that the incorporation of FA in concrete significantly decreases the EI and cost of concrete. Thus, the simultaneous incorporation of FA and RCA decrease the EI, cost, use of landfill space and natural resources extraction. Nonetheless, the leaching metals of FA decrease when they are incorporated in concrete. Relative to FA, the incorporation of RCA does not significantly affect the EI and cost of concrete, but it significantly reduces the use of landfill space and the need of virgin materials.

Performance Evaluation of Hot Mix Asphalt with Different Proportions of RAP Content

Directory of Open Access Journals (Sweden)

Kamil Arshad Ahmad

2018-01-01

Full Text Available Reclaimed Asphalt Pavement (RAP is old asphalt pavement that has been removed from a road by milling or full depth removal. The use of RAP in hot mix asphalt (HMA eliminates the need to dispose old asphalt pavements and conserves asphalt binders and aggregates, resulting in significant cost savings and benefits to society. This paper presents a study on HMA with different RAP proportions carried out to evaluate the volumetric properties and performance of asphalt mixes containing different proportions of RAP. Marshall Mix Design Method was used to produce control mix (0% RAP and asphalt mixes containing 15% RAP, 25% RAP and 35% RAP in accordance with Specifications for Road Works of Public Works Department, Malaysia for AC14 dense graded asphalt gradation. Volumetric analysis was performed to ensure that the result is compliance with specification requirements. The resilient modulus test was performed to measure the stiffness of the mixes while the Modified Lottman test was conducted to evaluate the moisture susceptibility of these mixes. The Hamburg wheel tracking test was used to evaluate the rutting performance of these mixes. The results obtained showed that there were no substantial difference in Marshall Properties, moisture susceptibility, resilient modulus and rutting resistance between asphalt mixes with RAP and the control mix. The test results indicated that recycled mixes performed as good as the performance of conventional HMA in terms of moisture susceptibility and resilient modulus. It is recommended that further research be carried out for asphalt mixes containing more than 35% RAP material.

Studies of detailed biofilm characterization on fly ash concrete in comparison with normal and superplasticizer concrete in seawater environments.

Science.gov (United States)

Vishwakarmaa, Vinita; George, R P; Ramachandran, D; Anandkumar, B; Mudalib, U Kamachi

2014-01-01

In cooling water systems, many concrete structures in the form of tanks, pillars and reservoirs that come in contact with aggressive seawater are being deteriorated by chemical and biological factors. The nuclear industry has decided to partially replace the Portland cement with appropriate pozzolans such as fly ash, which could densify the matrix and make the concrete impermeable. Three types of concrete mixes, viz., normal concrete (NC), concrete with fly ash and superplasticizer (FA) and concrete with only superplasticizer (SP) were fabricated for short- and long-term exposure studies and for screening out the better concrete in seawater environments. Biofilm characterization studies and microscopic studies showed excellent performance of FA concrete compared to the other two. Laboratory exposure studies in pure cultures of Thiobacillus thiooxidans and Fusarium oxysporum were demonstrated for the inhibition of microbial growth on fly ash. Epifluorescence and scanning electron microscopic studies supported the better performance of the FA specimen. Thus, the present study clearly showed that FA concrete is less prone to biofilm formation and biodeterioration.

Choosing mineral carrier of nanoscale additives for asphalt concrete

Directory of Open Access Journals (Sweden)

Inozemtsev Sergey Sergeevich

2014-03-01

Full Text Available At present time the operation life of the majority of roads is essentially shorter than required. The reason for it is the increase in traffic intensity and axle loads of automobile transport. The obvious reasons for early wear of roads are the low quality of the components used and low industrial standards while producing asphalt pavement. In this paper the mineral material was selected as a carrier of nanoscale additives for asphalt. The optimal modes for grinding mineral materials were identified, which provide correspondence of their structure parameters with the developed model. The influence of different mineral nanomodifier carriers on the structure formation processes was estimated. It is shown that among a number of mineral materials diatomite has high activity in relation to the bitumen, because it has a highly porous structure. It is also shown that as a result of lighter fractions of bitumen adsorption on the border of phase interface, diatomite and bitumen changes from the free state to the film, and solvate shell of bitumen is saturated with asphaltenes. With the help of IR spectroscopy the authors defined the nature of the diatomite and bitumen interaction and proved that in the process of their interaction there occurs physical adsorption with additional absorption of bitumen components into the pore space of diatomite grains.

Storm Water General Permit 3 for Rock and Asphalt

Data.gov (United States)

Iowa State University GIS Support and Research Facility — General permit #3 for storm water discharges associated with industrial activity for Asphalt Plants, Concrete Batch Plants, Rock Crushing Plants and Construction...

Review of warm mix rubberized asphalt concrete : Towards a sustainable paving technology

NARCIS (Netherlands)

Wang, H.; Liu, X.; Apostolidis, P.; Scarpas, Athanasios

2018-01-01

In recent years, transportation agencies and the general public alike are demanding increased considerations of sustainability in transport infrastructure. Warm mix asphalt (WMA) is developed for reducing energy consumptions and emissions in asphalt paving industry. In addition, the use of

Depth Profiling (ICP-MS Study of Toxic Metal Buildup in Concrete Matrices: Potential Environmental Impact

Directory of Open Access Journals (Sweden)

Ghada Bassioni

2010-10-01

Full Text Available This paper explores the potential of concrete material to accumulate toxic trace elements using ablative laser technology (ICP-MS. Concrete existing in offshore structures submerged in seawater acts as a sink for hazardous metals, which could be gradually released into the ocean creating pollution and anoxic conditions for marine life. Ablative laser technology is a valuable tool for depth profiling concrete to evaluate the distribution of toxic metals and locate internal areas where such metals accumulate. Upon rapid degradation of concrete these “hotspots” could be suddenly released, thus posing a distinct threat to aquatic life. Our work simulated offshore drilling conditions by immersing concrete blocks in seawater and investigating accumulated toxic trace metals (As, Be, Cd, Hg, Os, Pb in cored samples by laser ablation. The experimental results showed distinct inhomogeneity in metal distribution. The data suggest that conditions within the concrete structure are favorable for random metal accumulation at certain points. The exact mechanism for this behavior is not clear at this stage and has considerable scope for extended research including modeling and remedial studies.

Residual characteristic properties of ternary blended steel fibre reinforced concrete subjected to sustained elevated temperature

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Sinha Deepa A.

2013-09-01

Full Text Available To study the behavior of ternary blended steel fibre reinforced concrete when subjected to 800 Deg.C and 1000 Deg.C for 3 hours. It has been found that the ternary blended steel fibre reinforced concrete containing (FA+GGBFS and (FA+MK offer higher resistance to sustained elevated temperatures upto 800 Deg.C, where as the blend containing (FA+SF does not offer any resistance at this temperature. The study reveals that the blend containing (FA+GGBFS and (FA+MK gives highest resistance at replacement levels of (10+20 and (15+15 respectively at sustained exposure to 800 Deg.C.

The Acoustical Durability of Thin Noise Reducing Asphalt Layers

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Cedric Vuye

2016-05-01

Full Text Available Within the context of the European Noise Directive, traffic noise action plans have been established. One of those actions is to deepen the knowledge about low noise roads, as they are considered the most cost-efficient measure for traffic noise abatement. Therefore, ten test sections were installed in May 2012 in Belgium, with the objective of integrating Thin noise-reducing Asphalt Layers (TAL in the Flemish road surface policy in a later stage. Eight test sections are paved with TAL with a thickness of a maximum of 30 mm and a maximum content of accessible voids of 18%. The other two sections consist of a Double-layer Porous Asphalt Concrete (DPAC and a Stone Mastic Asphalt (SMA-10 as a reference section. The acoustical quality of the asphalt surfaces has been monitored in time using Statistical Pass-By (SPB and Close-ProXimity (CPX measurements up to 34 months after construction. Texture measurements performed with a laser profilometer are linked to the noise measurement results. Very promising initial noise reductions were found, up to 6 dB(A, but higher than expected acoustic deterioration rates and the presence of raveling led to noise reductions of a max. of 1 dB(A after almost three years. It is shown that the construction process itself has a large influence on the acoustical quality over time.

Improving Asphalt Mixtures Performance by Mitigating Oxidation Using Anti-Oxidants Additives

Science.gov (United States)

Dessouky, Samer; Diaz, Manuel

Polymer modified additives are typically used to improve rheological properties of asphalt binder as well as mechanical properties of asphalt concrete mix. In this study, polymer-modified binder PG70-22 is mixing with two co-polymers enhanced with anti-oxidant agents namely; Solution Styrene-Butadiene Rubber (SSBR) and Solution Ethylene-Butylene/Styrene (SEBS). The objective of this study is to characterize the effect of those additives into the rheological properties of the asphalt binder using temperature sweep test and mechanical properties of asphalt mixes. The aging index is determined to evaluate the role of additives to reduce brittleness after aging of the binder. The performance of asphalt mixes were characterized by Hamburg Wheel Tracking Test for moisture damage, Beam Fatigue Test for fatigue properties and Flow Number Test for rutting performance. It is found that the asphalt mixes with enhanced binders are improving its rutting and moisture resistance but decreased its fatigue life compared to the control mix.

Non-destructive analysis of chlorine in fly ash cement concrete

International Nuclear Information System (INIS)

Naqvi, A.A.; Garwan, M.A.; Nagadi, M.M.; Maslehuddin, M.; Al-Amoudi, O.S.B.; Khateeb-ur-Rehman

2009-01-01

Preventive measures against reinforcement corrosion in concrete require increasing concrete density to prevent the diffusion of chloride ions to the steel surface. Pozzolanic materials, such as fly ash (FA), silica fume (SF), and blast furnace slag (BFS) are added to concrete to increase its density. Monitoring the chloride concentration in concrete is required to assess the chances of reinforcement corrosion. In this study, FA was added to Portland cement concrete to increase its density. Prompt gamma neutron activation analysis (PGNAA) technique was utilized to analyze the concentration of chlorine in concrete. The chlorine concentration in the FA cement concrete was evaluated by determining the yield of 1.16, 1.95, 6.11, 6.62, 7.41, 7.79, and 8.58 MeV gamma-rays of chlorine from the FA concrete specimen containing 0.4-3.5 wt% chlorine. An excellent agreement was noted between the experimental yield of the prompt gamma-rays and the calculated yield obtained through the Monte Carlo simulations. The Minimum Detectable Concentration (MDC) of chlorine in FA cement concrete was also calculated. The best value of MDC limit of chlorine in the FA cement concrete was found to be 0.022±0.007 and 0.038±0.017 wt% for 1.16 and 6.11 MeV prompt gamma-rays, respectively. Within the statistical uncertainty, the lower bound of MDC meets the maximum permissible limit of 0.03 wt% of chlorine in concrete set by American Concrete Institute Committee 318.

Non-destructive analysis of chlorine in fly ash cement concrete

Energy Technology Data Exchange (ETDEWEB)

Naqvi, A.A. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)], E-mail: aanaqvi@kfupm.edu.sa; Garwan, M.A.; Nagadi, M.M. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Maslehuddin, M. [Center for Engineering Research, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Al-Amoudi, O.S.B. [Department of Civil Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Khateeb-ur-Rehman [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

2009-08-11

Preventive measures against reinforcement corrosion in concrete require increasing concrete density to prevent the diffusion of chloride ions to the steel surface. Pozzolanic materials, such as fly ash (FA), silica fume (SF), and blast furnace slag (BFS) are added to concrete to increase its density. Monitoring the chloride concentration in concrete is required to assess the chances of reinforcement corrosion. In this study, FA was added to Portland cement concrete to increase its density. Prompt gamma neutron activation analysis (PGNAA) technique was utilized to analyze the concentration of chlorine in concrete. The chlorine concentration in the FA cement concrete was evaluated by determining the yield of 1.16, 1.95, 6.11, 6.62, 7.41, 7.79, and 8.58 MeV gamma-rays of chlorine from the FA concrete specimen containing 0.4-3.5 wt% chlorine. An excellent agreement was noted between the experimental yield of the prompt gamma-rays and the calculated yield obtained through the Monte Carlo simulations. The Minimum Detectable Concentration (MDC) of chlorine in FA cement concrete was also calculated. The best value of MDC limit of chlorine in the FA cement concrete was found to be 0.022{+-}0.007 and 0.038{+-}0.017 wt% for 1.16 and 6.11 MeV prompt gamma-rays, respectively. Within the statistical uncertainty, the lower bound of MDC meets the maximum permissible limit of 0.03 wt% of chlorine in concrete set by American Concrete Institute Committee 318.

Initial Self-Healing Temperatures of Asphalt Mastics Based on Flow Behavior Index

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Chao Li

2018-05-01

Full Text Available Increasing temperature is a simple and convenient method to accelerate the self-healing process of bitumen. However, bitumen may not achieve the healing capability at lower temperature, and may be aged if temperature is too high. In addition, the bitumen is mixed with mineral filler and formed as asphalt mastic in asphalt concrete, so it is more accurate to study the initial self-healing from the perspective of asphalt mastic. The primary purpose of this research was to examine the initial self-healing temperature of asphalt mastic, which was determined by the flow behavior index obtained from the flow characteristics. Firstly, the texture and geometry characteristics of two fillers were analyzed, and then the initial self-healing temperature of nine types of asphalt mastic, pure bitumen (PB and styrene-butadiene-styrene (SBS modified bitumen were determined by the flow behavior index. Results demonstrate that the average standard deviation of gray-scale texture value of limestone filler (LF is 21.24% lower than that of steel slag filler (SSF, showing that the steel slag filler has a better particle distribution and geometry characteristics. Also the initial self-healing temperatures of asphalt mastics with 0.2, 0.4 and 0.6 LF-PB volume ratio are 46.5 °C, 47.2 °C and 49.4 °C, which are 1.4 °C, 0.8 °C and 0.4 °C higher than that of asphalt mastics with SSF-PB, but not suitable for the evaluation of asphalt mastic contained SBS modified bitumen because of unique structure and performance of SBS.

Validation of a dynamic modulus predictive equation on the basis of spanish asphalt concrete mixtures

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Mateos, A.

2015-03-01

Full Text Available Dynamic modulus is defined as the ratio of peak cyclic stress to peak cyclic strain under harmonic loading. It is one of the most important properties of asphalt mixtures, since it determines the strain response characteristics as a function of loading rate and temperature. Different simplified models exist that can predict this variable from mixture composition and binder rheological data, with Witczak and Hirsh models being the most widely accepted. These models have been evaluated in the present study, on the basis of 352 data points from eight asphalt concrete mixtures that were tested between −5 and 60 °C. A new model is also formulated which improves predictions of the previous ones for Spanish mixtures, even though it is a relatively simple equation that requires very limited binder rheological data compared to Witczak and Hirsch models.El módulo dinámico es la relación entre los picos de tensión y deformación bajo carga armónica. Es una de las propiedades más importantes de las mezclas bituminosas, ya que determina la respuesta deformacional en función de la velocidad de carga y la temperatura. Existen diferentes modelos simplificados que permiten predecir esta variable a partir de la composición de la mezcla y de las características reológicas del betún, siendo los de Witczak y el de Hirsch los más ampliamente aceptados. Dichos modelos han sido evaluados en el presente estudio a partir de 352 puntos procedentes de ocho mezclas tipo hormigón bituminoso que fueron ensayadas entre −5 y 60 °C. Así mismo, se ha formulado un nuevo modelo que mejora las predicciones de los anteriores para las mezclas españolas, aun tratándose de una ecuación relativamente simple que requiere una mínima información reológica del betún en comparación con los modelos de Witczak y Hirsch.

Dismantling of asphalt and recycling road materials in asphalt layers

OpenAIRE

Antunes, M. L.; Batista, F. A.

2009-01-01

Este registo pertence ao Repositório Científico do LNEC The interest of recycling of asphalt and other road materials for pavement construction and rehabilitation has been generally growing in Portugal, for the last 15 years. After some occasional demonstration projects dealing with hot and cold in situ recycling of asphalt layers, the first significant experiences with cold in situ recycling and hot mix plant recycling of asphalt applied in full scale rehabilitation projects, ...

Introductory asphalt technology; Nyumon asphalt gijutsu

Energy Technology Data Exchange (ETDEWEB)

Muroga, G. [Mitsubishi Oil Co. Ltd., Tokyo (Japan)

1994-12-28

The type and applications, manufacturing method, characteristics, road pavement etc. of asphalt were introduced. Among the petroleum asphalts, straight asphalt is used for road pavement,industry, and combustion, while blown asphalt is mainly used for the waterproofness of a building. Also, the demand for modified asphalt where rubber or thermoplastic elastomer was mixed is increasing. Straight asphalt is obtained by allowing atmospheric distillation tower bottom oil to be subjected to reduced pressure distillation and drawing reduced pressure gas oil and lubrication oil cut. Blown asphalt is produced by the oxidation dehydrogeneration and condensation polymerization reaction of soft straight asphalt. Rheology characteristics of asphalt are expressed by stiffness, relaxation elastic modulus, complex elastic modulus, etc. Also, asphalt has high electrical dielectric properties. Asphalt pavement has functions for dispersing traffic load and then transferring it to a lower layer, for resisting wear and cracking, and for preventing penetration of rainwater. 30 refs., 5 figs., 4 tabs.

ADDITIVES FOR COLD ASPHALT-CONCRETE MADE FROM EMULSION-MINERAL MIXES

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P. V. Vavilov

2015-01-01

Full Text Available The article considers the additives use for cold asphalt emulsion mixes. Urgency of the issue consists in the necessity of usage justification and regulation of additive for cold mixes properties adjustment. The article is represented as the general result of analysis of regulatory, literary and other sources related to additive using for CAEM.The main part of the article proposes and justifies the classification of CAEM additives according to their functional purpose (the main purpose of additive: increasing of strength, water resistance, durability, regulating curing and technological modifiers. Depending on the purpose the criteria of technical efficiency of additive using are presented. For each criteria provided the methods determining one or more quality indicators. The quality indicator changing is indicator of additive efficiency. There is provided the formula determining the efficiency of CAEM curing period reduction additives. As an example provided efficiency calculation and evaluation of additives for regulation (acceleration CAEM curing according to the previously published experimental data. The efficiency of curing regulating additives was determined according to the function of temporal changes of CAEM compressing strength and dynamic modulus of elasticity.The article provides the example list of materials that could be or currently used as additives for cold mixes. The conclusion states that proposed classification and criteria give base to purposive regulation of cold asphalt emulsion mixture compositions and their properties.

Decontamination by shotblasting of radioactivity deposited on an asphalt road

International Nuclear Information System (INIS)

Warming, L.

1987-01-01

Long-lived fission products may be deposited in the environment after a serious reactor accident. From previous experiments it is known that if firehosing is to be used for decontamination it has to be done soon after the deposition. It is therefore worthwhile to study another decontamination method. An experimental study has been conducted of how well shotblasting can remove contamination from an asphalt road. In shotblasting a thin layer of the surface is loosened by the impact of small steel balls, and in the same procedure the surface dust is vacuumed up and the steel balls recovered. The contaminant was 86 Rb, which behaves as caesium. As reference, the weathering of identical contamination on an asphalt road, a concrete road and a road covered with small concrete stones was studied concurrently. (author)

Numerical Simulation for Mechanical Behavior of Asphalt Pavement with Graded Aggregate Base

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Dongliang He

2018-01-01

Full Text Available The performance of asphalt pavement is determined by the combination of its material properties, road structure, and loading configurations. A DEM numerical simulation study was conducted to determine stress distribution and deformation behavior of asphalt pavement with graded aggregate base under standard traffic loading. Stress contour and displacement contour were presented via a self-made program. Compressive stress concentrated area located in both sides of wheel, while tensile stress concentrated area appeared in lower part of the asphalt layer. The traffic loading transferred downward by graded aggregate base and to both sides at the same time, and has a trend to expand gradually with increasing depth within graded aggregate base. Therefore, stress was well distributed in the subgrade soil layer with a great action scope, and the value decreased obviously because of the stress dispersion of graded aggregate base. Vertical displacement was the main displacement of the asphalt layer, and on the both sides of traffic loading, displacement was downward and inclined slightly to the central of loading. Vertical and horizontal deformations included in both graded aggregate base layers, and displacement extended to both sides gradually with increasing depth corresponding to stress-distribution trends. Vertical displacement was dominated in the subgrade soil layer which was relatively small.

Full-scale turbine-missile concrete impact experiments. Final report

International Nuclear Information System (INIS)

Woodfin, R.L.

1983-02-01

Four full-scale experiments were conducted at Sandia National Laboratories' rocket sled facility to provide data on the response of reinforced concrete containment walls to impact and penetration by postulated turbine-produced missiles. The missiles' mass, velocity, and attitude, and the steel liner thickness, were varied. A 1476-kg, 120 0 segment cut from a shrunk-on turbine disc was used for three experiments, and a 2100-kg, 137 0 segment of another disc was used for one experiment. The targets were concrete panels fabricated of commercial ready-mix concrete of strength 24 to 28 MPa at 28 days and heavily reinforced (approx. = 5% by volume) with No. 18 (57-mm-dai) bars. Impacts were perpendicular to the targets at their centers. Three impacts were with the sharp corner of the missile forward (piercing) and one was with the rounded side forward (blunt). Rebar strains, liner strains, and rear face kinematic quantities were recorded for each test. Internal pressure pulses generated by the impacts were recorded on two tests. High-speed camera coverage was extensive. Depth of penetration was the primary measure diameter. Penetration depths into the 1.37-m-thick panels ranged from 33 cm for the blunt impact of the 1476-kg missile at 92 m/s to 65 cm for the piercing impact of the 2100-kg missile at 115m/s. Impact at the piercing attitude caused significantly more severe rear face cracking than did impact at the blunt attitude, but since rear face panel displacements in excess of 6 cm and velocities greater than 7 m/s were measured, results suggested that impact at a blunt attitude might cause scabbing at lower velocities than impact at a piercing attidude. In these tests, the presence of a 9.5-mm-thick steel liner on the rear face of the panel in the latter two tests precluded scabbing. Results also indicated that design formulas in common use give conservative results

Risk management of low air void asphalt concrete mixtures.

Science.gov (United States)

2013-07-01

Various forms of asphalt pavement distress, such as rutting, shoving and bleeding, can be attributed, in many cases, to low air voids in : the mixtures during production and placement. The occurrence of low air void contents during plant production m...

A Study on the Rheological Properties of Recycled Rubber-Modified Asphalt Mixtures

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Murat Karacasu

2015-01-01

Full Text Available Using waste rubber in asphalt mixes has become a common practice in road construction. This paper presents the results of a study on the rheological characteristics of rubber-modified asphalt (RMA concrete under static and dynamic loading conditions. A number of static and dynamic creep tests were conducted on RMA mix specimens with different rubber sizes and contents, and a series of resonant column tests were conducted to evaluate the shear modulus and damping values. To simulate the stress-strain response of traffic-induced loading, the measurements were taken for different confining pressures and strain levels. The results of the study indicated that rubber modification increases stiffness and damping ratio, making it a very attractive material for use in road construction. However the grain size of the rubber is very important. Although RMA may cost up to 100% more than regular asphalt, the advantages it brings, such as an increased service life of the road and proper waste utilization contributing to a more sustainable infrastructure, may justify the added cost.

Optimum Mix for Pervious Geopolymer Concrete (GEOCRETE Based on Water Permeability and Compressive Strength

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Abdulsalam Arafa Salaheddin

2017-01-01

Full Text Available The production of ordinary Portland cement (OPC consumes considerable natural resources and energy, and it also affects the emission of a significant quantity of CO2 in the atmosphere. This pervious geopolymer concrete study aims to explore an alternative binder without OPC. Pervious geopolymer concretes were prepared from fly ash (FA, sodium silicate (NaSiO3, sodium hydroxide (NaOH solution, and coarse aggregate (CA. The effects of pervious geopolymer concrete parameters that affect water permeability and compressive strength are evaluated. The FA to CA ratios of 1:6, 1:7,1:8, and 1:9 by weight, CA sizes of 5–10, 10–14, and 14–20 mm, constant NaSiO3/NaOH ratio of 2.5, alkaline liquid to fly ash (AL/FA ratios of 0.4, 0.5, and 0.6, and NaOH concentrations of 8, 10, and 12 M were the pervious geopolymer concrete mix proportions. The curing temperature of 80 °C for 24 h was used. The results showed that a pervious geopolymer concrete with CA of 10 mm achieved water permeability of 2.3 cm/s and compressive strength of 20 MPa with AL/FA ratio of 0.5, NaOH concentration of 10 M, and FA:CA of 1:7. GEOCRETE is indicated to have better engineering properties than does pervious concrete that is made of ordinary Portland cement.

Aging Influence on Fatigue Characteristics of RAC Mixtures Containing Warm Asphalt Additives

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Feipeng Xiao

2010-01-01

Full Text Available Aging is an important factor to affect the long-term performance of asphalt pavement. The fatigue life of a typical warm mix asphalt (WMA is generally related to various factors of rheological and mechanical properties of the mixture. The study of the fatigue behavior of the specific rubberized WMA is helpful in recycling the scrap tires and saving energy in terms of the conventional laboratory aging process. This study explores the utilization of the conventional fatigue analysis approach in investigating the cumulative dissipated, stiffness, and fatigue life of rubberized asphalt concrete mixtures containing the WMA additive after a long-term aging process. The aged beams were made with one rubber type (−40 mesh ambient crumb rubber, two aggregate sources, two WMA additives (Asphamin and Sasobit, and tested at 5 and 20ºC. A total of 55 aged fatigue beams were tested in this study. The test results indicated that the addition of crumb rubber extends the fatigue resistance of asphalt binder while WMA additive exhibits a negative effect. The study indicated that the WMA additive generally has an important influence on fatigue life. In addition, test temperature and aggregate source play an important role in determining the cumulative dissipated energy, stiffness, and fatigue life of an aged mixture.

Performance Evaluation of Hot Mix Asphalt with Different Proportions of RAP Content

Science.gov (United States)

Kamil Arshad, Ahmad; Awang, Haryati; Shaffie, Ekarizan; Hashim, Wardati; Rahman, Zanariah Abd

2018-03-01

Reclaimed Asphalt Pavement (RAP) is old asphalt pavement that has been removed from a road by milling or full depth removal. The use of RAP in hot mix asphalt (HMA) eliminates the need to dispose old asphalt pavements and conserves asphalt binders and aggregates, resulting in significant cost savings and benefits to society. This paper presents a study on HMA with different RAP proportions carried out to evaluate the volumetric properties and performance of asphalt mixes containing different proportions of RAP. Marshall Mix Design Method was used to produce control mix (0% RAP) and asphalt mixes containing 15% RAP, 25% RAP and 35% RAP in accordance with Specifications for Road Works of Public Works Department, Malaysia for AC14 dense graded asphalt gradation. Volumetric analysis was performed to ensure that the result is compliance with specification requirements. The resilient modulus test was performed to measure the stiffness of the mixes while the Modified Lottman test was conducted to evaluate the moisture susceptibility of these mixes. The Hamburg wheel tracking test was used to evaluate the rutting performance of these mixes. The results obtained showed that there were no substantial difference in Marshall Properties, moisture susceptibility, resilient modulus and rutting resistance between asphalt mixes with RAP and the control mix. The test results indicated that recycled mixes performed as good as the performance of conventional HMA in terms of moisture susceptibility and resilient modulus. It is recommended that further research be carried out for asphalt mixes containing more than 35% RAP material.

Direct Tensile Test to Assess Healing in Asphalt

NARCIS (Netherlands)

Leegwater, G.A.; Scarpas, Athanasios; Erkens, Sandra

2016-01-01

Asphalt concrete has the advantageous ability to heal. During rest
periods, damage present In the material is restored to a certain extent.
Healing of the material can be observed in iis regaining of strength
and stiffness after rest periods. In this paper, a new test method is

Direct tensile test to assess healing in asphalt

NARCIS (Netherlands)

Leegwater, G.A.; Scarpas, T.; Erkens, S.

2016-01-01

Asphalt concrete has the advantageous ability to heal. During rest periods, damage present in the material is restored to a certain extent. Healing of the material can be observed in its regaining of strength and stiffness after rest periods. In this paper, a new test method is presented. It was

Development of probabilistic fatigue curve for asphalt concrete based on viscoelastic continuum damage mechanics

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Himanshu Sharma

2016-07-01

Full Text Available Due to its roots in fundamental thermodynamic framework, continuum damage approach is popular for modeling asphalt concrete behavior. Currently used continuum damage models use mixture averaged values for model parameters and assume deterministic damage process. On the other hand, significant scatter is found in fatigue data generated even under extremely controlled laboratory testing conditions. Thus, currently used continuum damage models fail to account the scatter observed in fatigue data. This paper illustrates a novel approach for probabilistic fatigue life prediction based on viscoelastic continuum damage approach. Several specimens were tested for their viscoelastic properties and damage properties under uniaxial mode of loading. The data thus generated were analyzed using viscoelastic continuum damage mechanics principles to predict fatigue life. Weibull (2 parameter, 3 parameter and lognormal distributions were fit to fatigue life predicted using viscoelastic continuum damage approach. It was observed that fatigue damage could be best-described using Weibull distribution when compared to lognormal distribution. Due to its flexibility, 3-parameter Weibull distribution was found to fit better than 2-parameter Weibull distribution. Further, significant differences were found between probabilistic fatigue curves developed in this research and traditional deterministic fatigue curve. The proposed methodology combines advantages of continuum damage mechanics as well as probabilistic approaches. These probabilistic fatigue curves can be conveniently used for reliability based pavement design. Keywords: Probabilistic fatigue curve, Continuum damage mechanics, Weibull distribution, Lognormal distribution

Low temperature rheological properties of asphalt mixtures containing different recycled asphalt materials

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Ki Hoon Moon

2017-01-01

Full Text Available Reclaimed Asphalt Pavement (RAP and Recycled Asphalt Shingles (RAS are valuable materials commonly reused in asphalt mixtures due to their economic and environmental benefits. However, the aged binder contained in these materials may negatively affect the low temperature performance of asphalt mixtures. In this paper, the effect of RAP and RAS on low temperature properties of asphalt mixtures is investigated through Bending Beam Rheometer (BBR tests and rheological modeling. First, a set of fourteen asphalt mixtures containing RAP and RAS is prepared and creep stiffness and m-value are experimentally measured. Then, thermal stress is calculated and graphically and statistically compared. The Huet model and the Shift-Homothety-Shift in time-Shift (SHStS transformation, developed at the École Nationale des Travaux Publics de l'État (ENTPE, are used to back calculate the asphalt binder creep stiffness from mixture experimental data. Finally, the model predictions are compared to the creep stiffness of the asphalt binders extracted from each mixture, and the results are analyzed and discussed. It is found that an addition of RAP and RAS beyond 15% and 3%, respectively, significantly change the low temperature properties of asphalt mixture. Differences between back-calculated results and experimental data suggest that blending between new and old binder occurs only partially. Based on the recent finding on diffusion studies, this effect may be associated to mixing and blending processes, to the effective contact between virgin and recycled materials and to the variation of the total virgin-recycled thickness of the binder film which may significantly influence the diffusion process. Keywords: Reclaimed Asphalt Pavement (RAP, Recycled Asphalt Shingles (RAS, Thermal stress, Statistical comparison, Back-calculation, Binder blending

Thermodynamics between RAP/RAS and virgin aggregates during asphalt concrete production : a literature review.

Science.gov (United States)

2015-09-01

In hot-mix asphalt (HMA) plants, virgin aggregates are heated and dried separately before being mixed with : RAP/RAS and virgin asphalt binder. RAP/RAS materials are not heated or dried directly by a burner to avoid : burning of aged binder coating o...

Constructing better roads with asphalt rubber

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Pais Jorge C.

2015-12-01

Full Text Available Brazilians mixtures containing asphalt rubber were evaluated by mechanical laboratory tests. A conventional mixture with asphalt CAP-50/70 was produced as a mixture control. With the aim of compare the Brazilians mixtures performance, a Portuguese asphalt rubber mixture was tested as well. The testing set involved the determination of the mechanical properties, fatigue and permanent deformation, of asphalt rubber produced by wet process through two different systems: continuous blend and terminal blend. The asphalt rubber morphology was evaluated in order to determine the compatibility of the systems. The asphalt rubber mixtures exhibit good resistance to permanent deformation and prolonged fatigue life in relation to mixture control. Therefore it is concluded that the application of asphalt rubber alters the characteristics of asphalt mixture in a very beneficial way.

Investigation of Self Consolidating Concrete Containing High Volume of Supplementary Cementitious Materials and Recycled Asphalt Pavement Aggregates

Science.gov (United States)

Patibandla, Varun chowdary

The use of sustainable technologies such as supplementary cementitiuous materials (SCMs), and/or recycled materials is expected to positively affect the performance of concrete mixtures. However, it is important to study and qualify such mixtures and check if the required specifications of their intended application are met before they can be implemented in practice. This study presents the results of a laboratory investigation of Self Consolidating concrete (SCC) containing sustainable technologies. A total of twelve concrete mixtures were prepared with various combinations of fly ash, slag, and recycled asphalt pavement (RAP). The mixtures were divided into three groups with constant water to cementitiuous materials ratio of 0.37, and based on the RAP content; 0, 25, and 50% of coarse aggregate replaced by RAP. All mixtures were prepared to achieve a target slump flow equal to or higher than 500 mm (24in). A control mixture for each group was prepared with 100% Portland cement whereas all other mixtures were designed to have up to 70% of portland cement replaced by a combination of supplementary cementitiuous materials (SCMs) such as class C fly ash and granulated blast furnace slag. The properties of fresh concrete investigated in this study include flowability, deformability; filling capacity, and resistance to segregation. In addition, the compressive strength at 3, 14, and 28 days, the tensile strength, and the unrestrained shrinkage up to 80 days was also investigated. As expected the inclusion of the sustainable technologies affected both fresh and hardened concrete properties. Analysis of the experimental data indicated that inclusion of RAP not only reduces the ultimate strength, but it also affected the compressive strength development rate. Moreover, several mixes satisfied compressive strength requirements for pavements and bridges; those mixes included relatively high percentages of SCMs and RAP. Based on the results obtained in this study, it is not

Oriented heat release in asphalt pavement induced by high-thermal-conductivity rods

International Nuclear Information System (INIS)

Du, Yinfei; Wang, Shengyue

2015-01-01

In this paper, a new principle of using aligned high-thermal-conductivity rods to enhance the oriented heat conduction in asphalt pavement was proposed. The results showed that the designed structure absorbed more heat during the day. The heat flow in the designed structure presented a non-uniform horizontal distribution. At the depth of 4 cm, the horizontal and vertical heat fluxes through steel rods were thirteen and ten times higher than those through asphalt mixture, respectively. The maximum temperature of the designed structure reduced by 3.6 °C–6.5 °C at the depth of 4 cm. The results of indoor irradiation test showed a trend consistent with those of numerical simulation. After 500 thousand times of standard axis load were applied, the rutting depth of the designed structure reduced by 43.4%. The principle proposed is expected to be used to induce an oriented heat release accumulated in asphalt pavement and reduce pavement temperature and rutting. - Highlights: • Steel rods were inserted in the middle and bottom layers to build thermal channels. • Steel rods absorbed heat from asphalt mixture and rapidly released them to subgrade. • The heat flux through asphalt mixture decreased and pavement temperature reduced.

Economic effects of full corrosion surveys for aging concrete structures

NARCIS (Netherlands)

Polder, R.B.; Peelen, W.H.A.; Raupach, M.; Reichling, K.

2013-01-01

This paper investigates the economic effects of full corrosion surveys of concrete structures. The background is that the existing concrete infrastructure is aging, while being exposed to aggressive influences, which increases the occurrence of corrosion and related concrete damage over time. The

Dicty_cDB: SLC409 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available SL (Link to library) SLC409 (Link to dictyBase) - - - Contig-U14931-1 SLC409Z (Link... to Original site) - - SLC409Z 483 - - - - Show SLC409 Library SL (Link to library) Clone ID SLC409 (Link to...ycdb.biol.tsukuba.ac.jp/CSM/SL/SLC4-A/SLC409Q.Seq.d/ Representative seq. ID SLC40...9Z (Link to Original site) Representative DNA sequence >SLC409 (SLC409Q) /CSM/SL/SLC4-A/SLC409Q.Seq.d/ XXXXX... SLH501 (SLH501Q) /CSM/SL/SLH5-A/SLH501Q.Seq.d/ 858 0.0 SLF191 (SLF191Q) /CSM/SL/SLF1-D/SLF191Q.Seq.d/ 858 0.0 SLC409 (SLC4

Asphalt emulsion; Asphalt nyuzai ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Suzuki, T. [Toa Doro Kogyo Co. Ltd., Tokyo (Japan)

1994-12-28

The emulsification, manufacture, type, applications, etc. of asphalt emulsion were introduced. The emulsification of asphalt is obtained by mixing heated asphalt into an emulsification liquid where emulsifier is added to water and then agitating it. The emulsifier has both hydrophilic and lipophilic parts in the same molecule, prevents collision between asphalt particles after being arranged properly on the surface of asphalt particles, and prevent separation into water and asphalt. The emulsion is available for penetration and for mixing depending on applications and can be classified into cation emulsion, anion emulsion, and nonionic emulsion according to the property. The emulsion is mainly applied to road pavement, reaching approximately 90 % of the total manufactured emulsion. It is also used for other areas such as the filler of a slab race of each bullet train of Sanyo, Tohoku, and Jyoetsu and is also applied to the formation of a water-proof layer by spraying a high-concentration emulsion with rubber, agricultural water channels using asphalt emulsion and nonwoven cloth, etc. in civil engineering and agricultural fields. 2 refs., 13 figs., 8 tabs.

Effect of mineral additives on structure and properties of concrete for pavements

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Sobol Khrystyna

2017-12-01

Full Text Available Concrete pavements is an attractive alternative to asphalt pavements because of its lower cost and higher durability. Major contribution to sustainable development can be made by partial replacement of cement in concrete pavement with supplementary cementitious materials of different nature and origin. In this paper, the effect of natural zeolite and perlite additives in complex with chemical admixtures on the structure and properties of concrete for pavement was studied. Compressive and flexural strength test was used to study the mechanical behavior of designed concrete under load. Generally, the compressive strength of both control concrete and concrete containing mineral additives levels at the later ages of hardening. The microstructure analysis of concrete with mineral additives of different nature activity showed the formation of additional amount of hydration products such as tobermorite type calcium hydrosilicate which provide self-reinforcement of hardening concrete system.

Aging of Asphalt Symposium, September 17th 2014, Delft, the Netherlands

NARCIS (Netherlands)

Erkens, S.M.J.G.; Scarpas, A.; Blab, R.; Glaser, R.; Glover, C.; Oeser, M.; Porot, L.; Soenen, H.

2015-01-01

Technical specifications for the asphalt concrete properties are developed to be able to specify mixtures that will perform well in pavement applications. Being able to identify and determine properties related to pavement performance in practice is crucial for both road authorities and contractors,

Aging of Asphalt Symposium : Delft, the Netherlands September 17th 2014

NARCIS (Netherlands)

Erkens, Sandra; Scarpas, Athanasios

2015-01-01

Technical specifications for the asphalt concrete properties are developed to be able to specify mixtures that will perform well in pavement applications. Being able to identify and determine properties related to pavement performance in practice is crucial for both road authorities and contractors,

Life cycle uses of concrete for more sustainable construction

Energy Technology Data Exchange (ETDEWEB)

Horvath, A. [Univ. of California, Berkeley, CA (United States). Dept. of Civil and Environmental Engineering

2001-07-01

This paper examined ways in which the environmental burdens of construction in general and concrete production in particular can be reduced. Aggregates for concrete production include sand, gravel and stone. They account for most (80 per cent) of the materials used in the United States. This paper argued that given the fact that environmental concerns are an important social issue, the issue of natural resource conservation should be addressed. Some of the life-cycle assessments and comparative design issues associated with concrete construction were summarized. The author presented the example that often the initial cost of a new pavement application may indicate a lower environmental impact than an equivalent design when asphalt is used over reinforced concrete. However, annualized impacts may result in comparable environmental assessments. The same is true for bridge girders, reinforced concrete also seems to be a better environmental choice than steel. This paper also described end-of-life options that involve the use of waste products and recycled products in concrete and other materials to reduce the overall environmental impacts of a product or facility. This paper was divided into several sections entitled: life cycle assessments; life cycle inventory assessment of concretes and asphalt pavements; and, life cycle inventory assessment of concrete and steel bridge girders. 16 refs., 4 tabs.

Modified asphalt; Kairyo asphalt ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Takarabe, A. [Mitsubishi Oil Co. Ltd., Tokyo (Japan)

1994-12-28

Modified asphalt in the area of road pavement in the relation of measures against flow on a road surface was introduced. The condition of road damage includes the print of a wheel, crack, and wear and semi-blown asphalt whose deformation is difficult even if temperature is increased to approximately 60 {degree}C and asphalt with rubber and resin are used to prevent these. The semi-blown asphalt is obtained by adding cut-back material to the normal asphalt, heating it, blowing air into it, and then oxidizing and polymerizing it, is harder and is more elastic than the normal asphalt, and has smaller viscosity change due to temperature change. The viscosity at 60 {degree}C was determined to be 10000{plus_minus}2000 poise according to the relationship between viscosity and crack using a large-scale execution experiment. The asphalt with rubber and resin is formed by adding modified material of styrene - butadiene copolymer and by adding thermoplastic elastomer and the former is used for preventing slide and the latter is used for preventing flow and wear. 10 refs., 6 figs., 2 tabs.

Improving the sustainability of asphalt pavements through developing a predictive model with fundamental material properties.

Science.gov (United States)

2009-08-01

This study presents the numerical implementation and validation of general constitutive relationships for describing the : nonlinear behavior of asphalt concrete mixes. These constitutive relationships incorporate nonlinear viscoelasticity and : visc...

On the combined effect of moisture diffusion and cyclic pore pressure generation in asphalt concrete

NARCIS (Netherlands)

Varveri, A.; Scarpas, A.; Collop, A.; Erkens, S.M.J.G.

2014-01-01

In this paper, a new moisture conditioning protocol which attempts to distinguish the contributions of long- and short-term moisture damage, i.e. moisture diffusion and cyclic pore pressure generation, in asphalt mixtures is presented. The capability of the proposed protocol to rank various asphalt

Statistical Analysis and Evaluation of the Depth of the Ruts on Lithuanian State Significance Roads

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Erinijus Getautis

2011-04-01

Full Text Available The aim of this work is to gather information about the national flexible pavement roads ruts depth, to determine its statistical dispersijon index and to determine their validity for needed requirements. Analysis of scientific works of ruts apearance in the asphalt and their influence for driving is presented in this work. Dynamical models of ruts in asphalt are presented in the work as well. Experimental outcome data of rut depth dispersijon in the national highway of Lithuania Vilnius – Kaunas is prepared. Conclusions are formulated and presented. Article in Lithuanian

Time resolved analysis of water drainage in porous asphalt concrete using neutron radiography.

Science.gov (United States)

Poulikakos, L D; Sedighi Gilani, M; Derome, D; Jerjen, I; Vontobel, P

2013-07-01

Porous asphalt as a road surface layer controls aquaplaning as rain water can drain through its highly porous structure. The process of water drainage through this permeable layer is studied using neutron radiography. Time-resolved water configuration and distribution within the porous structure are reported. It is shown that radiography depicts the process of liquid water transport within the complex geometry of porous asphalt, capturing water films, filled dead end pores and water islands. Copyright © 2013 Elsevier Ltd. All rights reserved.

Microstructural Analysis on the NPP Concrete under Initial Frost Damage

International Nuclear Information System (INIS)

Koh, Kyung Teak; Park, Chun Jin; Kim, Si Hwan; Ryu, Gum Sung

2012-01-01

The concrete should secure the quality over certain standard regardless of construction location and period. Especially, because the fly ash (FA) is used in nuclear power plant concrete as a concrete substitute by 20%, the concrete using FA is hugely influenced according to temperature and humidity in terms of constructability, strength and durability due to the material properties. Accordingly, when building the nuclear power plant under various environmental conditions, it's important to secure the concrete quality equally through applying an appropriate curing method to control temperature and humidity. Although various according to concrete materials and mixture, the concrete-freezing temperature is usually known as about -0.5∼-3.0 .deg. C. In case the concrete is frozen early under the condition that the strength has not been sufficiently developed yet, because the volume expansion caused by the frozen free moisture inside concrete results in the relaxation and destruction of structure, the strength, watertightness and durability of the concrete get lower drastically even after being hardened. Accordingly, this study tried to review the quality of nuclear power plant concrete under early freezing through measuring strength, SEM and XRD after making the concrete frozen over certain standard in the early curing with targeting the nuclear power plant (NPP) concrete replaced with FA 20%

An experimental investigation on mechanical behaviour of eco - friendly concrete

Science.gov (United States)

Narender Reddy, A.; Meena, T.

2017-11-01

Fly ash (FA) and Alccofine are the eco-friendly materials that can be used in the production of concrete composites. Initially, concrete mixes of M30 grade with replacement of cement by 0%, 5%, 10%, 15%, 20% and 25% by weight of Fly ash were prepared. They were subjected to compression test so as to select the optimum replacement percentage of FA. Keeping this optimum percentage of FA as constant, additional replacement of cement with Alccofine was done varying its replacement in the range of 8%, 10%, 12% and 14%. The mechanical properties such as compressive, split tensile and flexural strengths of these mixes were computed for 7, 14 and 28 days. The results of Eco-Friendly Concrete (EFC) are compared with those of control concrete. It was observed that EFC mixes exhibited superior qualities like quick setting and enhanced workability, their mechanical properties were found to be higher than that of the conventional concrete. This goes to prove that the combination of FA and Alccofine together as replacement for cement would enhance the properties of EFC.

Investigation on the Rheological Behavior of Fly Ash Cement Composites at Paste and Concrete Level

Science.gov (United States)

Thiyagarajan, Hemalatha; Mapa, Maitri; Kushwaha, Rakhi

2018-06-01

Towards developing sustainable concrete, nowadays, high volume replacement of cement with fly ash (FA) is more common. Though the replacement of fly ash at 20-30% is widely accepted due to its advantages at both fresh and hardened states, applicability and acceptability of high volume fly ash (HVFA) is not so popular due to some adverse effects on concrete properties. Nowadays to suit various applications, flowing concretes such as self compacting concrete is often used. In such cases, implications of usage of HVFA on fresh properties are required to be investigated. Further, when FA replacement is beyond 40% in cement, it results in the reduction of strength and in order to overcome this drawback, additions such as nano calcium carbonate (CC), lime sludge (LS), carbon nano tubes (CNT) etc. are often incorporated to HVFA concrete. Hence, in this study, firstly, the influence of replacement level of 20-80% FA on rheological property is studied for both cement and concrete. Secondly, the influence of additions such as LS, CC and CNT on rheological parameters are discussed. It is found that the increased FA content improved the flowability in paste as well as in concrete. In paste, the physical properties such as size and shape of fly ash is the reason for increased flowability whereas in concrete, the paste volume contributes dominantly for the flowability rather than the effect due to individual FA particle. Reduced density of FA increases the paste volume in FA concrete thus reducing the interparticle friction by completely coating the coarse aggregate.

The use of Crumb Rubber as Substitute of Fine Aggregate for Hot Asphalt Mixture using Polymer Modified Bitumen

Science.gov (United States)

Setyawan, A.; Nugroho, S. K.; Irsyad, A. M.; Mutaqo, H. F.; Ramadhan, P.; Sumarsono, A.; Pramesti, F. P.

2018-03-01

The development of road pavement to fulfilled the need of modern life is not only focused on heavy duty road, but also a light duty road for the convenience of road users according to its function. For example the use of pavement on the jogging track, rail crossing, playground and so on. Due to the need of an alternative and the innovation of a comfortable pavement layer, but sufficiently strong in holding the load on the layer. The alternative innovation that can be used for the respective requirement is the utilization of waste old tires as substitute material in pavement construction. In this case the use of crumb rubber made from old tire rubber as an 100% fine aggregate substitute on the asphalt mixtures is investigated. To improve the strength and durability of the mixtures, the addition of polymer modified bitumen was incorporated. The two types of asphalt mixture selected in this study by using a continuous gradation of asphalt concrete and a gap gradation of hot roll asphalt. Testing to be implemented in this research is volumetric characteristics, Marshall characteristics, resistance to abrasion and impact and permeability. Replacement of fine aggregate with crumb rubber on asphalt concrete mixture with 60/70 penetration grade bitumen and polymer modified asphalt SBS E-55 in this research are expected to be an alternative in improving the quality of pavement and overcoming the environmental problems by reuse the waste materials.

Effects of Asphalt Mix Design Properties on Pavement Performance: A Mechanistic Approach

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Ahmad M. Abu Abdo

2016-01-01

Full Text Available The main objective of this study was to investigate the effects of hot mix asphalt material properties on the performance of flexible pavements via mechanistic approach. 3D Move Analysis software was utilized to determine rutting and cracking distresses in an asphalt concrete (AC layer. Fourteen different Superpave mixes were evaluated by utilizing results of the Dynamic Modulus (|E⁎| Test and the Dynamic Shear Modulus (|G⁎| Test. Results showed that with the increase of binder content, the tendency of rutting in AC layer increased. However, with the increase of binder content, the cracking of AC layer lessened. Furthermore, when different binder grades were evaluated, results showed that with the increase of the upper binder grade number, rutting decreased, and with the increase of the lower binder grade number, rutting increased. Furthermore, analysis showed that with the increase of the lower binder grade number, higher percent of bottom up cracks would result. As a result of the analysis, binder grade should not be solely considered for cracking in AC layer; binder content and aggregate structure play a big role. Finally, results illustrated that the mechanistic approach is a better tool to determine the performance of asphalt pavement than commonly used methods.

Properties of nano-silica modified pervious concrete

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Bashar S. Mohammed

2018-06-01

Full Text Available The aim of this study is to evaluate the effects of inclusion nano-silica (also known as nano-SiO2 on the properties of pervious concrete containing fly ash (FA as a partial replacement to cement. It has been found, for cementitious paste, that incorporating NS leads to reduce the cumulative pore volume by 13.4%. While the compressive strength of NS modified pervious concrete has been improved without adversely affecting its void ratio and permeability. The workability has been adversely affected by the inclusion of NS, which can be enhanced by incorporating the fly ash and superplasticizer. The porosity of cementitious paste has increased as the FA content is increased. These results are in good agreement with SEM results. For the pervious concrete voids ratio, permeability and infiltration rate were decreased against the increase of paste to the aggregate ratio Response surface methodology (RSM has also been used to develop a model for navigating the design space of NS modified pervious concrete. Models revealed 95% significance of confidence level with difference less than 0.2 between Pred R-Squared value of 0.9515 and Adj R-Squared. The general expression has been developed for all the responses with the different coefficients using the RSM. Keywords: Fly ash, Final setting time, Infiltration rate, Pervious concrete, Nano-silica

Evaluation of Asphalt Mixture Low-Temperature Performance in Bending Beam Creep Test.

Science.gov (United States)

Pszczola, Marek; Jaczewski, Mariusz; Rys, Dawid; Jaskula, Piotr; Szydlowski, Cezary

2018-01-10

Low-temperature cracking is one of the most common road pavement distress types in Poland. While bitumen performance can be evaluated in detail using bending beam rheometer (BBR) or dynamic shear rheometer (DSR) tests, none of the normalized test methods gives a comprehensive representation of low-temperature performance of the asphalt mixtures. This article presents the Bending Beam Creep test performed at temperatures from -20 °C to +10 °C in order to evaluate the low-temperature performance of asphalt mixtures. Both validation of the method and its utilization for the assessment of eight types of wearing courses commonly used in Poland were described. The performed test indicated that the source of bitumen and its production process (and not necessarily only bitumen penetration) had a significant impact on the low-temperature performance of the asphalt mixtures, comparable to the impact of binder modification (neat, polymer-modified, highly modified) and the aggregate skeleton used in the mixture (Stone Mastic Asphalt (SMA) vs. Asphalt Concrete (AC)). Obtained Bending Beam Creep test results were compared with the BBR bitumen test. Regression analysis confirmed that performing solely bitumen tests is insufficient for comprehensive low-temperature performance analysis.

Initial Self-Healing Temperatures of Asphalt Mastics Based on Flow Behavior Index.

Science.gov (United States)

Li, Chao; Wu, Shaopeng; Tao, Guanyu; Xiao, Yue

2018-05-29

Increasing temperature is a simple and convenient method to accelerate the self-healing process of bitumen. However, bitumen may not achieve the healing capability at lower temperature, and may be aged if temperature is too high. In addition, the bitumen is mixed with mineral filler and formed as asphalt mastic in asphalt concrete, so it is more accurate to study the initial self-healing from the perspective of asphalt mastic. The primary purpose of this research was to examine the initial self-healing temperature of asphalt mastic, which was determined by the flow behavior index obtained from the flow characteristics. Firstly, the texture and geometry characteristics of two fillers were analyzed, and then the initial self-healing temperature of nine types of asphalt mastic, pure bitumen (PB) and styrene-butadiene-styrene (SBS) modified bitumen were determined by the flow behavior index. Results demonstrate that the average standard deviation of gray-scale texture value of limestone filler (LF) is 21.24% lower than that of steel slag filler (SSF), showing that the steel slag filler has a better particle distribution and geometry characteristics. Also the initial self-healing temperatures of asphalt mastics with 0.2, 0.4 and 0.6 LF-PB volume ratio are 46.5 °C, 47.2 °C and 49.4 °C, which are 1.4 °C, 0.8 °C and 0.4 °C higher than that of asphalt mastics with SSF-PB, but not suitable for the evaluation of asphalt mastic contained SBS modified bitumen because of unique structure and performance of SBS.

Influence of curing conditions on the sorptivity and weight change characteristics of self-compacting concrete

International Nuclear Information System (INIS)

Caliskan, S.

2006-01-01

This paper reports on a study carried out to investigate the influence of curing conditions on the capillary water absorption and weight change characteristics of self compacting concrete (SCC). Specimens were prepared using three types of concrete (SCC, Portland cement (PC), Fly ash (FA) concretes) and were cured under three different curing conditions (20C water and 20C and 40C air cure) for 28 days. Weight gain (water intake) in water curing and weight loss (water loss) in 20C and 40C air curing were recorded throughout the curing period. Compressive strength, water absorption and capillary water absorption tests were carried out at 28 days. The results indicated that FA concrete gained about 0.5% whilst PC and self-compacting concretes gained about 1.0% of the initial weight. This indicates that due to the slower reaction process more free water remains within FA concrete avoiding further water intake. In the weight loss study, FA concrete lost about 4.0% and 6.0% of the initial weight at 20C and 40C air curing, respectively; whereas SCC and PC concretes (both had almost identical values) lost about 3.2 and 5.2% at 20C and 40C, respectively. The absorption test results indicated that SCC gave the lowest captivity coefficient values followed by PC and FA concretes in all curing conditions. (author)

Rheological Characterization of Warm-Modified Asphalt Mastics Containing Electric Arc Furnace Steel Slags

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M. Pasetto

2016-01-01

Full Text Available The environmental sustainability of road materials and technologies plays a key role in pavement engineering. In this sense, the use of Warm Mix Asphalt (WMA, that is, a modified asphalt concrete that can be produced and applied at lower temperature, is considered an effective solution leading to environmental and operational benefits. The environmental sustainability of WMA can be further enhanced with the inclusion of steel slag in partial substitution of natural aggregates. Nevertheless, such innovative material applied at lower temperatures containing warm additives and steel slag should be able to guarantee at least the same performance of traditional hot mix asphalts, thus assuring acceptable mechanical properties and durability. Therefore, the purpose of this study is to investigate the rheological behaviour of bituminous mastics obtained combining a warm-modified binder and a filler (material passing to 0.063 mm coming from electric arc furnace steel slag. To evaluate the influence of both warm additive and steel slag, a plain binder and limestone filler were also used for comparison purposes. Complex modulus and permanent deformation resistance of bitumens and mastics were assessed using a dynamic shear rheometer. Experimental results showed that steel slag warm mastics assure enhanced performance demonstrating promising applicability.

Performance prediction of hot mix asphalt from asphalt binders

International Nuclear Information System (INIS)

Hafeez, I.; Kamal, M.A.; Shahzad, Q.; Bashir, N.; Ahadi, M.R.

2012-01-01

Asphalt binder being a high weight hydrocarbon contains asphaltene and maltene and is widely used as cementing materials in the construction of flexible pavements. Its performance in hot mix asphalt also depends on combining with different proportions of aggregates. The main objective of this study was to characterize asphalt cement rheological behavior and to investigate the influence of asphalt on asphalt-aggregate mixtures prepared with virgin binders and using polymers. Binder rheology and mixtures stiffness were determined under a range of cyclic loadings and temperature conditions. Master curves were developed for the evaluation of relationship between parameters like complex modulus and phase angle at different frequencies. Horizontal shift factors were also computed to determine time and temperature response of binders and mixes. The results showed that the stiffness of both the binder and the mixes depends on temperature and frequency of load. Polymer modified binder is least susceptible to temperature variations as compared to other virgin asphalt cement. Performance of asphalt mixtures can be predicted from those of asphalt binders using the master curve technique. (author)

Properties of Direct Coal Liquefaction Residue Modified Asphalt Mixture

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Jie Ji

2017-01-01

Full Text Available The objectives of this paper are to use Direct Coal Liquefaction Residue (DLCR to modify the asphalt binders and mixtures and to evaluate the performance of modified asphalt mixtures. The dynamic modulus and phase angle of DCLR and DCLR-composite modified asphalt mixture were analyzed, and the viscoelastic properties of these modified asphalt mixtures were compared to the base asphalt binder SK-90 and Styrene-Butadiene-Styrene (SBS modified asphalt mixtures. The master curves of the asphalt mixtures were shown, and dynamic and viscoelastic behaviors of asphalt mixtures were described using the Christensen-Anderson-Marasteanu (CAM model. The test results show that the dynamic moduli of DCLR and DCLR-composite asphalt mixtures are higher than those of the SK-90 and SBS modified asphalt mixtures. Based on the viscoelastic parameters of CAM models of the asphalt mixtures, the high- and low-temperature performance of DLCR and DCLR-composite modified asphalt mixtures are obviously better than the SK-90 and SBS modified asphalt mixtures. In addition, the DCLR and DCLR-composite modified asphalt mixtures are more insensitive to the frequency compared to SK-90 and SBS modified asphalt mixtures.

Volumetric characteristics and compactability of asphalt rubber mixtures with organic warm mix asphalt additives

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A. M. Rodríguez-Alloza

2017-04-01

Full Text Available Warm Mix Asphalt (WMA refers to technologies that reduce manufacturing and compaction temperatures of asphalt mixtures allowing lower energy consumption and reducing greenhouse gas emissions from asphalt plants. These benefits, combined with the effective reuse of a solid waste product, make asphalt rubber (AR mixtures with WMA additives an excellent environmentally-friendly material for road construction. The effect of WMA additives on rubberized mixtures has not yet been established in detail and the lower mixing/compaction temperatures of these mixtures may result in insufficient compaction. In this sense, the present study uses a series of laboratory tests to evaluate the volumetric characteristics and compactability of AR mixtures with organic additives when production/compaction temperatures are decreased. The results of this study indicate that the additives selected can decrease the mixing/compaction temperatures without compromising the volumetric characteristics and compactability.

State of the art: Asphalt for airport pavement surfacing

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Greg White

2018-01-01

Full Text Available Airport runways and taxiways are commonly comprised of a flexible pavement with an asphalt surface. Marshall-designed asphalt with sawn grooves is the most frequent airport asphalt surface material. However, some airports have adopted alternate asphalt mixtures for improved resistance to shear stress and for increased surface texture, allowing grooving to be avoided. Of the alternate asphalt mixtures, stone mastic asphalt is the most commonly reported. Resistance to shear stress is a critical performance requirement for airport surface asphalt. Shear stress resistance minimises the risk of rutting, shoving and groove closure. However, fracture resistance must not be ignored when developing even more shear resistance asphalt mixtures. Significant distress in airport asphalt surfaces, compliant with the traditional prescriptive specification, has increased interest in a performance-based airport asphalt specification. Commonly reported distresses include groove closure in slow moving aircraft areas and shearing in heavy aircraft braking zones. Development of reliable performance-indicative test methods is expected in the future and will enable warranted performance-based asphalt mixture design for airport surfaces. Keywords: Airport, Pavement, Asphalt, Surface

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

Experimental study on the shrinkage properties and cracking potential of high strength concrete containing industrial by-products for nuclear power plant concrete

International Nuclear Information System (INIS)

KIm, Baek Joong; Yi, Chong Ku

2017-01-01

In Korea, attempts have been made to develop high strength concrete for the safety and design life improvement of nuclear power plants. In this study, the cracking potentials of nuclear power plant-high strength concretes (NPP-HSCs) containing industrial by-products with W/B 0.34 and W/B 0.28, which are being reviewed for their application in the construction of containment structures, were evaluated through autogenous shrinkage, unrestrained drying shrinkage, and restrained drying shrinkage experiments. The cracking potentials of the NPP-HSCs with W/B 0.34 and W/B 0.28 were in the order of 0.34FA25 > 0.34FA25BFS25 > 0.34BFS50 > 0.34BFS65SF5 and 0.28FA25SF5 >> 0.28BFS65SF5 > 0.28BFS45SF5 > 0.28 FA20BFS25SF5, respectively. The cracking potentials of the seven mix proportions excluding 0.28FA25SF5 were lower than that of the existing nuclear power plant concrete; thus, the durability of a nuclear power plant against shrinkage cracking could be improved by applying the seven mix proportions with low cracking potentials

Experimental study on the shrinkage properties and cracking potential of high strength concrete containing industrial by-products for nuclear power plant concrete

Energy Technology Data Exchange (ETDEWEB)

KIm, Baek Joong; Yi, Chong Ku [School of Civil, Environmental and Architectural Engineering, Korea University, Seoul (Korea, Republic of)

2017-02-15

In Korea, attempts have been made to develop high strength concrete for the safety and design life improvement of nuclear power plants. In this study, the cracking potentials of nuclear power plant-high strength concretes (NPP-HSCs) containing industrial by-products with W/B 0.34 and W/B 0.28, which are being reviewed for their application in the construction of containment structures, were evaluated through autogenous shrinkage, unrestrained drying shrinkage, and restrained drying shrinkage experiments. The cracking potentials of the NPP-HSCs with W/B 0.34 and W/B 0.28 were in the order of 0.34FA25 > 0.34FA25BFS25 > 0.34BFS50 > 0.34BFS65SF5 and 0.28FA25SF5 >> 0.28BFS65SF5 > 0.28BFS45SF5 > 0.28 FA20BFS25SF5, respectively. The cracking potentials of the seven mix proportions excluding 0.28FA25SF5 were lower than that of the existing nuclear power plant concrete; thus, the durability of a nuclear power plant against shrinkage cracking could be improved by applying the seven mix proportions with low cracking potentials.

Objectification of Modulus Elasticity of Foam Concrete Poroflow 17-5 on the Subbase Layer

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Hájek Matej

2016-05-01

Full Text Available Principles of sustainable development create the need to develop new building materials. Foam concrete is a type of lightweight concrete that has many advantages compared to conventional building materials, for example low density and thermal insulation characteristics. With current development level, any negatively influencing material features are constantly eliminated as well. This paper is dealing with substitution of hydraulically bound mixtures by cement foam concrete Poroflow 17-5. The executed assessment is according to the methodology of assessing the existing asphalt pavements in Slovak Republic. The ex post calculation was used to estimate modulus range for Poroflow 17-5 based on the results of static load tests conducted using the Testing Experiment Equipment.

Resistance to Corrosion of Reinforcement of High Volume Fly Ash Concrete

International Nuclear Information System (INIS)

Kwon, S. O.; Bae, S. H.; Lee, H. J.; Lee, K. M.; Jung, S. H.

2014-01-01

Due to the increasing of interest about the eco-friendly concrete, it is increased to use concretes containing by-products of industry such as fly ash(FA), ground granulated blast furnace slag(GGBFS), silica fume(SF), and etc. Especially, these are well known for improving the resistances to reinforcement corrosion in concrete and decreasing chloride ion penetration. The purpose of this experimental research is to evaluate the resistance against corrosion of reinforcement of high volume fly ash(HVFA) concrete which is replaced with high volume fly ash for cement volume. For this purpose, the concrete test specimens were made for various strength level and replacement ratio of FA, and then the compressive strength and diffusion coefficient for chloride ion of them were measured for 28, 91, and 182 days, respectively. Also, corrosion monitoring by half cell potential method was carried out for the made lollypop concrete test specimens to detect the time of corrosion initiation for reinforcement in concrete. As a result, it was observed from the test results that the compressive strength of HVFA concrete was decreased with increasing replacement ratio of FA but long-term resistances against reinforcement corrosion and chloride ion penetration of that were increased

Evaluation of density, moisture content and percentage compaction of concrete using direct transmission and backscatter methods

International Nuclear Information System (INIS)

Attobrah, A. T

2012-01-01

The nuclear method widely used in determining the density and moisture content of soil - aggregates, asphalt concretes, roller compacted concretes and Portland cement concretes, is the radiometry technique. Generally, all radiometry systems consist of a source of radiation, the sample being examined and a radiation detector. In operation, a radioactive source and a detector are placed on the same or opposite sides of a concrete sample. A portion of radiation from the source which passes through the concrete sample and reaches the detector produces a series of electrical pulses which when counted gives a measure of the dimensions or physical characteristics of the concrete sample. In this research work, concrete beams were fabricated using a 500 x 225 x 200mm wooden mould whiles a table vibrator was used to consolidate the concrete after placement in the mould. The mass of the beam was determined and the actual density calculated and inputted in the gauge. Measurements were performed on the unhardened and hardened concrete using the backscatter method and the direct transmission method at depths of 50mm, 100mm and 150mm. The measuring times of 15, 60 and 240 second were use to take the measurements. The study provided information on the variation of density with depth and this was observed to be within the range of 0 kg/m 3 to 1 kg/m 3 and 13 kg/m 3 to 23 kg/m 3 for the unhardened concrete samples in which density increased with depth and those in which density decreased with depth respectively. For the hardened concrete sample, the average change in density with depth was between 4 - 11 kg/m 3 for the samples in which density increased with depth and between 11 - 21 kg/m 3 for the samples in which density decreased with depth. The study also provided information about the degree of consolidation of Portland cement concrete which on the average was between 95% - 97% for the unhardened concrete samples and increased to between 97% - 99% for the hardened concrete

Chlorine detection in fly ash concrete using a portable neutron generator.

Science.gov (United States)

Naqvi, A A; Kalakada, Zameer; Al-Matouq, Faris A; Maslehuddin, M; Al-Amoudi, O S B

2012-08-01

The chlorine concentration in chloride-contaminated FA cement concrete specimens was measured using a portable neutron generator based prompt gamma-ray neutron activation (PGNAA) setup with the neutron generator and the gamma-ray detector placed side-by-side on one side of the concrete sample. The minimum detectable concentration of chlorine in FA cement concrete measured in the present study was comparable with previous results for larger accelerator based PGNAA setup. It shows the successful application of a portable neutron generator in concrete corrosion studies. Copyright © 2012 Elsevier Ltd. All rights reserved.

Installation report : evaluation of recycled hot mix asphaltic concrete on Route 220.

Science.gov (United States)

1982-01-01

This report describes a project in which the bituminous pavement on an approximately 8-mi. (13-km) section of roadway was removed, recycled through a conventional asphalt batch plant, and relaid. The project was accomplished with little difficulty an...

Arrangement for the measurement of the quantity of asphalt in an asphaltic compound

International Nuclear Information System (INIS)

Noma, I.; Taniguchi, K.

1978-01-01

The arrangement for the measurement of the quantity of asphalt in an asphaltic compound in an apparatus for the mixture of asphalt components and an aggregate for the formation of an asphaltic compound characterized by the inclusion of a member for the transmission of a neutron beam which reacts with the hydrogen atoms in the asphaltic compound in such a way that the energy of a neutron beam is adsorbed; a continuous transport device feeds a continuous supply of the asphalt compound past the neutron beam; a member responds to an automatic detector for the quantity of asphaltic components in the asphaltic compound and provides an adjustment so that the quantity [of asphaltic components in asphaltic compound] may be held at a constant value. (G.C.)

A novel technique for the production of cool colored concrete tile and asphalt shingle roofing products

Energy Technology Data Exchange (ETDEWEB)

Levinson, Ronnen; Akbari, Hashem; Berdahl, Paul [Heat Island Group, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Wood, Kurt; Skilton, Wayne; Petersheim, Jerry [Arkema, Inc., Philadelphia, PA (United States)

2010-06-15

The widespread use of solar-reflective roofing materials can save energy, mitigate urban heat islands and slow global warming by cooling the roughly 20% of the urban surface that is roofed. In this study we created prototype solar-reflective nonwhite concrete tile and asphalt shingle roofing materials using a two-layer spray coating process intended to maximize both solar reflectance and factory-line throughput. Each layer is a thin, quick-drying, pigmented latex paint based on either acrylic or a poly(vinylidene fluoride)/acrylic blend. The first layer is a titanium dioxide rutile white basecoat that increases the solar reflectance of a gray-cement concrete tile from 0.18 to 0.79, and that of a shingle surfaced with bare granules from 0.06 to 0.62. The second layer is a ''cool'' color topcoat with weak near-infrared (NIR) absorption and/or strong NIR backscattering. Each layer dries within seconds, potentially allowing a factory line to pass first under the white spray, then under the color spray. We combined a white basecoat with monocolor topcoats in various shades of red, brown, green and blue to prepare 24 cool colored prototype tiles and 24 cool colored prototypes shingles. The solar reflectances of the tiles ranged from 0.26 (dark brown; CIELAB lightness value L{sup *}=29) to 0.57 (light green; L{sup *}=76); those of the shingles ranged from 0.18 (dark brown; L{sup *}=26) to 0.34 (light green; L{sup *}=68). Over half of the tiles had a solar reflectance of at least 0.40, and over half of the shingles had a solar reflectance of at least 0.25. (author)

Tire wear emissions for asphalt rubber and Portland cement concrete pavement surfaces.

Science.gov (United States)

2006-04-01

Since 1990, it has been the policy of the State of Arizona that the recycling and reuse of : waste tires are the highest priority. The Arizona Department of Transportation (ADOT) : has long supported the use of recycled waste tire rubber in asphalt r...

Research on the characteristics of temperature field of asphalt pavement in seasonal frozen region

International Nuclear Information System (INIS)

Qiao, Jiangang; Liu, Weizheng

2014-01-01

The characteristics of climate in seasonal frozen area are low temperature and a large range of temperature variation between day and night in winter. These characteristics often lead to problems of asphalt pavement, especially transverse cracks. To reduce the problems of asphalt pavement, it is necessary to examine the distribution of the temperature range of asphalt pavement. A three-dimensional finite element model was used, taking the SMA asphalt pavement as an example with solid70 and plane55 unit features of ANSYS software. It can obtain the relationship between temperature gradient and time and the relationship between temperature gradient and depth. In addition, a function relation model of stress and time was also established. It can provide a theoretical basis for the prevention and treatment of problems of asphalt pavement in seasonal frozen area. Moreover, it has an important significance for improving asphalt pavement design

Accelerated degradation and durability of concrete in cold climates.

Science.gov (United States)

2011-08-01

Degradation of aggregate in concrete can be caused by erosion or fracture, and both cementitious materials and aggregate age over time. : The specification requirements for the degradation of aggregates have been established for hot mix asphalt and f...

RELATIONSHIP BETWEEN FOAMING BEHAVIOR AND SURFACE ENERGY OF ASPHALT BINDER

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Jian-ping Xu

2017-12-01

Full Text Available To solve the problem of insufficiency in microscopic performance of foamed asphalt binder, surface energy theory was utilized to analyze the foaming behavior and wettability of asphalt binder. Based on the surface energy theory, the Wilhelmy plate method and universal sorption device method were employed to measure the surface energy components of asphalt binders and aggregates, respectively. Combined with the traditional evaluation indictor for foamed asphalt, the relationship between the foaming property and surface energy of asphalt binder was analyzed. According to the surface energy components, the wettability of asphalt binder to aggregate was calculated to verify the performance of foamed asphalt mixture. Results indicate that the foaming behavior of asphalt will be influenced by surface energy, which will increase with the decline of surface energy. In addition, the surface energy of asphalt binder significantly influences the wettability of asphalt binder to aggregates. Meanwhile, there is an inversely proportional relationship between surface energy of asphalt binder and wettability. Therefore, it can be demonstrated that surface energy is a good indictor which can be used to evaluate the foaming behavior of the asphalt binder. And it is suggested to choose the asphalt binder with lower surface energy in the process of design of foamed asphalt mixture.

Impulse response measurements as dependent on crack depth. Delamination

International Nuclear Information System (INIS)

Ulriksen, Peter

2011-02-01

sizes were used. The vibrations of the concrete surface was measured with an accelerometer pushed manually to the surface and also by an adjacent microphone. The results indicate clearly that the small hammer generates a spectrum better suited to the present resonance frequencies and that both the accelerometer- and microphone signals can be used to detect delamination down to a depth of 120 mm. This is somewhat deeper than what was possible with the vibrator and impedance head, which may be attributed to higher energy in the hammer blows. The large hammer was not suited for the present resonance frequencies. The possibility of using a microphone as a vibration sensor opens for a remote application, when the microphone is fixed in the room and only a modally tuned hammer is used for striking the concrete. The third part of the project is using the big hammer to strike two types of hand held impedance heads. One measures force and velocity F/v the other measures force and acceleration F/a. There are three experiments in the third part a-c. a) The first experiment showed that the small hard-metal points used to improve contact with the concrete contributed undesired oscillations in the F/v impedance head. For this reason these points have not been used in further experiments. b) The second experiment showed that the F/v impedance head produce results that better couple to the properties like delamination depth and width than does the F/a impedance head. It also showed that the two parameters measured in the time domain: Fmax/vmax-impedance and concrete spring constant F/d are good indicators of these delamination properties. The experiment demonstrated that it is best to measure the spring constant in the rebound movement of the concrete surface. c) The third experiment demonstrated that it is possible to use the F/v impedance head for measurements in the frequency domain. However the dominating frequency was lower than that obtained with the vibrator and with the small

Asphalt cement poisoning

Science.gov (United States)

... petroleum material that hardens when it cools. Asphalt cement poisoning occurs when someone swallows asphalt. If hot ... found in: Road paving materials Roofing materials Tile cements Asphalt may also be used for other purposes.

Effect of Different Supplementary Cementitious Materials on Mechanical and Durability Properties of Concrete

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Rahul Sharma

2016-09-01

Full Text Available Concrete is the most widely used composite in the world. Ordinary Portland cement (OPC is the most commonly used binding material but the energy required for its production is large and its production leads to release of green house gases in the atmosphere therefore, the need for supplementary cementitious material is real. The utilization of Fly Ash (FA, Silica Fume (SF,Metakaolin (MK and Ground Granulated Blast Furnace Slag (GGBS, as a pozzolanic material for concrete has received considerable attention in the recent years. This interest is a part of the widely spread attention directed towards the utilization of wastes and industrial byproducts in order to minimize the Portland cement consumption, the manufacture of which is being environment damaging. The paper reviews were carried out on the use of FA, SF, MK and GGBS as partial pozzolanic replacement for cement in concrete. The literature demonstrates that GGBS was found to increase the mechanical and durability properties at later age depending upon replacement level. Silica fume concrete performed better than OPC concrete even at early period for production of high strength concrete and high performance concrete. Fly ash increases the later age strength due to slow rate of pozzlanic reaction. Metakaolin was found to improve early age strength as well as long term strength but had poor workability.

Quality and seasonal variation of rainwater harvested from concrete, asphalt, ceramic tile and green roofs in Chongqing, China.

Science.gov (United States)

Zhang, Qianqian; Wang, Xiaoke; Hou, Peiqiang; Wan, Wuxing; Li, Ruida; Ren, Yufen; Ouyang, Zhiyun

2014-01-01

There is an urgent requirement to examine the quality of harvested rainwater for potable and non-potable purposes, based on the type of roofing material. In this study, we examined the effect on the quality of harvested rainwater of conventional roofing materials (concrete, asphalt and ceramic tile roofs) compared with alternative roofing materials (green roof). The results showed that the ceramic tile roof was the most suitable for rainwater-harvesting applications because of the lower concentrations of leachable pollutants. However, in this study, the green roof was not suitable for rainwater harvesting applications. In addition, seasonal trends in water quality parameters showed that pollutants in roof runoff in summer and autumn were lower than those in winter and spring. This study revealed that the quality of harvested rainwater was significantly affected by the roofing material; therefore, local government and urban planners should develop stricter testing programs and produce more weathering resistant roofing materials to allow the harvesting of rainwater for domestic and public uses. Copyright © 2013 Elsevier Ltd. All rights reserved.

Petroleum contaminated soil in Oman: evaluation of bioremediation treatment and potential for reuse in hot asphalt mix concrete.

Science.gov (United States)

Jamrah, Ahmad; Al-Futaisi, Ahmed; Hassan, Hossam; Al-Oraimi, Salem

2007-01-01

This paper presents a study that aims at evaluating the leaching characteristics of petroleum contaminated soils as well as their application in hot mix asphalt concrete. Soil samples are environmentally characterized in terms of their total heavy metals and hydrocarbon compounds and leachability. The total petroleum hydrocarbon (TPH) present in the PCS before and after treatment was determined to be 6.8% and 5.3% by dry weight, indicating a reduction of 1% in the TPH of PCS due to the current treatment employed. Results of the total heavy metal analysis on soils indicate that the concentrations of heavy metals are lower when extraction of the soil samples is carried out using hexane in comparison to TCE. The results show that the clean soils present in the vicinity of contaminated sites contain heavy metals in the following decreasing order: nickel (Ni), followed by chromium (Cr), zinc (Zn), copper (Cu), lead (Pb), and vanadium (V). The current treatment practice employed for remediation of the contaminated soil reduces the concentrations of nickel and chromium, but increases the concentrations of all remaining heavy metals.

Spread of smoke and heat along narrow air cavity in double-skin façade fires

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Chow Lun Cheuk

2014-01-01

Full Text Available A scenario on double-skin façade fire was identified earlier for hazard assessment. A flashover room fire occurred next to the façade, broke the interior glass pane and spread to the façade cavity. As observed in experiments, hot gas moved up as a vertical channel flow for narrow façade cavity. Heat and smoke spread along the narrow air cavity of a double-skin façade will be studied in this paper. A simple mathematical model is developed from basic heat transfer theory for studying the vertical air temperature profiles of the hot gas flowing along the cavity. Assuming one-dimensional flow for hot gas moving up the façade cavity, conservation equations on mass and enthalpy were solved. Experimental results on two double-skin façade rigs of height 6 m and 15 m with narrow cavity depth were used to justify the results. A total of 11 tests were carried out. Correlation expressions between cavity air temperature and the height above ceiling of the fire room were derived.

Full Scale Reinforced Concrete Beam-Column Joints Strengthened with Steel Reinforced Polymer Systems

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Alessandro De Vita

2017-07-01

Full Text Available This paper presents the results of an experimental campaign performed at the Laboratory of Materials and Structural Testing of the University of Salerno (Italy in order to investigate the seismic performance of reinforced concrete (RC beam-column joints strengthened with steel reinforced polymer (SRP systems. With the aim to represent typical façade frames’ beam-column subassemblies found in existing RC buildings, specimens were provided with two short beam stubs orthogonal to the main beam and were designed with inadequate seismic details. Five members were strengthened by using two different SRP layouts while the remaining ones were used as benchmarks. Once damaged, two specimens were also repaired, retrofitted with SRP, and subjected to cyclic test again. The results of cyclic tests performed on SRP strengthened joints are examined through a comparison with the outcomes of the previous experimental program including companion specimens not provided with transverse beam stubs and strengthened by carbon fiber-reinforced polymer (CFRP systems. In particular, both qualitative and quantitative considerations about the influence of the confining effect provided by the secondary beams on the joint response, the suitability of all the adopted strengthening solutions (SRP/CFRP systems, the performances and the failure modes experienced in the several cases studied are provided.

Behavior of Reinforced Concrete Hybrid Trapezoidal Box Girders Using Ordinary and Highly Strength Concrete

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Nameer A. Alawsh

2018-03-01

Full Text Available In this paper, the general behavior of reinforced concrete hybrid box girders is studied by experimental and numerical investigation. Experimental work is included casting monolithically five specimens of box girders with trapezoidal cross section and testing it as simply supported under two point loading. Two specimens were cast as homogenous box girders (full normal strength concrete (NSC (about 35 MPa and full high strength concrete (HSC (about 55 MPa and three specimens were cast as hybrid box girders (HSC in upper flange only, HSC in upper flange and half depth of webs, and HSC in bottom flange and total depth of webs. Experimental results showed significant effects of concrete hybridization on the structural behavior of box girders specimens such as: cracking loads, cracking patterns, ultimate strengths, and failure modes. The ultimate strength of Hybrid box girders increased by 23% as average when compared with the homogenous box girder (full NSC and decreased by 9% as average when compared with homogenous box girder (full HSC. In numerical investigation, the tested specimens were modeled and analyzed using three dimensional non-linear finite element analysis. The analysis was carried out by using a computer program (ANSYS V16.1. The numerical results showed an acceptable agreement with the experimental work with difference about (3.12% and 9.588% as average for ultimate load and deflection, respectively.

Investigation of Asphalt Mixture Creep Behavior Using Thin Beam Specimens

International Nuclear Information System (INIS)

Zofka, Adam; Marasteanu, Mihai; Turos, Mugur

2008-01-01

The asphalt pavement layer consists of two or more lifts of compacted asphalt mixture; the top of the layer is also exposed to aging, a factor that significantly affects the mixture properties. The current testing specifications use rather thick specimens that cannot be used to investigate the gradual change in properties with pavement depth. This paper investigates the feasibility of using the 3-point bending test with thin asphalt mixture beams (127x12.7x6.35 mm) to determine the low-temperature creep compliance of the mixtures. Several theoretical and semi-empirical models, from the theory of composites, are reviewed and evaluated using numerical and experimental data. Preliminary results show that this method can be used for low-temperature mixture characterization but several crucial factors need further inspection and interpretation

CONCRETE BLOCKS' ADVERSE EFFECTS ON INDOOR AIR AND RECOMMENDED SOLUTIONS

Science.gov (United States)

Air infiltration through highly permeable concrete blocks can allow entry of various serious indoor air pollutants. An easy approach to avoiding these pollutants is to select a less–air-permeable concrete block. Tests show that air permeability of concrete blocks can vary by a fa...

Mechanical Properties of Warm Mix Asphalt Prepared Using Foamed Asphalt Binders

Science.gov (United States)

2011-03-01

Warm mix asphalt (WMA) is a name given to a group of technologies that have the common purpose of reducing the viscosity : of the asphalt binders. This reduction in viscosity offers the advantage of producing asphalt-aggregate mixtures at lower mixin...

Utilization of ferrochrome wastes such as ferrochrome ash and ferrochrome slag in concrete manufacturing.

Science.gov (United States)

Acharya, Prasanna K; Patro, Sanjaya K

2016-08-01

Solid waste management is one of the subjects essentially addressing the current interest today. Due to the scarcity of land filling area, utilization of wastes in the construction sector has become an attractive proposition for disposal. Ferrochrome ash (FA) is a dust obtained as a waste material from the gas cleaning plant of Ferro alloy industries. It possesses the chemical requirements of granulated slag material used for the manufacture of Portland cement. Ferrochrome slag (FS) is another residue that is obtained as a solid waste by the smelting process during the production of stainless steel in Ferroalloy industries. FS possesses the required engineering properties of coarse aggregates. The possibility of using FA with lime for partial replacement of ordinary Portland cement (OPC) and FS for total replacement of natural coarse aggregates is explored in this research. The combined effect of FA with lime and FS-addition on the properties of concrete, such as workability, compressive strength, flexural strength, splitting tensile strength and sorptivity, were studied. Results of investigation revealed improvement in strength and durability properties of concrete on inclusion of FA and FS. Concrete mix containing 40% FA with 7% lime (replacing 47% OPC) and100% of FS (replacing 100% natural coarse aggregate) achieved the properties of normal concrete or even better properties at all ages. The results were confirmed by microscopic study such as X-ray diffraction and petrography examination. Environmental compatibility of concrete containing FA and FS was verified by the toxicity characteristic leaching procedure test. © The Author(s) 2016.

Durability of Geopolymer Lightweight Concrete Infilled LECA in Seawater Exposure

Science.gov (United States)

Razak, R. A.; Abdullah, M. M. A. B.; Yahya, Z.; Hamid, M. S. A.

2017-11-01

This paper describes a development of lightweight concrete using lightweight expanded clay aggregate (LECA) in fly ash (FA) based geopolymer immersed in seawater. The objective of this research is to compare the performance of geopolymer concrete (GPC) with ordinary Portland cement (OPC) concrete infilled lightweight expanded clay aggregate (LECA) in seawater exposure. Geopolymer concrete is produced by using alkaline activator to activate the raw material, FA. The highest compressive strength of this study is 42.0 MPa at 28 days and 49.8 MPa at 60 days. The density for this concrete is in the range of 1580 kg/m3 to 1660 kg/m3. The result for water absorption is in the range of 6.82% to 14.72%. However, the test results of weight loss is in the range between 0.30% to 0.43%.

Impact of Volcanic Ash on Road and Airfield Surface Skid Resistance

Directory of Open Access Journals (Sweden)

Daniel M. Blake

2017-08-01

Full Text Available Volcanic ash deposited on paved surfaces during volcanic eruptions often compromises skid resistance, which is a major component of safety. We adopt the British pendulum test method in laboratory conditions to investigate the skid resistance of road asphalt and airfield concrete surfaces covered by volcanic ash sourced from various locations in New Zealand. Controlled variations in ash characteristics include type, depth, wetness, particle size and soluble components. We use Stone Mastic Asphalt (SMA for most road surface experiments but also test porous asphalt, line-painted road surfaces, and a roller screed concrete mix used for airfields. Due to their importance for skid resistance, SMA surface macrotexture and microtexture are analysed with semi-quantitative image analysis, microscopy and a standardised sand patch volumetric test, which enables determination of the relative effectiveness of different cleaning techniques. We find that SMA surfaces covered by thin deposits (~1 mm of ash result in skid resistance values slightly lower than those observed on wet uncontaminated surfaces. At these depths, a higher relative soluble content for low-crystalline ash and a coarser particle size results in lower skid resistance. Skid resistance results for relatively thicker deposits (3–5 mm of non-vesiculated basaltic ash are similar to those for thin deposits. There are similarities between road asphalt and airfield concrete, although there is little difference in skid resistance between bare airfield surfaces and airfield surfaces covered by 1 mm of ash. Based on our findings, we provide recommendations for maintaining road safety and effective cleaning techniques in volcanic ash environments.

Quantification of the inherent uncertainty in the relaxation modulus and creep compliance of asphalt mixes

Science.gov (United States)

Kassem, Hussein A.; Chehab, Ghassan R.; Najjar, Shadi S.

2017-08-01

Advanced material characterization of asphalt concrete is essential for realistic and accurate performance prediction of flexible pavements. However, such characterization requires rigorous testing regimes that involve mechanical testing of a large number of laboratory samples at various conditions and set-ups. Advanced measurement instrumentation in addition to meticulous and accurate data analysis and analytical representation are also of high importance. Such steps as well as the heterogeneous nature of asphalt concrete (AC) constitute major factors of inherent variability. Thus, it is imperative to model and quantify the variability of the needed asphalt material's properties, mainly the linear viscoelastic response functions such as: relaxation modulus, E(t), and creep compliance, D(t). The objective of this paper is to characterize the inherent uncertainty of both E(t) and D(t) over the time domain of their master curves. This is achieved through a probabilistic framework using Monte Carlo simulations and First Order approximations, utilizing E^{*} data for six AC mixes with at least eight replicates per mix. The study shows that the inherent variability, presented by the coefficient of variation (COV), in E(t) and D(t) is low at small reduced times, and increases with the increase in reduced time. At small reduced times, the COV in E(t) and D(t) are similar in magnitude; however, differences become significant at large reduced times. Additionally, the probability distributions and COVs of E(t) and D(t) are mix dependent. Finally, a case study is considered in which the inherent uncertainty in D(t) is forward propagated to assess the effect of variability on the predicted number of cycles to fatigue failure of an asphalt mix.

Radiation Exposure to Concrete in Israel

International Nuclear Information System (INIS)

Haquin, G.; Kovler, K.; Yungrais, G. Z.; Lavi, N.

2014-01-01

Most building materials of terrestrial origin contain small amounts of radionuclides of natural origin, mainly from the Uranium (238U) and Thorium (232Th) decay chains and the radioactive isotope of potassium, 40K. The external radiation exposure is caused by gamma emitting radionuclides, which in the uranium series mainly belong to the decay chain segment starting with Radium (226Ra). The internal (by inhalation) radiation exposure is due to Radon (222Rn), and its short lived decay products, exhaled from building materials into the room air. Due to economical and environmental reasons there is an increased tendency to use industrial by-products containing relatively high concentrations of radionuclides of natural origin in the building material industry. Fly ash (FA), produced as by-product in the combustion of coal, is extensively used in Israel since mid eighties of the last century in concrete and as an additive to cement . The increase of 226Ra activity concentration, the mineralogical characteristics of the FA and of the concrete may influence on the radon exhalation rate and consequently on the radon exposure of the public. The recently published Israeli Standard 5098 (IS 5098) 'Content of natural radioactive elements in building products' limits the content of natural radionuclides as well as the radon emanation from concrete. This paper presents a compilation of three studies conducted at Soreq Nuclear Research Centre (SNRC), Technion, NRG and Environmental Lab BGU (ELBGU) to investigate and quantify the influence of FA addition in concrete

Study of Antiultraviolet Asphalt Modifiers and Their Antiageing Effects

Directory of Open Access Journals (Sweden)

Jinxuan Hu

2017-01-01

Full Text Available Ultraviolet (UV radiation causes serious ageing problems on pavement surface. In recent years, different UV blocking materials have been used as modifiers to prevent asphalt ageing during the service life of the pavement. In this study, three different materials have been used as modifiers in base asphalt to test their UV blocking effects: layered double hydroxides (LDHs, organomontmorillonite (OMMT, and carbon black (CB. UV ageing was applied to simulate the ageing process and softening point, penetration, ductility, DSR (Dynamic Shear Rheometer test, and Fourier Transform Infrared Spectroscopy (FTIR test were conducted to evaluate the anti-UV ageing effects of the three UV blocking modifiers. Physical property tests show that base asphalt was influenced more seriously by UV radiation compared to the modified asphalt. DSR test results indicate that the complex modulus of asphalt before UV ageing is increased because of modifiers, while the complex modulus of base asphalt after UV ageing is higher than that of the modified asphalt, which shows that the UV blocking modifiers promote the antiageing effects of asphalt. FTIR test reveals that the increment of carbonyl groups and sulfoxide groups of modified asphalt is less than that in base asphalt. Tests indicate the best UV blocking effect results for samples with LDHs and the worst UV blocking effect results for samples with CB.

Microstructural and Microanalytical Study on Concrete Exposed to the Sulfate Environment

Science.gov (United States)

Qing, Fang; Beixing, Li; Jiangang, Yin; Xiaolu, Yuan

2017-11-01

Microstructural properties have been examined to investigate the effect of mineral admixtures on the sulfate resistance of concrete. Concrete and cement paste specimens made with ordinary Portland cement (OPC) or ordinary Portland cement incorporating 20% fly ash (FA) or 30% ground blast furnace slag (GBFS), were made and exposed to 250 cycles of the cyclic sulfate environment. Microstructural and Microanalytical study was conducted by means of x-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and mercury intrusion porosimetry (MIP). Results indicate that the pore structure of concrete after sulfate exposure possesses the fractal feature. The OPC concrete presents more complex pore internal surface, higher porosity and less micro-pores than the concrete incorporating fly ash and GBFS. Portlandite in OPC concrete and OPC-FA concrete is mainly converted to gypsum; while for OPC-GBFS concrete, both gypsum and ettringite are formed. In the cyclic sulfate environment, repeated hydration and dehydration of sulfates produce the expansive stress in pores, aggravating the demolishment of concrete structure.

The analysis of mechanical properties of non autoclaved aerated concrete with the substitution of fly ash and bottom ash

Science.gov (United States)

Karolina, R.; Muhammad, F.

2018-02-01

Based on PP. No.85 of 1999 on the management of hazardous and toxic (B3), fly ash and bottom ash wastes are categorized into B3 waste because there are heavy metal oxide contents that can pollute the environment. One form of environmental rescue that can be applied is to utilize waste fly ash and bottom ash in the manufacture of concrete. In this research, fly ash and bottom ash waste are used as substitution of cement and fine aggregate to make lightweight concrete. The purpose of this research is to know the mechanical properties of non-autoclaved aerated lightweight concrete (NAAC) with FA and BA substitution to cement and fine aggregate which is expected to improve the quality of concrete. The NAAC lightweight concrete in this study is divided into 4 categories: normal NAAC lightweight concrete, NAAC lightweight NAAC substituted concrete with FA, NAAC lightweight concrete substituted with BA, and NAAC combined light weight from FA and BA with variations of 10%, 20% And 30%. The test specimen used in cylindrical shape, which was tested at the age of 28 days, amounted to 90 pieces and consisted of 10 variations. Each variation amounted to 9 samples. Based on the test results with FA and BA substitutions of 10%, 20%, and 30%, the highest compressive strength was achieved in samples with FA 30% of 12.687 MPa, maximum tensile strength achieved in samples with FA 30% of 1,540 MPa, The highest absorption was achieved in normal NAAC of 5.66%. Based on the weight of the contents of all samples, samples can be categorized in lightweight concrete, since the weight of the contents is less than 1900 kg / m3.

CONCRETE MIX DESIGN FOR STRUCTURES SUBJECTED TO EXPOSURE CLASS XC1 DEPENDING ON CONCRETE COVER

Directory of Open Access Journals (Sweden)

O. Yu. Cherniakevich

2016-01-01

Full Text Available The reinforced steel corrosion which is the most important problem of reinforced concrete structures durability is generally stipulated for carbonization of concrete surrounding it. Concrete cover calculation at the design stage is predicated one because of the differences in manufacturing conditions and use of constructions. The applying of the probabilistic approaches to the carbonation process modeling allows to get predicated grade of the depth of carbonization of concrete and, thus, to settle minimum concrete cover thickness for a given projected service life of a construction. The procedures for concrete mix design for different strength classes of concrete are described in the article. Current recommendations on assignment of concrete strength class as well as concrete cover are presented. The European Standard EN 206:2013 defines the content requirements for the concrete structures operated in the exposure class XC1, including the minimum values of water-cement ratio, minimum cement content, and minimum strength class of concrete. Since the standard does not include any basis or explanations of the requirements, we made an effort to develop a scientific justification for the mentioned requirements. We developed the probabilistic models for the process of carbonation of concrete based on the concrete mix which was designed using the software VTK-Korroziya. The reinforced concrete structures with concrete cover 20–35 mm operated in the most unfavorable conditions within the exposure class XC1 were analyzed. The corresponding probabilistic calculations of the depth of carbonated concrete are described in the article. 

Adhesion Evaluation of Asphalt-Aggregate Interface Using Surface Free Energy Method

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Jie Ji

2017-02-01

Full Text Available The influence of organic additives (Sasobit and RH and water on the adhesion of the asphalt-aggregate interface was studied according to the surface free energy theory. Two asphalt binders (SK-70 and SK-90, and two aggregate types (limestone and basalt were used in this study. The sessile drop method was employed to test surface free energy components of asphalt, organic additives and aggregates. The adhesion models of the asphalt-aggregate interface in dry and wet conditions were established, and the adhesion work was calculated subsequently. The energy ratios were built to evaluate the effect of organic additives and water on the adhesiveness of the asphalt-aggregate interface. The results indicate that the addition of organic additives can enhance the adhesion of the asphalt-aggregate interface in dry conditions, because organic additives reduced the surface free energy of asphalt. However, the organic additives have hydrophobic characteristics and are sensitive to water. As a result, the adhesiveness of the asphalt-aggregate interface of the asphalt containing organic additives in wet conditions sharply decreased due to water damage to asphalt and organic additives. Furthermore, the compatibility of asphalt, aggregate with organic additive was noted and discussed.

Engineering characterisation of epoxidized natural rubber-modified hot-mix asphalt.

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Ramez A Al-Mansob

Full Text Available Road distress results in high maintenance costs. However, increased understandings of asphalt behaviour and properties coupled with technological developments have allowed paving technologists to examine the benefits of introducing additives and modifiers. As a result, polymers have become extremely popular as modifiers to improve the performance of the asphalt mix. This study investigates the performance characteristics of epoxidized natural rubber (ENR-modified hot-mix asphalt. Tests were conducted using ENR-asphalt mixes prepared using the wet process. Mechanical testing on the ENR-asphalt mixes showed that the resilient modulus of the mixes was greatly affected by testing temperature and frequency. On the other hand, although rutting performance decreased at high temperatures because of the increased elasticity of the ENR-asphalt mixes, fatigue performance improved at intermediate temperatures as compared to the base mix. However, durability tests indicated that the ENR-asphalt mixes were slightly susceptible to the presence of moisture. In conclusion, the performance of asphalt pavement can be enhanced by incorporating ENR as a modifier to counter major road distress.

Use of Adhesion Promoters in Asphalt Mixtures

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Cihlářová Denisa

2018-03-01

Full Text Available The purpose of asphalt binder as a significant binder in road constructions is to permanently bind aggregates of different compositions and grain sizes. The asphalt binder itself does not have suitable adhesiveness, so after a period of time, bare grains can appear. This results in a gradual separation of the grains from an asphalt layer and the presence of potholes in a pavement. Adhesion promoters or adhesive agents are important and proven promoters in practice. They are substances mainly based on the fatty acids of polyamides which should increase the reliability of the asphalt’s binder adhesion to the aggregates, thus increasing the lifetime period of the asphalt mixture as well as its resistance to mechanical strain. The amount of a promoter or agent added to the asphalt mixture is negligible and constitutes about 0.3% of the asphalt’s binder weight. Nevertheless, even this quantity significantly increases the adhesive qualities of an asphalt binder. The article was created in cooperatation with the Slovak University of Technology, in Bratislava, Slovakia, and focuses on proving the new AD2 adhesive additive and comparing it with the Addibit and Wetfix BE promoters used on aggregates from the Skuteč - Litická and Bystřec quarries.

Thermal Properties of Asphalt Mixtures Modified with Conductive Fillers

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Byong Chol Bai

2015-01-01

Full Text Available This paper investigates the thermal properties of asphalt mixtures modified with conductive fillers used for snow melting and solar harvesting pavements. Two different mixing processes were adopted to mold asphalt mixtures, dry- and wet-mixing, and two conductive fillers were used in this study, graphite and carbon black. The thermal conductivity was compared to investigate the effects of asphalt mixture preparing methods, the quantity, and the distribution of conductive filler on thermal properties. The combination of conductive filler with carbon fiber in asphalt mixture was evaluated. Also, rheological properties of modified asphalt binders with conductive fillers were measured using dynamic shear rheometer and bending beam rheometer at grade-specific temperatures. Based on rheological testing, the conductive fillers improve rutting resistance and decrease thermal cracking resistance. Thermal testing indicated that graphite and carbon black improve the thermal properties of asphalt mixes and the combined conductive fillers are more effective than the single filler.

Reinforcement of Recycled Foamed Asphalt Using Short Polypropylene Fibers

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Yongjoo Kim

2013-01-01

Full Text Available This paper presents the reinforcing effects of the inclusion of short polypropylene fibers on recycled foamed asphalt (RFA mixture. Short polypropylene fibers of 10 mm length with a 0.15% by weight mixing ratio of the fiber to the asphalt binder were used. The Marshall stability test, the indirect tensile strength test, the resilient modulus test, and wheel tracking test of the RFA mixtures were conducted. The test results were compared to find out the reinforcing effects of the inclusion of the fiber and the other mixtures, which included the conventional recycled foamed asphalt (RFA mixtures; the cement reinforced recycled foamed asphalt (CRFA mixtures; the semihot recycled foamed asphalt (SRFA mixtures; and recycled hot-mix asphalt (RHMA mixtures. It is found that the FRFA mixture shows higher Marshall stability than the RFA and SRFA mixtures, higher indirect tensile strength than the RFA mixture, and higher rut resistance than the RFA, SRFA, and RHMA mixtures as seen from the wheel tracking test.

New methods for testing fire resistance of wood façade systems

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Mårtensson August

2016-01-01

Full Text Available Arson in schools has been a huge problem in Sweden over the last fifteen years. The average amount of school arsons between 2000 and 2014 was 285 cases each year which corresponds to 50% of the total amount of reported fires in school buildings. This is a well-known problem and a lot of research has been done in this area. Investigations has been done about fire and heat detection systems, different technical factors significance in fire scenarios and how to prevent adolescents from starting fires. Another part of the problem that partly been investigated is how the schools are constructed. Roughly 50% of the arsons are outside of the school building. In Sweden one and two storey buildings are allowed to be built with wooden façades in accordance with the building code, which is one of the reasons many schools are built with wooden façade systems. The most critical part in a wood façade system from a fire safety perspective is concluded to be the eaves because of how they usually are built to let air pass through. Even though a wood façade isn't as well resistant to fire compared to a concrete façade, three versions of new test methods for combustible façades have been developed to make it possible to make sure in advance that a construction is resistant enough. The new test methods are focused on specific details and parts of a façade system to provide a more informative and useful result compared to SP Fire 105. Observations and measurements of flame spread and temperature changes in the eave, over the window joints and in the air gap are made. With these parameters in consideration criteria's has been chosen for a critical temperature of 280 ∘C at a critical time of 20 minutes.

Nanoscale study on water damage for different warm mix asphalt binders

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Kefei Liu

2016-11-01

Full Text Available In order to analyze the water damage to different warm mix asphalt binders from the micro scale, five kinds of asphalt binders, 70#A base asphalt, sasobit warm mix asphalt, energy champion 120 °C (EC120 warm mix asphalt, aspha-min warm mix asphalt, sulfur-extended asphalt modifier (SEAM warm mix asphalt, under different conditions (dry/wet, original/aging are prepared for laboratory tests. The atomic force microscope (AFM is used to observe the surface properties and measure the adhesion force between the asphalt and the mineral aggregate. The obtained results show that under the dry condition aspha-min warm mix asphalt and SEAM warm mix asphalt show stronger adhesive ability with the mineral aggregate compared with other asphalt binders, but also have relatively large dispersion and fluctuation in the tested results; under the wet condition, aspha-min warm mix asphalt and SEAM warm mix asphalt show stronger water damage resistance ability. The EC120 warm mix asphalt and aspha-min warm mix asphalt are less sensitive to moist, and their corresponding adhesion force is less susceptible to the change of external moisture conditions, leading to a better ability to resist water erosion. The aging process significantly lowers the moisture erosion resistance ability, which further impairs the water damage resistance ability. The base asphalt is more sensitive to moisture and more vulnerable to water damage, no matter whether it is under original or aging conditions. The aging aspha-min warm mix asphalt has the least loss of adhesion force, the smallest dispersion of the tested adhesion force, the strongest water damage resistance ability, no matter it is dry or wet. Keywords: Road engineering, Warm mix asphalt, Moisture damage, Atomic force microscope, Microcosmic

An experimental investigation on bending stiffness and neutral axis depth variation of over-reinforced high strength concrete beams

International Nuclear Information System (INIS)

Mohammadhassani, Mohammad; Bin Jumaat, Mohd Zamin; Chemrouk, Mohamed; Akbar Maghsoudi, Ali; Jameel, Mohammed; Akib, Shatirah

2011-01-01

Highlights: → Improvement of the assessment of correspond stress for calculation of modules of elasticity → better evaluation of cracked moment of inertia. → Low distinction of neutral axis depth → low bending stiffness variation. → Rate of slope in the line connecting the origin of first crack to yield point of N.A.D-LOAD graph → rate of ductility of beam section. - Abstract: The present work is an attempt to study the neutral axis variation and the evolution of the moment inertia with the loading of over reinforced high strength concrete sections in conjunction with ACI 318-05. In this sense, four high strength concrete beams, having different tension reinforcement quantities expressed as proportions of the balanced steel ratio (0.75ρ b , 0.85ρ b , ρ b , 1.2ρ b ) were tested. Measurements of the deflection and the reinforcement and concrete strains of all specimens were made during the loading process. The load-neutral axis depth variation and the load-section stiffness curves were drawn. The slope of the line connecting the origin of the first crack to the initial yielding of the failure point in the neutral axis depth-load graphs shows the rate of ductility; ductile behaviour in the beam increases as the slope becomes steeper. Based on the results of this study, it is recommended that the modulus of elasticity of concrete E c be reviewed and evaluated at a stress higher than 0.5f ' c for the determination of the cracked moment of inertia.

Sustainable asphalt pavement: Application of slaughterhouse waste oil and fly ash in asphalt binder

Science.gov (United States)

Sanchez Ramos, Jorge Luis

Increasing energy costs, lack of sufficient natural resources and the overwhelming demand for petroleum has stimulated the development of alternative binders to modify or replace petroleum-based asphalt binders. In the United States, the petroleum-based asphalt binder is mainly used to produce the Hot Mix Asphalt (HMA). There are approximately 4000 asphalt plants that make 500 million tons of asphalt binder valued at roughly 3 billion/year. The instability of the world's oil market has pushed oil prices to more than 80 per barrel in 2012, which increased the cost of asphalt binder up to $570 per ton. Therefore, there is a timely need to find alternative sustainable resources to the asphalt binder. This paper investigates the possibility of the partial replacement of the asphalt binder with slaughterhouse waste and/or fly ash. In order to achieve this objective, the asphalt binder is mixed with different percentages of waste oil and/or fly ash. In order to investigate the effect of these additives to the performance of the asphalt binder, a complete performance grade test performed on multiple samples. The results of the performance grade tests are compared with a control sample to observe how the addition of the waste oil and/or fly ash affects the sample. Considering the increasing cost and demand of asphalt, the use of slaughterhouse waste oil and/or fly ash as a partial replacement may result in environmental and monetary improvements in the transportation sector.

Biodecontamination of concrete

International Nuclear Information System (INIS)

Hamilton, M.A.; Rogers, R.D.; Benson, J.

1996-01-01

A novel technology for biologically decontaminating concrete is being jointly developed by scientists at the Idaho National Engineering Laboratory (INEL) and British Nuclear Fuels plc (BNFL). The technology exploits a naturally occurring phenomenon referred to as microbially influenced degradation (MID) in which bacteria produce acids that dissolve the cement matrix of concrete. Most radionuclide contamination of concrete is fixed in the outer few mm of the concrete surface. By capturing and controlling this natural process, a biological method of removing the surface of concrete to depths up to several mm is being developed. Three types of bacteria are known to be important in MID of concrete: nitrifying bacteria that produce nitric acid, sulfur oxidizing bacteria that produce sulfuric acid, and certain heterotrophic bacteria that produce organic acids. An investigation of natural environments demonstrated with scanning electron microscopy the presence of bacteria on concrete surfaces of a variety of structures, such as bridges and dams, where corrosion is evident. Enumeration of sulfur oxidizing and nitrifying bacteria revealed their presence and activity on structures to varying degrees in different environments. Under ideal conditions, Thiobacillus thiooxidans, a sulfur oxidizing bacteria, attached to and colonized the surface of concrete specimens. Over 1mm depth of material from a 10 cm x 10 cm square surface was removed in 68 days in the Thiobacillus treated specimen compared to a sterile control. Laboratory and field demonstrations are currently being conducted using experimental chambers designed to be mounted directly to concrete surfaces where radionuclide contamination exists. Data is being obtained in order to determine actual rates of surface removal and limitations to the system. This information will be used to develop a full scale decontamination technology

The Effect of Aging on the Cracking Resistance of Recycled Asphalt

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Mojtaba Mohammadafzali

2017-01-01

Full Text Available Fatigue cracking is an important concern when a high percentage of Reclaimed Asphalt Pavement (RAP is used in an asphalt mixture. The aging of the asphalt binder reduces its ductility and makes the pavement more susceptible to cracking. Rejuvenators are often added to high-RAP mixtures to enhance their performance. The aging of a rejuvenated binder is different from virgin asphalt. Therefore, the effect of aging on a recycled asphalt mixture can be different from its effect on a new one. This study evaluated the cracking resistance of 100% recycled asphalt binders and mixtures and investigated the effect of aging on this performance parameter. The cracking resistance of the binder samples was tested by a Bending Beam Rheometer. An accelerated pavement weathering system was used to age the asphalt mixtures and their cracking resistance was evaluated by the Texas Overlay Test. The results from binder and mixture tests mutually indicated that rejuvenated asphalt has a significantly better cracking resistance than virgin asphalt. Rejuvenated mixtures generally aged more rapidly, and the rate of aging was different for different rejuvenators.

Analysis of the usage of rubberized asphalt in hot mix asphalt using Reclaimed Asphalt Pavement (RAP)

Science.gov (United States)

Dwidarma Nataadmadja, Adelia; Prahara, Eduardi; Sumbung, Pierre Christian

2017-12-01

There has been an increasing demand in using more environmentally friendly materials in pavement construction. One of the alternative materials that have been widely used is the Reclaimed Asphalt Pavement (RAP) aggregates. The RAP aggregates are derived from the crushed and screened pavement materials that contain asphalt and aggregates. This material is usually combined with natural aggregates and virgin asphalt binder to construct a new pavement. There have been numerous positive feedbacks in using this material although RAP aggregates also have certain weaknesses, such as questionable interaction between virgin and recycled materials and increased stiffness of RAP binder. Moreover, there has been a push on using rubber as an additive to asphalt binder to improve the welfare of rubber farmers. This research combines the usage of both latex and RAP as the ingredients to design hot mix asphalt (HMA) as latex could help in improving the flexibility of HMA and the interaction between the virgin and recycled materials. The main objective of this research is to find a suitable percentage of RAP aggregates to be used in HMA with certain percentage of latex as the binder additive.

Mechanical characterization of porous asphalt mixes modified with fatty acid amides -FAA-

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Vanessa Senior Arrieta

2017-01-01

Full Text Available Porous asphalt mixes (PAM, form a special road surface for asphalt pavement structures, have a special particle size distribution that lets infiltrate to the runoff storm water through of it because of its voids content about 20 %. Many researchers conducted studies and have concluded that the use of modified asphalts is completely necessary to design PAM. Organic and chemical additives and special procedures as foamed asphalt have enhanced the performance of PAM, during their service life. This paper is focused on the mechanical characterization of PAM and how the asphalt modified with fatty acid amides, influenced on their behavior and performance. Based on an experimental methodology with laboratory tests aimed at establishing a comparison between porous asphalt mixes, using for its design and production a penetration 60-70 pure asphalt and another one asphalt modified with fatty acid amides.

Performance evaluation of stone matrix asphalt using indonesian natural rock asphalt as stabilizer

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Nyoman Suaryana

2016-09-01

Full Text Available One type of road pavement material which is developed to be more resistant to permanent deformation is the SMA (Stone Matrix Asphalt. Utilization of the SMA mix in Indonesia has constraints in gain stabilizer and also difficulty to comply the gradations, mainly because it needs a relatively large amount of filler. Alternative of local materials that can be used is asbuton (natural rock asphalt from Buton Island. Asbuton is expected to act as a stabilizer and simultaneously provides an additional filler. The objective of this research is to evaluate the performance of the SMA that uses the asbuton. The methodology used in this research is the experimental method, its starts from material testing, design mix and performance testing that includes dynamic modulus, permanent deformation and fatigue resistance. The results obtained showed asbuton can prevent asphalt draindown as well as increase the proportion of filler. Draindown asphalt can be prevented by using binder absorbers with fiber cellulose and viscosity boosters with asbuton. Asbuton (LGA 50/25 can behave as a stabilizer as well as cellulose fiber. Addition of asbuton also improves the performance of the SMA mix, as shown with increase in the value of dynamic stability. In terms of resistance to fatigue, SMA with cellulosa as stabilizer and SMA with asbuton as stabilizer, relatively have the same performance. Master curve of dynamic modulus indicates SMA with asbuton as stabilizer is relatively stiffer at high temperatures (more than 4.4 °C, but relatively less stiff (less brittle at low temperatures. Keywords: Stone matrix asphalt, Asbuton, Draindown, Dynamic modulus, Permanent deformation

How PE tape performs under concrete coating

International Nuclear Information System (INIS)

Dritt, H.J.

1984-01-01

The program objectives were to evaluate the performance of polyethylene tape plant coating and fusion bonded epoxy powder systems with particular respect to the following: 1. Concrete coating application procedures; 2. The shear resistance during laying and retrieving operations of the coating at the various interfaces (a) Pipe and anti-corrosion coating; (b) Anti-corrosion coating and outerwrap; (c) Overlap areas of the anti-corrosion and outerwrap layers; (d) Between concrete and the various corrosion coatings during laying and retrieving operations. 3. Resistance to damage of the coating as a consequence of cracking or slippage of the concrete weight coating. 4. Ability of various coatings to withstand the damage during concrete application by both impact and compression methods; 5. Evaluation of tape and shrink sleeve joint coatings at the cut-back area as well as performance of tape under hot asphalt coating

Mix design and pollution control potential of pervious concrete with non-compliant waste fly ash.

Science.gov (United States)

Soto-Pérez, Linoshka; Hwang, Sangchul

2016-07-01

Pervious concrete mix was optimized for the maximum compressive strength and the desired permeability at 7 mm/s with varying percentages of water-to-binder (W/B), fly ash-to-binder (FA/B), nano-iron oxide-to-binder (NI/B) and water reducer-to-binder (WR/B). The mass ratio of coarse aggregates in sizes of 4.75-9.5 mm to the binder was fixed at 4:1. Waste FA used in the study was not compliant with a standard specification for use as a mineral admixture in concrete. One optimum pervious concrete (Opt A) targeting high volume FA utilization had a 28-day compressive strength of 22.8 MPa and a permeability of 5.6 mm/s with a mix design at 36% W/B, 35% FA/B, 6% NI/B and 1.2% WR/B. The other (Opt B) targeting a less use of admixtures had a 28-day compressive strength and a permeability of 21.4 MPa and 7.6 mm/s, respectively, at 32% W/B, 10% FA/B, 0.5% NI/B and 0.8% WR/B. During 10 loads at a 2-h contact time each, the Opt A and Opt B achieved the average fecal coliform removals of 72.4% and 77.9% and phosphorus removals of 49.8% and 40.5%, respectively. Therefore, non-compliant waste FA could be utilized for a cleaner production of pervious concrete possessing a greater structural strength and compatible hydrological property and pollution control potential, compared to the ordinary pervious concrete. Copyright © 2016 Elsevier Ltd. All rights reserved.

Asphalt Roofing Shingles Into Energy Project Summary Report

Energy Technology Data Exchange (ETDEWEB)

Jameson, Rex, PE

2008-04-28

Based on a widely cited September, 1999 report by the Vermont Agency of Natural Resources, nearly 11 million tons of asphalt roofing shingle wastes are produced in the United States each year. Recent data suggests that the total is made up of about 9.4 million tons from roofing tear-offs and about 1.6 million tons from manufacturing scrap. Developing beneficial uses for these materials would conserve natural resources, promote protection of the environment and strengthen the economy. This project explored the feasibility of using chipped asphalt shingle materials in cement manufacturing kilns and circulating fluidized bed (CFB) boilers. A method of enhancing the value of chipped shingle materials for use as fuel by removing certain fractions for use as substitute raw materials for the manufacture of new shingles was also explored. Procedures were developed to prevent asbestos containing materials from being processed at the chipping facilities, and the frequency of the occurrence of asbestos in residential roofing tear-off materials was evaluated. The economic feasibility of each potential use was evaluated based on experience gained during the project and on a review of the well established use of shingle materials in hot mix asphalt. This project demonstrated that chipped asphalt shingle materials can be suitable for use as fuel in circulating fluidized boilers and cement kilns. More experience would be necessary to determine the full benefits that could be derived and to discover long term effects, but no technical barriers to full scale commercial use of chipped asphalt shingle materials in these applications were discovered. While the technical feasibility of various options was demonstrated, only the use of asphalt shingle materials in hot mix asphalt applications is currently viable economically.

Design Method for Proportion of Cement-Foamed Asphalt Cold Recycled Mixture

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Li Junxiao

2018-01-01

Full Text Available Through foaming experiment of Zhongtai AH-70 asphalt, the best foaming temperature water consumption and influence factors of foamed asphalt’s foaming features are determined; By designing the proportion of foamed asphalt cold in-place recycled mixture combined with the water stability experiment, for this mixture the best foamed asphalt addition is 3%, and proportion of the mixture is RAP: fine aggregate: cement=75:23:2. Using SEM technology, the mechanism of increasing on the intensity of foamed asphalt mixture resulted by the addition of cement was analysed. This research provides reference for cement admixture’s formulation in the designing of foamed asphalt cold in-place recycled mixture.

Evaluating the performance of sustainable perpetual pavements using recycled asphalt pavement in China

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Saud A. Sultan

2016-10-01

Full Text Available The vast highways network in China is moving from the phase of construction to the phase of maintenance, and with the introduction of new technique of perpetual pavement in last decade, it is necessary to consider recycling as one of the promising solutions for rehabilitation of old asphalt concrete pavement and ultimately to convert them into perpetual pavements. The aim is to reuse the existing pavement materials for several reasons, mainly to preserve natural resources such as aggregates, and to satisfy economic requirements by reducing the cost of highway construction and rehabilitation. A detailed testing program has been carried out on recycled asphalt pavements materials (RAP to evaluate their mechanical and structural characteristics to be used for the construction and rehabilitation of road pavements. Different types of RAP mixes have been stabilized by Portland cement to find the most suitable one from the point of view of design, construction, economy and environment. The analysis of life cycle costs has been carried out using system analysis and management of pavement program (SAMP5. The analysis of life cycle costs showed that the use of Portland cements with small percentages improves the structural characteristics of recycled asphalt materials to be used as stabilized base pavement layers for new or rehabilitated old road pavements and also for the construction and rehabilitation of perpetual pavements. A large amount of savings in construction and rehabilitation cost has been achieved by the use of stabilized RAP materials in addition to important contributions to the environment and preserving of natural resources.

Phase 1 sampling and analysis plan for the 304 Concretion Facility closure activities

International Nuclear Information System (INIS)

Adler, J.G.

1994-01-01

This document provides guidance for the initial (Phase 1) sampling and analysis activities associated with the proposed Resource Conservation and Recovery Act of 1976 (RCRA) clean closure of the 304 Concretion Facility. Over its service life, the 304 Concretion Facility housed the pilot plants associated with cladding uranium cores, was used to store engineering equipment and product chemicals, was used to treat low-level radioactive mixed waste, recyclable scrap uranium generated during nuclear fuel fabrication, and uranium-titanium alloy chips, and was used for the repackaging of spent halogenated solvents from the nuclear fuels manufacturing process. The strategy for clean closure of the 304 Concretion Facility is to decontaminate, sample (Phase 1 sampling), and evaluate results. If the evaluation indicates that a limited area requires additional decontamination for clean closure, the limited area will be decontaminated, resampled (Phase 2 sampling), and the result evaluated. If the evaluation indicates that the constituents of concern are below action levels, the facility will be clean closed. Or, if the evaluation indicates that the constituents of concern are present above action levels, the condition of the facility will be evaluated and appropriate action taken. There are a total of 37 sampling locations comprising 12 concrete core, 1 concrete chip, 9 soil, 11 wipe, and 4 asphalt core sampling locations. Analysis for inorganics and volatile organics will be performed on the concrete core and soil samples. Separate concrete core samples will be required for the inorganic and volatile organic analysis (VOA). Analysis for inorganics only will be performed on the concrete chip, wipe, and asphalt samples

A COST-REDUCTION OF SELF-COMPACTING CONCRETE INCORPORATING RAW RICE HUSK ASH

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H. AWANG

2016-01-01

Full Text Available The higher material cost of self-compacting concrete (SCC as compared to normal vibrated concrete is mainly due to its higher cement content. In order to produce economical SCC, a significant amount of cement should be replaced with cheaper material options, which are commonly found in byproduct materials such as limestone powder (LP, fly ash (FA and raw rice husk ash (RRHA. However, the use of these byproduct materials to replace the high volumes of cement in an SCC mixture will produce deleterious effects such as strength reduction. Thus, the objective of this paper is to investigate the optimum SCC mixture proportioning capable of minimizing SCC’s material cost. A total of fifteen mixes were prepared. This study showed that raw rice husk ash exhibited positive correlations with fly ash and fine limestone powder and were able to produce high compressive and comparable to normal concrete. The SCC-mix made with quaternary cement-blend comprising OPC/LP/FA/RRHA at 55/15/15/15 weight percentage ratio is found to be capable of maximizing SCC’s material-cost reduction to almost 19% as compared with the control mix

Application and properties of pure lime façades - case study

Directory of Open Access Journals (Sweden)

Violeta Bokan Bosiljkov

2008-01-01

Full Text Available The paper presents experiences obtained during application and testing of different pure lime façades that could be successfully used in restoration of historical buildings in Slovenia. The lime façade consists of a rendering layer (rough mortar, a finishing layer (fine mortar and a protective layer of lime wash. For the design of the mortars different industrially and traditionally produced limes were chosen, based on the results of preliminary studies of the authors and experiences of a small enterprise (SE involved in the study. The façade layers were applied to the most problematic northern wall of the historic chapel made from rubble masonry. The chapel belongs to the castle Crnelo, built at the end of the 17th century in the village Turnše, not far from Ljubljana, the capital of Slovenia. The façade layers were made by skilled workers of SE, with about one year time difference between application of rendering and finishing layers, and with a protective layer of coloured lime wash applied to one to three day old finishing layers. On the rendering layers, visual inspection, water absorption tests and determination of carbonation depth were carried out before subsequent finishing layers were applied. The same on-site tests were carried out also on finished façade layers. So far, parallel to the on-site tests, compressive and water absorption tests on prisms prepared from rough mortars were carried out in laboratory.

Preparation and Performance of Asphalt Compound Modified with Waste Crumb Rubber and Waste Polyethylene

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Yuqiao Yang

2016-01-01

Full Text Available Three kinds of modified asphalt were prepared by adding waste crumb rubber (WCR, waste polyethylene (WPE, and WCR/WPE to base asphalt, respectively. The influence of different doses on the performance of modified asphalt, such as 25°C penetration, softening point, 5°C ductility, and 135°C, 165°C viscosity, was studied, and the modification mechanism of modified asphalt was discussed through the fluorescence microscope. As the waterproofing materials, the waterproofness of WCR/WPE compound modified asphalt was tested. The results show that the WPE modified asphalt has excellent resistance to high temperature and WCR modified asphalt has good low temperature resistance. The resistance to deformation ability of WPE modified asphalt is better than that of the WCR modified asphalt. The 135°C viscosity of compound modified asphalt is better than that of WPE and WCR modified asphalt. In addition, the waterproofness of compound modified asphalt using waterproofing materials is better than that of common waterproofing materials.

Appropriate models for estimating stresses and strains in asphalt layers

CSIR Research Space (South Africa)

Jooste, FJ

1998-09-01

Full Text Available The broad objective is to make recommendations for appropriate modelling procedures to be used in the structural design of asphalt layers. Findings of this investigation are intended to be used in refining and validating existing asphalt pavement...

Evaluation of the performance of aggregate in hot-mix asphalt

CSIR Research Space (South Africa)

Komba, Julius J

2014-07-01

Full Text Available The overall performance of an asphalt mix is dependent on, amongst others, the properties of the constituent materials, which include aggregate, binder and filler. The aggregate for production of asphalt mixes is usually sourced from a quarry, which...

Production and performance of desulfurized rubber asphalt binder

Directory of Open Access Journals (Sweden)

Yanping Sheng

2017-05-01

Full Text Available Asphalt rubber binder typically exhibits disadvantages like segregation and high viscosity; however, this can be improved by the incorporation of desulfurized rubber powder. This study examined the swelling principle of desulfurized rubber asphalt (DRA. In addition, it evaluated the performance of DRA fabricated with various rubber powder contents under different shear conditions and development time. Superpave binders tests, including Brookfield viscosity, dynamic shear rheometer (DSR and bending beam rheometer (BBR tests, were applied on three control binders (i.e., neat, 20 mesh asphalt rubber binder, 40 mesh asphalt rubber binder and a DRA binder. Binder testing results indicated that rubber powder swelled into the base binder and resulted in enhanced stability. Optimum performance of the DRA binder was achieved by adding 20% (by weight of rubber powder into the base binder at shear rate, shear temperature, shear time and development time of 7000 r/min, 170 °C, 60 min and 45 min, respectively. Modified ranges of production conditions were also provided to widen the application of DRA in field construction. It appeared that DRA binder benefited from the recovered plasticity and viscosity of the rubber and consequently, exhibited superior performance over the neat and conventional asphalt rubber binders. Preliminary mixture evaluation was also conducted and the DRA binder was found to significantly improve the mixture resistance to permanent deformation and water damage. Overall, the DAR binder is encouraged to be used as a modified binder for flexible pavements. Keywords: Desulfurized rubber asphalt, Swelling model, Production process, Asphalt performance, Rubber asphalt

Effect of Soorh Metakaolin on Concrete Compressive Strength and Durability

Directory of Open Access Journals (Sweden)

A. Saand

2017-12-01

Full Text Available Concrete durability is a key aspect for forecasting the expected life time of concrete structures. In this paper, the effect of compressive strength and durability of concrete containing metakaolin developed from a local natural material (Soorh of Thatta Distict of Sindh, Pakistan is investigated. Soorh is calcined by an electric furnace at 8000C for 2 hours to produce metakaolin. One mix of ordinary concrete and five mixes of metakaolin concrete were prepared, where cement is replaced by developed metakaolin from 5% to 25% by weight, with 5% increment step. The concrete durability was tested for water penetration, carbonation depth and corrosion resistance. The obtained outcomes demonstrated that, 15% replacement level of local developed metakaolin presents considerable improvements in concrete properties. Moreover, a considerable linear relationship was established between compressive strength and concrete durability indicators like water penetration, carbonation depth and corrosion resistance.

Differential responsiveness of obese (fa/fa) and lean (Fa/Fa) Zucker rats to cytokine-induced anorexia.

Science.gov (United States)

Plata-Salamán, C R; Vasselli, J R; Sonti, G

1997-01-01

Pathophysiological and pharmacological concentrations of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) in the cerebrospinal fluid (CSF) induce anorexia in normal rats. Obesity in humans and rodents is associated with increased TNF-alpha messenger RNA and protein levels in various cell types. This suggests that obese individuals may have differential regulation of cytokine production and dissimilar responsiveness to cytokines. In the present study, we investigated the effects of the intracerebroventricular (ICV) microinfusion of TNF-alpha (50, 100, and 500 ng/rat), IL-1 beta (1.0, 4.0, and 8.0 ng), and TNF-alpha (100 ng) plus IL-1 beta (1.0 ng) on obese (fa/fa) and lean (Fa/Fa) Zucker rats. The results show that: TNF-alpha and IL-1 beta, and the concomitant administration of TNF-alpha and IL-1 beta decreased the short-term (4 hours), nighttime (12 hours), and total daily food intakes in obese and lean rats; IL-1 beta was more potent relative to TNF-alpha; obese rats showed greater responsiveness to IL-1 beta: 8.0 ng IL-1 beta, for example, decreased the 12-hour food intake by 52% in obese and 22% in lean rats. On the other hand, obese and lean rats did not exhibit a significantly different responsiveness to the anorexia induced by 50, 100, or 500 ng TNF-alpha at the 4-hour period; and the concomitant ICV administration of TNF-alpha and IL-1 beta induced anorexia with additive (4-hour period) or synergistic (12-hour and 24-hour periods) effects in obese rats. The effect of TNF-alpha plus IL-1 beta in lean rats was greater than additive for the 12-hour and 24-hour periods. The difference in suppression of total daily food intake by TNF-alpha plus IL-1 beta in obese (-43%) versus lean (-23%) rats was significantly different (p < 0.01). The results show that obese (fa/fa) and lean (Fa/Fa) Zucker rats have differential responsiveness to the ICV microinfusion of two different classes of cytokines.

Plastic Bottles Waste Utilization as Modifier for Asphalt Mixture Production

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Jan Hakeem

2017-01-01

Full Text Available Plastic Bottles was used as the polymeric waste to investigate performance of asphalt mixture Aggregates obtained from Margalla, Burhan and Karak quarries. 12 samples were prepared for conventional asphalt mixtures and 48 samples were prepared for PB modified asphalt mixture of each quarries at various proportions of PB waste. The PB used for modification according to wet process are 15%, 20%, 25% and 30% by weight of Optimum Bitumen Content (OBC. OBC of 4.2 % was concluded for conventional asphalt mixtures. The stability and flow values of the conventional and modified Asphalt Mixture were compared. The average Stability of the modified Margalla asphalt mixtures when 15% PB was used was much higher as compared to conventional asphalt mixtures. But when PB was used beyond 15%, the Marshall stability showed a decreasing trend for Margalla aggregates, increasing trend for Karak aggregates and decreasing trend for Burhan aggregates. This decline in stability is attributed to a decline in interlocking of aggregates due to lubricating effect. The corresponding flow for the Modified asphalt mixtures first showed a decreasing trend for Margalla aggregates at 15% PB modification but beyond 15%, an increasing trend in flow as compared to conventional asphalt mixtures The decrease in flow or increase in Marshall Stability is attributed to improvement in interlocking and decline in flow or stability is attributed to a decline in interlocking offered by binder and PB coated aggregate particles in modified asphalt.

Performance Evaluation and Improving Mechanisms of Diatomite-Modified Asphalt Mixture

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Chao Yang

2018-04-01

Full Text Available Diatomite is an inorganic natural resource in large reserve. This study consists of two phases to evaluate the effects of diatomite on asphalt mixtures. In the first phase, we characterized the diatomite in terms of mineralogical properties, chemical compositions, particle size distribution, mesoporous distribution, morphology, and IR spectra. In the second phase, road performances, referring to the permanent deformation, crack, fatigue, and moisture resistance, of asphalt mixtures with diatomite were investigated. The characterization of diatomite exhibits that it is a porous material with high SiO2 content and large specific surface area. It contributes to asphalt absorption and therefore leads to bonding enhancement between asphalt and aggregate. However, physical absorption instead of chemical reaction occurs according to the results of FTIR. The resistance of asphalt mixtures with diatomite to permanent deformation and moisture are superior to those of the control mixtures. But, the addition of diatomite does not help to improve the crack and fatigue resistance of asphalt mixture.

Experimental investigation of basic oxygen furnace slag used as aggregate in asphalt mixture.

Science.gov (United States)

Xue, Yongjie; Wu, Shaopeng; Hou, Haobo; Zha, Jin

2006-11-16

Chinese researchers have commenced a great deal of researches on the development of application fields of basic oxygen steel making furnace slag (BOF slag) for many years. Lots of new applications and properties have been found, but few of them in asphalt mixture of road construction engineering. This paper discussed the feasibility of BOF steel slag used as aggregate in asphalt pavement by two points of view including BOF steel slag's physical and micro-properties as well as steel slag asphalt materials and pavement performances. For the former part, this paper mainly concerned the mechanochemistry and physical changes of the steel slag and studied it by performing XRD, SEM, TG and mercury porosimeter analysis and testing method. In the second part, this paper intended to use BOF steel slag as raw material, and design steel slag SMA mixture. By using traditional rutting test, soak wheel track and modified Lottman test, the high temperature stability and water resistance ability were tested. Single axes compression test and indirect tensile test were performed to evaluate the low temperature crack resistance performance and fatigue characteristic. Simultaneously, by observing steel slag SMA pavement which was paved successfully. A follow-up study to evaluate the performance of the experimental pavement confirmed that the experimental pavement was comparable with conventional asphalt pavement, even superior to the later in some aspects. All of above test results and analysis had only one main purpose that this paper validated the opinion that using BOF slag in asphalt concrete is feasible. So this paper suggested that treated and tested steel slag should be used in a more extensive range, especially in asphalt mixture paving projects in such an abundant steel slag resource region.

The mechanical behavior of two warm-mix asphalts

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H. A. Rondón-Quintana

2016-09-01

Full Text Available This paper presents results stemming from a comparative experimental analysis of two warm-mix asphalts (WMA and a dense-graded hot-mix asphalt (HMA. In order to evaluate asphalt mixture behavior, physical and rheological tests were conducted, including tests on resilient modulus, resistance to moisture-induced damage, resistance to fatigue and resistance to permanent deformation. Samples studied were subjected to short (STOA and long-term (LTOA aging. As far as asphalt mixture composition is concerned, the same particle size distribution and coarse aggregate were employed for both mixture types. The control HMA mixture was produced with AC 60-70, and the WMAs used the same asphalt cement modified with two chemical additives (Rediset WMX® and Cecabase RT®. The modified mixtures exhibited better resistance to permanent deformation, aging and moisture-induced damage (versus the control mixture. Likewise, WMAs generally saw increased fatigue resistance under controlled-stress loading, which rheological characterization showed is mainly attributable to binder additives and their concomitant modifications.

Improvement of Concrete Paving Blocks Properties by Mineral Additions

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Aqeel Hatem Chkheiwer

2017-03-01

Full Text Available This research presents the results of experimental work on the various properties concrete paving blocks (CPB made with concrete containing different mineral additions.in this study, three types of mineral additions;Fly Ash (FA,Metakaolin (MK and Silica Fume (SF were used. Thirteen concretes mixes were cast at a water/binder ratio of 0.45 with 0, 5, 10,15and 20% cement replaced by either Fly ash,Metakaolin or Silica Fume. Theconcrete mixes were tested for slump, compressive strength, water absorption, and abrasion resistance.Metakaolin-contained concrete showed a better workability than fly ash and silica fume concrete. As the replacement level wasincreased, the 28-days compressive strength of the CPB containing MK increased similarly to that of the silica fume-containedCPB up to 20% replacement ratio. The replacement ratio of MK and SF from 5 to 20 % reduced water absorptionof CPB from5 to 19 than that of control mix. The increase in replacement ratio of MK andSF from 5 to 20 % leads to increasing abrasion resistance from 8 to 18% that of control mix

Domestic Wastewater Reuse in Concrete Using Bench-Scale Testing and Full-Scale Implementation

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Ayoup M. Ghrair

2016-08-01

Full Text Available Demand for fresh water by the construction sector is expected to increase due to the high increase in the growth of construction activities in Jordan. This study aims to evaluate the potential of scale-up of the application of treated domestic wastewater in concrete from bench-scale to a full-scale. On the lab scale, concrete and mortar mixes using Primary and Secondary Treated Wastewater (PTW, STW and Distilled Water (DW were cast and tested after various curing ages (7, 28, 120, and 200 days. Based on wastewater quality, according to IS 456-2000, the STW is suitable for mortar and concrete production. Mortar made with STW at curing time up to 200 days has no significant negative effect on the mortar’s compressive strength. Conversely, the PTW exceeded the maximum permissible limits of total organic content and E coli. for concrete mixing-water. Using PTW results, a significant increase in the initial setting time of up to 16.7% and a decrease in the concrete workability are observed. In addition, using PTW as mixing water led to a significant reduction in the compressive strength up to 19.6%. The results that came out from scaling up to real production operation of ready-mix concrete were in harmony with the lab-scale results.

Effect of mineral additives on structure and properties of concrete for pavements

Science.gov (United States)

Sobol, Khrystyna; Markiv, Taras; Hunyak, Oleksii

2017-12-01

Concrete pavements is an attractive alternative to asphalt pavements because of its lower cost and higher durability. Major contribution to sustainable development can be made by partial replacement of cement in concrete pavement with supplementary cementitious materials of different nature and origin. In this paper, the effect of natural zeolite and perlite additives in complex with chemical admixtures on the structure and properties of concrete for pavement was studied. Compressive and flexural strength test was used to study the mechanical behavior of designed concrete under load. Generally, the compressive strength of both control concrete and concrete containing mineral additives levels at the later ages of hardening. The microstructure analysis of concrete with mineral additives of different nature activity showed the formation of additional amount of hydration products such as tobermorite type calcium hydrosilicate which provide self-reinforcement of hardening concrete system.

Effectiveness of noise barriers installed adjacent to transverse grooved concrete pavement : executive summary report.

Science.gov (United States)

2009-10-16

In recent years the Ohio Department of Transportation (ODOT) has reconstructed a number of roadways where asphalt pavements were replaced with concrete pavements which were finished with a random transverse grooved surface texture (ODOT specification...

EVALUATION OF TIRE RUBBER DISPOSAL IN CONCRETE FOR PAVEMENTS

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Rosa Cristina Cecche Lintz

2009-01-01

Full Text Available The production of waste by the tire industry has been a growing problem, indicating the need for its reuse. More than thirty million tires are discharged per year in Brazil, where regulation for the environment states that for each four new tires, five unusable ones must be adequately disposed by manufacturers and importers. Paving consumes an extremely large quantity of materials, which can be the source of rational application of waste and rejected materials. Research shows that tire rubber can be added to asphalt, which increases its durability and improves pavement quality and safety conditions by absorbing the rubber elastic properties, and also be used for architectural applications, among others. This study deals with the addition of rubber fibers from tire crushing in concrete for roadway pavements in order to provide proper indication about the alternative material disposal through an evaluation of the mechanical behavior of the modified concrete. Different concrete mixes were produced, within which, part of fine aggregates were substituted by tire rubber and mechanical experiment tests were performed, which show that, due to great resistance losses, the disposal of this alternative material in concrete should be considered for light traffic pavements, with the addition of rubber ranging up to 10% in mass.

EVALUATION OF TIRE RUBBER DISPOSAL IN CONCRETE FOR PAVEMENTS

Directory of Open Access Journals (Sweden)

Rosa Cristina Cecche Lintz

2009-12-01

Full Text Available The production of waste by the tire industry has been a growing problem, indicating the need for its reuse. More than thirty million tires are discharged per year in Brazil, where regulation for the environment states that for each four new tires, five unusable ones must be adequately disposed by manufacturers and importers. Paving consumes an extremely large quantity of materials, which can be the source of rational application of waste and rejected materials. Research shows that tire rubber can be added to asphalt, which increases its durability and improves pavement quality and safety conditions by absorbing the rubber elastic properties, and also be used for architectural applications, among others. This study deals with the addition of rubber fibers from tire crushing in concrete for roadway pavements in order to provide proper indication about the alternative material disposal through an evaluation of the mechanical behavior of the modified concrete. Different concrete mixes were produced, within which, part of fine aggregates were substituted by tire rubber and mechanical experiment tests were performed, which show that, due to great resistance losses, the disposal of this alternative material in concrete should be considered for light traffic pavements, with the addition of rubber ranging up to 10% in mass.

Mechanical Properties of Warm Mix Asphalt Prepared Using Foamed Asphalt Binders : Executive Summary Report

Science.gov (United States)

2011-03-01

Hot mix asphalt (HMA) is a mixture containing aggregates and asphalt binders prepared at specified : proportions. The aggregates and asphalt binder proportions are determined through a mix design : procedure such as the Marshall Mix Design or the Sup...

Investigation of Warm Mix Asphalt (WMA) Technologies and Increased Percentages of Reclaimed Asphalt Pavement (RAP) in Asphalt Mixtures

Science.gov (United States)

2011-04-01

The implementation of warm-mix asphalt (WMA) is becoming more widespread with a growing number of contractors utilizing various WMA technologies. Early research suggests WMA may be more susceptible to moisture damage than traditional hot-mix asphalt ...

Evaluation of Different Mineral Filler Aggregates for Asphalt Mixtures

Science.gov (United States)

Wasilewska, Marta; Małaszkiewicz, Dorota; Ignatiuk, Natalia

2017-10-01

Mineral filler aggregates play an important role in asphalt mixtures because they fill voids in paving mix and improve the cohesion of asphalt binder. Limestone powder containing over 90% of CaCO3 is the most frequently used type of filler. Waste material from the production of coarse aggregate can be successfully used as a mineral filler aggregate for hot asphalt concrete mixtures as the limestone powder replacement. This paper presents the experimental results of selected properties of filler aggregates which were obtained from rocks with different mineral composition and origin. Five types of rocks were used as a source of the mineral filler aggregate: granite, gabbro, trachybasalt, quartz sandstone and rocks from postglacial deposits. Limestone filler was used in this study as the reference material. The following tests were performed: grading (air jet sieving), quality of fines according to methylene blue test, water content by drying in a ventilated oven, particle density using pyknometer method, Delta ring and ball test, Bitumen Number, fineness determined as Blaine specific surface area. Mineral filler aggregates showed significant differences when they were mixed with bitumen and stiffening effect in Delta ring and ball test was evaluated. The highest values were achieved when gabbro and granite fillers were used. Additionally, Scanning Electron Microscopy (SEM) analysis of grain shape and size was carried out. Significant differences in grain size and shape were observed. The highest non-homogeneity in size was determined for quartz sandstone, gabbro and granite filler. Their Blaine specific surface area was lower than 2800 cm2/g, while for limestone and postglacial fillers with regular and round grains it exceeded 3000 cm2/g. All examined mineral filler aggregates met requirements of Polish National Specification WT-1: 2014 and could be used in asphalt mixtures.

Some Properties of Emulsified Asphalt Paving Mixture at Iraqi Environmental Conditions

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Shakir.A.Al-Mishhadani* Hasan.H.Al-Baid

2014-04-01

Full Text Available Cold emulsified asphalt mixture is generally a mix made of emulsified asphalt withaggregate. Emulsified asphalt is manufactured from base asphalt, emulsifier agent and waterwith approximate percentage of 40% to 75% asphalt, 0.1% to 2.5% emulsifier and 25% to60% water plus some minor components. This study aims to use the cold emulsified asphaltmixtures for road construction and maintenance in Iraq as an alternative to the hot asphaltmixtures, due to its economical, practical and environmental advantages. This studyfocusedto test and evaluates the emulsified asphalt material properties to be used as paving mixture.The tested properties of emulsified asphalt mixture were bulk density, air voids, dry Marshallstability, wet Marshall stability, retained Marshall stability, flow tests and compared with thecommon used specification.The results indicate that the emulsified asphalt type cationic slowsetting low viscosity (CSS-1 is very suitable with quartz type of aggregate from Al-Nibaayquarry. From many trial mixes it is found that the best percentages of initial residual bitumencontent to produced adequateresults for coating test ,mixing ,compaction ,curing and Marshallstability were ranged from (2.5%, 3%,3.5%,4% and 4.5%, andthe optimum percentage is(3.5%.Finally it can be conducted that the emulsified asphalt mixture is a suitable alternativemixture to the hot asphalt mixture for road construction and maintenance in Iraq.  

Some Properties of Emulsified Asphalt Paving Mixture at Iraqi Environmental Conditions

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Shakir.A.Al-Mishhadani

2014-02-01

Full Text Available Cold emulsified asphalt mixture is generally a mix made of emulsified asphalt withaggregate. Emulsified asphalt is manufactured from base asphalt, emulsifier agent and waterwith approximate percentage of 40% to 75% asphalt, 0.1% to 2.5% emulsifier and 25% to60% water plus some minor components. This study aims to use the cold emulsified asphaltmixtures for road construction and maintenance in Iraq as an alternative to the hot asphaltmixtures, due to its economical, practical and environmental advantages. This studyfocusedto test and evaluates the emulsified asphalt material properties to be used as paving mixture.The tested properties of emulsified asphalt mixture were bulk density, air voids, dry Marshallstability, wet Marshall stability, retained Marshall stability, flow tests and compared with thecommon used specification.The results indicate that the emulsified asphalt type cationic slowsetting low viscosity (CSS-1 is very suitable with quartz type of aggregate from Al-Nibaayquarry. From many trial mixes it is found that the best percentages of initial residual bitumencontent to produced adequateresults for coating test ,mixing ,compaction ,curing and Marshallstability were ranged from (2.5%, 3%,3.5%,4% and 4.5%, andthe optimum percentage is(3.5%.Finally it can be conducted that the emulsified asphalt mixture is a suitable alternativemixture to the hot asphalt mixture for road construction and maintenance in Iraq.

Experimental testing of hot mix asphalt mixture made of recycled aggregates.

Science.gov (United States)

Rafi, Muhammad Masood; Qadir, Adnan; Siddiqui, Salman Hameed

2011-12-01

The migration of population towards big cities generates rapid construction activities. These activities not only put pressure on natural resources but also produce construction, renovation and demolition waste. There is an urgent need to find out ways to handle this waste owing to growing environmental concerns. This can reduce pressure on natural resources as well. This paper presents the results of experimental studies which were carried out on hot mix asphalt mixture samples. These samples were manufactured by adding recycled aggregates (RA) with natural crushed stone aggregates (CSA). Three levels of addition of RA were considered in the presented studies. RA were obtained from both the concrete waste of construction, renovation and demolition activities and reclaimed asphalt pavement. Separate samples were manufactured with the coarse and fine aggregate fractions of both types of RA. Samples made with CSA were used as control specimens. The samples were prepared and tested using the Marshall method. The performance of the samples was investigated in terms of density-void and stability/flow analysis and was compared with the performance criteria as given by National Highway Authority for wearing course material in Pakistan. Based on this data optimum asphalt contents were determined. All the samples made by adding up to 50% RA conform to the specification requirements of wearing course material as given by National Highway Authority in terms of optimum asphalt contents, voids in mineral aggregates and stability/flow. A statistical analysis of variation of these samples confirmed that addition is also possible statistically.

Effect of using of reclaimed asphalt and/or lower temperature asphalt on the availability of the road network

NARCIS (Netherlands)

Nicholls, C.; Wayman, M.; Mollenhauer, K.; McNally, C.; Tabakovic, A.; Varveri, A.; Cassidy, S.; Shahmohammadi, R.; Taylor, R.

2015-01-01

The use of reclaimed asphalt, secondary component materials and/or additives and lower temperature asphalt are being increasingly used in order to improve the sustainability of asphalt production. The use of reclaimed asphalt reduces the need for virgin materials whilst lower temperature asphalts

Effect of Rice Husk Ash and Fly Ash on the workability of concrete mixture in the High-Rise Construction

Science.gov (United States)

Van Tang, Lam; Bulgakov, Boris; Bazhenova, Sofia; Aleksandrova, Olga; Pham, Anh Ngoc; Dinh Vu, Tho

2018-03-01

The dense development of high-rise construction in urban areas requires a creation of new concretes with essential properties and innovative technologies for preparing concrete mixtures. Besides, it is necessary to develop new ways of presenting concrete mixture and keeping their mobility. This research uses the mathematical method of two-factors rotatable central compositional planning to imitate the effect of amount of rice husk (RHA) and fly ash of thermal power plants (FA) on the workability of high-mobility concrete mixtures. The results of this study displays regression equation of the second order dependence of the objective functions - slump cone and loss of concrete mixture mobility due to the input factors - the amounts RHA (x1) and FA (x2), as well as the surface expression image of these regression equations. An analysis of the regression equations also shows that the amount of RHA and FA had a significant influence on the concrete mixtures mobility. In fact, the particles of RHA and FA will play the role as peculiar "sliding bearings" between the grains of cement leading to the dispersion of cement in the concrete mixture. Therefore, it is possible to regulate the concrete mixture mobility when transporting fresh concrete to the formwork during the high-rise buildings construction in the hot and humid climate of Vietnam. Although the average value of slump test of freshly mixed concrete, measured 60 minutes later after the mixing completion, decreased from 18.2 to 10.52 cm, this value still remained within the allowable range to maintain the mixing and and the delivery of concrete mixture by pumping.

Investigation on performances of asphalt mixtures made with Reclaimed Asphalt Pavement: Effects of interaction between virgin and RAP bitumen

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Luca Noferini

2017-07-01

Full Text Available According to most recent surveys, the European area produced 265 mil tonnes of asphalt for road applications in 2014. In the same year, the amount of available RAP was more than 50 mil tonnes. The use of RAP in new blended mixes reduces the need of neat bitumen, making RAP recycling economically attractive. Despite the economic and environmental benefits, road authorities tend to limit the use of RAP in asphalt mixes due to uncertainty about field performances. The present study focuses on the interaction between neat and RAP bitumen in asphalt mixes made with different RAP content. The effects of RAP on physical and rheological properties of the final bituminous blend were investigated. This study is part of a wider research, where a specific type of asphalt mixture was produced with different RAP contents being 10%, 20% and 30% by mass of the mix. Bitumen was extracted and recovered from asphalt mixes, then it was subjected to the following laboratory tests: standard characterization, dynamic viscosity and rheological analysis with DSR. Findings showed that the effects of RAP bitumen on the final blend varied in proportion to RAP content. A threshold value of RAP content was found, below which bitumen was not subjected to significant changes in physical and rheological properties. Practical implications on production methods and paving of RAP mixes are also proposed. Keywords: Reclaimed Asphalt Pavement (RAP, Recycling, Bitumen blending, Bitumen rheology

Laboratory Evaluation of Ground Tire Rubber in Stone Mastic Asphalt

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R. Muniandy

2004-12-01

Full Text Available Stone mastic asphalt (SMA is a gap-graded mix whereby stiffer asphalt cement is required to bind the stone matrix or arrangement of stones together. Although various asphalt additives are traditionally available, the use of rubber crumbs in SMA is still a new rresearch endeavor. Many countries around the world are facing serious problems on what to do with reject or discarded tires. In the present study, commercial truck tires, containing 70% natural rubber, were ground and pre-blended in 80-100 penetration asphalt for use in SMA mixtures. An assessment was made of the laboratory performance of rubberized SMA in terms of stability, resilent modulus, dynamic creep and tensile strength ratio. It was observed that the performance of SMA with ground tire rubber was for superior as compared to SMA mix with unmodified asphalt. Sulfur and Styrene Butadeline Rubber (SBR were used in rubberized SMA mixes as additives to test the sensitivity of SMA mixtures. As standard practice a 0.3% newly developed cellulose oil palm fiber was used in SMA to minimize the asphalt drain-down effects.

14 CFR 302.409 - Default.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Default. 302.409 Section 302.409 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) PROCEDURAL REGULATIONS RULES OF PRACTICE IN PROCEEDINGS Rules Applicable to Enforcement Proceedings § 302.409 Default...

Strain transfer analysis of optical fiber based sensors embedded in an asphalt pavement structure

International Nuclear Information System (INIS)

Wang, Huaping; Xiang, Ping

2016-01-01

Asphalt pavement is vulnerable to random damage, such as cracking and rutting, which can be proactively identified by distributed optical fiber sensing technology. However, due to the material nature of optical fibers, a bare fiber is apt to be damaged during the construction process of pavements. Thus, a protective layer is needed for this application. Unfortunately, part of the strain of the host material is absorbed by the protective layer when transferring the strain to the sensing fiber. To account for the strain transfer error, in this paper a theoretical analysis of the strain transfer of a three-layered general model has been carried out by introducing Goodman’s hypothesis to describe the interfacial shear stress relationship. The model considers the viscoelastic behavior of the host material and protective layer. The effects of one crack in the host material and the sensing length on strain transfer relationship are been discussed. To validate the effectiveness of the strain transfer analysis, a flexible asphalt-mastic packaged distributed optical fiber sensor was designed and tested in a laboratory environment to monitor the distributed strain and appearance of cracks in an asphalt concrete beam at two different temperatures. The experimental results indicated that the developed strain transfer formula can significantly reduce the strain transfer error, and that the asphalt-mastic packaged optical fiber sensor can successfully monitor the distributed strain and identify local cracks. (paper)

Strain transfer analysis of optical fiber based sensors embedded in an asphalt pavement structure

Science.gov (United States)

Wang, Huaping; Xiang, Ping

2016-07-01

Asphalt pavement is vulnerable to random damage, such as cracking and rutting, which can be proactively identified by distributed optical fiber sensing technology. However, due to the material nature of optical fibers, a bare fiber is apt to be damaged during the construction process of pavements. Thus, a protective layer is needed for this application. Unfortunately, part of the strain of the host material is absorbed by the protective layer when transferring the strain to the sensing fiber. To account for the strain transfer error, in this paper a theoretical analysis of the strain transfer of a three-layered general model has been carried out by introducing Goodman’s hypothesis to describe the interfacial shear stress relationship. The model considers the viscoelastic behavior of the host material and protective layer. The effects of one crack in the host material and the sensing length on strain transfer relationship are been discussed. To validate the effectiveness of the strain transfer analysis, a flexible asphalt-mastic packaged distributed optical fiber sensor was designed and tested in a laboratory environment to monitor the distributed strain and appearance of cracks in an asphalt concrete beam at two different temperatures. The experimental results indicated that the developed strain transfer formula can significantly reduce the strain transfer error, and that the asphalt-mastic packaged optical fiber sensor can successfully monitor the distributed strain and identify local cracks.

Preparation of Flame Retardant Modified with Titanate for Asphalt Binder

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Bo Li

2014-01-01

Full Text Available Improving the compatibility between flame retardant and asphalt is a difficult task due to the complex nature of the materials. This study explores a low dosage compound flame retardant and seeks to improve the compatibility between flame retardants and asphalt. An orthogonal experiment was designed taking magnesium hydroxide, ammonium polyphosphate, and melamine as factors. The oil absorption and activation index were tested to determine the effect of titanate on the flame retardant additive. The pavement performance test was conducted to evaluate the effect of the flame retardant additive. Oxygen index test was conducted to confirm the effect of flame retardant on flame ability of asphalt binder. The results of this study showed that the new composite flame retardant is more effective in improving the compatibility between flame retardant and asphalt and reducing the limiting oxygen index of asphalt binder tested in this study.

Benchmarking of FA2D/PARCS Code Package

International Nuclear Information System (INIS)

Grgic, D.; Jecmenica, R.; Pevec, D.

2006-01-01

FA2D/PARCS code package is used at Faculty of Electrical Engineering and Computing (FER), University of Zagreb, for static and dynamic reactor core analyses. It consists of two codes: FA2D and PARCS. FA2D is a multigroup two dimensional transport theory code for burn-up calculations based on collision probability method, developed at FER. It generates homogenised cross sections both of single pins and entire fuel assemblies. PARCS is an advanced nodal code developed at Purdue University for US NRC and it is based on neutron diffusion theory for three dimensional whole core static and dynamic calculations. It is modified at FER to enable internal 3D depletion calculation and usage of neutron cross section data in a format produced by FA2D and interface codes. The FA2D/PARCS code system has been validated on NPP Krsko operational data (Cycles 1 and 21). As we intend to use this code package for development of IRIS reactor loading patterns the first logical step was to validate the FA2D/PARCS code package on a set of IRIS benchmarks, starting from simple unit fuel cell, via fuel assembly, to full core benchmark. The IRIS 17x17 fuel with erbium burnable absorber was used in last full core benchmark. The results of modelling the IRIS full core benchmark using FA2D/PARCS code package have been compared with reference data showing the adequacy of FA2D/PARCS code package model for IRIS reactor core design.(author)

Reviewing the Carbonation Resistance of Concrete

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S P Singh

2016-07-01

Full Text Available The paper reviews the studies on one of the important durability properties of concrete i.e. Carbonation. One of the main causes of deterioration of concrete is carbonation, which occurs when carbon dioxide (CO2 penetrates the concrete’s porous system to create an environment with lower pH around the reinforcement in which corrosion can proceed. Carbonation is a major cause of degradation of concrete structures leading to expensive maintenance and conservation operations. Herein, the importance, process and effect of various parameters such as water/cement ratio, water/binder ratio, curing conditions, concrete cover, super plasticizers, type of aggregates, grade of concrete, porosity, contaminants, compaction, gas permeability, supplementary cementitious materials (SCMs/ admixtures on the carbonation of concrete has been reviewed. Various methods for estimating the carbonation depth are also reported briefly

23 CFR 710.409 - Disposals.

Science.gov (United States)

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Disposals. 710.409 Section 710.409 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RIGHT-OF-WAY AND ENVIRONMENT RIGHT-OF-WAY AND REAL ESTATE Real Property Management § 710.409 Disposals. (a) Real property interests determined to be excess...

Performance on Water Stability of Cement-Foamed Asphalt Cold Recycled Mixture

Directory of Open Access Journals (Sweden)

Li Junxiao

2018-01-01

Full Text Available Through designing the mixture proportion of foamed asphalt cold in-place recycled mixture combined with the water stability experiment, it shows that the addition of cement can obviously improve foamed asphalt mixture’s water stability and the best cement admixture is between 1% ~ 2%; Using digital imaging microscope and SEM technology, the mechanism of increasing on the intensity of foamed asphalt mixture resulted by adding cement was analyzed. It revealed that the cement hydration products contained in the foamed asphalt mixture hydrolyzed into space mesh structure and wrapped up the aggregate particle, this is the main reason that the cement can enhance the mixture’s intensity as well as the water stability. This research provides reference for cement admixture’s formulation in the designing of foamed asphalt cold in-place recycled mixture.

A Review of the Application of Zeolite Materials in Warm Mix Asphalt Technologies

Directory of Open Access Journals (Sweden)

Agnieszka Woszuk

2017-03-01

Full Text Available Among warm mix asphalt (WMA technologies, asphalt foaming techniques offer high potential in terms of decreasing production temperature. Reluctance of manufacturers to introduce this technology is connected with the concerns of a large investment costs. However, there are known additives which, through asphalt foaming, allow a decrease in temperatures by approximately 30 °C; the use of these additives do not involve expensive investment in order to change the asphalt mix production method. These additives are zeolites, that is, minerals of the aluminosilicate group, the crystalline structure of which contains water bound in a specific way. Its release, at mix asphalt production temperatures, causes asphalt foaming. It is currently known that zeolites can be used in WMA, including natural and synthetic zeolites obtained using chemical reagents and waste. This review presents the results of studies of WMA technology, including the effects of zeolite addition on asphalt properties and mix asphalt, as well as related environmental, economic, and technological benefits.

Fatigue Evaluation of Recycled Asphalt Mixture Based on Energy-Controlled Mode

Directory of Open Access Journals (Sweden)

Tao Ma

2017-01-01

Full Text Available The fatigue properties of asphalt mixtures are important inputs for mechanistic-empirical pavement design. To understand the fatigue properties of asphalt mixtures better and to predict the fatigue life of asphalt mixtures more precisely, the energy-controlled test mode was introduced. Based on the implementation theory, the laboratory practice for the energy-controlled mode was realized using a four-point-bending fatigue test with multiple-step loading. In this mode, the fatigue performance of typical AC-20 asphalt specimens with various reclaimed asphalt pavement (RAP contents was tested and evaluated. Results show that the variation regulation of the dissipated energy and accumulative energy is compatible with the loading control principle, which proves the feasibility of the method. In addition, the fatigue life of the asphalt mixture in the energy-controlled mode was between that for the stress-controlled and strain-controlled modes. The specimen with a higher RAP content has a longer fatigue life and better fatigue performance.

Feasibility Assessment of the Use of Recycled Aggregates for Asphalt Mixtures

Directory of Open Access Journals (Sweden)

F. C. G. Martinho

2018-05-01

Full Text Available The use of recycled aggregates, manufactured from several by-products, to replace virgin aggregates in the production of pavement asphalt mixtures needs to be encouraged. Nevertheless, there are some concerns and uncertainties about the actual environmental, economic and mechanical performance resulting from the incorporation of recycled aggregates in asphalt mixtures. Therefore, this paper has the goal of discussing important features to help decision makers to select recycled aggregates as raw materials for asphalt mixtures. Based on the literature review carried out and the own previous experience of the authors, the article’s main findings reveal that incorporating some of the most common recycled aggregates into asphalt mixtures is feasible, even in a life-cycle analysis perspective. Although some specific technical operations are sometimes necessary when using recycled aggregates in asphalt mixtures, some benefits in terms of environmental impacts, energy use and costs are likely to be achieved, as well as in what concerns the mechanical performance of the asphalt mixtures.

Evaluation of the Strength Variation of Normal and Lightweight Self-Compacting Concrete in Full Scale Walls

DEFF Research Database (Denmark)

Hosseinali, M.; Ranjbar, M. M.; Rezvani, S. M.

2011-01-01

-destructive testing. Self-compacting concrete (SCC) and lightweight self-compacting concrete (LWSCC) with different admixtures were tested and compared with normal concrete (NC). The results were also compared with results for standard cubic samples. The results demonstrate the effect of concrete type on the in situ......The strength of cast concrete along the height and length of large structural members might vary due to inadequate compaction, segregation, bleeding, head pressure, and material type. The distribution of strength within a series of full scale reinforced concrete walls was examined using non...

The Effect of SBS Polymer on the Dynamic Properties of Asphalt

Directory of Open Access Journals (Sweden)

H. Ziari

2008-12-01

Full Text Available Polymer application for the improvement and modification of the bitumen used in roads surfaces has expanded in recent decades. The roads engineers and constructors, therefore, have used the modified bitumen in asphalts helping in this way to increase roads and pavements service life and improving the durability of the roads and asphalts. The bitumen used in asphalt mixture constitutes only a low percentage of the weight of this mixture (between 4% and 6%, but even this small amount has a significant effect on asphalt performance. The polymers that are mostly used in promoting the bitumen specifications are polymer modifiers including: styrenebutadiene- styrene (SBS, as well as similar polymers such as styrene-butadiene-rubber (SBR, ethylene-vinylacetate (EVA and polyethylene (PE. Polymers as the most important family of bitumen modifiers are added to bitumen to improve bitumen performance and to increase its effectiveness. Among the existing polymers, SBS is considered as the best bitumen modifier. In this research, SBS as one of the elastomer-thermoplast modifiers was added in different weights (2%-5% to bitumen 60/70 in Isfahan Refinery and its effect on asphalt properties were investigated. Adding this polymer to bitumen improves the Marshall stability of sample asphalt, flow, module of rupture and asphalt content voids. However, it has a minor effect on asphalt special weight. Adding SBS would also lead to asphalt fatigue life.

Aging of Rejuvenated Asphalt Binders

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Mojtaba Mohammadafzali

2017-01-01

Full Text Available An important concern that limits the RAP content in asphalt mixtures is the fact that the aged binder that is present in the RAP can cause premature cracking. Rejuvenators are frequently added to high RAP mixtures to enhance the properties of the binder. There is no existing method to predict the longevity of a rejuvenated asphalt. This study investigated the aging of rejuvenated binders and compared their durability with that of virgin asphalt. Various samples with different types and proportions of RAP, virgin binder, and rejuvenator were aged by RTFO and three cycles of PAV. DSR and BBR tests were conducted to examine the high-temperature and low-temperature rheological properties of binders. Results indicated that the type and dosage of the rejuvenator have a great influence on the aging rate and durability of the binder. Some rejuvenators make the binder age slower, while others accelerate aging. These observations confirm the importance of evaluating the long-term aging of recycled binders. For this purpose, critical PAV time was proposed as a measure of binder’s longevity.

Mechanical Property and Analysis of Asphalt Components Based on Molecular Dynamics Simulation

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Rui Li

2017-01-01

Full Text Available The asphalt-aggregate interface interaction plays a significant role in the overall performances of asphalt mixture. In order to analyze the chemical constitution of asphalt effects on the asphalt-aggregate interaction, the average structure C64H52S2 is selected to represent the asphalt, and the colloid, saturated phenol, and asphaltene are selected to represent the major constitutions in asphalt. The molecular models are established for the three compositions, respectively, and the Molecular Dynamics (MD simulation was conducted for the three kinds of asphaltene-aggregate system at different presses. Comparing the E value of Young modulus of these three polymers, the maximum modulus value of asphaltene was 2.80 GPa, the modulus value of colloid was secondary, and the minimum modulus of saturated phenol was 0.52 GPa. This result corresponds to conventional understanding.

Caltrans use of scrap tires in asphalt rubber products: a comprehensive review

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Haiping Zhou

2014-02-01

Full Text Available The California Department of Transportation (Caltrans has been using scrap tire rubber in asphalt pavements since the 1970s in chip seals and the 1980s in rubberized hot mix asphalt(RHMA. Both the wet (field blend and dry processes were used in early trials. Caltrans has also used rubber modified binders containing both crumb rubber modifier and polymer modifier that could be manufactured at a refinery facility, a terminal blend wet process. Since the beginning of this century, Caltrans increased the use of scrap tire rubber in paving projects and invested considerable resources in developing technically sound, cost effective, and environmentally friendly strategies for using scrap tire rubber in roadway applications. By the end of year 2010, approximately 31%of all hot mix asphalt (HMA placed by Caltrans was rubberized HMA, roughly 1.2 million tons. Caltrans efforts in using asphalt rubber products were also demonstrated in its research and technology development. These included the construction of two full-scale field experiments, five warranty projects, and an accelerated pavement study using a heavy vehicle simulator. Additionally, terminal blend asphalt rubber and rubberized warm mix asphalts began to be experimented on trial basis. This paper provides a comprehensive review of Caltrans experience over four decades with asphalt rubber products. Current practices and future outlook are also discussed.

Cyclic behavior of self-consolidated concrete.

Science.gov (United States)

2014-08-01

This reports highlights on the production of Self-Consolidating concrete using local materials from Las Vegas, Nevada. 4 SCC : mixtures were worked on with 2 different levels of FA replacement and the inclusion of superplasticizers, ADVA 195 and V-MA...

42 CFR 409.48 - Visits.

Science.gov (United States)

2010-10-01

... INSURANCE BENEFITS Home Health Services Under Hospital Insurance § 409.48 Visits. (a) Number of allowable... home health visits. All Medicare home health services are covered under hospital insurance unless there... 42 Public Health 2 2010-10-01 2010-10-01 false Visits. 409.48 Section 409.48 Public Health CENTERS...

Optimization and influence of parameter affecting the compressive strength of geopolymer concrete containing recycled concrete aggregate: using full factorial design approach

Science.gov (United States)

Krishnan, Thulasirajan; Purushothaman, Revathi

2017-07-01

There are several parameters that influence the properties of geopolymer concrete, which contains recycled concrete aggregate as the coarse aggregate. In the present study, the vital parameters affecting the compressive strength of geopolymer concrete containing recycled concrete aggregate are analyzedby varying four parameters with two levels using full factorial design in statistical software Minitab® 17. The objective of the present work is to gain an idea on the optimization, main parameter effects, their interactions and the predicted response of the model generated using factorial design. The parameters such as molarity of sodium hydroxide (8M and 12M), curing time (6hrs and 24 hrs), curing temperature (60°C and 90°C) and percentage of recycled concrete aggregate (0% and 100%) are considered. The results show that the curing time, molarity of sodium hydroxide and curing temperature were the orderly significant parameters and the percentage of Recycled concrete aggregate (RCA) was statistically insignificant in the production of geopolymer concrete. Thus, it may be noticeable that the RCA content had negligible effect on the compressive strength of geopolymer concrete. The expected responses from the generated model showed a satisfactory and rational agreement to the experimental data with the R2 value of 97.70%. Thus, geopolymer concrete comprising recycled concrete aggregate can solve the major social and environmental concerns such as the depletion of the naturally available aggregate sources and disposal of construction and demolition waste into the landfill.

Laboratory Evaluation of Aging Behaviour of SBS Modified Asphalt

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Jie Wang

2017-01-01

Full Text Available To study the effect of aging SBS modified asphalt on the performance of asphalt pavement, aging at various times and temperatures was conducted with thin film oven, and then tests were made about the penetration, softening point, ductility, viscosity, toughness, and fluorescence microscopy of modified asphalt with different aging levels. The results show that, with the increasing of aging time, the penetration and ductility of modified asphalt decrease while its softening point and viscosity increase, and the variation trend of the toughness and tenacity is related to the aging temperature; the aging dynamic model with viscosity as parameter can well characterize the aging process of modified asphalt; at microlevel, with the decreasing of SBS particle size, the uniformity of particle size is better. Analysis of macroscopic properties, microscopic characteristics, and significance shows that the SBS particle area ratio has a significant correlation with tenacity as the aging temperature changes. When the aging temperature is 163°C, the SBS particle area ratio still has a significant correlation with tenacity as the aging time changes.

40 CFR 81.409 - Hawaii.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Hawaii. 81.409 Section 81.409... Visibility Is an Important Value § 81.409 Hawaii. Area name Acreage Public Law establishing Federal land manager Haleakala NP 27,208 87-744 USDI-NPS Hawaii Volcanoes 217,029 64-171 USDI-NPS ...

Experimental investigation of asphalt mixture containing Linz-Donawitz steel slag

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Jens Groenniger

2017-08-01

Full Text Available Standard asphalt mixtures for road infrastructures consist of natural aggregate and bitumen. A number of research efforts have successfully investigated the possibility of replacing the conventional aggregate skeleton with industrial by-products such as slag originating from steel production process. However, little is known on the effect of steel slag on the mixtures performance properties such as resistance to low-temperature cracking and to permanent deformation, stiffness and fatigue. This paper presents a comprehensive investigation on the fundamental performance properties of different types of asphalt mixtures prepared with 100% LD slag aggregate and a conventional asphalt mixture containing natural Gabbro aggregate. Sophisticated testing methods were used to evaluate the key performance parameters for the set of asphalt mixtures investigated. In this study, low temperature cracking was addressed through thermal stress restrained specimen tests. Penetration tests and cyclic compression tests were used to evaluate the response of asphalt binder and asphalt mixture to permanent deformation due repeated loading, respectively. The cyclic indirect tensile test was selected for investigating both stiffness properties and fatigue resistance. For this purpose the complex stiffness modulus was measured to quantify material stiffness under different temperature and loading conditions providing information on the visco-elasto-plastic material behavior. Fatigue tests were used to determine the progressive and localized material damage caused by cyclic loading. The experimental results indicate that asphalt mixtures prepared with LD slag are suitable for asphalt pavement construction and that in most cases they perform better than conventional asphalt mixtures prepared with Gabbro aggregate.

Penetration analysis of projectile with inclined concrete target

Directory of Open Access Journals (Sweden)

Kim S.B.

2015-01-01

Full Text Available This paper presents numerical analysis result of projectile penetration with concrete target. We applied dynamic material properties of 4340 steels, aluminium and explosive for projectile body. Dynamic material properties were measured with static tensile testing machine and Hopkinson pressure bar tests. Moreover, we used three concrete damage models included in LS-DYNA 3D, such as SOIL_CONCRETE, CSCM (cap model with smooth interaction and CONCRETE_DAMAGE (K&C concrete models. Strain rate effect for concrete material is important to predict the fracture deformation and shape of concrete, and penetration depth for projectiles. CONCRETE_DAMAGE model with strain rate effect also applied to penetration analysis. Analysis result with CSCM model shows good agreement with penetration experimental data. The projectile trace and fracture shapes of concrete target were compared with experimental data.

Framework for benchmarking FA-based string recognizers

CSIR Research Space (South Africa)

Ngassam, EK

2010-10-01

Full Text Available of suggested algorithms by domain-specific FA-implementers requires prior knowledge of the behaviour (performance-wise) of each algorithm in order to make an informed choice. The authors propose a based string recognizers such that FA-implementers could capture...

CALCULATION PECULIARITIES OF RE-PROCESSED ROAD COVERING UNIT COST

Directory of Open Access Journals (Sweden)

Dilyara Kyazymovna Izmaylova

2017-09-01

Full Text Available In the article there are considered questions of economic expediency of non-waste technology application for road covering repair and restoration. Determined the conditions of asphalt-concrete processing at plants. Carried out cost changing analysis of asphalt granulate considering the conditions of transportation and preproduction processing. Given an example of expense calculation of one conventional unit of asphalt-concrete mixture volume preparation with and without processing.

Impact of Modificated Asphalt Mixtures on Paving Functioning and Environment

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Gediminas Gribulis

2016-10-01

Full Text Available Atmospheric pollution began to increase in the beginning of 19th century, when the global economy and industrial development started the signal grow. The current problem of global warming is partly related with emission of carbon dioxide (CO2 to environment, which one of the sources are industrial production companies. Warm asphalt mix is usually used in the practice of Lithuania and the world for equipment of road paving. These mixes are produced in specialized asphalt mixers where stone dosing, drying and its mixing with bituminous binders are performed. The temperature of produced hot asphalt mix in mixer reach 150–180 °C and 120–160 °C of mixture laying on the road. Various pollutants, carbon dioxide, formaldehydes, and other are spread to the environment. The carried out researches in Lithuania and the world have showed that while using special additives it is possible to reduce the temperatures of warm asphalt production and laying on the road. Such reduction of temperature helps not to worsen the quality of asphalt layer, to lower the emission of pollutants to environment, to improve the conditions of road workers and to economically use the gas for production of asphalt mixes. Production technologies of different asphalt mixes, their advantages and disadvantages, and results of laboratory tests are analyzed in this article. Equipment samples of experimental road sections, using the warm mixing asphalt mixtures are given.

Mechanical Properties of Portland Cement Concrete With Recycled Asphalt Pavement as Partial Replacement for Coarse Aggregate

Science.gov (United States)

2016-06-01

Finding constructive uses for construction waste byproducts contributes to green engineering principles. One such plentiful material is recycled asphalt pavement (RAP). This report looks at the mechanical viability of including RAP in a high strength...

Properties of concrete containing scrap-tire rubber--an overview.

Science.gov (United States)

Siddique, Rafat; Naik, Tarun R

2004-01-01

Solid waste management is one of the major environmental concerns in the United States. Over 5 billion tons of non-hazardous solid waste materials are generated in USA each year. Of these, more than 270 million scrap-tires (approximately 3.6 million tons) are generated each year. In addition to this, about 300 million scrap-tires have been stockpiled. Several studies have been carried out to reuse scrap-tires in a variety of rubber and plastic products, incineration for production of electricity, or as fuel for cement kilns, as well as in asphalt concrete. Studies show that workable rubberized concrete mixtures can be made with scrap-tire rubber. This paper presents an overview of some of the research published regarding the use of scrap-tires in portland cement concrete. The benefits of using magnesium oxychloride cement as a binder for rubberized concrete mixtures are also presented. The paper details the likely uses of rubberized concrete.

Mechanical characteristics of hardened concrete with different mineral admixtures: a review.

Science.gov (United States)

Ayub, Tehmina; Khan, Sadaqat Ullah; Memon, Fareed Ahmed

2014-01-01

The available literature identifies that the addition of mineral admixture as partial replacement of cement improves the microstructure of the concrete (i.e., porosity and pore size distribution) as well as increasing the mechanical characteristics such as drying shrinkage and creep, compressive strength, tensile strength, flexural strength, and modulus of elasticity; however, no single document is available in which review and comparison of the influence of the addition of these mineral admixtures on the mechanical characteristics of the hardened pozzolanic concretes are presented. In this paper, based on the reported results in the literature, mechanical characteristics of hardened concrete partially containing mineral admixtures including fly ash (FA), silica fume (SF), ground granulated blast furnace slag (GGBS), metakaolin (MK), and rice husk ash (RHA) are discussed and it is concluded that the content and particle size of mineral admixture are the parameters which significantly influence the mechanical properties of concrete. All mineral admixtures enhance the mechanical properties of concrete except FA and GGBS which do not show a significant effect on the strength of concrete at 28 days; however, gain in strength at later ages is considerable. Moreover, the comparison of the mechanical characteristics of different pozzolanic concretes suggests that RHA and SF are competitive.

Chlorine signal attenuation in concrete.

Science.gov (United States)

Naqvi, A A; Maslehuddin, M; Ur-Rehman, Khateeb; Al-Amoudi, O S B

2015-11-01

The intensity of prompt gamma-ray was measured at various depths from chlorine-contaminated silica fume (SF) concrete slab concrete specimens using portable neutron generator-based prompt gamma-ray setup. The intensity of 6.11MeV chloride gamma-rays was measured from the chloride contaminated slab at distance of 15.25, 20.25, 25.25, 30.25 and 35.25cm from neutron target in a SF cement concrete slab specimens. Due to attenuation of thermal neutron flux and emitted gamma-ray intensity in SF cement concrete at various depths, the measured intensity of chlorine gamma-rays decreases non-linearly with increasing depth in concrete. A good agreement was noted between the experimental results and the results of Monte Carlo simulation. This study has provided useful experimental data for evaluating the chloride contamination in the SF concrete utilizing gamma-ray attenuation method. Copyright © 2015 Elsevier Ltd. All rights reserved.

Present status and future of various rubber materials. ; Asphalt. Kakushu gomu zairyo no genjo to kongo. ; Asphalt

Energy Technology Data Exchange (ETDEWEB)

Wakisaka, S. (Toa Doro Kogyo Co. Ltd., Tokyo (Japan))

1991-12-15

Asphalt is obtained at a rate of about 25 Kg per 1 Kl of oil and is produced at about 5 million tons per annum in Japan, 80 % of which is now used for the pavement of road. The purpose of this study is to examine the possibilities of developing new applications of asphalt to the anti-vibration, vibration-control and anti-noise materials, though its uses have already been diversified in fields other than for road paving, due to excellent performance regardless of cheap cost. In the paper, firstly, under a title of what is asphalt, the history, the composition and internal structure of asphalt were considered. Secondly, the dynamic characteristics of asphalt were considered. And lastly, under a title of the application of asphalt, examples of the application of asphalt to anti-noise materials were examined in the field of architecture, automobile and civil engineering respectively. Especially, in the field of civil engineering, improvements of flexibility and vibration-control by using the cement asphalt mortar (CAM) in the anti-vibration A-type slab track for railway, and also anti-noise and anti-vibration technologies applied to the road pavement body by using the ferrite asphalt were reviewed. 11 refs., 10 figs., 8 tabs.

Recovery of asphalt from bituminous minerals

Energy Technology Data Exchange (ETDEWEB)

Jossinet, J

1881-12-31

A process is disclosed for the recovery of asphalt from bituminous minerals, consisting in that the mineral is extracted with mineral oil, which is recovered by distilling the raw asphalt and distilling the solution to obtain on the one hand the liquid oil contained in the raw asphalt for use in the extraction and on the other hand distilled asphalt.

Moving research to practice through partnership: a case study in Asphalt Paving.

Science.gov (United States)

Chang, Charlotte; Nixon, Laura; Baker, Robin

2015-08-01

Multi-stakeholder partnerships play a critical role in dissemination and implementation in health and safety. To better document and understand construction partnerships that have successfully scaled up effective interventions to protect workers, this case study focused on the collaborative processes of the Asphalt Paving Partnership. In the 1990s, this partnership developed, evaluated, disseminated, and achieved near universal, voluntary adoption of paver engineering controls to reduce exposure to asphalt fumes. We used in-depth interviews (n = 15) and document review in the case study. We describe contextual factors that both facilitated and challenged the formation of the collaboration, central themes and group processes, and research to practice (r2p) outcomes. The Asphalt Paving Partnership offers insight into how multi-stakeholder partnerships in construction can draw upon the strengths of diverse members to improve the dissemination and adoption of health and safety innovations and build a collaborative infrastructure to sustain momentum over time. © 2015 Wiley Periodicals, Inc.

Synthesis and Characterization of New ‎Copolymers as Asphalt Additives

Directory of Open Access Journals (Sweden)

Firyal M. ‎ A

2017-12-01

Full Text Available Rheological properties of asphalt S50  were improved by adding different prepared copolymers as additives with high homogeneity of asphalts  samples.  Three types of copolymers were prepared  Poly  (Indene –Co- maleic anhydride(A1 Poly (Acrylonitrile –Co- Maleic anhydride (A2 and Poly (Dipentine –Co-Maleic anhydride (A3, the cross linking of (A3 to (A3d. by using sulfur.              These copolymers  were designed by inserting Maleic anhydride as  rings  containing through backbone of polymer chains to be high potentially to react with water to protect the crack of pavement .And moisture with inhibit bonding of crack of pavement, Many factors should be considered when prepared the additives to enhanced performance to be convenience cost, beneficial thermal safety ,   extended life of the asphalt, preparing conditions which gave high thermal resistance with more stabilities, all these prepared copolymer have been characterized by FTIR and H-NMR spectroscopies .Intrinsic viscosities were calculated. softening point and penetration were observed for all asphalts blends which were  compared with the  asphalt samples, which gave high thermal resistance with more stabilities.                                          The results  showed high properties of these blends when  compared with the original asphalt. The physical properties of a specific polymers are determined by the sequence and chemical structure , When polymers are added to asphalt , the properties of the modified asphalt cement depend on polymer characteristic of asphalt and compatibility of polymer with asphalt. All these prepared copolymers were tested by softening points and penetration for all  asphalt blends which were compared with the asphalt sample. All the Improvements made by adding polymers to asphalt included the Increasing the viscosity of the binder service, the thermal susceptibility of the binder

Field site leaching from recycled concrete aggregates applied as sub-base material in road construction.

Science.gov (United States)

Engelsen, Christian J; Wibetoe, Grethe; van der Sloot, Hans A; Lund, Walter; Petkovic, Gordana

2012-06-15

The release of major and trace elements from recycled concrete aggregates used in an asphalt covered road sub-base has been monitored for more than 4 years. A similar test field without an asphalt cover, directly exposed to air and rain, and an asphalt covered reference field with natural aggregates in the sub-base were also included in the study. It was found that the pH of the infiltration water from the road sub-base with asphalt covered concrete aggregates decreased from 12.6 to below pH 10 after 2.5 years of exposure, whereas this pH was reached within only one year for the uncovered field. Vertical temperature profiles established for the sub-base, could explain the measured infiltration during parts of the winter season. When the release of major and trace elements as function of field pH was compared with pH dependent release data measured in the laboratory, some similar pH trends were found. The field concentrations of Cd, Ni, Pb and Zn were found to be low throughout the monitoring period. During two of the winter seasons, a concentration increase of Cr and Mo was observed, possibly due to the use of de-icing salt. The concentrations of the trace constituents did not exceed Norwegian acceptance criteria for ground water and surface water Class II. Copyright © 2012 Elsevier B.V. All rights reserved.

Influence of superplasticizer on the rheology of fresh cement asphalt paste

Directory of Open Access Journals (Sweden)

Jianwei Peng

2015-12-01

Full Text Available Cement asphalt (CA paste is an organic–inorganic composite material of cement and asphalt emulsion. Its complicated rheological behavior affects its site application in high speed railway. Superplasticizers (SPs are usually used to improve the construction properties of fresh CA mortar. However, the principle of SPs acting on the rheology of CA paste is seldom studied. In this paper, the effects of polycarboxylate (PCA and naphthalenesulfonate (PNS on the rheological properties of CA pastes, asphalt emulsions (both anionic and cationic and cement pastes were studied, respectively from the viewpoint of adsorption and zeta potential. Centrifugation method was used to determine the adsorption of asphalt onto cement particle, electroacoustic method was employed to study the zeta potential of cement particles of concentrated paste, and optical microscopy was used to observe the dispersion of particles. The results suggest that both PCA and PNS can decrease the yield stress and apparent viscosity of CA pastes. The effect of SPs on the rheology of CA paste can be explained by two reasons. First, PNS can adsorb on both asphalt and cement surface, change the zeta potential and then decrease their yield stress and viscosity, while PCA only adsorb on cement surface. Second, the competitive adsorption of SPs and asphalt prevents asphalt from adsorbing on cement surface and then more asphalt droplets are released into aqueous solution, thereby enhancing the particle dispersion.

Determination of in-depth contamination in concrete using a non-destructive technique

International Nuclear Information System (INIS)

Boden, S.; Cantrel, E.

2007-01-01

The decommissioning of the BR3 (Belgian Reactor 3) approaches its final phase, in which the building structures are being decontaminated and either denuclearized for possible reuse or demolished. Apart from the presence of naturally occurring radionuclides in building materials, other radionuclides might be present due to activation or contamination. The BR3 bioshield has been exposed to rather high neutron leakage fluxes during the reactor operation and is therefore activated. Building structure contamination usually results from leakages during reactor operation, releases due to maintenance works or even dismantling operations. In case of in-depth contamination in concrete it is important to know the exact in-depth profile before decontamination, in order to minimize the amount of radioactive waste that will be produced during the decontamination process and to optimize both the decontamination process and the final control measurements. Common non-destructive analyses used in decommissioning are usually based on the measurement of beta radiation, using e.g. hand-held plastic scintillators. This kind of measurement technique can not be used to determine in-depth contamination. Therefore, most of the decontamination specialists currently base themselves on the results of the radiological analysis of samples taken by core drilling. The use of such a destructive method implies a number of disadvantages: it is time consuming and therefore costly and the different sample preparation steps can conceivably lead to cross-contamination. Moreover, one only receives results of a limited number of points, while the in-depth contamination is usually very inhomogeneously distributed and the relationship between in-depth contamination and surface contamination and/or dose rate (hotspot detection) is generally rather poor.The objective therefore is to test the use of the ISOCS (In Situ Object Counting System) for the determination of contamination depth

A simple test procedure for evaluating low temperature crack resistance of asphalt concrete : executive summary report.

Science.gov (United States)

2009-03-01

Low temperature cracking is one of the major : distress modes in asphalt pavement and is : disastrous to pavement performance and service : life. A poor riding surface leads to an increase in : maintenance and eventual early replacement of : the pave...

Retrofitting of Reinforced Concrete Beams using Reactive Powder Concrete (RPC)

Science.gov (United States)

Karthik, S.; Sundaravadivelu, Karthik

2017-07-01

Strengthening of existing damaged structures is one of the leading studies in civil engineering. The purpose of retrofitting is to structurally treat the member with an aim to restore the structure to its original strength. The focus of this project is to study the behaviour of damaged Reinforced Concrete beam retrofitted with Reactive Powder Concrete (RPC) Overlay. Reinforced concrete beams of length 1200 mm, width 100 mm and depth 200 mm were casted with M30 grade of concrete in the laboratory and cured for 28 days. One beam is taken as control and are tested under two point loading to find out ultimate load. Remaining beams are subjected to 90 % ultimate load of control beams. The partially damaged beams are retrofitted with Reactive Powder Concrete Overlay at the full tension face of the beam and side overlay depends upon the respectable retrofitting techniques with 10 mm and 20 mm thick layer to find optimum. Materials like steel fibres are added to enhance the ductility by eliminating coarse particle for homogeneity of the structure. Finally, the modes of failure for retrofitted beams are analysed experimentally under two point loading & compared the results with Control beam.

Rutting resistance of asphalt mixture with cup lumps modified binder

Science.gov (United States)

Shaffie, E.; Hanif, W. M. M. Wan; Arshad, A. K.; Hashim, W.

2017-11-01

Rutting is the most common pavement distress in pavement structures which occurs mainly due to several factors such as increasing of traffic volume, climatic conditions and also due to construction design errors. This failure reduced the service life of the pavement, reduced driver safety and increase cost of maintenance. Polymer Modified Binder has been observed for a long time in improving asphalt pavement performance. Research shows that the use of polymer in bituminous mix not only improve the resistance to rutting but also increase the life span of the pavement. This research evaluates the physical properties and rutting performance of dense graded Superpave-designed HMA mix. Two different types of dense graded Superpave HMA mix were developed consists of unmodified binder mix (UMB) and cup lumps rubber (liquid form) modified binder mix (CLMB). Natural rubber polymer modified binder was prepared from addition of 8 percent of cup lumps into binder. Results showed that all the mixes passed the Superpave volumetric properties criteria which indicate that these mixtures were good with respect to durability and flexibility. Furthermore, rutting results from APA rutting test was determined to evaluate the performance of these mixtures. The rutting result of CLMB demonstrates better resistance to rutting than those prepared using UMB mix. Addition of cup lumps rubber in asphalt mixture was found to be significant, where the cup lumps rubber has certainly improves the binder properties and enhanced its rutting resistance due to greater elasticity offered by the cup lumps rubber particles. It shows that the use of cup lumps rubber can significantly reduce the rut depth of asphalt mixture by 41% compared to the minimum rut depth obtained for the UMB mix. Therefore, it can be concluded that the cup lumps rubber is suitable to be used as a modifier to modified binder in order to enhance the properties of the binder and thus improves the performance of asphalt mixes.

Large Scale Glazed Concrete Panels

DEFF Research Database (Denmark)

Bache, Anja Margrethe

2010-01-01

Today, there is a lot of focus on concrete surface’s aesthitic potential, both globally and locally. World famous architects such as Herzog De Meuron, Zaha Hadid, Richard Meyer and David Chippenfield challenge the exposure of concrete in their architecture. At home, this trend can be seen...... in the crinkly façade of DR-Byen (the domicile of the Danish Broadcasting Company) by architect Jean Nouvel and Zaha Hadid’s Ordrupgård’s black curved smooth concrete surfaces. Furthermore, one can point to initiatives such as “Synlig beton” (visible concrete) that can be seen on the website www.......synligbeton.dk and spæncom’s aesthetic relief effects by the designer Line Kramhøft (www.spaencom.com). It is my hope that the research-development project “Lasting large scale glazed concrete formwork,” I am working on at DTU, department of Architectural Engineering will be able to complement these. It is a project where I...

State of the Art Study on Aging of Asphalt Mixtures and Use of Antioxidant Additives

Directory of Open Access Journals (Sweden)

Okan Sirin

2018-01-01

Full Text Available The detrimental effects of hardening in asphalt pavements were first recognized by pioneering pavement engineers in the 1900s and have been studied extensively during the last 70 years. This hardening process, referred to as asphalt aging, is generally defined as change in the rheological properties of asphalt binders/mixtures due to changes in chemical composition during construction and its service life period. Aging causes the asphalt material to stiffen and embrittle, which affects the durability and leads to a high potential for cracking. This paper presents the state of the art on asphalt and asphalt mixture aging and use of antioxidant additives to retard the aging. A picture of complex molecular structure of asphalt and its changes due to atmospheric condition and various protocols used to simulate aging in laboratory environment are also discussed. Emphasis is given on recent studies on simulation of aging of asphalt mixtures as there has been limited research on mixtures compared to the asphalt binder. Finally, this paper presents the application of antiaging techniques and its mechanism, use of various types of antioxidant additives to retard aging of asphalt and, hence, improve the performance of asphalt pavements.

Durability of European Asphalt Mixtures Containing Reclaimed Asphalt and Warm-Mix Additives

NARCIS (Netherlands)

Varveri, A.; Avgerinopoulos, S.; Scarpas, Athanasios

2016-01-01

This paper investigates the moisture susceptibility of European asphalt mixtures (SMA) containing reclaimed asphalt (RA) and warm mix (WMA) additives. Test sections of a typical SMA mixture have been laid, from which cylindrical samples were cored and utilized for laboratory testing. Four variants

Laboratory Measurements of Particulate Matter Concentrations from Asphalt Pavement Abrasion

Directory of Open Access Journals (Sweden)

Fullová Daša

2016-12-01

Full Text Available The issue of emissions from road traffic is compounded by the fact that the number of vehicles and driven kilometres increase each year. Road traffic is one of the main sources of particulate matter and traffic volume is still increasing and has unpleasant impact on longevity of the pavements and the environment. Vehicle motions cause mechanical wearing of the asphalt pavement surface - wearing course by vehicle tyres. The contribution deals with abrasion of bituminous wearing courses of pavements. The asphalt mixtures of wearing courses are compared in terms of mechanically separated particulate matter. The samples of asphalt mixtures were rutted in wheel tracking machine. The particulate matter measurements were performed in laboratory conditions. The experimental laboratory measurements make it possible to sample particulates without contamination from exhaust emissions, abraded particles from vehicles, resuspension of road dust and climate affects. The contribution offers partial results of measurements on six trial samples of asphalt mixtures with different composition. It presents particulate matter morphology and the comparison of rutted asphalt samples in terms of PM mass concentrations and chemical composition.

Durability of lightweight concrete : Phase I : concrete temperature study.

Science.gov (United States)

1968-08-01

This report describes a study conducted to determine the temperature gradient throughout the depth of a six inch concrete bridge deck. The bridge deck selected for study was constructed using lightweight concrete for the center spans and sand and gra...

Performance of Hot Asphalt Mixtures Containing Plastic Bottles as Additive

Directory of Open Access Journals (Sweden)

Jan Hakeem

2017-01-01

Full Text Available This study focuses on evaluating the resistance of polymer modified asphalt mixes and the role played by asphalt in the realm of construction is undeniably important. Addition of polymers(PB as additives to asphalt helps to improve the strength and water repellent property of the mix and as well as helps environment in various ways and at the same time, analyzing its lower maintenance activities and service life is most important. The use of inexpensive polymers, in this case, waste polymers has without any doubt proven to be the most convenient way of reducing the cost of construction and at the same time maintaining quality. The main resolve for this research was to establish the effects of the use of plastic bottles on hot asphalt and its mixtures. In order to put this into perspective, varying percentages of asphalt mixtures were calculated and subjected to laboratory tests. The two-factor variance analysis (ANOVA was conducted to determine the significance at various confidence limits. The results indicate that the inclusion of Polyethylene Terephthalate (PET had a particularly substantial effect on the properties of asphalt. Consequently, it can encourage the re-utilization of waste in the manufacturing industry in an ecologically friendly and cost-effective way.

Decision of National and Provincial Highway Asphalt Pavement Structure Based on Value Engineering

Directory of Open Access Journals (Sweden)

Yingwei Ren

2014-01-01

Full Text Available It is important that decision of asphalt pavement structure requires overall considerations of the performance and financial investment. To have asphalt pavement structure fulfilling good reliability, the asphalt pavement structure decision was researched based on value engineering theory. According to the national and provincial highway investigation data in Shandong Province during the last decade, the asphalt pavement performance attenuation rules of traffic levels and asphalt layer thicknesses were developed, and then the road performance evaluation method was presented. In addition, the initial investments, the costs of road maintenance, and middle-scale repair in a period were analyzed. For the light traffic and medium traffic example, using the value engineering method, the pavement performance and costs of which thickness varies from 6 cm to 10 cm were calculated and compared. It was concluded that value engineering was an effective method in deciding the asphalt pavement structure.

42 CFR 409.49 - Excluded services.

Science.gov (United States)

2010-10-01

... HOSPITAL INSURANCE BENEFITS Home Health Services Under Hospital Insurance § 409.49 Excluded services. (a... individual's dialysis, are excluded from coverage under the Medicare home health benefit. (f) Prosthetic... 42 Public Health 2 2010-10-01 2010-10-01 false Excluded services. 409.49 Section 409.49 Public...

42 CFR 409.60 - Benefit periods.

Science.gov (United States)

2010-10-01

... 42 Public Health 2 2010-10-01 2010-10-01 false Benefit periods. 409.60 Section 409.60 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICARE PROGRAM HOSPITAL INSURANCE BENEFITS Scope of Hospital Insurance Benefits § 409.60 Benefit periods. (a) When benefit...

Partial substitution of asphalt pavement with modified sulfur

Directory of Open Access Journals (Sweden)

E.R. Souaya

2015-12-01

Full Text Available The use of sulfur in pavement laying was developed in 1980 but it was restricted in the late 19th century due to its environmental problems and its high reactivity toward oxidation processes which give sulfuric acid products that are capable of destroying the asphalt mixture. The study involved the conversion of elemental sulfur to a more stable modified one using a combination of byproducts of olefin hydrocarbons that were obtained from petroleum fractional distillates and cyclic hydrocarbon bituminous residue at 145 °C. The changes in the structural characteristics and morphology of prepared modified sulfur were studied using XRD and SEM respectively. Also DSC curves help us to elucidate the changes in sulfur phases from α-orthorhombic to β-mono clinic structure. The technique of nanoindentation helps us to compare the mechanical properties of modified and pure sulfur including modulus of elasticity and hardness. The hot mixture asphalt designs were prepared according to the Marshall Method in which the asphalt binder content was partially substituted with 20%, 30%, 40%, and 50% modified sulfur. The mechanical properties were measured including Marshall Stability, flow, air voids, and Marshall Stiffness. From the overall study, the results indicated that asphalt could partially be substituted with modified sulfur with no significant deleterious effect on performance and durability of hot mixed asphalt.

Effect of shear span, concrete strength and strrup spacing on behavior of pre-stressed concrete beams

International Nuclear Information System (INIS)

Ahmad, S.; Bukhari, I.A.

2007-01-01

The shear strength of pre-stressed concrete beams is one of the most important factors to be considered in their design. The available data on shear behavior of pre-tensioned prestressed concrete beams is very limited. In this experimental study, pre-tensioned prestressed concrete I-beams are fabricated with normal and high- strength concretes, varying stirrup spacing and shear span-to-depth ratios. 1Wenty one I-beam specimens that are 300 mm deep and 3745-4960mm long are tested up to failure while deflections, cracking pattern, cracking and failure loads were recorded. The research results are compared with ACI 318-02 and Structure Analysis Program, Response 2000. It was observed that with the decrease in concrete strength, failure mode of prestressed concrete beams changes from flexure shear to web shear cracking for values of shear span-to-depth ratio less than 4.75. Increase in stirrup spacing decreased the effectiveness of stirrups in transmitting shear across crack as a result of which failure mode is changed to web shear cracking especially for beams with lower values of shear span-to-depth ratios. ACI code underestimates the shear carrying capacity of prestressed concrete beams with lower values of shear span- to-depth ratios. Response 2000 can be used more effectively in predicting shear behavior of normal strength prestressed concrete beams. (author)

Influence of Diatomite and Mineral Powder on Thermal Oxidative Ageing Properties of Asphalt

Directory of Open Access Journals (Sweden)

Yongchun Cheng

2015-01-01

Full Text Available Ageing of asphalt affects the performances of asphalt pavement significantly. Therefore, effects of diatomite and mineral powder on ageing properties of asphalt were investigated systematically in order to improve the antiageing property of mixture. Thin film oven test (TFOT was used to conduct the short term ageing in laboratory. Softening points, penetrations, force ductility, low temperature creep properties, and viscosities of asphalt mastics were tested before and after TFOT, respectively. Results indicated that percent retained penetration (PRP increased with the increasing of fillers. Increment of softening point (ΔT, ductility retention rate (DRR, deformation energy ageing index (JAI, and viscosity ageing index (VAI of asphalt mastics nonlinearly decreased with the increasing of fillers. Ageing of asphalt was reduced by diatomite and mineral powder. And the antiageing effect of diatomite was better than that of mineral powder as a result of its porous structure. It is suggested that the mineral powder could be reasonably replaced by diatomite in order to reduce thermal oxidative ageing of asphalt mixture. The optimal content of diatomite 12.8% is also suggested for engineering.

Role of urban surface roughness in road-deposited sediment build-up and wash-off

Science.gov (United States)

Zhao, Hongtao; Jiang, Qian; Xie, Wenxia; Li, Xuyong; Yin, Chengqing