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Sample records for concrete masonry construction

  1. 75 FR 60480 - Concrete and Masonry Construction; Extension of the Office of Management and Budget's (OMB...

    Science.gov (United States)

    2010-09-30

    ... Occupational Safety and Health Administration Concrete and Masonry Construction; Extension of the Office of...) approval of the information collection requirements specified in the Standard on Concrete and Masonry...., compressors, mixers, screens or pumps used for concrete and masonry construction) specified by paragraphs 1926...

  2. Statics of historic masonry constructions

    CERN Document Server

    Como, Mario

    2016-01-01

    This successful book, which is now appearing in its second edition, presents a comprehensive new Statics of Masonry Constructions. Masonry constructions are the great majority of the buildings in Europe’s historic centres and the most important monuments in its architectural heritage. Given the age of these constructions, the demand for safety assessments and restoration projects is pressing and constant. The book you hold in hands contributes to fill this demand. The second edition integrates the original text of the first edition with new developments, widening and revisions, due to recent research studies achievements. The result is a book that gives a complete picture of the behaviour of the Masonry Constructions. First of all, it gives the fundamentals of its Statics, based on the no-tension assumption, and then it develops the Limit Analysis for the Masonry Constructions. In this framework, through an interdisciplinary approach combining Engineering and Architecture, the book also investigates the sta...

  3. Statics of Historic Masonry Constructions

    CERN Document Server

    Como, Mario

    2013-01-01

    Masonry constructions are the great majority of the buildings in Europe’s historic centres and the most important monuments in its architectural heritage. Given the age of much of these constructions, the demand for safety assessments and restoration projects is pressing and constant. This book aims to help fill this demand presenting a comprehensive new statics of masonry constructions. The book, result of thirty years of research and professional experience, gives the fundamentals of statics of the masonry solid, then applied to the study of statics of arches, piers and vaults. Further, combining engineering and architecture and through an interdisciplinary approach, the book investigates the statical behaviour of many historic monuments, as the Pantheon, the Colosseum,  the domes of S. Maria del Fiore in Florence and of St. Peter in Rome, the Tower of Pisa, the Gothic Cathedrals and the Masonry Buildings under seismic actions.

  4. Statics of historic masonry constructions

    CERN Document Server

    Como, Mario

    2017-01-01

    Masonry constructions are the great majority of the buildings in Europe’s historic centres and the most important monuments of its architectural heritage. Given the age of these constructions, the demand for safety assessments and restoration projects is pressing and constant; still within the broad studies in the subject it is not yet recognised, in particular within the seismic area, a unitary approach to deal with Masonry structures. This successful book contributes to clarify the issues with a rigorous approach offering a comprehensive new Statics of Masonry Constructions. This third edition has been driven by some recent developments of the research in the field, and it gives the fundamentals of Statics with an original and rigorous mathematical formulation, further in-depth inquired in this new version. With many refinements and improvements, the book investigates the static behaviour of many historic monuments, such as the Gothic Cathedrals, the Mycenaean Tholoi, the Pantheon, the Colosseum, the dome...

  5. Assessment of Historic Concrete and Masonry by Broadband Vibration Testing

    Science.gov (United States)

    2010-08-01

    reinforcement Voids Reinforcement corrosion 3 Beams: Voids Areas of segregation (in concrete placed without proper controls, the cement paste...of bond between wythes cracking environmental deterioration of masonry units. Brick masonry ( veneer ): Most problems visible to inspection

  6. Masonry constructions mechanical models and numerical applications

    CERN Document Server

    Lucchesi, Massimiliano; Padovani, Cristina

    2008-01-01

    Numerical methods for the structural analysis of masonry constructions can be of great value in assessing the safety of artistically important masonry buildings and optimizing potential operations of maintenance and strengthening in terms of their cost-effectiveness, architectural impact and static effectiveness. This monograph firstly provides a detailed description of the constitutive equation of masonry-like materials, clearly setting out its most important features. It then goes on to provide a numerical procedure to solve the equilibrium problem of masonry solids. A large portion of the w

  7. Engineered cementitious composites for strengthening masonry infilled reinforced concrete frames

    DEFF Research Database (Denmark)

    Dehghani, Ayoub; Nateghi-Alahi, Fariborz; Fischer, Gregor

    2015-01-01

    The results of the second part of a comprehensive experimental program, aimed at investigating the behavior of masonry infilled reinforced concrete (RC) frames strengthened with fiber reinforced engineered cementitious composites (ECC) used as an overlay on the masonry wall, are presented in this...... and energy absorption capacity of the infilled frame, prevent brittle failure modes in the infill wall, and provide a reasonable system overstrength....

  8. Experimental evaluation of the prevention methods for the interface between masonry infill walls and concrete columns

    Directory of Open Access Journals (Sweden)

    A. P. Tramontin

    Full Text Available Cracks that form at the interfaces between masonry structures are common uncontrolled occurrences in buildings. Numerous methods have been proposed by the construction industry to address this problem. Cracks continuously form in the joints between concrete columns and masonry infill walls. In this study, the most common methods for preventing these types of cracks were evaluated in laboratory experiments. Column masonry models were constructed using different types of joints between concrete columns and masonry infill walls, such as steel bars and steel mesh. The efficiency of each type of joint method was evaluated by performing direct tensile tests (pullout tests on the models and monitoring the evolution of the crack opening in the joint between the column and wall, as a function of load applied to the model. The results from this study indicate that the model composed of "electrowelded wire mesh without steel angles" is the best model for controlling cracking in the joints between concrete columns and masonry infill walls.

  9. Cement treated recycled crushed concrete and masonry aggregates for pavements

    NARCIS (Netherlands)

    Xuan, D.X.

    2012-01-01

    This research is focusing on the characterization of the mechanical and deformation properties of cement treated mixtures made of recycled concrete and masonry aggregates (CTMiGr) in relation to their mixture variables. An extensive laboratory investigation was carried out, in which the mechanical p

  10. Resistance of Membrane Retrofit Concrete Masonry Walls to Lateral Pressure

    Science.gov (United States)

    2008-04-01

    determined to be as effective as steel jackets in improving deformation capacity levels of columns subjected to seismic loading. Experimental testing of...for seismic loading were later investigated for their use in strengthening concrete masonry structures against blast. For instance, column- jacketing ... Seismic Investigations ...............................................................................................................6 2.2 Blast Load

  11. Fire behaviour of EPS ETICS on concrete or masonry facades

    Directory of Open Access Journals (Sweden)

    Afipeb

    2016-01-01

    Full Text Available In France, fire safety of facades for establishments open to the public has been governed by the Technical Instruction n∘249 since 1982; its current version was made regulatory on May 24th, 2010. Considering this revision, the Ministry of Interior requested industrials firms to revalidate the fire behaviour of their external insulation systems through testing. AFIPEB, SIPEV and SNMI decided therefore to launch a test campaign. After a preliminary analysis of Single Burning Item (SBI data related to EPS ETICS and some full-scale orientation tests, the polyvalent, representative and reliable LEPIR 2 test protocol was implemented. Three EPS ETICS configurations under various renders were tested: one under thick hydraulic renders, another under thin mixed renders and a third under thin organic renders. These tests were successful. For the first 30 minutes of each test: there was no ignition nor vertical spread of fire to the facade at its second level, there was also no lateral spread of fire along the facade width. Moreover, after 60 minutes, the outer skin above the horizontal line at 5.2 m was not damaged. The campaign confirms that EPS ETICS under thin, thick or mixed renders perfectly comply with fire safety regulations. AFIPEB, SIPEV and SNMI wrote a recommendation guide based on approved laboratories assessment. It describes construction solutions limiting fire propagation on a concrete or masonry facade insulated by EPS ETICS. This guide currently supplements IT 249 (2010.

  12. Damage detection of concrete masonry structures by enhancing deformation measurement using DIC

    Science.gov (United States)

    Bolhassani, Mohammad; Rajaram, Satish; Hamid, Ahmad A.; Kontsos, Antonios; Bartoli, Ivan

    2016-04-01

    This study focuses on deformability and damage detection of a concrete masonry wall. It employed point-to-point traditional strain gages and full-field measurement technique using digital image correlation (DIC) to investigate the damage and deformability of a partially grouted (PG) reinforced masonry wall. A set of ungrouted and grouted assemblages and full-scale concrete masonry shear wall were constructed and tested under displacement control loading. The wall was constructed according with masonry standards joint committee (MSJC 2013) and tested under constant vertical compression load and horizontal lateral load using quasi-static displacement procedure. The DIC method was used to determine non-uniform strain contours on the assemblages. This method was verified by comparing strains along the selected directions with traditional TML gage results. After a successful comparison, the method was used to investigate the state of damage and deformability of the wall specimen. Panel deformation, crack pattern, displacement at the top, and the base strain of the wall were captured using full-field measurement and results were in a good agreement with traditional strain gages. It is concluded that full-filed measurements using DIC is promising especially when the test specimens experience inelastic deformation and high degree of damage. The ability to characterize and anticipate failure mechanisms of concrete masonry systems by depicting strain distribution, categorizing structural cracks and investigating their effects on the behavior of the wall were also shown using DIC. In addition to monitoring strains across the gage length, the DIC method provided full-field strain behavior of the test specimens and revealed strain hotspots at locations that corresponded to failure.

  13. Experimental study on the compressive strength of grouted concrete block masonry based on nondestructive detection methods

    Institute of Scientific and Technical Information of China (English)

    JIANG Hong-bin; LI Long-fei

    2009-01-01

    Existing nondestructive detection methods were adopted to test the compressive strength of grouted concrete block masonry, i.e. the rebound method, pulling-out method and core drilling method were employed to test the strength of block, mortar and grouted concrete, respectively. The suitability of these methods for the testing of strength of grouted concrete block masonry was discussed, and the comprehensive strength of block masonry was appraised by combining existing nondestructive or micro-destructive detection methods. The nondestructive detection test on 25 grouted concrete block masonry specimens was carried out. Experimental results show that these methods mentioned above are applicable for the strength detection of grouted concrete block masonry. Moreover, the formulas of compressive strength, detection methods and proposals are given as well.

  14. Concrete construction engineering handbook

    CERN Document Server

    Nawy, Edward G

    2008-01-01

    Provides coverage of concrete construction engineering and technology. This work features discussions focusing on: the advances in engineered concrete materials; reinforced concrete construction; specialized construction techniques; and, design recommendations for high performance.

  15. The Construction Technique of Autoclaved Lightweight Concrete (NALC)Masonry Free Plastering%轻质蒸压加气混凝土(NALC)砌块免抹灰式施工技术

    Institute of Scientific and Technical Information of China (English)

    孙国芳

    2011-01-01

    介绍了轻质蒸压加气混凝土(NALC)砌块的适用范围,论述了NALC砌块免抹灰施工的工艺流程及操作特点,质量标准及保证措施.%It introduces the applicable scope, and the process principle ot Autoclaved Lightweight Concrete( N ALC)Masonry.It tells the process and the operating characteristics of NALC Masonry Free Plastering, and the assurance measures.

  16. Blast Design of Reinforced Concrete and Masonry Components Retrofitted with FRP

    Science.gov (United States)

    2010-07-01

    ultimate flexural and shear resistance of the upgraded walls. The methodology for estimating the flexural resistance of concrete and masonry components...recommended value not including any environmental effects or debonding The FRP reinforcement is typically applied to a concrete or masonry wall...have enough tensile and shear strength to transfer the force and develop the strength of the bonded FRP reinforcement . The durability of the

  17. Experimental Study on a Self-Centering Earthquake-Resistant Masonry Pier with a Structural Concrete Column

    Directory of Open Access Journals (Sweden)

    Lijun Niu

    2017-01-01

    Full Text Available This paper proposes a slotting construction strategy to avoid shear behavior of multistory masonry buildings. The aspect ratio of masonry piers increases via slotting between spandrels and piers, so that the limit state of piers under an earthquake may be altered from shear to rocking. Rocking piers with a structural concrete column (SCC form a self-centering earthquake-resistant system. The in-plane lateral rocking behavior of masonry piers subjected to an axial force is predicted, and an experimental study is conducted on two full-scale masonry piers with an SCC, which consist of a slotting pier and an original pier. Meanwhile, a comparison of the rocking modes of masonry piers with an SCC and without an SCC was conducted in the paper. Experimental verification indicates that the slotting strategy achieves a change of failure modes from shear to rocking, and this resistant system with an SCC incorporates the self-centering and high energy dissipation properties. For the slotting pier, a lateral story drift ratio of 2.5% and a high displacement ductility of approximately 9.7 are obtained in the test, although the lateral strength decreased by 22.3% after slotting. The predicted lateral strength of the rocking pier with an SCC has a margin of error of 5.3%.

  18. Self healing phenomena in concretes and masonry mortars: A microscopic study

    NARCIS (Netherlands)

    Nijland, T.G.; Larbi, J.A.; Hees, R.P.J. van; Lubelli, B.A.; Rooij, M.R. de

    2007-01-01

    A microscopic survey of over 1000 of samples of concrete and masonry mortars from structures in the Netherlands shows that, in practice, self healing occurs in historic lime and lime – puzzolana mortars, in contrast to modern cement bound concretes and mortars. Self healing may be effected by the fo

  19. Self healing phenomena in concretes and masonry mortars: A microscopic study

    NARCIS (Netherlands)

    Nijland, T.G.; Larbi, J.A.; Hees, R.P.J. van; Lubelli, B.A.; Rooij, M.R. de

    2007-01-01

    A microscopic survey of over 1000 of samples of concrete and masonry mortars from structures in the Netherlands shows that, in practice, self healing occurs in historic lime and lime – puzzolana mortars, in contrast to modern cement bound concretes and mortars. Self healing may be effected by the

  20. The use of polyurethane foam to provide a watertight concrete masonry wall and a sealed connection of the wall to the foundation

    Energy Technology Data Exchange (ETDEWEB)

    Janopaul, P. Jr.

    1999-07-01

    This paper outlines a construction procedure used to insure a watertight masonry wall and a sealed connection, of this same wall, to the foundation. This procedure was discovered as the byproduct of using an insulted dual cavity concrete masonry unit that is foamed in the field. This insulated concrete masonry system has been developed in the past 12 years, and has been utilized in almost 100 buildings (in Arizona, California, Nevada, Oregon, and Utah) with climates that range from hot desert to Sierra Nevada snow country to the Pacific Northwest rainfall. The critical elements in perfecting this procedure are the detailing of the base of the wall, with a continuous exterior first course foam side cleanout, then following this detailing in the field construction of the wall, and properly foaming the constructed wall with polyurethane foam. The polyurethane foam must be poured into the foam cavity after the face shells have been replace at the first course cleanout.

  1. Thermal performance of concrete masonry unit wall systems

    Energy Technology Data Exchange (ETDEWEB)

    Kosny, J.

    1995-12-31

    New materials, modern building wall technologies now available in the building marketplace, and unique, more accurate, methods of thermal analysis of wall systems create an opportunity to design and erect buildings where thermal envelopes that use masonry wall systems can be more efficient. Thermal performance of the six masonry wall systems is analyzed. Most existing masonry systems are modifications of technologies presented in this paper. Finite difference two-dimensional and three-dimensional computer modeling and unique methods of the clear wall and overall thermal analysis were used. In the design of thermally efficient masonry wall systems is t to know how effectively the insulation material is used and how the insulation shape and its location affect the wall thermal performance. Due to the incorrect shape of the insulation or structural components, hidden thermal shorts cause additional heat losses. In this study, the thermal analysis of the clear wall was enriched with the examination of the thermal properties of the wall details and the study of a quantity defined herein the Thermal Efficiency of the insulation material.

  2. THE EVOLUTION OF THE DESIGN AND CONSTRUCTION OF MASONRY BUILDINGS IN THE UNITED STATES

    Directory of Open Access Journals (Sweden)

    Richard E. Klingner

    2012-12-01

    Full Text Available In this paper, the process used to develop building codes in the United States of America (USA is summarized, with emphasis on masonry. Masonry materials used in the USA are discussed. Types of masonry construction in the USA are reviewed, addressing historical as well as modern masonry. Current non-structural and structural applications of masonry in the USA are reviewed. Historical development of masonry codes in the USA is summarized, with emphasis on the current Masonry Standards Joint Committee (MSJC Code and Specification. Future trends in that document are predicted. The paper closes with a list of challenges to the masonry industry, and a list of focused research topics intended to meet those challenges.

  3. A Study of Potential Load Bearing Masonry (LBM System in Malaysia Construction Industry

    Directory of Open Access Journals (Sweden)

    Ramli N.A.

    2014-01-01

    Full Text Available To overcome the problems in increasing of material prices, land prices, shortage of skilled workers, equipping low cost housing demands and maintained the cost of the constructing at an affordable price, there is a need to find the alternative solution for constructing method. The use of the load bearing masonry system (LBM has been identified as a sustainable and an effective alternative method for the construction industry. The system offers several advantages in term of cost and speed of the construction, durability, strength, environmentally friendly practices and aesthetic qualities. Despite these advantages, unfortunately, this system has not been widely used in Malaysia compared to reinforced concrete (RC frame construction. Therefore, this paper aims to discuss the advantages and potential of the system implementation to Malaysia construction industry in the future.

  4. Image-based method for monitoring of crack opening on masonry and concrete using Mobile Platform

    Directory of Open Access Journals (Sweden)

    A. P. Martins

    Full Text Available This paper proposes an automatic method based on the computing vision, implemented in a mobile platform, to inspect cracks in masonry and concrete. The developed algorithm for image processing performs this task from images of the cracks evolution. The contribution of this paper is the development of a mobile tool with quick response aiming to assist technicians in periodic visits when monitoring the crack opening in masonry and concrete. The obtained results show, successfully, the dimensional alterations of cracks detected by mobile phone in a faster and accurate way compared with the conventional measurement technique. Regardless the irregular shape of the cracks, the proposed method has the advantage of producing results statistically significant in measurement repetition by decreasing the subjectivity inherent to manual measurement technique.

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

    Directory of Open Access Journals (Sweden)

    Ece Erdogmus

    2015-02-01

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

  6. Nonlinear Modeling of Autoclaved Aerated Concrete Masonry Wall Strengthened using Ferrocement Sandwich Structure

    KAUST Repository

    M., Abdel-Mooty

    2011-01-01

    Autoclaved Aerated Concrete (AAC) block are used mainly as non-load-bearing walls that provide heat insulation. This results in considerable saving in cooling energy particularly in hot desert environment with large variation of daily and seasonal temperatures. However, due to the relatively low strength there use load bearing walls is limited to single storey and low-rise construction. A system to enhance the strength of the AAC masonry wall in resisting both inplane vertical and combined vertical and lateral loads using ferrocement technology is proposed in this research. The proposed system significantly enhances the load carrying capacity and stiffness of the AAC wall without affecting its insulation characteristics. Ferrocement is made of cement mortar reinforced with closely spaced wire mesh. Full scale wall specimens with height of 2100mm and width of 1820mm were tested with different configuration of ferrocement. A finite elementmodel is developed and verified against the experimentalwork. The results of the finite element model correlates well with the experimental results.

  7. THE EVOLUTION OF THE DESIGN AND CONSTRUCTION OF MASONRY BUILDINGS IN BRAZIL

    Directory of Open Access Journals (Sweden)

    Márcio R. S. Corrêa

    2012-12-01

    Full Text Available This paper presents an overview of the use of masonry in Brazil. Some historical remarks are presented showing how masonry was introduced and has been developed in the country. A brief on the Brazilian Universities is also reviewed, showing the extensive efforts made to improve the educational system and to insert Brazil into the international masonry research environment. Current materials are shown, focusing on the use of structural and non-structural masonry. The paper points out the development of Codes, considering the most important regulated characteristics of masonry in order to be used in Brazilian constructions. The building situation is addressed, stressing the large housing demands and how the masonry industry can help to partly solve the problem. Finally, present and future challenges are discussed, showing Brazil’s constructions needs, as an emerging country.

  8. Determination of shear parameters of concrete filled head-straight masonry brick walls

    Directory of Open Access Journals (Sweden)

    Reza Amiraslanzadeh

    2015-03-01

    Full Text Available The aim of present study was determination of shear parameters of reinforced and unreinforced masonry brick walls assembled with Head-straight texture order. Experimental tests carried out on triplets in order to define shear parameters of brick mortar interface, and diagonal compression test in order to define shear strength of masonry panels. According to various interpretations on evaluation of shear strength using diagonal compression test, comparison between mentioned values and those obtained by laboratory tests on shear triplets are presented. The results showed that, although the generated internal columns have not been tied together on top and bottom sides, they contributed to a significant improvement on shear resistance of the masonry panels. Referring to the interpretations on test outcomes, it was perceived that the formula which was obtained by adopting the Turnašek- Cacovic criterion is the most suitable and reliable one. It was concluded that filling the voids of Head-straight texture masonry walls using steel fiber concrete, significantly increase these walls shear parameters.

  9. Innovative Retrofit Insulation Strategies for Concrete Masonry Foundations

    Energy Technology Data Exchange (ETDEWEB)

    Huelman, P. [NorthernSTAR, St. Paul, MN (United States); Goldberg, L. [NorthernSTAR, St. Paul, MN (United States); Jacobson, R. [NorthernSTAR, St. Paul, MN (United States)

    2015-05-01

    Basements in climates 6 and 7 can account for a fraction of a home's total heat loss when fully conditioned. Such foundations are a source of moisture, with convection in open block cavities redistributing water from the wall base, usually when heating. Even when block cavities are capped, the cold foundation concrete can act as a moisture source for wood rim joist components that are in contact with it. Because below-grade basements are increasingly used for habitable space, cold foundation walls pose challenges for moisture contribution, energy use, and occupant comfort.

  10. Lightweight concrete masonry units based on processed granulate of corn cob as aggregate

    Directory of Open Access Journals (Sweden)

    Faustino, J.

    2015-06-01

    Full Text Available A research work was performed in order to assess the potential application of processed granulate of corn cob (PCC as an alternative lightweight aggregate for the manufacturing process of lightweight concrete masonry units (CMU. Therefore, CMU-PCC were prepared in a factory using a typical lightweight concrete mixture for non-structural purposes. Additionally, lightweight concrete masonry units based on a currently applied lightweight aggregate such as expanded clay (CMU-EC were also manufactured. An experimental work allowed achieving a set of results that suggest that the proposed building product presents interesting material properties within the masonry wall context. Therefore, this unit is promising for both interior and exterior applications. This conclusion is even more relevant considering that corn cob is an agricultural waste product.En este trabajo de investigación se evaluó la posible aplicación de granulado procesado de la mazorca de maiz como un árido ligero alternativo en el proceso de fabricación de unidades de mampostería de hormigón ligero. Con esta finalidad, se prepararon en una fábrica diversas unidades de mampostería no estructural con granulado procesado de la mazorca de maiz. Además, se fabricaran unidades de mampostería estándar de peso ligero basado en agregados de arcilla expandida. Este trabajo experimental permitió lograr un conjunto de resultados que sugieren que el producto de construcción propuesto presenta interesantes propiedades materiales en el contexto de la pared de mampostería. Por lo tanto, esta solución es prometedora tanto para aplicaciones interiores y exteriores. Esta conclusión es aún más relevante teniendo en cuenta que la mazorca de maíz es un producto de desecho agrícola.

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

    OpenAIRE

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

    2010-01-01

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

  12. In-Plane Behaviour of a Reinforcement Concrete Frame with a Dry Stack Masonry Panel

    Directory of Open Access Journals (Sweden)

    Kun Lin

    2016-02-01

    Full Text Available In order to improve the energy dissipation of the masonry infilled frame structure while decreasing the stiffening and strengthening effects of the infill panels, a new dry stacked panel (DSP semi-interlocking masonry (SIM infill panel has been developed. In this paper, the material properties of DSP and a traditional unreinforced masonry (URM panel have been evaluated experimentally. A series of cyclic tests were performed to investigate the cyclic behaviour of the reinforcement concrete (RC frame with different infill panels. The failure modes, damage evolution, hysteretic behaviour, stiffness degradation and energy dissipation were compared and analysed. We concluded that DSP is capable of significantly improving the seismic energy dissipation due to its hysteretic behaviour when the frame is in elastic stage without increasing the stiffness of the frame. Therefore, DSP or SIM panels can be considered as frictional dampers. Based on the experimental results, the influence of DSP was examined. Using the parallel model, the hysteretic loops of DSP subjected to different load cases were achieved. The typical full hysteretic loop for DSP could be divided into three distinct stages of behaviour: packing stage, constant friction stage and equivalent strut stage. The connection between the panel and the frame had a great effect on the transferring of different mechanical stages. The constant friction stage was verified to provide substantial energy dissipation and benefits to the ductility of the structure, which, therefore, is suggested to be prolonged in reality.

  13. Analytical Predictions of Fragment Penetration through Hollow Concrete Masonry Units

    Directory of Open Access Journals (Sweden)

    David Bogosian

    2008-01-01

    Full Text Available Modeling steel casing fragment impacts on hollow CMU poses some problems, since the fragments will typically penetrate through the front face and may also penetrate the back face. Techniques are needed for predicting (a the size of the hole created by the penetration, (b the size of the annular region of damaged concrete around the hole, and (c the residual velocity of the fragment. A series of calculations using the AUTODYN code were performed to investigate the accuracy and reliability of the model. The model uses the smooth particle hydrodynamics (SPH approach to represent the CMU. A variety of steel fragment sizes were projected at a layer of CMU, and the resulting hole size, damage, and fragment residual velocity were tabulated. Results were validated against existing empirical relationships to insure the model's applicability, while additional analyses demonstrated trends and parametric sensitivity.

  14. Innovative Retrofit Insulation Strategies for Concrete Masonry Foundations

    Energy Technology Data Exchange (ETDEWEB)

    Huelman, P. [Univ. of Minnesota, St. Paul, MN (United States). NorthernSTAR Building America Partnership; Goldberg, L. [Univ. of Minnesota, St. Paul, MN (United States). NorthernSTAR Building America Partnership; Jacobson, R. [Univ. of Minnesota, St. Paul, MN (United States). NorthernSTAR Building America Partnership

    2015-05-06

    This study was designed to test a new approach for foundation insulation retrofits, with the goal of demonstrating improved moisture control, improved occupant comfort, and reduced heat loss. Because conducting experimental research on existing below-grade assemblies is very difficult, most of the results are based on simulations. The retrofit approach consists of filling open concrete block cores with an insulating material and adding R-10 exterior insulation that extends 1 ft below grade. The core fill is designed to improve the R-value of the foundation wall and increase the interior wall surface temperature, but more importantly to block convection currents that could otherwise increase moisture loads on the foundation wall and interior space. The exterior insulation significantly reduces heat loss through the most exposed part of the foundation and further increases the interior wall surface temperature. This improves occupant comfort and decreases the risk of condensation. Such an insulation package avoids the full-depth excavation necessary for exterior insulation retrofits, reduces costs, and eliminates the moisture and indoor air quality risks associated with interior insulation retrofits. Retrofit costs for the proposed approach were estimated at roughly half those of a full-depth exterior insulation retrofit.

  15. A proposal for the maximum use of recycled concrete sand in masonry mortar design

    Directory of Open Access Journals (Sweden)

    Fernández-Ledesma, E.

    2016-03-01

    Full Text Available Natural sand mining from rivers and seashores is causing serious environmental problems in many parts of the world, whereas the fine fraction from recycling concrete waste is underutilized as a construction material. The aim of this paper is to determine the maximum replacement level of natural sand by recycled sand in the manufacturing of masonry mortar (M-10. For this purpose, five replacement levels were tested: 0%, 25%, 50%, 75% and 100% by volume. The mixes were made using cement CEM II/BL 32.5 N in a volumetric proportion of cement-to-aggregate of 1:5. A commercial admixture was used at a constant content. The amount of water was variable to achieve a consistency of 175±10 mm. The short- and long-term mortar properties were evaluated. The data were analyzed using a one-way ANOVA. In conclusion, a maximum percentage of 50% recycled concrete sand can be used in an indoor environment.La extracción de arena natural de ríos y costas está provocando graves problemas ambientales en muchas partes del mundo, mientras que la fracción fina de los áridos reciclados de residuos de hormigón está infrautilizada como material de construcción. El objetivo de este artículo es determinar el máximo porcentaje de sustitución de arena natural por arena reciclada en la fabricación de morteros M-10. Cinco niveles de sustitución en volumen fueron ensayados: 0%, 25%, 50%, 75% y 100%. Las mezclas fueron hechas con cemento CEM II/BL 32,5 N en una relación volumétrica cemento-árido de 1:5. Se utilizó un aditivo comercial a dosis constante. El agua se ajustó experimentalmente para conseguir una consistencia de 175±10 mm. Se evaluaron las propiedades de los morteros a corto y largo plazo. Los datos se analizaron mediante una ANOVA-simple. En conclusión, un porcentaje máximo del 50% de arena reciclada de hormigón puede usarse en interiores.

  16. Hybrid Reinforced Concrete Frame Building with Pumice Brick Masonry Infill under Static Lateral Loading

    Directory of Open Access Journals (Sweden)

    Akmaluddin

    2012-08-01

    Full Text Available The purpose of this study is to investigate the behaviour of hybrid reinforced concrete frame with pumice brick masonry infill under static lateral loading. The term hybrid herein is referred to the frame composed of precast block masonry unit and cast in-place reinforced concrete beams. Parameters considered in this study were frame opening representing doors and windows commonly used in the wall system. Six types of frame namely FS, FB, FDE, FDC, FWE and FWC designation for solid frame, bare frame, frame with door opening at edge, frame with door opening at centre, frame with window opening at edge and frame with window opening at centre respectively were considered. Test results indicated that the FS has a maximum lateral strength greater than that of FB. The lateral strength of FS was about 3.68 of FB. The frames with various openings have lateral strength nearly 2.3 of lateral strength of the bare frame, FB. Ductility factor of the frames varied from 2.4 to 4.92. The residual strength of the frame with openings were varies between 2.33 and 3.35 of the bare frame. The stiffness of the infilled frames with opening were varied from 3.56 to 3.67 of the bare frame. The presence of openings in the infilled frame did not affect the frame stiffness considerably.

  17. Preparation and characterization of masonry units, lightweight concrete based and agro-industrial wastes: a review

    Science.gov (United States)

    Díaz-Fuentes, C. X.

    2013-11-01

    Discussion about the new composite materials that integrate agro industrial residues for the masonry unit's production, which are directed towards its implementation in projects of affordable housing, is a subject of interest to the public and productive sector of the country. For this reason, it presents a descriptive review of primary and secondary sources, which support the project under study. The methodology consisted in finding research articles in databases supported by the scientific community, which are ordered, integrated and prioritized, creating a matrix synthesis, which condensed the objectives, type of material, studied properties and main results found. It was found that the composite materials for masonry use mainly clay or cement as matrix and as reinforcement, agro waste like paper fibers, bamboo, rice husks, among others are used. Moreover, the properties that determine its potential use are low density, stress resistance and low thermal conductivity. Comparing the results with traditional specimens as the block of clay, concrete, adobe vs. experimental models made of the compounds analyzed, favorable results were obtained in the case of integrating waste materials into its composition, optimized their properties. Thus, science and architecture converge through recognition of the properties of materials that expand the alternatives of building spaces, economic and environmentally sustainable.

  18. Axial compression behavior of concrete masonry wallettes strengthened with cement mortar overlays

    Directory of Open Access Journals (Sweden)

    F. L. De Oliveira

    Full Text Available This paper presents the results of a series of axial compression tests on concrete block wallettes coated with cement mortar overlays. Different types of mortars and combinations with steel welded meshes and fibers were tested. The experimental results were discussed based on different theoretical approaches: analytical and Finite Element Method models. The main conclusions are: a the application of mortar overlays increases the wall strength, but not in a uniform manner; b the strengthening efficiency of wallettes loaded in axial compression is not proportional to the overlay mortar strength because it can be affected by the failure mechanisms of the wall; c steel mesh reinforced overlays in combination with high strength mortar show better efficiency, because the steel mesh mitigates the damage effects in the block wall and in the overlays themselves; d simplified theoretical methods of analysis as described in this paper can give satisfactory predictions of masonry wall behavior up to a certain level.

  19. Anchorage in concrete construction

    CERN Document Server

    Eligehausen, Rolf; Silva, John F

    2013-01-01

    A comprehensive treatment of current fastening technology using inserts (anchor channels, headed stud), anchors (metal expansion anchor, undercut anchor, bonded anchor, concrete screw and plastic anchor) as well as power actuated fasteners in concrete. It describes in detail the fastening elements as well as their effects and load-bearing capacities in cracked and non-cracked concrete. It further focuses on corrosion behaviour, fire resistance and characteristics with earthquakes and shocks. It finishes off with the design of fastenings according to the European Technical Approval Guideline (ETAG 001), the Final Draft of the CEN Technical Specification 'Design of fastenings for use in concrete' and the American Standards ACI 318-05, Appendix D and ACI 349-01, Appendix B.

  20. Coda Wave Interferometry Method Applied in Structural Monitoring to Assess Damage Evolution in Masonry and Concrete Structures

    Science.gov (United States)

    Masera, D.; Bocca, P.; Grazzini, A.

    2011-07-01

    In this experimental program the main goal is to monitor the damage evolution in masonry and concrete structures by Acoustic Emission (AE) signal analysis applying a well-know seismic method. For this reason the concept of the coda wave interferometry is applied to AE signal recorded during the tests. Acoustic Emission (AE) are very effective non-destructive techniques applied to identify micro and macro-defects and their temporal evolution in several materials. This technique permits to estimate the velocity of ultrasound waves propagation and the amount of energy released during fracture propagation to obtain information on the criticality of the ongoing process. By means of AE monitoring, an experimental analysis on a set of reinforced masonry walls under variable amplitude loading and strengthening reinforced concrete (RC) beams under monotonic static load has been carried out. In the reinforced masonry wall, cyclic fatigue stress has been applied to accelerate the static creep and to forecast the corresponding creep behaviour of masonry under static long-time loading. During the tests, the evaluation of fracture growth is monitored by coda wave interferometry which represents a novel approach in structural monitoring based on AE relative change velocity of coda signal. In general, the sensitivity of coda waves has been used to estimate velocity changes in fault zones, in volcanoes, in a mining environment, and in ultrasound experiments. This method uses multiple scattered waves, which travelled through the material along numerous paths, to infer tiny temporal changes in the wave velocity. The applied method has the potential to be used as a "damage-gauge" for monitoring velocity changes as a sign of damage evolution into masonry and concrete structures.

  1. Materials development and field demonstration of high-recycled-content concrete for energy-efficient building construction

    Energy Technology Data Exchange (ETDEWEB)

    Ostowari, Ken; Nosson, Ali

    2000-09-30

    The project developed high-recycled-content concrete material with balanced structural and thermal attributes for use in energy-efficient building construction. Recycled plastics, tire, wool, steel and concrete were used as replacement for coarse aggregates in concrete and masonry production. With recycled materials the specific heat and thermal conductivity of concrete could be tailored to enhance the energy-efficiency of concrete buildings. A comprehensive field project was implemented which confirmed the benefits of high-recycled-content concrete for energy-efficient building construction.

  2. Design and performance of masonry mortars made with recycled concrete aggregates

    Directory of Open Access Journals (Sweden)

    Frías, M.

    2009-07-01

    Full Text Available The present paper discusses the technical feasibility ofusing the fine fraction of recycled aggregate fromconcrete rubble to manufacture cement mortar andpossible conditions.An initial study of the chemical and physical-mechanicalcharacteristics of fines recycled from selected concreteshowed that their high absorptivity and high sulfatecontent compared to natural limestone sands were thelimiting factors to their in masonry mortars.As in the caseof structural concrete, a blend of recycled and naturalaggregate would appear to be suitable for masonrymortars.A study of the mix proportions and characteristics ofmortars made with recycled concrete aggregate showedthat up to 25% recycled aggregate can be used incement-based masonry mortars with no significant declinein performance and no new admixtures or higher cementcontent requires.El presente trabajo presenta y discute las condiciones de viabilidad técnica para la utilización de la fracción fina de áridos reciclados, procedentes de escombro de hormigón, en la fabricación de morteros de albañilería utilizando cemento como conglomerante.Inicialmente, se estudian las características químicas y físico- mecánicas de los áridos reciclados finos procedentes de hormigón seleccionado. Se concluye que las características limitantes del árido reciclado para su uso en morteros de albañilería resultan ser la alta absorción y el elevado contenido en sulfatos, en comparación con las arenas naturales de naturaleza caliza. De forma análoga a lo recomendado en el hormigón estructural, se apunta hacia la utilización de mezclas de áridos reciclados y naturales en la fabricación de morteros de albañilería.Del estudio de dosificaciones y caracterización de morteros, elaborados con áridos reciclados de hormigón, se establece que los morteros de albañilería base cemento pueden incorporar un 25% como máximo de árido reciclado sin evidenciar pérdidas significativas de prestaciones. Y, no

  3. Laboratory evaluation to reduce respirable crystalline silica dust when cutting concrete roofing tiles using a masonry saw.

    Science.gov (United States)

    Carlo, Rebecca V; Sheehy, John; Feng, H Amy; Sieber, William K

    2010-04-01

    Respirable crystalline silica dust exposure in residential roofers is a recognized hazard resulting from cutting concrete roofing tiles. Roofers cutting tiles using masonry saws can be exposed to high concentrations of respirable dust. Silica exposures remain a serious threat for nearly two million U.S. construction workers. Although it is well established that respiratory diseases associated with exposure to silica dust are preventable, they continue to occur and cause disability or death. The effectiveness of both a commercially available local exhaust ventilation (LEV) system and a water suppression system in reducing silica dust was evaluated separately. The LEV system exhausted 0.24, 0.13, or 0.12 m(3)/sec of dust laden air, while the water suppression system supplied 0.13, 0.06, 0.03, or 0.02 L/sec of water to the saw blade. Using a randomized block design, implemented under laboratory conditions, the aforementioned conditions were evaluated independently on two types of concrete roofing tiles (s-shape and flat) using the same saw and blade. Each engineering control (LEV or water suppression) was replicated eight times, or four times for each type of tile. Analysis of variance was performed by comparing the mean airborne respirable dust concentrations generated during each run and engineering control treatment. The use of water controls and ventilation controls compared with the "no control" treatment resulted in a statistically significant (p capture velocity, additional weight of the saw with the LEV system, electricity connections, and cost of air handling unit.

  4. Mechanical Properties of Unreinforced Brick Masonry, Section1

    Energy Technology Data Exchange (ETDEWEB)

    Mosalam, K; Glascoe, L; Bernier, J

    2009-10-02

    Before the advent of concrete and steel, masonry helped build civilizations. From Egypt in Africa, Rome in Europe, Maya in the America to China in Asia, masonry was exploited to construct the most significant, magnificent and long lasting structures on the Earth. Looking at the Egyptian pyramids, Mayan temples, Roman coliseum and Chinese Great Wall, one cannot stop wondering about the significance and popularity that masonry has had through out history. Lourenco et al (1989) summed up the reasons for the popularity of masonry in the following, 'The most important characteristic of masonry construction is its simplicity. Laying pieces of stone or bricks on top of each other, either with or without cohesion via mortar, is a simple, though adequate, technique that has been successful ever since remote ages. Other important characteristics are the aesthetics, solidity, durability, low maintenance, versatility, sound absorption and fire protection' Despite these advantages, masonry is no longer preferred structural material in many parts of the developed world, especially in seismically active parts of the world. Partly, masonry and especially unreinforced masonry (URM) has mechanical properties such as strength and ductility inferior to those of reinforced concrete and steel. Moreover, masonry structures were traditionally built based on rules of thumb acquired over many years of practice and/or empirical data from testing. Accordingly, we do not have a rigorous and uniform method of analysis and design for masonry. Nevertheless, the world still possesses numerous historic and ordinary masonry structures, which require maintenance and strengthening to combat the assault of time and nature. Hence, it is important to study fundamental properties of masonry so that new masonry structures can be effectively designed and built, and the cost for servicing old structures and for building new ones will be less expensive.

  5. Experimental studies on behavior of fully grouted reinforced-concrete masonry shear walls

    Science.gov (United States)

    Zhao, Yan; Wang, Fenglai

    2015-12-01

    An experimental study is conducted on fully grouted reinforced masonry shear walls (RMSWs) made from concrete blocks with a new configuration. Ten RMSWs are tested under reversed cyclic lateral load to investigate the influence of different reinforcements and applied axial stress values on their seismic behavior. The results show that flexural strength increases with the applied axial stress, and shear strength dominated by diagonal cracking increases with both the amount of horizontal reinforcement and applied axial stress. Yield displacement, ductility, and energy dissipation capability can be improved substantially by increasing the amount of horizontal reinforcement. The critical parameters for the walls are derived from the experiment: displacement ductility values corresponding to 15% strength degradation of the walls reach up to 2.6 and 4.5 in the shear and flexure failure modes, respectively; stiffness values of flexure- and shear-dominated walls rapidly degrade to 17%-19% and 48%-57% of initial stiffness at 0.50 D max (displacement at peak load). The experiment suggests that RMSWs could be assigned a higher damping ratio (˜14%) for collapse prevention design and a lower damping value (˜7%) for a fully operational limit state or serviceability limit state.

  6. Resistance of Membrane Retrofit Concrete Masonry Walls to Lateral Pressure (POSTPRINT)

    Science.gov (United States)

    2008-04-01

    The earliest in-depth investigation of the arching action theory of unreinforced masonry walls was carried out by McDowell et al. (1956). It...Sevin, E. (1956), "Arching Action Theory of Masonry Walls", Journal of Structural Division, Proceedings ofASCE, ST 2, Paper 915, PP 1-18. Paulay

  7. A Study of Potential Load Bearing Masonry (LBM) System in Malaysia Construction Industry

    OpenAIRE

    2014-01-01

    To overcome the problems in increasing of material prices, land prices, shortage of skilled workers, equipping low cost housing demands and maintained the cost of the constructing at an affordable price, there is a need to find the alternative solution for constructing method. The use of the load bearing masonry system (LBM) has been identified as a sustainable and an effective alternative method for the construction industry. The system offers several advantages in term of cost and speed of ...

  8. Flood hazards and masonry constructions: a probabilistic framework for damage, risk and resilience at urban scale

    Science.gov (United States)

    Mebarki, A.; Valencia, N.; Salagnac, J. L.; Barroca, B.

    2012-05-01

    This paper deals with the failure risk of masonry constructions under the effect of floods. It is developed within a probabilistic framework, with loads and resistances considered as random variables. Two complementary approaches have been investigated for this purpose: - a global approach based on combined effects of several governing parameters with individual weighted contribution (material quality and geometry, presence and distance between columns, beams, openings, resistance of the soil and its slope. . .), - and a reliability method using the failure mechanism of masonry walls standing out-plane pressure. The evolution of the probability of failure of masonry constructions according to the flood water level is analysed. The analysis of different failure probability scenarios for masonry walls is conducted to calibrate the influence of each "vulnerability governing parameter" in the global approach that is widely used in risk assessment at the urban or regional scale. The global methodology is implemented in a GIS that provides the spatial distribution of damage risk for different flood scenarios. A real case is considered for the simulations, i.e. Cheffes sur Sarthe (France), for which the observed river discharge, the hydraulic load according to the Digital Terrain Model, and the structural resistance are considered as random variables. The damage probability values provided by both approaches are compared. Discussions are also developed about reduction and mitigation of the flood disaster at various scales (set of structures, city, region) as well as resilience.

  9. 75 FR 81663 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Concrete...

    Science.gov (United States)

    2010-12-28

    ...; Concrete and Masonry Construction Standard ACTION: Notice. SUMMARY: The Department of Labor (DOL) hereby... collection request (ICR) titled, ``Concrete and Masonry Construction Standard'' to the Office of Management... concrete formwork are required to post warning signs/barriers in accordance with 29 CFR 1926.701(c)(2) to...

  10. Uncertainty in Seismic Capacity of Masonry Buildings

    Directory of Open Access Journals (Sweden)

    Nicola Augenti

    2012-07-01

    Full Text Available Seismic assessment of masonry structures is plagued by both inherent randomness and model uncertainty. The former is referred to as aleatory uncertainty, the latter as epistemic uncertainty because it depends on the knowledge level. Pioneering studies on reinforced concrete buildings have revealed a significant influence of modeling parameters on seismic vulnerability. However, confidence in mechanical properties of existing masonry buildings is much lower than in the case of reinforcing steel and concrete. This paper is aimed at assessing whether and how uncertainty propagates from material properties to seismic capacity of an entire masonry structure. A typical two-story unreinforced masonry building is analyzed. Based on previous statistical characterization of mechanical properties of existing masonry types, the following random variables have been considered in this study: unit weight, uniaxial compressive strength, shear strength at zero confining stress, Young’s modulus, shear modulus, and available ductility in shear. Probability density functions were implemented to generate a significant number of realizations and static pushover analysis of the case-study building was performed for each vector of realizations, load combination and lateral load pattern. Analysis results show a large dispersion in displacement capacity and lower dispersion in spectral acceleration capacity. This can directly affect decision-making because both design and retrofit solutions depend on seismic capacity predictions. Therefore, engineering judgment should always be used when assessing structural safety of existing masonry constructions against design earthquakes, based on a series of seismic analyses under uncertain parameters.

  11. Sequestering Lead in Paint by Utilizing Deconstructed Masonry Materials as Recycled Aggregate in Concrete. Revision 1

    Science.gov (United States)

    2008-05-27

    at Holcim Ltd. donated masonry materials and cement, respectively, to the project. ix EXECUTIVE SUMMARY A systematic study has been conducted to... Holcim Type I ordinary portland cement (which meets the requirements of ASTM [American Society for Testing and Materials] C150) and Polar Bear CSAcement

  12. Study of sticky rice-lime mortar technology for the restoration of historical masonry construction.

    Science.gov (United States)

    Yang, Fuwei; Zhang, Bingjian; Ma, Qinglin

    2010-06-15

    Replacing or repairing masonry mortar is usually necessary in the restoration of historical constructions, but the selection of a proper mortar is often problematic. An inappropriate choice can lead to failure of the restoration work, and perhaps even further damage. Thus, a thorough understanding of the original mortar technology and the fabrication of appropriate replacement materials are important research goals. Many kinds of materials have been used over the years in masonry mortars, and the technology has gradually evolved from the single-component mortar of ancient times to hybrid versions containing several ingredients. Beginning in 2450 BCE, lime was used as masonry mortar in Europe. In the Roman era, ground volcanic ash, brick powder, and ceramic chip were added to lime mortar, greatly improving performance. Because of its superior properties, the use of this hydraulic (that is, capable of setting underwater) mortar spread, and it was adopted throughout Europe and western Asia. Perhaps because of the absence of natural materials such as volcanic ash, hydraulic mortar technology was not developed in ancient China. However, a special inorganic-organic composite building material, sticky rice-lime mortar, was developed. This technology was extensively used in important buildings, such as tombs, in urban constructions, and even in water conservancy facilities. It may be the first widespread inorganic-organic composite mortar technology in China, or even in the world. In this Account, we discuss the origins, analysis, performance, and utility in historic preservation of sticky rice-lime mortar. Mortar samples from ancient constructions were analyzed by both chemical methods (including the iodine starch test and the acid attack experiment) and instrumental methods (including thermogravimetric differential scanning calorimetry, X-ray diffraction, Fourier transform infrared, and scanning electron microscopy). These analytical results show that the ancient masonry

  13. 29 CFR 1926.704 - Requirements for precast concrete.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Requirements for precast concrete. 1926.704 Section 1926..., DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Concrete and Masonry Construction § 1926.704 Requirements for precast concrete. (a) Precast concrete wall units, structural framing...

  14. Infilled masonry walls contribution in mitigating progressive collapse of multistory reinforced concrete structures according to UFC guidelines

    Science.gov (United States)

    Helmy, Huda; Hadhoud, Hamed; Mourad, Sherif

    2015-09-01

    A structure is subjected to progressive collapse when an element fails, resulting in failure of adjoining structural elements which, in their turn, cause further structural failure leading eventually to partial or total collapse. The failure of a primary vertical support might occur due to extreme loadings such as bomb explosion in a terrorist attack, gas explosion and huge impact of a car in the parking area. Different guidelines such as the General Services Administration (GSA 2003) and the Unified Facilities Criteria (UFC 2009) addressed the structural progressive collapse due to the sudden loss of a main vertical support. In the current study, a progressive collapse assessment according to the UFC guidelines is carried out for a typical ten-story reinforced concrete framed structure designed according to codes [(ACI 318-08) and (ASCE 7-10)] for minimum design loads for buildings and other structures. Fully nonlinear dynamic analysis for the structure was carried out using Applied Element Method (AEM). The investigated cases included the removal of a corner column, an edge column, an edge shear wall, internal columns and internal shear wall. The numerical analysis showed that simplification of the problem into 3D bare frames would lead to uneconomical design. It was found for the studied case that, the infilled masonry walls have a valuable contribution in mitigating progressive collapse of the reinforced concrete framed structures. Neglecting these walls would lead to uneconomical design.

  15. Recycled construction debris as an aggregates. Production of concrete blocks

    Directory of Open Access Journals (Sweden)

    Sousa, J. G. G.

    2003-12-01

    Full Text Available This paper analyzes the use of recycled construction and demolition debris as aggregate for the construction of concrete blocks to be used in sealing masonry. Initial studies addressed the definition of parameters used in the mix of conventional materials (traditionally used in the production of concrete blocks, involving cylindrical test specimens (100x200 mm, molded with the help of a vibratory table. In addition to these definitions, and based on the mixes showing the best results, a new granulometric range was established, against which the granulometry of the recycled aggregates was adjusted. After the initial studies, concrete blocks were molded with the following dimensions: 100x190x390 mm. Studies have determined the behavior of aggregates in relation to mold humidity specific mass, water absorption, and compression resistance in view of the percentage of recycled debris that composes the total aggregate. For the most part, results suggest that construction and demolition debris can potentially be used in the production of concrete blocks, as well as in other pre-molded artefacts.

    El objetivo de esta investigación es contribuir en la producción de bloques de hormigón para muros de albañilería mediante el aprovechamiento de áridos provenientes del reciclaje de residuos de la construcción civil. Los estudios preliminares tuvieron inicio con la definición de los parámetros de mezcla para los materiales convencionales (tradicionalmente utilizados en la construcción de bloques de hormigón, donde se emplearon probetas cilíndricas (100x200 mm, moldeadas con la ayuda de una mesa vibratoria. Cumplidas estas definiciones, se estableció un rango granulométrico a partir de las composiciones de mejores resultados, donde se buscó ajustar la granulometría de los áridos reciclados. Concluidos los estudios preliminares, se moldearon los bloques de hormigón con dimensiones (100x190x390 mm. Los estudios presentan como resultado el

  16. Load-bearing masonry system adoption and performance: A case study of construction company in a developing country

    Science.gov (United States)

    Ramli, Nor Azlinda; Abdullah, Che Sobry; Nawi, Mohd Nasrun Mohd; Bahaudin, Ahmad Yusni

    2016-08-01

    This study addresses the factors that influence the adoption of load-bearing masonry (LBM) system. A case study of the load-bearing masonry (LBM) system adoption is conducted through an interview to explore the situation of the technology adoption in a construction company. The finding indicates the factors influence the adoption of LBM system for the construction company are: organizational resources, usefulness, less maintenance, reduce construction time and cost. From the findings, these factors consistent with previous literature. Furthermore, the performance of the company was measured by looking into the financial and non-financial aspects. The LBM system brings good performance as it increased the profits of the company, a good quality of product and attracts more demand from customers. Thus, these factors should be considered for the other companies that are interested in implementing the LBM system in their projects.

  17. Innovative AE and NDT techniques for on-site measurement of concrete and masonry structures state-of-the-art report of the RILEM technical committee 239-MCM

    CERN Document Server

    2016-01-01

    This volume, in which on-site measurements of concrete and masonry structures by NDT techniques are comprehensively summarized, focuses on the visualization procedure of the results measured. The research and its outcomes presented in this book treat applications of NDT techniques to on-site measurements. These on-site measurements have been marginally successful as each technique requires a particular analysis. In this regard, visualization and imaging of results are in great demand for practitioners and engineers for inspection. The book will therefore be of great value to the field. .

  18. Reliability of Reinforced Concrete Buildings During Construction

    Institute of Scientific and Technical Information of China (English)

    方东平; 耿川东; 张传敏; 祝宏毅; 刘西拉

    2004-01-01

    The safety analysis of reinforced concrete buildings during construction should be based on the comprehensive understanding of loads, load effects, structural resistance, and available safety index of the structure. This paper analyzes the characteristics and probabilistic models of resistance, loads, and load effects. A method was developed to calculate the probability of failure based on Monte Carlo simulation and models proposed in previous articles. Construction examples were used to analyze the influence of live load on the probability of failure. The results show that when the live load increases, the maximum probability of failure increases with acceleration. The results suggest that the construction live load should be carefully addressed during construction.

  19. MECHANICAL MODEL AND ELASTIC MODULUS OF GROUTED CONCRETE BLOCK MASONRY IN COMPRESSION%灌孔混凝土砌块砌体受压力学模型及其弹性模量

    Institute of Scientific and Technical Information of China (English)

    梁建国; 龙腾

    2012-01-01

    灌孔混凝土砌块砌体是由砌体和灌孔混凝土两部分组合而成,为了得到竖向压力作用下两种材料的相互作用机理,该文基于最小势能原理推导了砌体对灌孔混凝土的套箍系数以及灌孔混凝土砌块砌体内的应力分布,得到了灌孔混凝土砌块砌体的弹性模量可近似按材料力学组合截面公式进行计算,其计算结果与收集的全国65组281个试件试验结果符合良好,并通过试验结果统计得到了灌孔混凝土砌块砌体弹性模量的建议公式。理论分析和试验结果表明,我国现行规范中灌孔混凝土砌块砌体弹性模量取值偏低,将使配筋砌块砌体结构的设计计算结果偏于不安全。%In order to obtain the interaction mechanism between the grout and masonry in grouted concrete block masonry structures under vertical load, the hooping factor which denotes the hooping action of the masonry to the grouted concrete and the stress distribution in the grouted concrete block masonry is studied based on the minimum potential energy principle. The elastic modulus of grouted concrete block masonry can be approximately calculated according to the assembled section formula in material mechanics, and the calculation results of this formula agree well with the test results of 281 specimens in 65 groups. Another proposed formula to calculate the elastic modulus of the grouted concrete block is derived base on the test results by regression analysis method. Theoretical analysis and test results show that the value of elastic modulus of grouted concrete block masonry in our current code is low, indicating it is unsafe to guide the design of reinforced concrete block masonry structures.

  20. 29 CFR 1926.703 - Requirements for cast-in-place concrete.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Requirements for cast-in-place concrete. 1926.703 Section..., DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Concrete and Masonry Construction § 1926.703 Requirements for cast-in-place concrete. (a) General requirements for formwork. (1...

  1. Experimental Study on the Compression Behavior of Lightweight Concrete Block Masonry%轻质混凝土砌块砌体受压性能试验研究

    Institute of Scientific and Technical Information of China (English)

    夏多田; 何明胜; 唐艳娟; 曾晓云

    2013-01-01

    An experimental study on the compression behavior of lightweight concrete small hollow block masonry is presented,considering the different grades of mortar strength effect on the compressive properties.The failure characteristics,the relationship between stress and strain and compressive strength of masonry are analyzed.The results show that the compression properties of lightweight concrete small hollow block masonry is similar to the ordinary concrete hollow block masonry,which was destroyed after the main crack forms and penetrates the specimen.Through the analysis of test data,the calculation formula of average compressive strength of the block masonry and the stress-strain relationships at the rise stage of the block masonry are suggested.%对轻质混凝土小型空心砌块砌体进行了抗压性能试验,主要研究不同砂浆强度等级对其抗压性能的影响,分析了砌体的破坏特征、抗压强度和应力与应变之间的关系.研究结果表明:轻质混凝土小型空心砌块砌体的抗压性能和普通混凝土砌块砌体的抗压性能基本相似,极限破坏状态为砌体被贯通裂缝分隔成小立柱后破坏.通过对试验数据的整理分析,给出了砌块砌体抗压强度平均值的计算公式和上升阶段的应力-应变关系式.

  2. Experimental and Numerical Analysis of the Compressive and Shear Behavior for a New Type of Self-Insulating Concrete Masonry System

    Directory of Open Access Journals (Sweden)

    Abu-Bakre Abdelmoneim Elamin Mohamad

    2016-08-01

    Full Text Available The developed study aimed at investigating the mechanical behavior of a new type of self-insulating concrete masonry unit (SCMU. A total of 12 full-grouted wall assemblages were prepared and tested for compression and shear strength. In addition, different axial stress ratios were used in shear tests. Furthermore, numerical models were developed to predict the behavior of grouted specimens using simplified micro-modeling technique. The mortar joints were modeled with zero thickness and their behavior was applied using the traction–separation model of the cohesive element. The experimental results revealed that the shear resistance increases as the level of precompression increases. A good agreement between the experimental results and numerical models was observed. It was concluded that the proposed models can be used to deduct the general behavior of grouted specimens.

  3. Using infrared thermography to determine the presence and correct placement of grouted cells in single-width concrete masonry unit (CMU) walls

    Science.gov (United States)

    Stockton, Gregory R.; Allen, Lee R.

    1999-03-01

    Determining the placement of reinforcing grout in single-width CMU (Concrete Masonry Unit) walls has, in the past, been a painstaking and destructive undertaking. Usually, a test is performed because -- by accident -- missing cells are discovered when a wall penetration is retrofitted or change order is executed, requiring that the wall be opened. Often, a hammer or hammer drill is used to punch holes where the grouting is supposed to be. The test results are used to extrapolate the extent of the problem. This method falls short, since the sample is so small, that only outright fraud can be found, and excess grouting cannot be determined. This paper discusses the results of a joint effort between Stockton Infrared Thermographic Services, Inc. (SITS) and Allen Applied Infrared Technology, Inc. (AAIT) to produce a methodology for using non-destructive infrared thermography to ensure that the design specifications are being met.

  4. 三块田水库混凝土砌石重力坝设计计算%The Design calculation of concrete masonry gravity dam of San Kuaitian Reservoir

    Institute of Scientific and Technical Information of China (English)

    冯建江

    2015-01-01

    三块田水库是一座以灌溉为主兼人饮的C10细石混凝土砌毛石重力坝,最大坝高29.2m。由于原坝址上下游地质条件较复杂不适宜大坝建设,结合工程特性,对采用原坝址的坝型、枢纽布置和坝体结构进行了深入设计研究。推荐浆砌石重力坝,坝身溢洪道泄洪设计方案。经多次优化调整后,坝址及坝型选择、枢纽建筑物布置、坝体结构、坝基处理等均满足设计规范要求,为工程投资决策提供了重要依据。%The SanKuaitian reservoir dam is a C10 fine aggregate concrete rubble masonry gravity dam which the maximum height of 29.2m with functions of irrigation and drinking water supply.Since the geologic condi-tion of the original dam upstream and downstream area is complicated ,not suitable for dam construction ,com-bining the project characters,the deep design research for dam type,dam hydro building layout and dam structure based on the original dam site has been done.The masonry gravity dam ,and spillway release flood on dam design scheme has been recommended.After doing some optimization and adjustment of the design scheme,the dam site and dam type,the dam building layout,the dam structure and the foundation treatment can meet the design standard requirements ,it provides an important reference for project investment decision.

  5. Manufacturing processes of cellular concrete products for the construction

    Directory of Open Access Journals (Sweden)

    Fakhratov Мuhammet

    2017-01-01

    Full Text Available Cellular concrete takes the lead in the world of construction as a structural insulation material used in the construction and reconstruction of buildings and constructions of various purposes. In this artificial stone building material, pores are distributed relatively evenly and occupy from 20 to 90% of the concrete volume, ensuring good thermal qualities, which allows cellular concrete houses to keep warmth well. For production of cellular concrete, Portland cement, “burnt lime”, and fine-pulverized blast furnace slags, with a hardening activator are used as binders. As silica components, quartz sand or “fly ash” obtained by combustion of pulverized fuel in power plants as well as secondary products of different ore dressing treatments are used. The low density and high thermal insulation properties of cellular concrete enables 3 times lighter wall weight than the weight of brick walls and 1.7 times lighter than the walls of ceramsite concrete. Thermal insulation and mechanical properties of cellular concrete make possible to construct of it single-layer protecting structures with the desired thermal resistance. Cellular concrete is divided into aerated concretes and foam concretes, whose physical/mechanical and operational performance is, ceteris paribus, almost identical. By the method of hydrothermal treatment cellular concretes are divided into two groups: concrete of autoclave and non-autoclave curing.

  6. External reinforcing of fiber concrete constructions by carbon fiber tapes

    OpenAIRE

    S.V. Klyuyev; Yu.V. Guryanov

    2013-01-01

    Strengthening the concrete and reinforced concrete structures with carbon fiber tapes is very actively applied in Europe nowadays. In Russia composites based on carbon fiber have also widely spread recently. The main advantages of these materials for strengthening structures are its high specific strength (strength-weight ratio) and strength-to-density ratio.Experimental studies on strengthening and restoration of the constructions were held. Flexible fiber concrete constructions based on man...

  7. APPLICATION OF MIKRODUR IN MASONRY SYSTEMS

    Directory of Open Access Journals (Sweden)

    Makarenkova Yuliya Viktorovna

    2012-10-01

    Full Text Available The author describes the problem of production of the ultra lightweight masonry mortar and methods of its solution. Conditions of optimization of the masonry mortar structure are considered in the article. Presently, Microdur is widely used in construction and repair of subsurface structures, tunnels, oil and gas wells. The use of Mikrodur may substantially improve the properties of the masonry mortar (ρр = 941.17 kg/m3, = 11.00 MPa, av = 66.25 kN, compression = 26.50 MPa, ρрstone = 570.47 kg/m3, per unit compression = 46.45 PMa/kg·103, per unit = 19.28 PMa/kg·103, λ = 0.190 Wt/m°С. The thermal conductivity of both bearing and thermal insulation porous concrete blocks is equal to 0.18…0.21 Wt/m°С. Thus, the new envelope structure of homogeneous thermal conductivity has a value of thermotechnical homogeneity ratio = 0.98.

  8. 混凝土模块式排水检查井施工工艺%Construction Technology of Concrete Modular Drainage Inspection Wells

    Institute of Scientific and Technical Information of China (English)

    裴艳

    2016-01-01

    The concrete modular drainage inspection well consists concrete shaft wall module, masonry mortar, filling and core concrete, coating, jointing, pulp, wipe and triangle ash concrete. The stress of its overall structure is clear, the masonry of the inspection wells with different structural sections and sizes is easy, simple and convenient. It is suitable for the outdoor rain of municipal, industrial and civil buildings and the non-corrosiveness sewage pipeline engineering. On the basis of engineering practice, this paper sums up the construction technology of concrete modular drainage inspection wells.%混凝土模块式排水检查井由混凝土井壁墙体模块、砌筑砂浆、灌芯混凝土、包封混凝土、勾缝、座浆、抹三角灰组成,整体结构受力明确,对于不同结构断面和尺寸的检查井易于砌筑,简单便捷,适用于市政、工业与民用建筑室外雨水及无腐蚀性污水管道工程。本文在工程实践的基础上,总结出混凝土模块式排水检查井施工工艺。

  9. Experimental investigations on dry stone masonry walls

    OpenAIRE

    2006-01-01

    Brick unreinforced masonry walls have been widely studied both from experimental and numerical point of view, but scarce experimental information is available for dry stone masonry walls that constitute the material more frequently used in the construction of ancient historical constructions. Therefore, the present work aims at increasing the insight about the behavior of typical ancient masonry walls under cyclic loading. To attain such goal, different experimental approaches are consi...

  10. Fly ash for durable concrete construction

    Energy Technology Data Exchange (ETDEWEB)

    Dhir, R.K. [University of Dundee, Dundee (United Kingdom). Dept. of Civil Engineering

    1994-12-31

    This is essentially a review paper, bringing together the various studies undertaken at the University of Dundee as well as many others selected from published work. A full range of durability properties have been considered dealing with the effects of fly ash (FA) in concrete. It is shown that the use of FA generally effects improvement in the resistance of concrete to various forms of attack. FA is shown to greatly improve concrete resistance to chloride ingress and to reduce expansion caused by ASR. In the case of sulphate attack the use of FA is recommended. With regard to carbonation, FA can slightly reduce the resistance. It is also shown that FA concrete will benefit more from curing than OPC concrete in developing its resistance to deterioration with age. 78 refs., 8 figs., 5 tabs.

  11. Innovative Materials and Techniques in Concrete Construction : ACES Workshop

    CERN Document Server

    2012-01-01

    Recent years have seen enormous advances in the technology of concrete as a material, through which its strength, compactness and ductility can reach levels never dreamed of before. Thanks to these improved material properties, the strength and durability of concrete structures is greatly improved, their weight and dimensions reduced, the scope of concrete as a structural material is widened and – despite the higher material costs – overall economy is possible, with positive impacts on sustainability as well. Similar advances are underway in reinforcing materials, notably high strength steel and fibre-reinforced polymers, and in the way they are combined with concrete into high performance structures. Developments in materials and equipment, as well as new concepts, have lead to innovative construction techniques, reducing cost and construction time and making possible the application of concrete under extreme conditions of construction or environment. All these advances will be highlighted in the book by...

  12. Dynamic behavior of reinforced concrete frame structure during construction

    Institute of Scientific and Technical Information of China (English)

    TIAN Ming-ge; YI Wei-jian

    2008-01-01

    The effects of concrete's time-variant elastic modulus, casting structural components, assembling temporary shoring framework system, and shock by operating construction equipment on dynamic behavior of the reinforced concrete frame structure during construction were investigated. The dynamic tests of an eight-storey reinforced concrete frame structure during full-scaled stages of the sixth storey construction cycle were carried out by ambient vibration. Natural frequencies, corresponding mode shapes and damping ratio were determined by power spectrum processing the tested signal data in frequency domain. The changes of frequencies, mode shapes and damping ratios at different construction stages were given. The results show that natural frequencies and modal damping ratios reach the maximum at stage of casting fresh concrete, especially for higher modes. Modal damping ratios at each construction stage are less than 5% of those during usage.

  13. An experimental study on the influence of composite materials used to reinforce masonry ring beams

    OpenAIRE

    Sisti, Romina; Corradi, Marco; Borri, Antonio

    2016-01-01

    For historic masonry constructions the out-of-plane wall behavior is critical to seismic performance. Because the main cause of out-of-plane collapses is the wall-to-wall level of connection, the application of a reinforced concrete (RC) ring beam at the eaves level of historic masonry buildings is an effective method to prevent an out-of-plane mechanism of a wall panel. However this effective reinforcing method presents some drawbacks. In order to address this, this paper describes the probl...

  14. Autoclaved aerated concrete masonry with external insulation. Features of moisture conditions during the initial period of operation (rus

    Directory of Open Access Journals (Sweden)

    Kuptaraeva P.D.

    2011-12-01

    Full Text Available Building designs at the moment of commissioning include the initial (building and technological moisture. Thermal insulation systems influence on the yield of the initial moisture from the structures. However, there are no specific design requirements about determining initial moisture content in insulation systems.In this article the features of the initial period of operation on an example of aerated concrete are defined: the results of field surveys and calculations are shown and compared. On the basis of this comparison basic advice on the accounting features of the initial period of operation of autoclaved aerated concrete structures with external insulation are given.

  15. The Behaviour of Palm Oil Fibre Block Masonry Prism under Eccentric Compressive Loading

    Science.gov (United States)

    Mokhtar, Mardiha; Kolop, Roslan; Baizura Hamid, Nor; Kaamin, Masiri; Farhan Rosdi, Mohd; Ngadiman, Norhayati; Sahat, Suhaila

    2017-08-01

    Dry-stacked masonry offers great benefits in constructing masonry buildings. Several examples from previous research show that dry masonry is reasonable alternative to the traditional building system. By addition of fibre, the ductility and the propagation of cracking will be improved. This study investigates the dry stack oil palm fibre block prisms which were subjected to eccentricity compression loads. These concrete blocks were cast using a single mould with suitable fibre-cement composition namely 1:4 (cement: sand) and 0.40 water to the cement ratio based on cement weight. Prisms test using 400 (length) × 150 (width) × 510 (height) mm specimen was carried under eccentric load. There were forty eight (48) prisms built with different configurations based on their volume of fibre. In this study, one types of grout were used namely the fine grout of mix 1:3:2 (cement: sand: aggregate (5mm maximum). Based on the test performed, the failure mechanism and influencing parameters were discussed. From compressive strength test result, it shows that the strength of concrete block decreased with the increase of fibre used. Although the control sample has the higher strength compared to concrete with EFB, it can be seen from mode failure of masonry prism that fibre could extend the cracking time. These results show that the oil palm fibre blocks can improve the failure behaviour and suitable to be used as load bearing wall construction in Malaysia.

  16. Sustainable construction: Composite use of tyres and ash in concrete

    Energy Technology Data Exchange (ETDEWEB)

    Snelson, D.G.; Kinuthia, J.M.; Davies, P.A.; Chang, S.R. [University of Glamorgan, Pontypridd (United Kingdom). Faculty of Advanced Technology

    2009-01-15

    An investigation was carried out to establish the physical, mechanical and chemical characteristics of a non-standard (unprocessed) pulverised fuel ash (PFA) and waste tyres from a former landfill site at the Power Station Hill near Church Village, South Wales, United Kingdom. Investigations are on-going to establish the suitability of the fly ash and/or tyres in road construction (embankment and pavement) and also in concrete to be used in the construction of the proposed highway. This paper reports on concrete-based construction where concrete blends (using various levels of PFA as partial replacement for Portland cement (PC), and shredded waste tyres (chips 15-20 mm) as aggregate replacement) were subjected to unconfined compressive strength tests to establish performance, hence, optimising mix designs. Strength development up to 180 days for the concrete made with PC-PFA blends as binders (PC-PFA concrete), with and without aggregate replacement with tyre chips, is reported. The binary PC-PFA concrete does not have good early strength but tends to improve at longer curing periods. The low early strength observed means that PC-PFA concrete cannot be used for structures, hence, only as low to medium strength applications such as blinding, low-strength foundations, crash barriers, noise reduction barriers, cycle paths, footpaths and material for pipe bedding.

  17. Performance Evaluation of Different Masonry Infill Walls with Structural Fuse Elements Based on In-Plane Cyclic Load Testing

    Directory of Open Access Journals (Sweden)

    Andrew Kauffman

    2014-09-01

    Full Text Available This paper discusses the performance of a structural fuse concept developed for use as a seismic isolation system in the design and retrofit of masonry infill walls. An experimental program was developed and executed to study the behavior of the structural fuse system under cyclic loads, and to evaluate the performance of the system with various masonry materials. Cyclic tests were performed by applying displacement controlled loads at the first, second, and third stories of a two-bay, three-story steel test frame with brick infill walls; using a quasi-static loading protocol to create a first mode response in the structural system. A parametric study was also completed by replacing the brick infill panels with infill walls constructed of concrete masonry units and autoclaved aerated concrete blocks, and applying monotonically increasing, displacement controlled loads at the top story of the test frame.

  18. Assessing Workability Complaints in Mass Concrete Construction

    Science.gov (United States)

    1993-04-01

    IL 171 Improper consolidation equipment/procedures 33 5216 Pegs 5 of 5 able 2 Survey Results of Contractor Staff 1. PROBLEMS RELATING TO MATERIALS A...plant and placement. Ap"encrm D Deta • d D"edpto of Complaint D29 Workability problems Usually a plant problem (excessive variation in concrete

  19. Concrete Production Using Technogenical, Constructional and Domestic Waste

    Directory of Open Access Journals (Sweden)

    Marija Vaičienė

    2011-04-01

    Full Text Available The article describes investigations carried out by the scientists from various countries in order to improve the physical and mechanical properties of concrete. The grained rubber of tyres, modified sawdust, crushed ceramic bricks, plastic waste and remains of glass are utilised to produce concrete mixtures. The results of research conducted by the scientists show that in the process of producing concrete we can use different types of waste to change natural aggregates and to get concrete with specific properties. Currently, waste handling and utilization are burning ecological problems. Therefore, intensive investigations are carried out in order to utilise technogenical, constructional and domestic waste for concrete mixtures. Article in Lithuanian

  20. Aspects of blast resistant masonry design

    Energy Technology Data Exchange (ETDEWEB)

    Volkman, D.E.

    1989-01-01

    Blast resistant design should be examined for building code incorporation, due to the potential of explosions occurring in an industrial society. Specifically, public and commercial structures of concrete masonry construction need additional building code criteria, since these buildings have high density populations to protect. Presently, blast resistant design is accomplished by using government published manuals, but these do not address industry standard construction. A design air blast load of 4.54 kg (10 lbs) of TNT, located 0.91 m (3 ft) above ground surface and 30.48 m (100 ft) from a structure should be considered standard criteria. This loading would be sufficient to protect against blast, resist progressive failure, and yet not be an economic impediment. Design details and adequate inspection must be observed to ensure blast resistant integrity. 10 refs., 3 figs., 1 tab.

  1. Final Report: Self Consolidating Concrete Construction for Modular Units

    Energy Technology Data Exchange (ETDEWEB)

    Gentry, Russell [Georgia Inst. of Technology, Atlanta, GA (United States); Kahn, Lawrence [Georgia Inst. of Technology, Atlanta, GA (United States); Kurtis, Kimberly [Georgia Inst. of Technology, Atlanta, GA (United States); Petrovic, Bojan [Georgia Inst. of Technology, Atlanta, GA (United States); Loreto, Giovanni [Georgia Inst. of Technology, Atlanta, GA (United States); Van Wyk, Jurie [Westinghouse Electric Company, Cranberry Township, PA (United States); Canterero-Leal, Carlos [Westinghouse Electric Company, Cranberry Township, PA (United States)

    2016-07-29

    This report outlines the development of a self-consolidating concrete (also termed “self-compacting concrete” or SCC) so that concrete placement can be made into steel plate composite (SC) modular structures without the need for continuous concrete placement. As part of the research, SCC mixtures were developed and validated to ensure sufficient shear capacity across cold-joints, while minimizing shrinkage and temperature increase during curing to enhance concrete bonding with the steel plate construction found in modular units. The self-roughening concrete produced as part of this research was assessed in SC structures at three scales: small-scale shear-friction specimens, mid-scale beams tested in in-plane and out-of-plane bending, and a full-scale validation test using an SC module produced by Westinghouse as part of the Plant Vogtle expansion. The experiments show that the self-roughening concrete can produce a cold-joint surface of 0.25 inches (6 mm) without external vibration during concrete placement. The experiments and subsequent analysis show that the shear friction provisions of ACI 318-14, Section 22.9 can be used to assess the shear capacity of the cold-joints in SC modular construction, and that friction coefficient of 1.35 is appropriate for use with these provisions.

  2. Concrete and steel construction quality control and assurance

    CERN Document Server

    El-Reedy, Mohamed A

    2014-01-01

    Starting with the receipt of materials and continuing all the way through to the final completion of the construction phase, Concrete and Steel Construction: Quality Control and Assurance examines all the quality control and assurance methods involving reinforced concrete and steel structures. This book explores the proper ways to achieve high-quality construction projects, and also provides a strong theoretical and practical background. It introduces information on quality techniques and quality management, and covers the principles of quality control. The book presents all of the quality control and assurance protocols and non-destructive test methods necessary for concrete and steel construction projects, including steel materials, welding and mixing, and testing. It covers welding terminology and procedures, and discusses welding standards and procedures during the fabrication process, as well as the welding codes. It also considers the total quality management system based on ISO 9001, and utilizes numer...

  3. STRUCTURAL VULNERABILITY ASSESSMENT OF MASONRY BUILDINGS IN TURKEY

    OpenAIRE

    KORKMAZ, Kasım Armagan; CARHOGLU, Asuman Isıl

    2011-01-01

    Turkey is located in an active seismic zone. Mid to high rise R/C building and low rise masonry buildings are very common construction type in Turkey. In recent earthquakes, lots of existing buildings got damage including masonry buildings. Masonry building history in Turkey goes long years back. For sure, it is an important structure type for Turkey. Therefore, earthquake behavior and structural vulnerability of masonry buildings are crucial issues for Turkey as a earthquake prone country. I...

  4. Rapid Reinforcement of Masonry Structure without Constructional Columns Using Steel Component and Performance Study%钢结构快速加固无构造柱砌体方法号陛能研究

    Institute of Scientific and Technical Information of China (English)

    李响; 练剑峰; 戴卜云

    2011-01-01

    以实际工程背景为例,针对典型的有图梁无构造柱砌体结构教室在抗震方面的不足,提出一种钢结构快速加固形成类似构造柱体系的加固方法。从理论上比较此种加固方法与传统的新增钢筋混凝土构造柱的加固方法的加固性能,验证此种加固方法的有效性,最后提出在实际工程中的设计建议。%Based on practical engineering,considering classroom which have ring beams and no constructional the seismic deficiencies of typical masonry structural columns,a rapid steel structural reinforcement method is proposed which can form a similar system of constructional column.The strengthening performance of this method is compared with traditional reinforcement method of adding reinforced concrete constructional column theoretically to verify the effectiveness of this method.In the end, design suggestion for practical engineering is proposed.

  5. Thick Concrete Specimen Construction, Testing, and Preliminary Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, Dwight A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hoegh, Kyle [Univ. of Minnesota, Minneapolis, MN (United States); Khazanovich, Lev [Univ. of Minnesota, Minneapolis, MN (United States)

    2015-03-01

    The purpose of the U.S. Department of Energy Office of Nuclear Energy’s Light Water Reactor Sustainability (LWRS) Program is to develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the operating lifetimes of nuclear power plants (NPPs) beyond 60 years. Since many important safety structures in an NPP are constructed of concrete, inspection techniques must be developed and tested to evaluate the internal condition. In-service containment structures generally do not allow for the destructive measures necessary to validate the accuracy of these inspection techniques. This creates a need for comparative testing of the various nondestructive evaluation (NDE) measurement techniques on concrete specimens with known material properties, voids, internal microstructure flaws, and reinforcement locations. A preliminary report detailed some of the challenges associated with thick reinforced concrete sections and prioritized conceptual designs of specimens that could be fabricated to represent NPP concrete structures for using in NDE evaluation comparisons. This led to the construction of the concrete specimen presented in this report, which has sufficient reinforcement density and cross-sectional size to represent an NPP containment wall. Details on how a suitably thick concrete specimen was constructed are presented, including the construction materials, final nominal design schematic, as well as formwork and rigging required to safely meet the desired dimensions of the concrete structure. The report also details the type and methods of forming the concrete specimen as well as information on how the rebar and simulated defects were embedded. Details on how the resulting specimen was transported, safely anchored, and marked to allow access for systematic comparative NDE testing of defects in a representative NPP containment wall concrete specimen are also given. Data collection using the MIRA Ultrasonic NDE equipment and

  6. Field documentation and client presentation of IR inspections on new masonry structures

    Science.gov (United States)

    McMullan, Phillip C.

    1991-03-01

    With the adoption of American Concrete Institute's Design Standard 530 (ACI 530-88/ASCE 5-88) and Specifications (ACI 530.1-88/ASCE 6-88) by more governing bodies throughout the United States, the level and method of inspecting masonry structures is rapidly changing. These new standards set forth inspection criteria such that the Professional of Record (i.e., Architect), can determine the level of inspection based on the type and complexity of the structure being built. For example, a hospital would require considerably more inspection than a Seven-Eleven mini-market. However, the standards require that all new masonry buildings must be inspected. Infrared thermography has proven to be an effective tool to assist in the required inspections. These inspections focus on evaluating masonry for compliance with the design specifications with regard to material, structural strength and thermal performance, the use of video infrared thermography provides a thorough systematic method for inspection of structural solids and thermal integrity of masonry structures. In conducting masonry inspections, the creation of a permanent, well-documented record is valuable in avoiding potential controversy over the inspection findings. Therefore, the inspection method, verification of findings, and presentation of the inspection data are key to the successful use of infrared thermography as an inspection tool. This paper will focus on the method of inspection which TSI employs in conducting new masonry inspections. Additionally, an important component of any work is the presentation of the data. We will look at the information which is generated during this type of inspection and how that data can be converted into a usable report for the various parties involved in construction of a new masonry building.

  7. Concrete

    OpenAIRE

    2015-01-01

    Concrete is a component of coherent transition between a concrete base and a wooden construction. The structure is based on a quantity of investigations of the design possibilities that arise when combining digital fabrication tools and material capacities.Through tangible experiments the project discusses materiality and digitally controlled fabrications tools as direct expansions of the architect’s digital drawing and workflow. The project sees this expansion as an opportunity to connect th...

  8. Shaking Table Tests Validating Two Strengthening Interventions on Masonry Buildings

    Science.gov (United States)

    De Canio, Gerardo; Muscolino, Giuseppe; Palmeri, Alessandro; Poggi, Massimo; Clemente, Paolo

    2008-07-01

    Masonry buildings constitute quite often a precious cultural heritage for our cities. In order to future generations can enjoy this heritage, thence, effective projects of protection should be developed against all the anthropical and natural actions which may irreparably damage old masonry buildings. However, the strengthening interventions on these constructions have to respect their authenticity, without altering the original conception, not only functionally and aesthetically of course, but also statically. These issues are of central interests in the Messina area, where the seismic protection of new and existing constructions is a primary demand. It is well known, in fact, that the city of Messina lies in a highly seismic zone, and has been subjected to two destructive earthquakes in slightly more than one century, the 1783 Calabria earthquake and the more famous 1908 Messina-Reggio Calabria earthquake. It follows that the retrofitting projects on buildings which survived these two events should be designed with the aim to save the life of occupants operating with "light" techniques, i.e. respecting the original structural scheme. On the other hand, recent earthquakes, and in particular the 1997 Umbria-Marche sequence, unequivocally demonstrated that some of the most popular retrofitting interventions adopted in the second half the last century are absolutely ineffective, or even unsafe. Over these years, in fact, a number of "heavy" techniques proliferated, and therefore old masonry buildings suffered, among others, the substitution of existing timber slabs with more ponderous concrete slabs and/or the insertion of RC and steel members coupled with the original masonry elements (walls, arches, vaults). As a result, these buildings have been transformed by unwise engineers into hybrid structures, having a mixed behaviour (which frequently proved to be also unpredictable) between those of historic masonry and new members. Starting from these considerations, a

  9. Properties of dry masonry mixtures based on hollow aluminosilicate microspheres

    Directory of Open Access Journals (Sweden)

    Semenov Vyacheslav

    2017-01-01

    Full Text Available At present, there is a steady increase in the volume of housing construction in the Russian Federation. The modern trends in the field of energy and resource saving determine the need of the use of efficient building materials that ensure the safety, comfort and minimum cost of housing construction. Among the materials, often used for erecting of fencing structures, it is possible to note effective small-piece elements (ceramic and light-weight concrete units, etc.. To ensure the solidity of such structures, it is necessary to use the masonry mortars whose properties correspond to those of the main wall material. The existing dry mixes for obtaining of such mortars are expensive and often do not meet the minimum physical-and-mechanical and exploitation requirements. The solution of this problem is the usage of the hollow ceramics (aluminosilicate microspheres as a filler for such mixes. The article presents the results of studies of the main physical-and-mechanical and exploitation characteristics of dry masonry mixes with hollow ceramics microspheres modified with various chemical additives. The effect of the compounding factors on the average density and strength of dry masonry mixes was studied. The compositions have been optimized by the methods of mathematical planning.

  10. Analysis of Masonry Construction and Quality Control%浅析砌体工程施工及质量控制

    Institute of Scientific and Technical Information of China (English)

    谢文怡

    2013-01-01

    如何更为有效地保证砌石工程的建设质量及其建设稳定性,已经成为每一个建筑工程管理人员都应该考虑的问题.本文将从其浆砌片石施工的角度出发,对其施工技术质量的控制作进一步的探讨.%How to ensure the construction quality and construction stability of masonry engineering more effectively has became the problem each construction project management should consider in China.This article gives a further discussion about control of the quality in the construction technology from the perspective of mortar rubble construction.

  11. Non Linear Seismic Analysis of Masonry Structures

    Directory of Open Access Journals (Sweden)

    Sirajuddin, M

    2011-12-01

    Full Text Available Nowadays, even though many new construction techniques have been introduced, masonry has got its own importance in building industry. Masonry structures fail miserably under lateral loading conditions like earth quakes and impact loads. The occurrence of recent earthquakes in India and in different parts of the world have highlighted that most of the loss of human lives and damage to property have been due to the collapse of masonry structures. Though an earthquake could not be prevented, the loss of life and property could be minimized, if necessary steps could be taken to reduce the damages on the existing masonry structures. This paper investigates the application ofNonlinear Seismic Analysis of a masonry building using ANSYS software and check the efficacy of retrofit measuresto protect the existing building.

  12. Experimental Study on the Seismic Performance of Recycled Concrete Brick Walls Embedded with Vertical Reinforcement

    Directory of Open Access Journals (Sweden)

    Wanlin Cao

    2014-08-01

    Full Text Available Recycled concrete brick (RCB is manufactured by recycled aggregate processed from discarded concrete blocks arising from the demolishing of existing buildings. This paper presents research on the seismic performance of RCB masonry walls to assess the applicability of RCB for use in rural low-rise constructions. The seismic performance of a masonry wall is closely related to the vertical load applied to the wall. Thus, the compressive performance of RCB masonry was investigated firstly by constructing and testing eighteen RCB masonry compressive specimens with different mortar strengths. The load-bearing capacity, deformation and failure characteristic were analyzed, as well. Then, a quasi-static test was carried out to study the seismic behavior of RCB walls by eight RCB masonry walls subjected to an axial compressive load and a reversed cyclic lateral load. Based on the test results, equations for predicting the compressive strength of RCB masonry and the lateral ultimate strength of an RCB masonry wall were proposed. Experimental values were found to be in good agreement with the predicted values. Meanwhile, finite element analysis (FEA and parametric analysis of the RCB walls were carried out using ABAQUS software. The elastic-plastic deformation characteristics and the lateral load-displacement relations were studied.

  13. Experimental Study on the Seismic Performance of Recycled Concrete Brick Walls Embedded with Vertical Reinforcement

    Science.gov (United States)

    Cao, Wanlin; Zhang, Yongbo; Dong, Hongying; Zhou, Zhongyi; Qiao, Qiyun

    2014-01-01

    Recycled concrete brick (RCB) is manufactured by recycled aggregate processed from discarded concrete blocks arising from the demolishing of existing buildings. This paper presents research on the seismic performance of RCB masonry walls to assess the applicability of RCB for use in rural low-rise constructions. The seismic performance of a masonry wall is closely related to the vertical load applied to the wall. Thus, the compressive performance of RCB masonry was investigated firstly by constructing and testing eighteen RCB masonry compressive specimens with different mortar strengths. The load-bearing capacity, deformation and failure characteristic were analyzed, as well. Then, a quasi-static test was carried out to study the seismic behavior of RCB walls by eight RCB masonry walls subjected to an axial compressive load and a reversed cyclic lateral load. Based on the test results, equations for predicting the compressive strength of RCB masonry and the lateral ultimate strength of an RCB masonry wall were proposed. Experimental values were found to be in good agreement with the predicted values. Meanwhile, finite element analysis (FEA) and parametric analysis of the RCB walls were carried out using ABAQUS software. The elastic-plastic deformation characteristics and the lateral load-displacement relations were studied. PMID:28788170

  14. Up-to-date technologies of producing reinforced concrete constructions in transport industry

    Directory of Open Access Journals (Sweden)

    Ю. А. Клімов

    2000-09-01

    Full Text Available Presented is the analysis of the works at XIII Congress of International Federeation of pre­reinforced concrete construction (FIP. Scientific researches and technical solutions of reinforced concrete constructions realized in the developed countries have determined the main trends in perfection of concrete constructions in the next century (perfection of data on quality of constructive solutions of reinforcement with on-metallic fibrous materials, energy saving technologies of concrete production, development and investigation of perspective technical solutions

  15. 77 FR 18973 - Reinforced Concrete in Construction, and Preventing Backover Injuries and Fatalities

    Science.gov (United States)

    2012-03-29

    ... Reinforced Concrete in Construction, and Preventing Backover Injuries and Fatalities AGENCY: Occupational... aware of employee safety risks in two areas, reinforcing operations in concrete work (construction only... following methods (submissions relating to Reinforced Concrete in Construction to Docket No. OSHA-2010-0058...

  16. Final Report: Self-Consolidating Concrete Construction for Modular Units

    Energy Technology Data Exchange (ETDEWEB)

    Gentry, Russell [Georgia Inst. of Technology, Atlanta, GA (United States); Kahn, Lawrence [Georgia Inst. of Technology, Atlanta, GA (United States); Kurtis, Kimberly [Georgia Inst. of Technology, Atlanta, GA (United States); Petrovic, Bojan [Georgia Inst. of Technology, Atlanta, GA (United States); Loreto, Giovanni [Georgia Inst. of Technology, Atlanta, GA (United States); Van Wyk, Jurie [Westinghouse Inc., Cranberry Township, PA (United States); Canterero-Leal, Carlos [Westinghouse Inc., Cranberry Township, PA (United States)

    2016-07-29

    This report focuses on work completed on DE-NE0000667, Self-Consolidating Concrete for Modular Units, in connection with the Department of Energy Nuclear Energy Enabling Technologies (DOE-NEET) program. This project was completed in the School of Civil and Environmental Engineering at the Georgia Institute of Technology, with Westinghouse Corporation as the industrial partner. The primary objective of this project was to develop self-consolidating concrete (also termed “self-compacting concrete” or SCC) mixtures so that concrete placement can be made into steel plate composite (SC) modular structures without the need for continuous concrete placement. As part of the research, SCC mixtures were developed and validated to ensure sufficient shear capacity across cold-joints, while minimizing shrinkage and temperature increase during curing to enhance concrete bonding with the steel plate construction found in modular units. The SCC mixtures developed were able to carry shearing forces across the cold-joint boundaries. This “self-roughening” was achieved by adding a tailored fraction of lightweight aggregate (LWA) to the concrete mix, some of which raised to the surface during curing, forming a rough surface on which subsequent concrete placements were made. The self-roughening behavior was validated through three sets of structural tests. Shear friction on small-scale specimens with cold joints was assessed using varying fractions of LWA and with varying amounts of external steel plate reinforcement. The results show that the shear friction coefficient, to be used with the provisions of ACI 318-14, Section 22.9, can be taken as 1.35. Mid-scale beam tests were completed to assess the cold-joint capacity in both in-plane and out-of-plane bending. The results showed that the self-roughened joints performed as well as monolithic joints. The final assessment was a full-scale test using a steel composite module supplied by Westinghouse and similar in construction to

  17. Masonry building envelope analysis

    Science.gov (United States)

    McMullan, Phillip C.

    1993-04-01

    Over the past five years, infrared thermography has proven an effective tool to assist in required inspections on new masonry construction. However, with more thermographers providing this inspection service, establishing a standard for conducting these inspections is imperative. To attempt to standardize these inspections, it is important to understand the nature of the inspection as well as the context in which the inspection is typically conducted. The inspection focuses on evaluating masonry construction for compliance with the design specifications with regard to structural components and thermal performance of the building envelope. The thermal performance of the building includes both the thermal resistance of the material as well as infiltration/exfiltration characteristics. Given that the inspections occur in the 'field' rather than the controlled environment of a laboratory, there are numerous variables to be considered when undertaking this type of inspection. Both weather and site conditions at the time of the inspection can vary greatly. In this paper we will look at the variables encountered during recent inspections. Additionally, the author will present the standard which was employed in collecting this field data. This method is being incorporated into a new standard to be included in the revised version of 'Guidelines for Specifying and Performing Infrared Inspections' developed by the Infraspection Institute.

  18. Innovative reuse of concrete slurry waste from ready-mixed concrete plants in construction products.

    Science.gov (United States)

    Xuan, Dongxing; Zhan, Baojian; Poon, Chi Sun; Zheng, Wei

    2016-07-15

    Concrete slurry waste (CSW) is generated from ready-mixed concrete plants during concrete production and is classified as a corrosive hazardous material. If it is disposed of at landfills, it would cause detrimental effects for our surrounding environment and ecosystems due to its high pH value as well as heavy metal contamination and accumulation. A new method in this study has been introduced to effectively reuse CSW in new construction products. In this method, the calcium-silicate rich CSW in the fresh state was considered as a cementitious paste as well as a CO2 capture medium. The experimental results showed that the pH values of the collected CSWs stored for 28 days ranged from 12.5 to 13.0 and a drastic decrease of pH value was detected after accelerated mineral carbonation. The theoretically calculated CO2 sequestration extent of CSWs was from 27.05% to 31.23%. The practical water to solid ratio in the fresh CSW varied from 0.76 to 1.12, which had a significant impact on the compressive strength of the mixture with CSWs. After subjecting to accelerated mineral carbonation, rapid initial strength development and lower drying shrinkage for the prepared concrete mixture were achieved.

  19. Experimental Measurements of Prestressed Masonry with using Sliding Joint

    Directory of Open Access Journals (Sweden)

    Stara Marie

    2014-06-01

    Full Text Available Contribution deals with experimental measurements of deformations in the place exposed to local load caused by additional pre-stressing. The measurements are made at the masonry corner built in the laboratory equipment. The laboratory equipment was designed at Faculty of Civil Engineering VŠB-Technical University of Ostrava for measurement tri-axial stress-strain conditions in masonry. In this masonry corner two pre-stressing bars are placed. These bars are in different height and are anchored to the anchor plates, which transfer pre-stressing forces to the masonry. The specimen for laboratory testing is performed in the proportion to the reality of 1:1. In the bottom part masonry is inserted asphalt strip. It operates in the masonry like a sliding joint and reduces the shear stress at interface between concrete and masonry structures. The results are compared with the results of masonry without the use of sliding joints, including comment on the effect of sliding joints on the pre-stressing masonry structures.

  20. Specifications for Supplementary Classroom Units "Standard Construction" and "Preframed Construction".

    Science.gov (United States)

    Waring, Robert B.; And Others

    The standards that should be applied to the construction of supplementary classroom units are discussed in this report. Areas dealt with are--(1) general mechanical and electrical work, (2) concrete, (3) masonry, (4) miscellaneous steel and iron, (5) metal windows, (6) carpentry at site, (7) millwork, (8) acoustic treatment, (9) thermal…

  1. Top-down cracking of rigid pavements constructed with fast setting hydraulic cement concrete

    CSIR Research Space (South Africa)

    Heath, AC

    2009-01-29

    Full Text Available Jointed plain concrete pavement (JPCP) test sections were constructed using fast setting hydrualic cement concrete (FSHCC) as part of the California accelerated pavement testing program (CAL/APT). Many of the longer slabs cracked under environmental...

  2. Assessment of leaching from Construction & Demolition Waste concrete

    DEFF Research Database (Denmark)

    Butera, Stefania; Christensen, Thomas Højlund; Astrup, Thomas

    2012-01-01

    Construction and demolition waste features two very important properties when considering its management options: the large amounts, and the low environmental hazardousness. Therefore, concrete waste can be recycled relatively easily: most common end-of-life option is utilization as unbound...... aggregates in road sub-bases, where it substitutes for natural aggregates such as gravel and crushed rocks. However, leaching of heavy metals may occur in such uncontrolled environmental conditions, and become a limiting factor for utilization. Therefore, proper assessment of leaching is crucial. Different...

  3. Cross-cultural comparison of concrete recycling decision-making and implementation in construction industry.

    Science.gov (United States)

    Tam, Vivian W Y; Tam, Leona; Le, Khoa N

    2010-02-01

    Waste management is pressing very hard with alarming signals in construction industry. Concrete waste constituents major proportions of construction and demolition waste of 81% in Australia. To minimize concrete waste generated from construction activities, recycling concrete waste is one of the best methods to conserve the environment. This paper investigates concrete recycling implementation in construction. Japan is a leading country in recycling concrete waste, which has been implementing 98% recycling and using it for structural concrete applications. Hong Kong is developing concrete recycling programs for high-grade applications. Australia is making relatively slow progress in implementing concrete recycling in construction. Therefore, empirical studies in Australia, Hong Kong, and Japan were selected in this paper. A questionnaire survey and structured interviews were conducted. Power spectrum was used for analysis. It was found that "increasing overall business competitiveness and strategic business opportunities" was considered as the major benefit for concrete recycling from Hong Kong and Japanese respondents, while "rising concrete recycling awareness such as selecting suitable resources, techniques and training and compliance with regulations" was considered as the major benefit from Australian respondents. However, "lack of clients' support", "increase in management cost" and "increase in documentation workload, such as working documents, procedures and tools" were the major difficulties encountered from Australian, Hong Kong, and Japanese respondents, respectively. To improve the existing implementation, "inclusion of concrete recycling evaluation in tender appraisal" and "defining clear legal evaluation of concrete recycling" were major recommendations for Australian and Hong Kong, and Japanese respondents, respectively.

  4. Recycling Of Concrete Waste Material from Construction Demolition

    Directory of Open Access Journals (Sweden)

    Aiyewalehinmi E.O1 and Adeoye T.E2

    2016-04-01

    Full Text Available This study investigates the engineering properties of demolished concrete aggregates wastes along Arakale Road, Akure. The purpose is to recycle and reduce the amount of construction wastes materials going into landfills and dumping pits. The study identifies about 15% to 20% of construction waste materials go into landfill and dumping pits in Akure. Four different mixes at 0.5, 0.55, 0.60 and 0.65 water/cement ratios were performed and a total of 96 (48 each concrete cube samples were cast, cured and crushed. The results showed that at lower percentage water/cement ratios, the compressive strength of used aggregates at day 28 were much lower than virgin aggregates (16.89N/mm2 , 19.93N/mm2 while at higher percentage water/cement ratios, the compressive strength of used aggregates at day 28 was almost the same as Virgin aggregates (18.07, 18.37. It shows that the used aggregates can attain the same compressive strength as virgin aggregates at higher water/cement ratios

  5. 投稿须知%Construction Technology for Fast-Track Concrete Pavement

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    In this paper, one of new contents: construction technology for fast-track concrete pavement is introduced in 《Technical Specification for Construction of Highway Cement Concrete Pavements》 (JTG F30) which is revised in 2010 in order to not only provide high-quality and long-lasting life, but also reduce the time of engineering in the new construction, reconstruction and resurfacing maintain of cement concrete pavements, to quickly and early open public traffic, and to reduce traffic interruptions.

  6. High performance fly ash mixed concrete in underground construction of Delhi metro

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, R.; Gupta, A.K.; Garg, R.; Gopalkrishnan, E. [DMRC, New Delhi (India)

    2003-07-01

    The paper describes the comprehensive concrete durability studies carried out for deciding the specifications for the MCIA contract for construction of 4 km of underground metro from Vishwa Vidyalaya station to Kashmere Gate station in India. The study involved adiabatic concrete temperature measurement tests to know the heat generation and temperature rising properties inside concrete mass. The paper describes the background for selection of fly ash as a part replacement up to 30% of cement in concrete including determination of specification, identification of source, collection and transportation by bulk carrier and transfer to storage silo at the concrete batching plant. Control of temperature of concrete during production and after placement requires detailed arrangements for cooling aggregates and water at batching plant and thermal insulation along with curing to the concrete placed at site. Fully tanked membrane waterproofing and special waterproofing details at construction joints also contribute towards achieving the high performance durable concrete structure. 3 refs., 6 figs., 11 tabs.

  7. Strengthening of Unreinforced Masonry Walls with Composite Materials

    Directory of Open Access Journals (Sweden)

    Ioana-Sorina Enţuc

    2004-01-01

    Full Text Available Unreinforced masonry (URM is considered one of the oldest construction materials being until the end of XIXth century, the basic material for: foundations, walls, columns, volts, staircases, floor joints, roofs, retaining walls, drainage channels, barrages, etc. Construction with URM elements posses a series of advantages such as: fire resistance, thermal an acoustic insulations between interior and outside spaces, humidity resistance. However the URM elements have some significant inconveniences such as: large self weight (heaviness causes cracks in the other elements of structures, reduced mechanical strengths in comparison with other traditional materials (steel and concrete, low tenacity, great manual labor consumptions, and vulnerability to earthquakes. Various factors cause deteriorations which must be overcome by strengthening solutions. Some strengthening solutions based on fiber reinforced polymers (FRP products applied directly on URM brick walls are presented in the paper.

  8. Construction of Plastic Concrete Impervious Wall with Permanent Mould%使用永久性胎模的现浇塑性混凝土防渗心墙施工

    Institute of Scientific and Technical Information of China (English)

    奉丽玲; 姜泽侯; 韩春秀; 赵发宾; 张玮

    2013-01-01

    Through the description to Wuding Jiyi Reservoir on plastic concrete impervious wall construction, expounds on the use of the new technology of permanent masonry template of the plastic concrete anti-seepage wall. The construction of plastic concrete anti-seepage wall, reduces the concrete disturbance destroy of roller compaction, and the difficulty of concrete pouring. Not only speeds up the progress, but also saves the cost, solves the problem of road construction, and brings better economic benefit.%  通过对武定己衣水库塑性混凝土防渗墙施工的描述,阐述使用永久性浆砌石模板的塑性混凝土防渗墙的新技术,这种塑性混凝土防渗墙施工方式,减少了碾压对混凝土的扰动破坏,降低了混凝土浇筑的难度。既加快了进度,还节省了成本,而且解决了场内施工道路的问题,带来良好的经济效益。

  9. 灌芯率及灌芯位置对配筋砌体墙混凝土框架的极限承载力的影响%Effects of Location Irrigation and Irrigation Rate on Bearing Capacity of Concrete Frame of Reinforced Masonry Wall

    Institute of Scientific and Technical Information of China (English)

    姜俊铭

    2014-01-01

    This paper analyzed, by finite element method, the bearing capacity of concrete frame of reinforced masonry wal of which the frame and the wal is constructed by rigid conn- ection and effects of different location irrigation and irrigation rate on bearing capacity. Research shows that, with the inc- rease of the grouted rate, the carrying capacity of structure tends to increase, but it is also affected by the irrigation of core position.%本文利用有限元方法分析了墙、框刚性连接的配筋砌体墙混凝土框架的极限承载力,以及不同灌芯率和灌芯位置对其承载力的影响。研究表明,随着灌芯率的提高,结构的极限承载力呈逐渐增大趋势,但亦受灌芯位置的影响。

  10. Construction-friendly ductile shear joints for precast concrete panels

    DEFF Research Database (Denmark)

    Sørensen, Jesper Harrild; Hoang, Linh Cao; Fischer, Gregor

    2015-01-01

    The scope of this paper is the shear capacity of in-situ cast joints between precast concrete panels. Current practice with vertical lowering of the wall panels experiences difficulties in the assembly phase, since the traditional U-bar connection requires an overlap in a horizontal plane to allow...... a construction-friendly design with U-bars overlapping in the same plane as the panel itself. The design allows for a trouble-free vertical lowering of the panels without pre or post processing of the preinstalled reinforcement loops. Furthermore, an overall more ductile behavior of the joint is obtained....... The solution is tested in a push-off experimental setup and the influence of important geometric parameters of the keyed shear joint is investigated. The first peak load carrying capacity is assessed using plasticity models, and the failure modes are identified by the use of digital image correlation...

  11. Nonlinear analysis of massive concrete at successive construction

    OpenAIRE

    2013-01-01

    The presented doctoral thesis deals with numerical analysis of fresh mass concrete, that is concrete whose temperature rise due to heat of cement hydration must be controlled. The thesis consists of two parts. In the first part, a numerical model which solves a fully coupled problem of water, moist air, and heat transfer in fresh concrete and mechanical analysis is presented. Basic equations are deduced from the model of the porous body, which describes concrete as a material, composed of ...

  12. Pseudorandom functions revisited: The cascade construction and its concrete security

    Energy Technology Data Exchange (ETDEWEB)

    Bellare, M. [Univ. of California at San Diego, La Jolla, CA (United States); Canetti, R.; Krawczyk, H. [IBM T.J. Watson Research Center, Yorktown Heights, NY (United States)

    1996-12-31

    Pseudorandom function families are a powerful cryptographic primitive, yielding, in particular, simple solutions for the main problems in private key cryptography. Their existence based on general assumptions (namely, the existence of one-way functions) has been established. In this work we investigate new ways of designing pseudorandom function families. The goal is to find constructions that are both efficient and secure, and thus eventually to bring the benefits of pseudorandom functions to practice. The basic building blocks in our design are certain limited versions of pseudorandom function families, called finite-length input pseudorandom function families, for which very efficient realizations exist in practical cryptography. Thus rather than starting from one-way functions, we propose constructions of {open_quote}full-fledged{close_quotes} pseudorandom function families from these limited ones. In particular we propose the cascade construction, and provide a concrete security analysis which relates the strength of the cascade to that of the underlying finite pseudorandom function family in a precise and quantitative way.

  13. The foundation mass concrete construction technology of Hongyun Building B tower raft

    Science.gov (United States)

    Liu, Yu; Yin, Suhua; Wu, Yanli; Zhao, Ying

    2017-08-01

    The foundation of Hongyun building B tower is made of raft board foundation which is 3300mm in the thickness and 2800mm beside side of the core tube. It is researched that the raft foundation mass concrete construction technology is expatiated from temperature and cracks of the raft foundation and the temperature control and monitoring of the concrete base slab construction and concrete curing.

  14. Comparison of Conventional and Advanced Concrete Technologies in terms of Construction Efficiency

    Directory of Open Access Journals (Sweden)

    Matej Špak

    2016-01-01

    Full Text Available Nowadays, high-performance concrete (HPC and ultra-high-performance concrete (UHPC are ranked among advanced concrete technologies. The application of the mentioned advanced technologies may have potential to improve the construction efficiency from several points of view. For instance, reducing of construction time and construction material, construction quality improving, environmental impact minimizing, and increasing of both durability and lifetime of structures as well as reducing of total construction costs may be obtained. Particular advanced concrete technologies are described and the possibilities of their utilization in both monolithic structures and precast units are presented in the article. The main benefits of modern methods of construction (MMC based on advanced concrete technologies application in precast elements production are presented. Regarding the selected aspects of construction efficiency assessment, a comparison of conventional and advanced concrete technologies that are applied in monolithic structures and precast units is made. The results of this comparison, estimated in semantic differential scale, are presented in the article. By the results of the comparison, the significance of applying the advanced concrete technologies in modern methods of concrete structures production is demonstrated in order to improve construction efficiency.

  15. Laterally loaded masonry

    DEFF Research Database (Denmark)

    Raun Gottfredsen, F.

    In this thesis results from experiments on mortar joints and masonry as well as methods of calculation of strength and deformation of laterally loaded masonry are presented. The strength and deformation capacity of mortar joints have been determined from experiments involving a constant compressive...... stress and increasing shear. The results show a transition to pure friction as the cohesion is gradually destroyed. An interface model of a mortar joint that can take into account this aspect has been developed. Laterally loaded masonry panels have also been tested and it is found to be characteristic...

  16. Retrofitting Masonry Walls with Carbon Mesh

    Directory of Open Access Journals (Sweden)

    Patrick Bischof

    2014-01-01

    Full Text Available Static-cyclic shear load tests and tensile tests on retrofitted masonry walls were conducted at UAS Fribourg for an evaluation of the newly developed retrofitting system, the S&P ARMO-System. This retrofitting system consists of a composite of carbon mesh embedded in a specially adapted high quality spray mortar. It can be applied with established construction techniques using traditional construction materials. The experimental study has shown that masonry walls reinforced by this retrofitting system reach a similar strength and a higher ductility than retrofits by means of bonded carbon fiber reinforced polymer sheets. Hence, the retrofitting system using carbon fiber meshes embedded in a high quality mortar constitutes a good option for static or seismic retrofits or reinforcements for masonry walls. However, the experimental studies also revealed that the mechanical anchorage of carbon mesh may be delicate depending on its design.

  17. EVALUATION OF CONCRETE BLOCKS FOR MASONRY WITH ADDITION OF TIRE RUBBER RESIDUES = AVALIAÇÃO DE BLOCOS DE CONCRETO PARA ALVENARIA COM ADIÇÃO DE RESÍDUOS DE BORRACHA DE PNEUS

    Directory of Open Access Journals (Sweden)

    Catiane Sebben Selung

    2013-01-01

    Full Text Available The steady growth in the number of freight and passenger vehicles in circulation causes an increased amount of tires requiring retreading or become useless. In order to contribute to a better utilization of tire rubber residues generated in the retreading process, this paper was conducted with the aim of evaluating the absorption and compressive strength of concrete blocks for masonry, with residues and aggregates found in the western region of Santa Catarina State. Thus, concrete blocks were prepared with partial replacement of coarse aggregate for rubber residues in proportions of 15%, 25% and 35%, in mass, which were compared with blocks of a reference mix without residue. The test results confirmed a tendency to increase the absorption and reduction of the compressive strength of the blocks with the increase of the amount of residues tire rubber in the concrete mix. However, the mixture with 15% residue satisfies the minimum value of 3.0 MPa for the characteristic compressive strength and a 10% maximal absorption for hollow concrete blocks with structural function for use in masonry elements above the ground level. = O constante crescimento do número de veículos de cargas e passageiros em circulação acarreta aumento da quantidade de pneus com necessidade de recapagem ou que se tornam inservíveis. No intuito de contribuir com o melhor aproveitamento dos resíduos de borracha de pneus gerados no processo de recapagem, este estudo foi desenvolvido com o objetivo de avaliar a absorção e resistência à compressão de blocos de concreto para alvenaria, confeccionados com resíduos e agregados encontrados na região oeste do Estado de Santa Catarina. Assim, foram confeccionados blocos de concreto com a substituição parcial de brita por resíduos de borracha nas proporções de 15%, 25% e 35%, em massa, os quais foram comparados com blocos de um traço de referência sem o resíduo. Os resultados dos ensaios confirmaram uma tendência de

  18. Testing of the masonry arches of the Brooklyn Bridge approaches

    Science.gov (United States)

    Limaye, Hemant S.

    1996-11-01

    Diagnostic procedures play an important role in performing a condition survey of a structure. Specialized tests are used during a field survey to supplement visual observations. The tests provide valuable information regarding the internal condition of the structure and quality of the construction materials. The tests also help in determining the extent of damage, if any. Recently, a team of consulting engineers performed a study to determine the remaining capacity of the Brooklyn Bridge approaches for the Department of Transportation, City of New York. Using advanced diagnostic procedures such as impact-echo and flatjack testing, additional information was gathered to assist in the study. Impact-echo testing was helpful in identifying the condition of the brick soffits which were covered with pneumatically- applied concrete, and flatjack testing was useful in determining in-situ compressive strength and compression modulus of the brick masonry. The paper describes the work and the testing results.

  19. Performance of masonry enclosure walls: lessons learned from recent earthquakes

    Science.gov (United States)

    Vicente, Romeu Silva; Rodrigues, Hugo; Varum, Humberto; Costa, Aníbal; Mendes da Silva, José António Raimundo

    2012-03-01

    This paper discusses the issue of performance requirements and construction criteria for masonry enclosure and infill walls. Vertical building enclosures in European countries are very often constituted by non-load-bearing masonry walls, using horizontally perforated clay bricks. These walls are generally supported and confined by a reinforced concrete frame structure of columns and beams/slabs. Since these walls are commonly considered to be nonstructural elements and their influence on the structural response is ignored, their consideration in the design of structures as well as their connection to the adjacent structural elements is frequently negligent or insufficiently detailed. As a consequence, nonstructural elements, as for wall enclosures, are relatively sensitive to drift and acceleration demands when buildings are subjected to seismic actions. Many international standards and technical documents stress the need for design acceptability criteria for nonstructural elements, however they do not specifically indicate how to prevent collapse and severe cracking, and how to enhance the overall stability in the case of moderate to high seismic loading. Furthermore, a review of appropriate measures to improve enclosure wall performance and both in-plane and out-of-plane integrity under seismic actions is addressed.

  20. 大断面煤仓分段掘砌作业法%Sectional Excavation and Masonry in Large Section Coal Bunker

    Institute of Scientific and Technical Information of China (English)

    段红民

    2015-01-01

    煤矿井下煤仓通常采用混凝土支护方式,为了保证混凝土体质量,在反井钻机施工导孔并扩孔的基础上,提出了分段掘砌作业法,即将整个煤仓分成上、下两段,上分段由上向下刷扩,由下向上砌筑;下分段由下向上刷扩并砌筑。采用该方法,不仅能够保证混凝土体质量,降低了施工风险,而且可提高施工速度,减轻劳动强度,是一种新型快速煤仓施工组织方式。%Coal bunker in mines usually adopts concrete support. To ensure concrete quality, sectional excavation and masonry working method was used on feeding hole and expanding hole with a raise-boring machine. The whole bunker was divided into two sections:upper and lower. The upper section used downward brush expansion and upward masonry and the lower section used upward brush expansion and masonry. The method could ensure the concrete quality, reduce construction risk, speed up construction process, reduce labor intensity, which is a new and fast construction method for the coal bunker.

  1. A Navy User’s Guide for Quality Assurance of New Concrete Construction

    Science.gov (United States)

    2012-06-01

    expected that military construction will incorporate it to achieve more sustainable reinforced concrete structures. The corner stone of the approach...concrete cylinders are made from the delivery of the ready- mix or batched precast concrete to validate that the concrete’s transport properties are...millimeter (0.02 inches) (a credit card is typically 0.5 to 0.75 mm thick [.02 to .03 inches) are repaired or sealed . The model accounts for the presence of

  2. Ultra-High Performance ‘Ductile’ Concrete Technology Toward Sustainable Construction

    OpenAIRE

    2011-01-01

    This paper briefly presents an overview of the material characteristics of a Malaysia blend of ultra-high performance ductile concrete (UHPdC) know as DURA®. Examples of the environmental impact calculations of UHPdC structures compared to that of conventional reinforced concrete design are presented. The comparison studies show that many structures constructed from UHPdC are generally more environmentally sustainable than built of the conventional reinforced concrete with respect to the redu...

  3. The Significance of Coordination for Industrialised Building System (IBS Precast Concrete in Construction Industry

    Directory of Open Access Journals (Sweden)

    Fitri Othman Mohd Khairul

    2017-01-01

    Full Text Available IBS precast concrete is construction system which is meant to improve the conventional construction process. However IBS precast concrete projects are suffering from serious problems such as cost overrun, delays and less quality of the end product. The absence of coordination is perceived as the reason for this issue. The purpose of this paper is to review the significance of coordination for IBS precast concrete in the construction industry. It if found that the fragmentation which occurs in the construction industry requires continuity of coordination due to the construction activities are intertwined in nature. Coordination is designated to assist stakeholders in completing and complementing each other with the paramount focus of achieving the objective. Proper coordination is required in delivering the desired construction product at the ideal time, cost and quality. As for the findings, the significance of coordination for IBS precast concrete can be seen through the precast concrete construction phases which consist of planning; design; manufacturing; transportation and installation/construction. These phases are meant to complement construction process with the purpose to reduce issues of fragmentation and enhance IBS precast concrete project delivery.

  4. Stereogeneous construction – fabric-formed concrete as material and process

    DEFF Research Database (Denmark)

    Manelius, Anne-Mette

    2012-01-01

    På engelsk: This paper contributes to studies of architectural potentials of fabric formwork for concrete by seeking to establish a theoretical concept that evaluates qualities of materials and principles of construction as well as aspects of the expression of concrete construction. Through plann...... experimental, practical and analytical investigations of fabric-formed concrete and the core formwork-tectonic elements of its making....... planning and teaching workshops with students, categorizing and interpreting experimental data, and reflecting and communicating knowledge, the concept Stereogeneity developed as a response to questions about the nature of concrete cast in fabric forms and the relation between the molded and the mold....... The word describes concrete as material and process. Fabric Formwork is the pivotal formwork-tectonic topic of investigation in the experimental and analytical parts of the thesis work on which this paper is based. The youth of the architectural application of construction methods for fabric formwork...

  5. A Survey of a System of Methods for Fire Safety Design of Traditional Concrete Constructions

    DEFF Research Database (Denmark)

    Hertz, Kristian

    2000-01-01

    During the years since 1978 the author has been developing a series of calculation methods and sup-porting test methods for the fire safety design of concrete constructions. The basic methods have been adopted in the fire chapters of the Eurocode ENV1992-1-2 and the Danish code for concrete const...

  6. Evaluation of recycled concrete aggregates for their suitability in construction activities: An experimental study.

    Science.gov (United States)

    Puthussery, Joseph V; Kumar, Rakesh; Garg, Anurag

    2017-02-01

    Construction and demolition waste disposal is a major challenge in developing nations due to its ever increasing quantities. In this study, the recycling potential of waste concrete as aggregates in construction activities was studied. The metal leaching from the recycled concrete aggregates (RCA) collected from the demolition site of a 50year old building, was evaluated by performing three different leaching tests (compliance, availability and Toxic Characteristic Leaching Procedure). The metal leaching was found mostly within the permissible limit except for Hg. Several tests were performed to determine the physical and mechanical properties of the fine and coarse aggregates produced from recycled concrete. The properties of recycled aggregates were found to be satisfactory for their utilization in road construction activities. The suitability of using recycled fine and coarse aggregates with Portland pozzolanic cement to make a sustainable and environmental friendly concrete mix design was also analyzed. No significant difference was observed in the compressive strength of various concrete mixes prepared by natural and recycled aggregates. However, only the tensile strength of the mix prepared with 25% recycled fine aggregates was comparable to that of the control concrete. For other mixes, the tensile strength of the concrete was found to drop significantly. In summary, RCA should be considered seriously as a building material for road construction, mass concrete works, lightly reinforced sections, etc. The present work will be useful for the waste managers and policy makers particularly in developing nations where proper guidelines are still lacking. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Utilization of Construction Waste Composite Powder Materials as Cementitious Materials in Small-Scale Prefabricated Concrete

    Directory of Open Access Journals (Sweden)

    Cuizhen Xue

    2016-01-01

    Full Text Available The construction and demolition wastes have increased rapidly due to the prosperity of infrastructure construction. For the sake of effectively reusing construction wastes, this paper studied the potential use of construction waste composite powder material (CWCPM as cementitious materials in small-scale prefabricated concretes. Three types of such concretes, namely, C20, C25, and C30, were selected to investigate the influences of CWCPM on their working performances, mechanical properties, and antipermeability and antifrost performances. Also the effects of CWCPM on the morphology, hydration products, and pore structure characteristics of the cement-based materials were analyzed. The results are encouraging. Although CWCPM slightly decreases the mechanical properties of the C20 concrete and the 7 d compressive strengths of the C25 and C30 concretes, the 28 d compressive strength and the 90 d flexural strength of the C25 and C30 concretes are improved when CWCPM has a dosage less than 30%; CWCPM improves the antipermeability and antifrost performances of the concretes due to its filling and pozzolanic effects; the best improvement is obtained at CWCPM dosage of 30%; CWCPM optimizes cement hydration products, refines concrete pore structure, and gives rise to reasonable pore size distribution, therefore significantly improving the durability of the concretes.

  8. Behavior of Reinforced Hybrid Concrete Corbel-Column Connection with Vertical Construction Joint

    Directory of Open Access Journals (Sweden)

    Ammar Yasir Ali

    2017-03-01

    Full Text Available In this paper, shear behavior of reinforced hybrid concrete connection of corbel-column is experimentally investigated. Nine homogenous and hybrid concrete corbel-column connections subjected to vertical applied loads were constructed and tested within two test groups (A, B. The experimental program included the effect of several variables such as type of hybrid concrete;high strength concrete (HSC or steel fiber reinforced concrete (SFRC, monolithic casting of hybrid concrete connection, and presence of construction joint at the interface of corbel-column. Experimental results showed significant effects of concrete hybridization on the structural behavior of connection specimens such as: ultimate strength, cracking loads, cracking patterns, and failure modes. Hybridization process in group (A included hybrid connection of corbel-column with HSC or SFRC corbel instated of NSC. This process led to increase the capacity of connection by (26%, 38% and shear cracking loads by (20%, 120% respectively. Moreover, connections of hybrid concrete corbels cast monolithically improved the shear capacity of corbels by (19%, 42% for HSC or SFRC respectively. In group (B, presence of construction joint at connection region reduced the shear capacity of connectionsby (10% to 22% and cracking loads by (23%-62% compared with connections cast monolithically.

  9. Rilem TC 203-RHM. Repair mortars for historic masonry. The role of mortar in masonry: an introduction to requirements for the design of repair mortars

    NARCIS (Netherlands)

    Hees, R.P.J. van; Groot, C.; Balen, K. van; Bicer-Simsir, B.; Binda, L.; Elsen, J.; Konow, T. von; Lindqvist, J.E.; Maurenbrecher, P.; Papayanni, I.; Subercaseaux, M.; Tedeschi, C.; Toumbakari, E.E.; Thompson, M.

    2012-01-01

    Mortar has been in use for many thousands of years and is integral to most masonry construction. Its use is widespread in every culture where masonry is constructed. It is present in the majority of the global built cultural heritage, and is therefore a major consideration in building conservation.

  10. Seismic performance of masonry-infilled RC frames

    Directory of Open Access Journals (Sweden)

    Mircea Bârnaure

    2016-09-01

    Full Text Available The masonry infill of RC frames structures is generally considered as non-structural. The design of the concrete frames is often made by ignoring the influence of the masonry infill, which is only accounted for its mass. The experience on buildings submitted to earthquakes shows that masonry infill walls completely change the behaviour of bare frames due to increased initial stiffness and low deformability. The way in which masonry infills affect the RC frames members is difficult to predict, as different failure modes can occur either in the masonry or in the surrounding frame. In addition to local effects, the position of the masonry infills at different levels can lead to structural irregularity, with a strong influence on the global seismic response of the building. Less infilled stories, also called soft stories, have a particularly unfavourable behaviour under seismic loads, as frame members at these levels are more susceptible to failure. This paper analyses the differences in the behaviour of bare and infilled frames through numerical modelling. Nonlinear push-over analyses of infilled frames are carried out under in-plane vertical and lateral loading. The infill panels are modelled as equivalent single diagonal struts. Several force-displacements laws are considered for these diagonals.

  11. Ultra-High Performance ‘Ductile’ Concrete Technology Toward Sustainable Construction

    Directory of Open Access Journals (Sweden)

    Yen Lei Voo

    2011-07-01

    Full Text Available This paper briefly presents an overview of the material characteristics of a Malaysia blend of ultra-high performance ductile concrete (UHPdC know as DURA®. Examples of the environmental impact calculations of UHPdC structures compared to that of conventional reinforced concrete design are presented. The comparison studies show that many structures constructed from UHPdC are generally more environmentally sustainable than built of the conventional reinforced concrete with respect to the reduction of CO2 emissions and embodied energy. The enhanced durability of UHPdC also provides for significant improvements in the design life, which further supporting the concept of sustainable construction.

  12. Stereogeneous construction – fabric-formed concrete as material and process

    DEFF Research Database (Denmark)

    Manelius, Anne-Mette

    2012-01-01

    På engelsk: This paper contributes to studies of architectural potentials of fabric formwork for concrete by seeking to establish a theoretical concept that evaluates qualities of materials and principles of construction as well as aspects of the expression of concrete construction. Through...... planning and teaching workshops with students, categorizing and interpreting experimental data, and reflecting and communicating knowledge, the concept Stereogeneity developed as a response to questions about the nature of concrete cast in fabric forms and the relation between the molded and the mold....... The word describes concrete as material and process. Fabric Formwork is the pivotal formwork-tectonic topic of investigation in the experimental and analytical parts of the thesis work on which this paper is based. The youth of the architectural application of construction methods for fabric formwork...

  13. Estudio experimental del Sistema de Albañilería Integral en la construcción de viviendas sismorresistentes. Experimental study of the Integral Masonry System in the construction of earthquake resistant houses

    OpenAIRE

    Bustamante Montoro, Rosa; Orta Rial, María Belén; Adell Argiles, Josep Maria

    2012-01-01

    This paper presents the application of the Integral Masonry System (IMS) to the construction of earthquake resistant houses and its experimental study. To verify the security of this new type of building in seismic areas of the third world two prototypes have been tested, one with adobe and the other with hollow brick. In both cases it’s a two-story 6x6x6 m3 house built to scale 1/2. The tests are carried out at the Laboratory of Antiseismic Structures of the Departmen...

  14. Analysis of Joint Masonry Moisture Content Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, Kohta [Building Science Corporation, Westford, MA (United States)

    2015-10-01

    Adding insulation to the interior side of walls of masonry buildings in cold (and wet) climates may cause performance and durability problems. Some concerns, such as condensation and freeze-thaw, have known solutions, but wood members embedded in the masonry structure will be colder (and potentially wetter) after an interior insulation retrofit. Moisture content & relative humidity were monitored at joist ends in historic mass brick masonry walls retrofitted with interior insulation in a cold climate (Zone 5A); data were collected from 2012-2015. Eleven joist ends were monitored in all four orientations. One limitation of these results is that the renovation is still ongoing, with limited wintertime construction heating and no permanent occupancy to date. Measurements show that many joists ends remain at high moisture contents, especially at north- and east-facing orientations, with constant 100% RH conditions at the worst cases. These high moisture levels are not conducive for wood durability, but no evidence for actual structural damage has been observed. Insulated versus non-insulated joist pockets do not show large differences. South facing joists have safe (10-15%) moisture contents. Given the uncertainty pointed out by research, definitive guidance on the vulnerability of embedded wood members is difficult to formulate. In high-risk situations, or when a very conservative approach is warranted, the embedded wood member condition can be eliminated entirely, supporting the joist ends outside of the masonry pocket.

  15. Critical Quality Source Diagnosis for Dam Concrete Construction Based on Quality Gain-loss Function

    Directory of Open Access Journals (Sweden)

    Bo Wang

    2014-06-01

    Full Text Available In dam concrete construction process, it not only has quality loss arising from quality fluctuation, but also gains quality compensation effect due to the mutual cooperation and adaptation coupling between working procedures (WPs. The calculation and transmission complexity of the quality loss and quality compensation affect the quality management of dam concrete construction. As the quality compensation effect existing in the production practice cannot be described by Taguchi quality loss function, the concept of quality gain-loss function was presented in this paper, which was based on endowing the constant term in the expansion of Taylor series with physical meaning—quality compensation. Based on quality gain-loss function theory, a new quality gain-loss transmission model of dam concrete construction based on GERT network was constructed and its effective algorithm was designed. WP quality gain-loss and its impact on the final product were reasonably measured, and the critical quality routes and critical quality WPs were detected and diagnosed in dam concrete construction network. Summer temperature-controlled concrete construction in the third phase of Three Gorges Project (TGP was taken as an example to carry out the study, and the calculation results showed the validity and practicability of the presented model and algorithm.

  16. Investigating the possibility of constructing low cost roller compacted concrete dam

    Directory of Open Access Journals (Sweden)

    Mohamed I. Abu-Khashaba

    2014-03-01

    Results clarified how FA interacts with Portland cement and showed its effect on concrete properties especially strength development ratio. FA long-term reaction refines the pore concrete structure to reduce water ingress and control its seepage. FA reduces the thermal stresses by reducing the concrete hydration heat and reduces temperature-related cracking due to low early young’s modulus and finally leads to durability improvement that minimizes the dam construction cost. Results indicated that RCCD could be effectively implemented with site local Egyptian materials. However, more further field measurements and a RCCD prototype are required to be examined analytically and verified with in situ data to evaluate that technique.

  17. The Greenhouse Gas Emission from Portland Cement Concrete Pavement Construction in China.

    Science.gov (United States)

    Ma, Feng; Sha, Aimin; Yang, Panpan; Huang, Yue

    2016-06-24

    This study proposes an inventory analysis method to evaluate the greenhouse gas (GHG) emissions from Portland cement concrete pavement construction, based on a case project in the west of China. The concrete pavement construction process was divided into three phases, namely raw material production, concrete manufacture and pavement onsite construction. The GHG emissions of the three phases are analyzed by a life cycle inventory method. The CO₂e is used to indicate the GHG emissions. The results show that for 1 km Portland cement concrete pavement construction, the total CO₂e is 8215.31 tons. Based on the evaluation results, the CO₂e of the raw material production phase is 7617.27 tons, accounting for 92.7% of the total GHG emissions; the CO₂e of the concrete manufacture phase is 598,033.10 kg, accounting for 7.2% of the total GHG emissions. Lastly, the CO₂e of the pavement onsite construction phase is 8396.59 kg, accounting for only 0.1% of the total GHG emissions. The main greenhouse gas is CO₂ in each phase, which accounts for more than 98% of total emissions. N₂O and CH₄ emissions are relatively insignificant.

  18. Implementation of sustainable processes in regional industries: recycling of metallurgical residual as a project to chance masonry used in construction in Bogotá, Colombia.

    Directory of Open Access Journals (Sweden)

    Leonardo Quijano B.

    2014-03-01

    Full Text Available Rev.esc.adm.neg This paper shows the analysis of the possibilities to implement a new process, viable from the environmental and economic point of view, which includes two regional industries within the framework of the generation of sustainable solutions for the regional economy. In it, the description of how to use residuals from the steel industry as a source to transform the masonry industry, both located in the region of Bogota.

  19. Analysis of Joist Masonry Moisture Content Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, Kohta [Building Science Corporation, Westford, MA (United States)

    2015-10-08

    There are many existing buildings with load-bearing mass masonry walls, whose energy performance could be improved with the retrofit of insulation. However, adding insulation to the interior side of walls of such masonry buildings in cold (and wet) climates may cause performance and durability problems. Some concerns, such as condensation and freeze-thaw have known solutions. But wood members embedded in the masonry structure will be colder (and potentially wetter) after an interior insulation retrofit. Moisture content & relative humidity were monitored at joist ends in historic mass brick masonry walls retrofitted with interior insulation in a cold climate (Zone 5A); data were collected from 2012-2015. Eleven joist ends were monitored in all four orientations. One limitation of these results is that the renovation is still ongoing, with limited wintertime construction heating and no permanent occupancy to date. Measurements show that many joists ends remain at high moisture contents, especially at north- and east-facing orientations, with constant 100% RH conditions at the worst cases. These high moisture levels are not conducive for wood durability, but no evidence for actual structural damage has been observed. Insulated vs. non-insulated joist pockets do not show large differences. South facing joists have safe (10-15%) moisture contents. Given the uncertainty pointed out by research, definitive guidance on the vulnerability of embedded wood members is difficult to formulate. In high-risk situations, or when a very conservative approach is warranted, the embedded wood member condition can be eliminated entirely, supporting the joist ends outside of the masonry pocket.

  20. Construction safety in DOE. Part 2, Students guide

    Energy Technology Data Exchange (ETDEWEB)

    Handwerk, E.C.

    1993-08-01

    This report is the second part of a compilation of safety standards for construction activities on DOE facilities. This report covers the following areas: floor and wall openings; cranes, derricks, hoists, elevators, and conveyors; motor vehicles, mechanized equipment, and marine operations; excavations; concrete and masonry construction; steel erection; underground construction, caisson, cofferdams, and compressed air; demolition; blasting and the use of explosives; power transmission and distribution; rollover protective structures, overhead protection; and ladders.

  1. Construction safety in DOE. Part 2, Students guide

    Energy Technology Data Exchange (ETDEWEB)

    Handwerk, E.C.

    1993-08-01

    This report is the second part of a compilation of safety standards for construction activities on DOE facilities. This report covers the following areas: floor and wall openings; cranes, derricks, hoists, elevators, and conveyors; motor vehicles, mechanized equipment, and marine operations; excavations; concrete and masonry construction; steel erection; underground construction, caisson, cofferdams, and compressed air; demolition; blasting and the use of explosives; power transmission and distribution; rollover protective structures, overhead protection; and ladders.

  2. Analysis of CO2 Emission Characteristics of Concrete Used at Construction Sites

    Directory of Open Access Journals (Sweden)

    Tae Hyoung Kim

    2016-04-01

    Full Text Available As the greenhouse gas reduction goal of 37% below business-as-usual (BAU by 2030, the construction industry is recognized as an anti-environment industry for mass consumption/mass waste; thus, members of the industry are requested to make efforts to transform it into an environment-friendly industry. Concrete, a common construction material, is known to emit large amounts of environmentally hazardous waste during the processes related to its production, construction, maintenance, and demolition. The amount of greenhouse gas (GHG emissions by the product is specified in a ready-mixed concrete report whenever concrete is sold commercially. Hence, there have been many studies addressing the quantitative evaluation and reduction of the environmental effects of concrete. This study aims to introduce a method for assessing the amount of carbon dioxide emission from the processes of producing concrete. Moreover, we measured the quantities of CO2 emission of about 10 under-construction projects, including office buildings, apartment buildings, and high-rise residential buildings in South Korea. Using the assessment result, we analyzed the CO2 reduction performance of an office building in South Korea and drew conclusions about measures for reducing CO2 emission.

  3. The Influence of Pier Stiffness Ratio on the Failure Modes of Masonry Structures

    Directory of Open Access Journals (Sweden)

    Yanru Wang

    2015-01-01

    Full Text Available Masonry structure is the main form of Chinese urban and rural housing construction structure. And heavy casualties and huge economic losses are caused by the damages of masonry structures in the previous destructive earthquake. So the failure modes of masonry structures are analyzed in the paper. ABAQUS software was used; and the Xuankou High School Student Dormitory of masonry structure in Yingxiu town, severely damaged under the Wenchuan earthquake, was taken for example. The influence of the stiffness ratio of pier between windows and spandrel on the failure modes of masonry structures is discussed. The results show that the failure modes in the earthquake could be changed by controlling the stiffness ratio. Suitable stiffness ratio helps proper design of masonry structures.

  4. Evaluation of Sulfur 'Concrete' for Use as a Construction Material on the Lunar Surface

    Science.gov (United States)

    Grugel, R. N.

    2008-01-01

    Combining molten sulfur with any number of aggregate materials forms, when solid, a mixture having attributes similar, if not better, to conventional water-based concrete. As a result the use of sulfur "concrete" on Earth is well established, particularly in corrosive environments. Consequently, discovery of troilite (FeS) on the lunar surface prompted numerous scenarios about its reduction to elemental sulfur for use, in combination with lunar regolith, as a potential construction material; not requiring water, a precious resource, for its manufacture is an obvious advantage. However, little is known about the viability of sulfur concrete in an environment typified by extreme temperatures and essentially no atmosphere. The experimental work presented here evaluates the response of pure sulfur and sulfur concrete subjected to laboratory conditions that approach those expected on the lunar surface, the results suggesting a narrow window of application.

  5. Evaluation of Sulfur 'Concrete' for Use as a Construction Material on the Lunar Surface

    Science.gov (United States)

    Grugel, R. N.

    2008-01-01

    Combining molten sulfur with any number of aggregate materials forms, when solid, a mixture having attributes similar, if not better, to conventional water-based concrete. As a result the use of sulfur "concrete" on Earth is well established, particularly in corrosive environments. Consequently, discovery of troilite (FeS) on the lunar surface prompted numerous scenarios about its reduction to elemental sulfur for use, in combination with lunar regolith, as a potential construction material; not requiring water, a precious resource, for its manufacture is an obvious advantage. However, little is known about the viability of sulfur concrete in an environment typified by extreme temperatures and essentially no atmosphere. The experimental work presented here evaluates the response of pure sulfur and sulfur concrete subjected to laboratory conditions that approach those expected on the lunar surface, the results suggesting a narrow window of application.

  6. SELF-CONSOLIDATING CONCRETE USED IN THE MONOLITHIC CONSTRUCTION OF EARTHQUAKE-RESISTANT TALL BUILDING

    Directory of Open Access Journals (Sweden)

    S. A. Aliev

    2016-01-01

    Full Text Available Objectives. The development of high-strength concrete based on experience both with domestic and foreign concretes has led to the production of a self-consolidating concrete (SCC formula. Method. Raw materials sourced from the Chechen Republic were used in the SUBconcrete formula, based on materials having different classes of compressive strength as well as the incorporation of polycarboxylate as an additive. Results. An investigation was carried out on natural and technogenic raw materials from the Chechen Republic and other regions of the country. Compositions of high-grade SCC with a compressive strength of B100 and higher are achieved with an integrated approach using both natural and man-made raw materials. The formulae of the basic concrete reinforcing technology are examined together with their physico-mechanical properties. The results of the study of locally sourced concrete, as well as that purchased from "Pavlovskgranit" and OOO "Progress" for testing from the Republic of North Ossetia–Alania, are provided. Of the various manufacturers' cements investigated, the highest quality Portland cement CEM I 4.5N was selected from the Tula cement manufacturers in the town of Chiri-Yurt. The fillers used were microsilica sourced from the Novokuznetsk plant, inactivated MP-1 mineral powder produced in Kaluga and fly ash sourced from Nevinnomyssk. Conclusion. The results of the studies show that the raw material potential of our country allows for the production of self-consolidating concrete from class B 25 to B100 and higher for use in monolithic construction, including high-rise. The concrete compositions arrived at are characterised by their high physical and mechanical properties and can be used in high-rise concrete construction sites operating in earthquake-prone areas. 

  7. Construction-friendly ductile shear joints for precast concrete panels

    DEFF Research Database (Denmark)

    Sørensen, Jesper Harrild; Hoang, Linh Cao; Fischer, Gregor

    2015-01-01

    The scope of this paper is the shear capacity of in-situ cast joints between precast concrete panels. Current practice with vertical lowering of the wall panels experiences difficulties in the assembly phase, since the traditional U-bar connection requires an overlap in a horizontal plane to allow....... The solution is tested in a push-off experimental setup and the influence of important geometric parameters of the keyed shear joint is investigated. The first peak load carrying capacity is assessed using plasticity models, and the failure modes are identified by the use of digital image correlation....... The upper bound models produce satisfactory results capturing the experimental tendencies and predicting the mode of shear failure in the shear keys....

  8. Lake Robertson hydroelectric project. Construction of a roller compacted concrete dam

    Energy Technology Data Exchange (ETDEWEB)

    Labelle, M.; Robitaille, F. [Hydro-Quebec, Montreal, PQ (Canada)

    1995-12-31

    Construction of the Lake Robertson hydroelectric project on Quebec`s Lower North Shore was discussed in detail. The dam and powerhouse, located on the HaHa River, consists of a 134 m long concrete gravity dam, and a 21 MW powerhouse with two 69 kV transmission lines and four substations. The climate, terrain, and geography of the region, all of them characterized as severe, and the logistics of construction of the dam and power lines, aggravated by the isolation and severe conditions at the site, were described. The roller compacted concrete design and construction were noted, and justification for a concrete dam over an earth-fill dam was provided. Economics, properties, and composition of the roller compacted concrete (RCC) were examined, and control test results for the RCC concrete were provided. The use of RCC for the Lake Robertson development was described as successful in terms of the quality, watertightness, and completion time. The experience gained by the participants will make it possible to offer RCC as an alternative on various other projects. 2 figs.

  9. HIGH-SPEED FLOW EROSION ON A NEW ROLLER COMPACTED CONCRETE DAM DURING CONSTRUCTION

    Institute of Scientific and Technical Information of China (English)

    WANG Xin; LUO Shao-ze; HU Ya-an; YUAN Qiang; WANG He-sheng; ZHAO Lan-hao

    2012-01-01

    A new roller compacted concrete dam of Fengman Hydropower Station is to be built in the toe of the old dam,which was identified as a dangerous dam.The new dam during construction would be influenced by the high-speed flow discharged from the old dam,which is an important problem to be considered for the first time in China,and which would affect the construction of the whole project.Therefore,a series of erosion experiments were conducted in this article.A high-speed flow erosion test apparatus was developed for the erosion experiments of the new dam materials.The maximum jet velocity goes up to 40 m/s and the section area of the nozzle is 0.0025 m2.In the process of experiments,the equipment shows a good performance.Erosive wear tests for two types of materials used in the new dam,a roller compacted concrete and a distorted concrete with four kinds of ages were carried out with the flow velocity in the range of 30 m/s-35 m/s.Erosion parameters and erosion laws for the two types of concretes with different ages were determined,and a general relationship between the erosion rate and the flow velocity is obtained as:N =cvP,with the velocity exponent P between 3.33 and 3.93.It is concluded that the erosion resistance of the distorted concrete is better than that of the roller compacted concrete and the mechanical properties of the concretes of over 14 d age are influenced slightly by the water impact.The test results might serve as a practical technique guide for the safety of this project during its construction in the flood season.

  10. Material characteristics and construction methods for a typical research reactor concrete containment in Iran

    Energy Technology Data Exchange (ETDEWEB)

    Ebrahimia, Mahsa; Suha, Kune Y. [Seoul National Univ., Seoul (Korea, Republic of); Eghbalic, Rahman; Jahan, Farzaneh Asadi malek [School of Architecture and Urbanism, Qazvin (Iran, Islamic Republic of)

    2012-10-15

    Generally selecting an appropriate material and also construction style for a concrete containment due to its function and special geometry play an important role in applicability and also construction cost and duration decrease in a research reactor (RR) project. The reactor containment enclosing the reactor vessel comprises physical barriers reflecting the safety design and construction codes, regulations and standards so as to prevent the community and the environment from uncontrolled release of radioactive materials. It is the third and the last barrier against radioactivity release. It protects the reactor vessel from such external events as earthquake and aircraft crash as well. Thus, it should be designed and constructed in such a manner as to withstand dead and live loads, ground and seismic loads, missiles and aircraft loads, and thermal and shrinkage loads. This study aims to present a construction method for concrete containment of a typical RR in Iran. The work also presents an acceptable characteristic for concrete and reinforcing re bar of a typical concrete containment. The current study has evaluated the various types of the RR containments. The most proper type was selected in accordance with the current knowledge and technology of Iran.

  11. Application of High Flowing Concrete Cementation and Rock Filled in the Construction of Power Station%高流态混凝土胶结堆石筑坝技术在电站建设中的应用

    Institute of Scientific and Technical Information of China (English)

    文江云

    2012-01-01

    静海水电站采用混凝土砌石重力坝作为水电站拦河坝,从方便施工和宜于质量控制两方面出发,拟用高流态混凝土胶结堆石筑坝技术,通过现场试验,论证了混凝土胶结堆石坝技术措施效果明显,该技术能够满足大坝设计要求,并且具有施工效率高、经济效益好、质量稳定等优点.%Jinghai Hydropower Station adopts concrete masonry gravity dam as hydropower dam. Considering of facilitating the construction and appropriate for quality control, the construction technology of cementation and rock filled with flowing concrete is a good choice. Through on-site test, the results show that the technology is very effective. The technology can meet the design requirements of the dam, and has the good construction efficiency, economic, and structure stability.

  12. Failure Criterion for Brick Masonry: A Micro-Mechanics Approach

    Directory of Open Access Journals (Sweden)

    Kawa Marek

    2015-02-01

    Full Text Available The paper deals with the formulation of failure criterion for an in-plane loaded masonry. Using micro-mechanics approach the strength estimation for masonry microstructure with constituents obeying the Drucker-Prager criterion is determined numerically. The procedure invokes lower bound analysis: for assumed stress fields constructed within masonry periodic cell critical load is obtained as a solution of constrained optimization problem. The analysis is carried out for many different loading conditions at different orientations of bed joints. The performance of the approach is verified against solutions obtained for corresponding layered and block microstructures, which provides the upper and lower strength bounds for masonry microstructure, respectively. Subsequently, a phenomenological anisotropic strength criterion for masonry microstructure is proposed. The criterion has a form of conjunction of Jaeger critical plane condition and Tsai-Wu criterion. The model proposed is identified based on the fitting of numerical results obtained from the microstructural analysis. Identified criterion is then verified against results obtained for different loading orientations. It appears that strength of masonry microstructure can be satisfactorily described by the criterion proposed.

  13. Shear-deforming textile reinforced concrete for the construction of double-curved structures

    NARCIS (Netherlands)

    Woodington, W.; Bergsma, O.K.; Schipper, H.R.

    2015-01-01

    A composite textile reinforced concrete (TRC) material is developed to overcome the difficulties of constructing double-curved freeform structures. This is possible by shear-deformation of the woven reinforcement. It affects the direction of reinforcement and thickness, resulting in variable orthotr

  14. Calibration of brick masonry partial safety factors for the South African Code

    CSIR Research Space (South Africa)

    Mahachi, J

    2007-09-01

    Full Text Available The current South African Code of Practice for structural use of masonry uses four partial safety factors gm, for materials depending on construction control and quality control. With the boom in the construction industry, new entrants...

  15. Fire Resistance of Concrete Constructions with Expanded Clay Aggregate

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl

    2003-01-01

    The paper describes briefly a series of full-scale tests made as documentation for extending the field of application of the reduced cross section method from the structural codes to constructions based on expanded clay aggregate. As a special result the tests verify that slabs with a short...

  16. Statistical analysis and conformity testing of concrete in port construction work

    Directory of Open Access Journals (Sweden)

    M. C. Larrossa

    Full Text Available Conformity control of concrete is part of a range of control and standard methods which must be employed in all construction work to assure its compliance with quality requirements. The compressive strength of the concrete is considered as a random variable that must be controlled by standardized sampling and testing in order to ensure the structural safety. Therefore, the use of a large amount of compressive strength test results of concretes with similar characteristics has been seen as an important tool in the assessment of current standard norms. This paper describes an analysis based on the conformity control used in large port construction works which have recently been carried out in the Rio Grande Port, located in Rio Grande, RS, Brazil. Statistical analyses were performed and acceptance tests of the product were conducted. They were based on the acceptance criteria of different methodologies from different continents and showed the variations that can occur in the results of the conformity testing, depending on the adopted model. It is worth mentioning that the concrete used in port construction works in the region has been in accordance with current Brazilian norms.

  17. 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.

  18. 砌体结构外套预制钢筋混凝土墙板加固及隔震加层振动台试验研究%Shaking table test of masonry structures strengthened with external prefabricated reinforced concrete wall and with added story isolation

    Institute of Scientific and Technical Information of China (English)

    王曙光; 苗启松; 刘金龙; 刘伟庆; 杜东升

    2012-01-01

    为研究砌体结构外套预制钢筋混凝土墙板加固技术的加固效果,并探讨在其顶部隔震加层的可行性,进行了3个相似比为1/4模型的振动台对比试验,模型分别是加固砌体结构模型、加固后加层非隔震结构模型和加固后加层隔震结构模型。试验测试了模型结构的动力特性及其在不同地震作用下的动力响应,为了分析结构震损后的动力响应,在试验模型经历罕遇地震作用下的损伤后又继续进行不同水准地震输入试验。试验结果表明:加层非隔震结构的上部钢框架鞭稍效应非常明显;加层隔震结构有效延长了结构自振周期,增大了结构阻尼比。加层隔震结构既有效降低了下部砌体结构的地震响应又降低了上部钢框架的地震响应,其加固效果和抗震性能优越。同时,震损后加层隔震结构的隔震效果明显降低,下部砌体的加速度反应可能大于加固结构和加层非隔震结构,建议在设计时充分考虑这种不利影响。%In order to research the reinforcement effects on masonry structure strengthened with external prefabricated reinforced concrete wall and investigate the possibility of added story isolation on the top of reinforced masonry structure, the shaking table tests of three 1/4. scaled models were conducted. These three models were reinforced masonry structure model, reinforced masonry structure with added story model and reinforced masonry structure with added story isolation model. The dynamic characteristics and seismic response of models were evaluated under different levels of earthquakes. And then, the models subjected to rare seismic cases were tested again to analyze the dynamic responses of damaged structures. The results indicate that added story isolation structure can prolong the structural vibration periods efficiently and increase the damping ratio. Whiplash effect of superstructure of added story non- isolation structure is very

  19. Construction of homogeneous loading functions for elastoplastic damage models for concrete

    Science.gov (United States)

    Zhang, Ji; Li, Jie

    2014-03-01

    Over the past 2 decades, tight restriction has been imposed on strength criteria of concrete by the combination of plasticity and damage in one theory. The present study aims at constructing plastic/damage loading functions for elastoplastic damage models for concrete that can perform more satisfactorily in 3D stress states. Numerous strength criteria of concrete are reorganized according to their simplest representations as Cartesian, cylindrical, mixed cylindrical-Cartesian, and other forms, and the homogeneity of loading functions discussed. It is found that under certain supplementary conditions from physical meanings, an unambiguous definition of the cohesion in a strength criterion, which is demanded in an elastoplastic damage model, is usually available in an explicit or implicit form, and in each case the loading function is still homogeneous. To apply and validate the presented theory, we construct the respective homogeneous damage and plastic loading functions and implant them into some widely used elastoplastic damage models for concrete, and their performances in triaxial compression prove to have improved significantly.

  20. Passive solar construction handbook

    Energy Technology Data Exchange (ETDEWEB)

    Levy, E.; Evans, D.; Gardstein, C.

    1981-08-01

    Many of the basic elements of passive solar design are reviewed. The unique design constraints presented in passive homes are introduced and many of the salient issues influencing design decisions are described briefly. Passive solar construction is described for each passive system type: direct gain, thermal storage wall, attached sunspace, thermal storage roof, and convective loop. For each system type, important design and construction issues are discussed and case studies illustrating designed and built examples of the system type are presented. Construction details are given and construction and thermal performance information is given for the materials used in collector components, storage components, and control components. Included are glazing materials, framing systems, caulking and sealants, concrete masonry, concrete, brick, shading, reflectors, and insulators. The Load Collector Ratio method for estimating passive system performance is appended, and other analysis methods are briefly summarized. (LEW)

  1. 29 CFR 1926.752 - Site layout, site-specific erection plan and construction sequence.

    Science.gov (United States)

    2010-07-01

    ... concrete in the footings, piers and walls and the mortar in the masonry piers and walls has attained, on... walls or the mortar in the masonry piers and walls has attained, on the basis of an appropriate...

  2. Composition and leaching of construction and demolition waste: Inorganic elements and organic compounds

    DEFF Research Database (Denmark)

    Butera, Stefania; Christensen, Thomas Højlund; Astrup, Thomas Fruergaard

    2014-01-01

    Thirty-three samples of construction and demolition waste collected at 11 recycling facilities in Denmark were characterised in terms of total content and leaching of inorganic elements and presence of the persistent organic pollutants PCBs and PAHs. Samples included (i) "clean" (i.e. unmixed......) concrete waste, (ii) mixed masonry and concrete, (iii) asphalt and (iv) freshly cast concrete cores; both old and newly generated construction and demolition waste was included. PCBs and PAHs were detected in all samples, generally in non-critical concentrations. Overall, PAHs were comparable to background...... for leaching, was observed indicating that the number of analysed samples may be critical in relation to decisions regarding management and utilisation of the materials. Higher leaching of chromium, sulphate and chloride were observed for masonry-containing and partly carbonated samples, indicating that source...

  3. Experimental study on perforation resistance of composite targets composed by granite block masonry and reinforced concrete plates%有限厚块石砌体钢筋混凝土结构板抗贯穿性能的实验研究

    Institute of Scientific and Technical Information of China (English)

    吴飚; 杨建超; 刘瑞朝

    2013-01-01

    Four kinds of finite thickness target plates were prepared, including granite (G) plates, steel wire-mesh reinforced concrete (RC) plates, composite GRC targets composed by granite (G) plates and steel wire-mesh reinforced concrete (RC) plates, and composite GBRC targets composed by granite block (GB)masonry and steel wire-mesh reinforced concrete (RC) plates. By using a 30-mm-caliber gun to accelerate two kinds of projectiles of the same shape which differ in material strength, penetration experiments were carried out for these prepared target plates, respectively. The damage effects of the target plates subjected to projectile penetration were compared. The results show that the well-designed GBRC targets have the best resistance to perforation. And the perforation resistance of the GBRC targets is closely related with the following factors: block stone size, strength, masonry way, and reinforced concrete structure.%用花岗岩和混凝土制备出了花岗岩板、钢丝网混凝土板、花岗岩与钢丝网混凝土组合板、花岗岩块石砌体钢筋混凝土结构板4种类型的有限厚靶板.采用口径为30 mm的火炮作为发射装置,利用形状相同、材料强度不同的2种弹体对上述靶板进行了侵彻贯穿实验,比较了各类靶板抗侵彻贯穿破坏现象.结果表明,设计良好的块石砌体钢筋混凝土结构板具有优良的抗贯穿性能,且其抗贯穿性能与块石粒径、块石强度、块石砌筑方式、粘结强度和钢筋混凝土结构形式密切相关.

  4. Concrete Construction Employees: When does procedural fairness shape self-evaluations?

    Science.gov (United States)

    Smith, Heather J; Thomas, Timothy R; Tyler, Tom R

    2006-03-01

    According to the Group Value Model, group authorities and procedures communicate symbolic information to people about whether the group values or respects them. Employees for a concrete construction company completed a questionnaire about their work experiences in either English or Spanish. Among employees who identified more strongly with the concrete construction company, the quality of supervisor treatment predicted employees' feelings of respect and personal self-efficacy. Further, for employees who identified with the company, feeling respected by their colleagues mediated the relationship between fair treatment by a single supervisor and self-efficacy. Even when the working context encourages short term and instrumental goals, these results suggest that employees who identify with the company still care about fair treatment because of the self-relevant information it communicates to them.

  5. Seismic Performance of Composite Shear Walls Constructed Using Recycled Aggregate Concrete and Different Expandable Polystyrene Configurations

    Science.gov (United States)

    Liu, Wenchao; Cao, Wanlin; Zhang, Jianwei; Qiao, Qiyun; Ma, Heng

    2016-01-01

    The seismic performance of recycled aggregate concrete (RAC) composite shear walls with different expandable polystyrene (EPS) configurations was investigated. Six concrete shear walls were designed and tested under cyclic loading to evaluate the effect of fine RAC in designing earthquake-resistant structures. Three of the six specimens were used to construct mid-rise walls with a shear-span ratio of 1.5, and the other three specimens were used to construct low-rise walls with a shear-span ratio of 0.8. The mid-rise and low-rise shear walls consisted of an ordinary recycled concrete shear wall, a composite wall with fine aggregate concrete (FAC) protective layer (EPS modules as the external insulation layer), and a composite wall with sandwiched EPS modules as the insulation layer. Several parameters obtained from the experimental results were compared and analyzed, including the load-bearing capacity, stiffness, ductility, energy dissipation, and failure characteristics of the specimens. The calculation formula of load-bearing capacity was obtained by considering the effect of FAC on composite shear walls as the protective layer. The damage process of the specimen was simulated using the ABAQUS Software, and the results agreed quite well with those obtained from the experiments. The results show that the seismic resistance behavior of the EPS module composite for shear walls performed better than ordinary recycled concrete for shear walls. Shear walls with sandwiched EPS modules had a better seismic performance than those with EPS modules lying outside. Although the FAC protective layer slightly improved the seismic performance of the structure, it undoubtedly slowed down the speed of crack formation and the stiffness degradation of the walls. PMID:28773274

  6. Seismic Performance of Composite Shear Walls Constructed Using Recycled Aggregate Concrete and Different Expandable Polystyrene Configurations

    Directory of Open Access Journals (Sweden)

    Wenchao Liu

    2016-03-01

    Full Text Available The seismic performance of recycled aggregate concrete (RAC composite shear walls with different expandable polystyrene (EPS configurations was investigated. Six concrete shear walls were designed and tested under cyclic loading to evaluate the effect of fine RAC in designing earthquake-resistant structures. Three of the six specimens were used to construct mid-rise walls with a shear-span ratio of 1.5, and the other three specimens were used to construct low-rise walls with a shear-span ratio of 0.8. The mid-rise and low-rise shear walls consisted of an ordinary recycled concrete shear wall, a composite wall with fine aggregate concrete (FAC protective layer (EPS modules as the external insulation layer, and a composite wall with sandwiched EPS modules as the insulation layer. Several parameters obtained from the experimental results were compared and analyzed, including the load-bearing capacity, stiffness, ductility, energy dissipation, and failure characteristics of the specimens. The calculation formula of load-bearing capacity was obtained by considering the effect of FAC on composite shear walls as the protective layer. The damage process of the specimen was simulated using the ABAQUS Software, and the results agreed quite well with those obtained from the experiments. The results show that the seismic resistance behavior of the EPS module composite for shear walls performed better than ordinary recycled concrete for shear walls. Shear walls with sandwiched EPS modules had a better seismic performance than those with EPS modules lying outside. Although the FAC protective layer slightly improved the seismic performance of the structure, it undoubtedly slowed down the speed of crack formation and the stiffness degradation of the walls.

  7. Development of Deflection Prediction Model for Concrete Block Pavement Considering the Block Shapes and Construction Patterns

    Directory of Open Access Journals (Sweden)

    Wuguang Lin

    2016-01-01

    Full Text Available Concrete block pavement (CBP is distinct from typical concrete or asphalt pavements. It is built by using individual blocks with unique construction patterns forming a discrete surface layer to bear traffic loadings. The surface structure of CBP varies depending on the block shapes and construction patterns, so it is hard to apply a general equivalent elastic modulus estimation method to define the surface structural strength. In this study, FEM analysis and dynamic loading test were carried out to develop a deflection prediction model for CBP considering the block shapes and construction patterns. Based on the analysis results, it was found that block shapes did not have much effect on load distribution, whereas construction patterns did. By applying the deflection prediction model to the rutting model for CBP proposed by Sun, the herringbone bond pattern showed the best performance comparing with stretcher bond or basket weave bond pattern. As the load repetition increased to 1.2 million, the rutting depth of CBP constructed by herringbone bond pattern was 2 mm smaller than those constructed by the other two patterns.

  8. Grouting of Multiple Leaf-Masonry Walls: Application on Some Islamic Historical Monuments in Cairo, Egypt

    Directory of Open Access Journals (Sweden)

    Sayed HEMEDA

    2012-12-01

    Full Text Available Present study summarizes an overview on the available experimental and practical data and results from laboratory testing (ungrouted and grouted three leaf masonry wallettes in compression and in diagonal compression. On the basis of the experimental results, (A the structural behavior of the multiple leaf-masonry walls studied in details (b the parameters that affect the behavior of ungrouted masonry are detected and commented upon, and (c the behavior of grouted masonry studied in details. Particularly attention to be paid to large walls whose construction may comprise different kinds of materials. Such walls include cavity walls; rubble filled masonry walls and veneered brick walls which have poor quality core. Not only may the interior of the wall be less capable of carrying load but movement of the core material may also be a source of new stresses. As the experimental results show that the key parameter for the improvement of the mechanical properties of masonry is not the compressive strength of the injected grout, emphasis is given to ternary, as well as to hydraulic lime based grouts: those materials are expected to ensure durable interventions, they lead to a significant enhancement of the mechanical properties of masonry. On the basis of the experimental data on wallettes, as well as based on recent data from tests on grouted cylinders made of filling materials, simple formulae are drived, allowing for the strength of masonry to be calculated, and scientifically interventions processes and techniques had been applied to selected historical monuments in Cairo.

  9. Deformation Pattern of Nickel Slag Bonding on the Development of Concrete Construction

    Science.gov (United States)

    Sujiono, E. H.; Husain, H.; Mulyadi, M.; Samnur, S.; Arsyad, M.

    2017-05-01

    This paper presents an experimental work to study the deformation and compressive strength on Portland cement concrete with nickel slag aggregate. The amount of nickel slag varied were towards the total mass of coarse aggregate are 0%, 20%, 40%, 60%, 80%, and 100%, respectively. Each variation of the samples was made with a dimension of 15 cm X 15 cm X 15 cm, and then through the curing process. After 28 days, the sample was checked using mechanical testing conducted to investigate the compressive strength. The surface of the concrete fracture after mechanical testing process shows that the bonding between the matrix of Portland cement and nickel slag is a very strong. The bonding has connected very well. Therefore, when the force was given, then the fractions of nickel slag aggregate will hold the connectivity until to the maximum of the pressure force value before the materials are a damaged. The maximum of pressure force caused by the cracks will follow the fracture pattern of the concrete materials. This indicates that the bonding between matrix Portland cement and nickel slag has become the key factor in construction high-quality concrete.

  10. 低强度砂浆灌孔砌块砌体抗压性能试验研究%EXPERIMENTAL RESEARCH ON COMPRESSIVE BEHAVIORS OF GROUTED BLOCK MASONRY WITH LOW-STRENGTH MORTAR

    Institute of Scientific and Technical Information of China (English)

    黄靓; 王辉; 陈胜云

    2012-01-01

    In order to study the effect of mortar strength on compressive behaviors of grouted concrete masonry,nine specimens using lime mortar were analyzed.According to failure pattern,cracking load,ultimate capacity and deformation capacity,a formula was provided to calculate the compressive capacity of grouted concrete masonry when the mortar strength is very low.The ratio of cracking load to ultimate load is very small,which affects the durability of masonry building.Therefore,this paper states that the mortar strength should be higher than a critical value when designing and constructing grouted concrete masonry.%为了研究低强度砂浆对灌孔砌块砌体抗压性能的影响,该文通过9个采用石灰砂浆砌筑的灌孔砌块砌体的抗压试验,对其抗压破坏形态、开裂荷载、极限荷载及变形能力进行了分析,提出了适用于砂浆强度很低的灌孔砌块砌体的抗压强度计算公式。分析表明:低强度砂浆砌块砌体的初裂荷载与极限荷载之比较小,而开裂荷载过低将会对砌体房屋的耐久性产生不利影响,因此,该文认为在进行灌孔砌块砌体的设计和施工时,砂浆的强度应得到保证,不能过低。

  11. Design Criteria for Deflection Capacity of Conventionally Reinforced Concrete Slabs. Phase II. Design and Construction Requirements.

    Science.gov (United States)

    1980-10-01

    A T DERECHO , M IGRAL N68305-79-C00 UNCLASSIFIED CEL-CR-.A07 NL .... DTIC tC’ 80-EV27 T-4 CIVIL ENGINEERING LABORATORY Naval Construction Battalion...Design and Construction Requirements by T. Takayanagi, A.T. Derecho , and M. Iqbal* 1. INTRODUCTION 1.1 Objective and Scope The primary objective of this...bars, lightweight concrete, etc., are not clearly de- fined . In addition, inconsistencies in the values of fh ob- tained by using ACI 318-77 have

  12. Nonlinear pushover analysis of infilled concrete frames

    Institute of Scientific and Technical Information of China (English)

    Chao Hsun Huang; Yungting Alex Tuan; Ruo Yun Hsu

    2006-01-01

    Six reinforced concrete frames with or without masonry infills were constructed and tested under horizontal cyclic loads. All six frames had identical details in which the transverse reinforcement in columns was provided by rectangular hoops that did not meet current ACI specifications for ductile frames. For comparison purposes, the columns in three of these frames were jacketed by carbon-fiber-reinforced-polymer (CFRP) sheets to avoid possible shear failure. A nonlinear pushover analysis, in which the force-deformation relationships of individual elements were developed based on ACI 318, FEMA 356,and Chen's model, was carried out for these frames and compared to test results. Both the failure mechanisms and impact of infills on the behaviors of these frames were examined in the study. Conclusions from the present analysis provide structural engineers with valuable information for evaluation and design of infilled concrete frame building structures.

  13. Ultra-High-Performance Concrete And Advanced Manufacturing Methods For Modular Construction

    Energy Technology Data Exchange (ETDEWEB)

    Sawab, Jamshaid [Univ. of Houston, Houston, TX (United States); Lim, Ing [Univ. of Houston, Houston, TX (United States); Mo, Yi-Lung [Univ. of Houston, Houston, TX (United States); Li, Mo [Univ. of Houston, Houston, TX (United States); Wang, Hong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Guimaraes, Maria [Electric Power Research Inst. (EPRI), Knoxville, TN (United States)

    2016-04-13

    Small modular reactors (SMR) allow for less onsite construction, increase nuclear material security, and provide a flexible and cost-effective energy alternative. SMR can be factory-built as modular components, and shipped to desired locations for fast assembly. This project successfully developed a new class of ultra-high performance concrete (UHPC), which features a compressive strength greater than 22 ksi (150 MPa) without special treatment and self-consolidating characteristics desired for SMR modular construction. With an ultra-high strength and dense microstructure, it will facilitate rapid construction of steel plate-concrete (SC) beams and walls with thinner and lighter modules, and can withstand harsh environments and mechanical loads anticipated during the service life of nuclear power plants. In addition, the self-consolidating characteristics are crucial for the fast construction and assembly of SC modules with reduced labor costs and improved quality. Following the UHPC material development, the capacity of producing self-consolidating UHPC in mass quantities was investigated and compared to accepted self-consolidating concrete standards. With slightly adjusted mixing procedure using large-scale gravity-based mixers (compared with small-scale force-based mixer), the self-consolidating UHPC has been successfully processed at six cubic yards; the product met both minimum compressive strength requirements and self-consolidating concrete standards. Steel plate-UHPC beams (15 ft. long, 12 in. wide and 16 in. deep) and wall panels (40 in. X 40 in. X 3 in.) were then constructed using the self-consolidating UHPC without any external vibration. Quality control guidelines for producing UHPC in large scale were developed. When the concrete is replaced by UHPC in a steel plate concrete (SC) beam, it is critical to evaluate its structural behavior with both flexure and shear-governed failure modes. In recent years, SC has been widely used for buildings and nuclear

  14. Earthqueake - Integral Masonry System tested in Lima: Buildings performances of Adobe & Hollow Brick

    OpenAIRE

    2010-01-01

    This paper presents an adaptation of the Integral Masonry System (IMS) developed in Europe under the trade name of the “AllWall System”, for adobe without mortar or hollow clay masonry walls with mortar, in order to allow the construction of housing in developing seismic areas. The prefabricated galvanized electrowelded wire truss-reinforcement is employed in the IMS. This truss-reinforcement may intersect in the three spatial directions and allows the construction of reinforced walls an...

  15. Microstructure of Concrete with Aggregates from Construction and Demolition Waste Recycling Plants.

    Science.gov (United States)

    Bravo, Miguel; Santos Silva, António; de Brito, Jorge; Evangelista, Luís

    2016-02-01

    This paper intends to analyze the microstructure of concrete with recycled aggregates (RA) from construction and demolition waste from various Portuguese recycling plants. To that effect, several scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analyses were performed. Various concrete mixes were evaluated in order to analyze the influence of the RA's collection point and consequently of their composition on the mixes' characteristics. Afterward all the mixes were subjected to the capillary water absorption test in order to quantitatively evaluate their porosity. Results from the SEM/EDS analysis were compared with those from capillary water absorption test. The SEM/EDS analysis showed that the bond capacity of aggregates to the new cement paste is greatly influenced by the RA's nature. On the other hand, there was an increase in porosity with the incorporation of RA.

  16. “ Study of Sesmic Analysis of Masonry Wall Structure”

    Directory of Open Access Journals (Sweden)

    Ms. Deshpande M. S

    2017-03-01

    Full Text Available Earthquakes are natural trouble under which disasters are mainly caused by damage or collapse of the structure and other man-made structures. When an earthquake occurs natural period of vibration is more on heavy loaded building and less in light loaded building. If the building is light weighted, i.e. steel is less then economy of structure is also achieved. Hence it is necessary to find out natural/fundamental time period when mass changes with different type of brick masonry and concrete masonry.This is necessary because IS 1893:2002 does not incorporate the effect of mass in a formula which they have mentioned for brick masonary structure. Thedesign will also analyze with ETAB software.

  17. Analytic model of deformation of construction interfaces of rolled control concrete dam

    Institute of Scientific and Technical Information of China (English)

    GU Chong-shi; HUANG Guang-ming; LAI Dao-ping

    2007-01-01

    The construction interfaces of RCCD have a distinct influence on the deformation of dams. The characters and rules on deformation of construction interfaces are studied. The methods simulating the deformation of the interfaces at different stages are proposed. A thickness analytic model and a no-thickness analytic model of construction interfaces are built. These models can reflect the elastic deformation, the attenuation creep deformation, the irreversible creep deformation and the accelerating creep deformation of interfaces. The example shows that these proposed models can simulate the deformation of the dam structure objectively. Especially, the results of the thickness analytic model which simulates the gradual changing regularities of interfaces can tally with those of monitoring in situ preferably. The methods proposed and the analytic models can be generalized and applied to general concrete dams, especially to the analysis on deformation rules of fault and interlayer in dam base.

  18. Berlin Brandenburg International (BER: planning and implementation of a concrete supply chain for the airport construction site

    Directory of Open Access Journals (Sweden)

    Guido Riedel

    2012-12-01

    Full Text Available Background: With the decision to extend the airport Berlin-Schönefeld to the new airport Berlin Brandenburg International (BER in 2006, a construction of superlatives has emerged. One of the biggest challenges was the supply of around 2.5 million cubic meters of high quality concrete that had to be produced for the construction of the airport. Due to the scale of this enterprise as well as its environment, the logistic solution of raw material supply has to be found.       Method: The planning of the concrete supply chain for the airport construction site BER had to be carried out with two major goals: the stability of the supply chain to assure that the demands of the construction site are met and delays are prevented, as well as assurance of the high quality standards of the concrete production and to avoid an alkali silica reaction and the resulting unavoidable disaggregation of the concrete. External effects, such as the carbon dioxide emission and the effect of the supply chain on adjoining residents were key factors that had to be integrated in a holistic supply chain concept.  The principle underlying method is an analysis of limiting conditions for two approaches: a centralized supply chain with on-site concrete factory and upstream transport of raw materials versus a decentralized supply chain with off-site factories and downstream transport of ready-mixed concrete. Results: The analysis of constraints and the effects on key requirements of the concrete supply chain for the BER airport construction site lead to the installation of the most modern concrete plant in Europe. The benefits of a centralized supply chain are significant. On one hand, the high quality standards can be met with the on-site mixture of the concrete and centralized quality assurance, on the other hand, the majority of the supply traffic for the construction site was moved from the road to train-bound logistics, meeting the emission requirements of the

  19. Performance estimation for concretes made with recycled aggregates of construction and demolition waste of some Brazilian cities

    Directory of Open Access Journals (Sweden)

    Antonio Eduardo Bezerra Cabral

    2012-12-01

    Full Text Available The aim of this paper is to verify the influence of composition variability of recycled aggregates (RA of construction and demolition wastes (CDW on the performance of concretes. Performance was evaluated building mathematical models for compressive strength, modulus of elasticity and drying shrinkage. To obtain such models, an experimental program comprising 50 concrete mixtures was carried out. Specimens were casted, tested and results for compressive strength, modulus of elasticity and drying shrinkage were statistically analyzed. Models inputs are CDW composition observed at seven Brazilian cities. Results confirm that using RA from CDW for concrete building is quite feasible, independently of its composition, once compressive strength and modulus of elasticity still reached considerable values. We concluded the variability presented by recycled aggregates of CDW does not compromise their use for concrete building. However, this information must be used with caution, and experimental tests should always be performed to certify concrete properties.

  20. Full-scale Blast Test Response of Partially Grouted Masonry Walls

    Science.gov (United States)

    2011-01-01

    collaborative research program among the Air Force Research Laboratory (AFRL), the Portland Cement Association (PCA), and the National Concrete Masonry... veneer with 2-inch thick extruded polystyrene rigid board insulation and a 1-inch air gap between the structural wythe and the veneer . The test program...collaborative research program between the Air Force Research Laboratory (AFRL), the Portland Cement Association (PCA), and the National Concrete

  1. Post-tensioned Discrete Concrete Elements Developed For Free-form Construction

    DEFF Research Database (Denmark)

    Egholm Pedersen, Ole; Larsen, Niels Martin; Pigram, Dave

    2015-01-01

    This paper presents a method for the construction of non-uniform precast concrete shell structures from unique parts. A novel method of discontinuous post-tensioning is introduced which allows tension to be taken through the connections. This increases the formal possibilities of the system beyond...... moulds in the right position during casting and algorithms to produce mold details to mediate between the unique components and the repeated rig forms. The last design experiment is the most elaborate, demonstrating a pavillion structure which incorporates all areas of development. The successful...

  2. Development of digital image correlation method to analyse crack variations of masonry wall

    Indian Academy of Sciences (India)

    Shih-Heng Tung; Ming-Hsiang Shih; Wen-Pei Sung

    2008-12-01

    The detection of crack development in a masonry wall forms an important study for investigating the earthquake resistance capability of the masonry structures. Traditionally, inspecting the structure and documenting the findings were done manually. The procedures are time-consuming, and the results are sometimes inaccurate. Therefore, the digital image correlation (DIC) technique is developed to identify the strain and crack variations. This technique is non-destructive for inspecting the whole displacement and strain field. Tests on two masonry wall samples were performed to verify the performance of the digital image correlation method. The phenomena of micro cracks, strain concentration situation and nonuniform deformation distribution which could not have been observed preciously by manual inspection are successfully identified using DIC. The crack formation tendencies on masonry wall can be observed at an earlier stage by this proposed method. These results show a great application potential of the DIC technique for various situations such as inspecting shrinkage-induced cracks in fresh concrete, masonry and reinforced concrete structures, and safety of bridges.

  3. Concrete structures

    CERN Document Server

    Setareh, Mehdi

    2017-01-01

    This revised, fully updated second edition covers the analysis, design, and construction of reinforced concrete structures from a real-world perspective. It examines different reinforced concrete elements such as slabs, beams, columns, foundations, basement and retaining walls and pre-stressed concrete incorporating the most up-to-date edition of the American Concrete Institute Code (ACI 318-14) requirements for the design of concrete structures. It includes a chapter on metric system in reinforced concrete design and construction. A new chapter on the design of formworks has been added which is of great value to students in the construction engineering programs along with practicing engineers and architects. This second edition also includes a new appendix with color images illustrating various concrete construction practices, and well-designed buildings. The ACI 318-14 constitutes the most extensive reorganization of the code in the past 40 years. References to the various sections of the ACI 318-14 are pro...

  4. 窗间墙锚固配筋砖混结构教学楼抗震性能试验研究%Experimental study on seismic performance of brick-concrete masonry school buildings with wall piers reinforced with anchored reinforcements

    Institute of Scientific and Technical Information of China (English)

    吴昊; 赵世春; 许浒; 张蓬勃; 吴刚

    2013-01-01

    Quasi-static tests on two half-scale two-story brick-concrete sub-structure models were carried out in order to improve the seismic performance of brick-concrete masonry school buildings. The wall piers between openings were partially reinforced with horizontal reinforcements that were reliably anchored using vertical reinforcements. The failure modes, load bearing capacity, deformability, rigidity degradation, ductility and hysteretic behavior of the two models, as well as failure modes of piers and failure mechanism of longitudinal walls were investigated. The results indicate that a story mechanism occurs in ordinary masonry model with the piers failing in shear failure. And the longitudinal walls exhibit strong spandrel-weak pier failure mechanism. However, partially reinforced wall piers are characterized by flexural failure with horizontal cracking in the mortar bed joints. Spandrels are severely damaged due to the formation of global failure mechanism. Strong pier-weak spandrel failure mechanism is guaranteed with uniform drift distribution. The level of damage, energy dissipation capacity and ductility of model are significantly improved.%为改善砖混结构教学楼的抗震性能,通过对其纵向窗间墙局部配筋并在墙体两端采用竖向钢筋进行锚固配筋,按照1/2的缩尺比例设计了2个砖混子结构模型.采用拟静力试验分别对普通窗间墙和配筋窗间墙的子结构模型的破坏模式、承载能力、变形能力、刚度退化、延性、耗能性能以及窗间墙的破坏模式和纵墙的破坏机制等进行了分析.结果表明:普通窗间墙模型表现为层间破坏机制,窗间墙发生剪切破坏,纵墙发生“强梁弱柱”式破坏;窗间墙局部配筋并进行锚固的模型发生整体型破坏,窗间墙弯曲破坏,纵墙的破坏机制具有“强柱弱梁”特征,层间变形均匀,模型的破坏形态、耗能能力和延性等均得到改善.

  5. Investigation of interior post-insulated masonry walls with wooden beam ends

    DEFF Research Database (Denmark)

    Morelli, Martin; Svendsen, Svend

    2013-01-01

    investigated using both thermal and hygrothermal simulation software. The results show that the risk to incurring moisture problems at the wooden beam ends can be resolved by not insulating that portion of the wall directly above and below the floor division. Additionally, this proposed retrofit measure would......The preponderant number of multistorey buildings constructed in Denmark in the period between 1850 and 1930 were built with masonry walls incorporating wooden floor beams. Given the nature of this construction, it is supposed that significant energy savings could be achieved by simply insulating...... of the wall, and this in turn may lead to increased freeze–thaw damages and moisture problems at the beam ends embedded in the masonry, when the masonry facade is subjected to driving rain. This article presents a method to investigate retrofit measures of interior-insulated masonry walls having wooden floor...

  6. Ensuring high quality and efficiency of the worksin the process of constructing the tunnels of in-situ concrete

    Directory of Open Access Journals (Sweden)

    Ginzburg Aleksandr Vladimirovich

    2014-01-01

    Full Text Available In the article the author describes the importance of the technological regulations development in the process of constructing various transport constructions: tunnels, subways, bridges and other important objects. In the article the peculiarities of the technological regulations development are fully taken into account; the dependence of the depth of their development and the quality of the concrete constructions, as well as the speed of the objects of transport infrastructure construction, including the examples of building the road tunnels in Moscow. The course of their development is shown with account for the main provisions, which should be included in technological regulations in order to ensure the most complete coverage of the issues arising in engineering, laboratory and Supervisory structure in the process of performing the works. The author proposes new effective materials and technologies of works. In particular, sufficient attention is paid to self-compacting concrete — a new type of concrete, which is able to flow and compact under its own weight, completely filling the formwork even in case of dense reinforcement, while maintaining the homogeneity and having no seals. The application experience of concrete self-sealing in the construction of the metro showed that labor costs for the concrete mixture sealing were 5-6 times reduced, and the speed of laying the concrete increased 2-3 times. When laying self-compacting concrete high-quality surfaces are formed, which do not require additional costs to bring them to the design parameters. In addition, the work shows the parameters of the technological processes and sets various types of works sequence: the article describes the features of formwork, placement and curing of the concrete in terms of year-round construction, shows the importance of thermo physical calculations of concrete hardening and the efficiency of using self-sealing concrete. Sufficient attention is also paid to

  7. Water absorption in brick masonry

    NARCIS (Netherlands)

    Brocken, H.J.P.; Smolders, H.R.

    1996-01-01

    The water absorption in brick, mortar that was cured separately, and masonry samples was studied using NMR. Models of the moisture transport are usually formulated on the basis of a diffusion equation. In the case of water absorption in separate brick and mortar samples, the moisture diffusivity in

  8. Glazed Concrete

    DEFF Research Database (Denmark)

    Bache, Anja Margrethe

    2010-01-01

    Why glazed concrete? Concrete hardens and finds its strength at room temperature whereas clay products must first be fired before they achieve this strength. They are stronger and three times as durable as clay products, which is a weighty reason for choosing concrete.5 Another reason, which....... If this succeeds, it will be possible to manufacture thin, large-scale glazed concrete panels comparable in size to concrete sandwich construction and larger which, with or without back-casting, can work as load-bearing construction elements....

  9. Glazed Concrete

    DEFF Research Database (Denmark)

    Bache, Anja Margrethe

    2010-01-01

    Why glazed concrete? Concrete hardens and finds its strength at room temperature whereas clay products must first be fired before they achieve this strength. They are stronger and three times as durable as clay products, which is a weighty reason for choosing concrete.5 Another reason, which....... If this succeeds, it will be possible to manufacture thin, large-scale glazed concrete panels comparable in size to concrete sandwich construction and larger which, with or without back-casting, can work as load-bearing construction elements....

  10. Civil engineering project construction in the concrete construction technical analysis%土建施工中混凝土施工技术分析

    Institute of Scientific and Technical Information of China (English)

    谢超禄

    2014-01-01

    土建项目工程不同于其它项目工程的是,它涉及面广、专业多、工程复杂,在土建工程建设中,混凝土施工是被广泛应用的施工方式[1]。混凝土施工技术的好坏直接决定着土建工程项目质量。本文结合一线施工经验,对土建施工建设中的混凝土施工技术做出简要分析,以期待能够为一线土建混凝土有效施工提供参考。%Civil engineering is different from other projects,it is broad,more professional,engineering complex, in the construction of civil engineering,concrete construction is a widely used way of construction.Concrete construction technology is good or bad directly decides the quality of civil engineering projects.At this point,in this paper,the author combined with a line of construction experience,to make a brief analysis of civil engineering construction in the concrete construction technology,hoping to provide reference for civil engineering concrete construction.

  11. PROPERTIES OF LIGHTWEIGHT MASONRY MORTARS WITH HOLLOW GLASS MICROSPHERES FOR WINTER CONDITIONS

    OpenAIRE

    Semenov Vyacheslav Sergeevich; Oreshkin Dmitriy Vladimirovich; Rozovskaya Tamara Alekseevna

    2012-01-01

    The authors provide their research findings concerning lightweight masonry mortars with hollow glass microspheres and antifreeze admixtures. These mortars are used in the construction of filler structures at negative temperatures. The application of multilayer filler structures causes reduction of their thermal homogeneity factor. Therefore, single-layer filler structures have the strongest potential. There is a need to employ lightweight masonry mortars to ensure the thermal homogeneity of s...

  12. Image-Based Delineation and Classification of Built Heritage Masonry

    Directory of Open Access Journals (Sweden)

    Noelia Oses

    2014-02-01

    Full Text Available Fundación Zain is developing new built heritage assessment protocols. The goal is to objectivize and standardize the analysis and decision process that leads to determining the degree of protection of built heritage in the Basque Country. The ultimate step in this objectivization and standardization effort will be the development of an information and communication technology (ICT tool for the assessment of built heritage. This paper presents the ground work carried out to make this tool possible: the automatic, image-based delineation of stone masonry. This is a necessary first step in the development of the tool, as the built heritage that will be assessed consists of stone masonry construction, and many of the features analyzed can be characterized according to the geometry and arrangement of the stones. Much of the assessment is carried out through visual inspection. Thus, this process will be automated by applying image processing on digital images of the elements under inspection. The principal contribution of this paper is the automatic delineation the framework proposed. The other contribution is the performance evaluation of this delineation as the input to a classifier for a geometrically characterized feature of a built heritage object. The element chosen to perform this evaluation is the stone arrangement of masonry walls. The validity of the proposed framework is assessed on real images of masonry walls.

  13. 7 CFR 2902.42 - Wood and concrete sealers.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Wood and concrete sealers. 2902.42 Section 2902.42... Items § 2902.42 Wood and concrete sealers. (a) Definition. (1) Products that are penetrating liquids formulated to protect wood and/or concrete, including masonry and fiber cement siding, from damage caused by...

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

    Directory of Open Access Journals (Sweden)

    Stelios Kallis

    2011-07-01

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

  15. Development and construction of low-cracking high-performance concrete (LC-HPC) bridge decks: Free shrinkage tests, restrained ring tests, construction experience, and crack survey results

    Science.gov (United States)

    Yuan, Jiqiu

    2011-12-01

    The development, construction, and evaluation of low-cracking high-performance concrete (LC-HPC) bridge decks are described based on laboratory test results and experiences gained during the construction of 13 LC-HPC bridge decks in Kansas, along with another deck bid under the LC-HPC specifications but for which the owner did not enforce the specification. This study is divided into four parts covering (1) an evaluation of the free shrinkage properties of LC-HPC candidate mixtures, (2) an investigation of the relationship between the evaporable water content in the cement paste and the free shrinkage of concrete, (3) a study of the restrained shrinkage performance of concrete using restrained ring tests, and (4) a description of the construction and preliminary evaluation of LC-HPC and control bridge decks constructed in Kansas. The first portion of the study involves evaluating the effects of the duration of curing, fly ash, and a shrinkage reducing admixture (SRA) on the free-shrinkage characteristics of concrete mixtures. The results indicate that an increase of curing period reduces free shrinkage. With 7 days of curing, concretes containing fly ash as a partial replacement for cement exhibit higher free shrinkage than concretes with 100% portland cement. When the curing period is increased to 14, 28, and 56 days, the adverse effect of adding fly ash on free shrinkage is minimized and finally reversed. The addition of an SRA significantly reduces free shrinkage for both the 100% portland cement mixture and the mixture containing fly ash. The second portion of the study investigates the relationship between the evaporable water content in the cement paste and the free shrinkage of concrete. A linear relationship between free shrinkage and evaporable water content in the cement paste is observed. For a given mixture, specimens cured for a longer period contain less evaporable water and exhibit lower free shrinkage and less weight loss in the free shrinkage

  16. A Report of Contemporary Rammed Earth Construction and Research in North America

    OpenAIRE

    Arno Schmidt; Bly Windstorm

    2013-01-01

    Contemporary stabilized rammed earth (SRE) draws upon traditional rammed earth (RE) methods and materials, often incorporating reinforcing steel and rigid insulation, enhancing the structural and energy performance of the walls while satisfying building codes. SRE structures are typically engineered by licensed Structural Engineers using the Concrete Building Code or the Masonry Building Code. The construction process of SRE creates structural walls of relatively high compressive strength app...

  17. Influence of construction interfaces on dynamic characteristics of roller compacted concrete dams

    Institute of Scientific and Technical Information of China (English)

    顾冲时; 王少伟; 包腾飞

    2015-01-01

    To study the influence of construction interfaces on dynamic characteristics of roller compacted concrete dams (RCCDs), mechanical properties of construction interfaces are firstly analyzed. Then, the viscous-spring artificial boundary (VSAB) is adopted to simulate the radiation damping of their infinite foundations, and based on the Marc software, a simplified seismic motion input method is presented by the equivalent nodal loads. Finally, based on the practical engineering of a RCC gravity dam, effects of radiation damping and construction interfaces on the dynamic characteristics of dams are investigated in detail. Analysis results show that dynamic response of the RCC gravity dam significantly reduces about 25%when the radiation damping of infinite foundation is considered. Hot interfaces and the normal cold interfaces have little influence on the dynamic response of the RCC gravity dam. However, nonlinear fracture along the cold interfaces at the dam heel will occur under the designed earthquake if the cold interfaces are combined poorly. Therefore, to avoid the fractures along the construction interfaces under the potential super earthquakes, combination quality of the RCC layers should be significantly ensured.

  18. Prediction of concrete compressive strength considering humidity and temperature in the construction of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Seung Hee; Jang, Kyung Pil [Department of Civil and Environmental Engineering, Myongji University, Yongin (Korea, Republic of); Bang, Jin-Wook [Department of Civil Engineering, Chungnam National University, Daejeon (Korea, Republic of); Lee, Jang Hwa [Structural Engineering Research Division, Korea Institute of Construction Technology (Korea, Republic of); Kim, Yun Yong, E-mail: yunkim@cnu.ac.kr [Structural Engineering Research Division, Korea Institute of Construction Technology (Korea, Republic of)

    2014-08-15

    Highlights: • Compressive strength tests for three concrete mixes were performed. • The parameters of the humidity-adjusted maturity function were determined. • Strength can be predicted considering temperature and relative humidity. - Abstract: This study proposes a method for predicting compressive strength developments in the early ages of concretes used in the construction of nuclear power plants. Three representative mixes with strengths of 6000 psi (41.4 MPa), 4500 psi (31.0 MPa), and 4000 psi (27.6 MPa) were selected and tested under various curing conditions; the temperature ranged from 10 to 40 °C, and the relative humidity from 40 to 100%. In order to consider not only the effect of the temperature but also that of humidity, an existing model, i.e. the humidity-adjusted maturity function, was adopted and the parameters used in the function were determined from the test results. A series of tests were also performed in the curing condition of a variable temperature and constant humidity, and a comparison between the measured and predicted strengths were made for the verification.

  19. Performance of masonry buildings during the 20 and 27 December 2007 Bala (Ankara earthquakes in Turkey

    Directory of Open Access Journals (Sweden)

    S. Adanur

    2010-12-01

    Full Text Available This paper evaluates the performance of masonry buildings during the 20 and 27 December 2007 Bala (Ankara earthquakes. Bala is a township located 50 km southeast from Ankara city in Turkey. The majority of the buildings in the affected region are built in masonry. Most of masonry buildings were formed with random or coursed stone and mud brick walls without any reinforcement. Many of these buildings were damaged or had collapsed. The cracking and failure patterns of the buildings are examined and interpreted according to current provisions for earthquake resistance of masonry structures. The damages are due to several reasons such as poor construction quality and poor workmanship of the buildings. In addition to these reasons, the two earthquakes hit the buildings within seven days, causing progressive damage.

  20. Department of Energy Construction Safety Reference Guide

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-01

    DOE has adopted the Occupational Safety and Health Administration (OSHA) regulations Title 29 Code of Federal Regulations (CFR) 1926 ``Safety and Health Regulations for Construction,`` and related parts of 29 CFR 1910, ``Occupational Safety and Health Standards.`` This nonmandatory reference guide is based on these OSHA regulations and, where appropriate, incorporates additional standards, codes, directives, and work practices that are recognized and accepted by DOE and the construction industry. It covers excavation, scaffolding, electricity, fire, signs/barricades, cranes/hoists/conveyors, hand and power tools, concrete/masonry, stairways/ladders, welding/cutting, motor vehicles/mechanical equipment, demolition, materials, blasting, steel erection, etc.

  1. Rilem TC 203-RHM: Repair mortars for historic masonry. Requirements for repointing mortars for historic masonry

    NARCIS (Netherlands)

    Hees, R.P.J. van; Groot, C.; Hughes, J.J.; Balen, K. van; Bicer-Simsir, B.; Binda, L.; Elsen, J.; Konow, T. von; Lindqvist, J.E.; Papayanni, I.; Subercaseaux, M.; Tedeschi, C.; Toumbakari, E.E.; Thompson, B.

    2012-01-01

    This paper gives a summary of functional and performance requirements for repointing mortars for historic masonry (design, execution and maintenance). Successful performance of repair and conservation of mortar in historic masonry requires more care with design and execution than with modern masonry

  2. Timbered masonry for earthquake resistance in Europe

    Directory of Open Access Journals (Sweden)

    Dutu, A.

    2012-12-01

    Full Text Available Europe is a continent that is subject to significant seismic activity. Thus, the buildings’ seismic behaviour must be analysed, including not only the new structures, designed under more rigorous codes, but also older ones. This article examines a traditional type of building that uses timber frame/masonry, which is found in Portugal, Turkey, France, England, Greece, Romania, Italy, Spain, Germany and Scandinavia. Although the structures differ in terms of construction details, their structural system is basically the same: the wooden structural system bears mainly the horizontal loads while the masonry supports the gravity loads. The study includes a brief report on the seismicity of each country where this traditional type of building made of timbered framed masonry is found, together with the description of these buildings’ constructive systems.

    Europa es un continente que está sujeto a una significativa actividad sísmica. Por esta razón, se debe analizar el comportamiento sísmico, no sólo de las nuevas estructuras, diseñadas sobre la base de códigos más exigentes, sino también de los diversos tipos de estructuras antiguas. En este artículo se analizan las estructuras constituidas por mampostería y madera, que se pueden encontrar en Portugal, Turquía, Francia, Inglaterra, Grecia, Rumania, Italia, España, Alemania y Escandinavia. Aunque estas estructuras presentan diferencias en cuanto a detalles constructivos, su sistema estructural es idéntico: el sistema estructural de madera absorbe principalmente las cargas horizontales, mientras que la mampostería garantiza la resistencia a la acción de la gravedad. El estudio presentado incluye un breve informe acerca de la sismicidad de los países en que existe el tipo de construcción mencionado, conjuntamente con la descripción de los sistemas constructivos específicos de cada país.

  3. Drying brick masonry by electro-osmosis

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Rörig-Dalgaard, Inge

    2006-01-01

    When a fine grained, porous medium is applied an electric DC field, transport of matter occurs, and the transport mechanism in focus of the present study is electro-osmosis, which is transport of water. In laboratory it was shown possible to transport water inside a brick and brick/mortar system...... in an applied electric field. Electrodes have been constructed and placed inside an old house with moisture problems from capillary rise of water. The water content of the experimental wall was about 14%(weight). The electro-osmotic effect was even more pronounced here than in the in the laboratory, and a clear...... movement of water towards the cathode was seen. Thus the basis for utilizing the electro-osmotic effect for drying brick masonry is present, but proper electrodes still needs to be developed....

  4. Energy Efficiency Improvement and Cost Saving Opportunities for the Concrete Industry

    NARCIS (Netherlands)

    Kermeli, Katerina; Worrell, E.; Masanet, Eric

    2011-01-01

    The U.S. concrete industry is the main consumer of U.S.-produced cement. The manufacturing of ready mixed concrete accounts for about 75% of the U.S. concrete production following the manufacturing of precast concrete and masonry units. The most significant expenditure is the cost of materials accou

  5. Seismic Assessment and Retrofit of Historical Masonry Structures

    OpenAIRE

    2009-01-01

    The Italian building heritage is composed mainly of masonry structures, which over the years have acquired historic significance and artistic values in the national culture. These buildings are particularly vulnerable to the seismic actions, because they were design for gravitational loads without considering seismic actions applied on them. Thus, the constructive details are not compliant with the present design code provisions (e.g. in plan or elevation structural regularity) and to avoid c...

  6. How Concrete is Concrete

    Directory of Open Access Journals (Sweden)

    Koeno Gravemeijer

    2010-07-01

    Full Text Available If we want to make something concrete in mathematics education, we are inclined introduce, what we call, ‘manipulatives’, in the form of tactile objects or visual representations. If we want to make something concrete in a everyday-life conversation, we look for an example. In the former, we try to make a concrete model of our own, abstract, knowledge; in the latter, we try to find an example that the others will be familiar with. This article first looks at the tension between these two different ways of making things concrete. Next another role of manipulatives, will be discussed, namely that of means for scaffolding and communication. In this role, manipulatives may function as means of support in a process that aims at helping students to build on their own thinking while constructing more sophisticated mathematics

  7. Physics Laboratory Investigation of Vocational High School Field Stone and Concrete Construction Techniques in the Central Java Province (Indonesia)

    Science.gov (United States)

    Purwandari, Ristiana Dyah

    2015-01-01

    The investigation aims in this study were to uncover the observations of infrastructures and physics laboratory in vocational high school for Stone and Concrete Construction Techniques Expertise Field or Teknik Konstruksi Batu dan Beton (TKBB)'s in Purwokerto Central Java Province, mapping the Vocational High School or Sekolah Menengah Kejuruan…

  8. Cold Weather Construction Materials. Part 2. Field Validation of Laboratory Tests on Regulated-Set Cement for Cold Weather Concreting.

    Science.gov (United States)

    1982-12-01

    patches, slipform tunnel liners and cast-in- place roof decking. Letters requesting information (construction problems, cracking, durability, cost, etc...this minimum mst be verified. Once known, this will also dictate the earliest times at which formwork or concrete protection could be removed. The

  9. Evaluation of stray current corrosion resistance of concrete in metro construction

    Institute of Scientific and Technical Information of China (English)

    Shucai YANG; Xu YANG

    2008-01-01

    By simulation tests of concrete specimens in saturated Ca(OH)2 solution and seawater, and based on micro mechanism analysis, this paper evaluates the stray current corrosion resistance of concrete specimens of dif-ferent mixture ratios, and reaches a conclusion that the capability to resist stray current corrosion of optimally designed concrete mixed with good-quality fly ash and powdered slag is increased by over 5 times more than the reference concrete with the same water to binder ratio, and the service life of such kind of concrete meets the basic requirement of a metro project.

  10. 浅述混凝土的冬季施工方法%Discussion on concrete winter construction methods

    Institute of Scientific and Technical Information of China (English)

    耿利宝; 杨勇

    2011-01-01

    Based on itself characteristics of concrete, this paper introduced the principles of concrete winter construction, elaborated several commonly used winter construction methods, including adjustment of mixture ratio method, thermal storage method, external heating etc. , pointed out that the construction process should be in the premise of assuring quality, considered the site actual condition and cost, ehoiced the reasonable construction methods.%基于混凝土自身特点,介绍了混凝土冬季施工的原理,阐述了几种常用的冬季施工方法,包括调整配合比方法,蓄热法,外部加热等,指出施工过程中应在保证质量的前提下,考虑工地实际情况及成本,选择合理的施工方法。

  11. Research and application of schemes for constructing concrete pillars in large section finishing cut in backfill coal mining

    Institute of Scientific and Technical Information of China (English)

    Sun Qiang; Zhang Jixiong; Ju Feng; Li Linyue; Zhao Xu

    2015-01-01

    Based on the technology of controlling surrounding rock deformation by constructing concrete pillars in large section finishing cut in backfill coal mining, the characteristics of vertical stress on concrete pillars and main factors influencing pillar stability are analyzed. By building a Winkler elastic foundation mechanical model for the support system constituted of coal pillar, backfill body and concrete pillars, mechanical calculation on stability of concrete pillar is carried out to evaluate the pillar stability and safety. Seven numeral models in three schemes with different pillar sizes, inter-row distances and com-pression ratios at the stopes were analyzed through numerical simulation according to width reduction principle. The practice of finishing cut at III644 workface at Yangzhuang coal mine shows that:when the actual compression ratio is 86.5%, construction size inside the finishing cut is 2000 mm ? 2000 mm and the interval between concrete pillars is 2000 mm ? 2000 mm, the pillars can be stable with the maxi-mum movement of two sides of each pillar being only 83 mm and 54 mm, which achieves the expected effect.

  12. Mechanical Behaviour of the Wood Masonry

    Directory of Open Access Journals (Sweden)

    Fazia FOUCHAL

    2011-09-01

    Full Text Available In this paper we study the walls wood masonry behaviour. First, we propose a regulatory validation of the walls wood masonry behaviour subjected to vertical and horizontal loads according to Eurocode 5. Then we present the numerical application on the wall wood supported two floors level.

  13. Development of Alkali Activated Geopolymer Masonry Blocks

    Science.gov (United States)

    Venugopal, K.; Radhakrishna; Sasalatti, Vinod

    2016-09-01

    Cement masonry units are not considered as sustainable since their production involves consumption of fuel, cement and natural resources and therefore it is essential to find alternatives. This paper reports on making of geopolymer solid & hollow blocks and masonry prisms using non conventional materials like fly ash, ground granulated blast furnace slag (GGBFS) and manufactured sand and curing at ambient temperature. They were tested for water absorption, initial rate of water absorption, dry density, dimensionality, compressive, flexural and bond-strength which were tested for bond strength with and without lateral confinement, modulus of elasticity, alternative drying & wetting and masonry efficiency. The properties of geopolymer blocks were found superior to traditional masonry blocks and the masonry efficiency was found to increase with decrease in thickness of cement mortar joints. There was marginal difference in strength between rendered and unrendered geopolymer masonry blocks. The percentage weight gain after 7 cycles was less than 6% and the percentage reduction in strength of geopolymer solid blocks and hollow blocks were 26% and 28% respectively. Since the properties of geopolymer blocks are comparatively better than the traditional masonry they can be strongly recommended for structural masonry.

  14. The 2011 Earthquake in Simav, Turkey and Seismic Damage to Reinforced Concrete Buildings

    Directory of Open Access Journals (Sweden)

    Yücel Güney

    2013-02-01

    Full Text Available Reinforced concrete buildings suffered significant damage in the region affected by the 29 May 2011 earthquake in Simav (Kutahya, Turkey. Typical building damage is classified and potential causes of damage are investigated. Reinforced concrete moment resisting frames with hollow brick infill walls are the most common structural system in and around the Simav city center while masonry construction is common in rural areas. Although the Simav earthquake, with a magnitude of 5.7 to 5.9, can be classified as a moderate earthquake, many buildings experienced damage varying from frequent diagonal cracking and brittle failure of infill walls to collapse or severe damage to frames due to short columns, soft stories or other reasons including insufficient or poor detailing of reinforcement. This study investigates and presents the seismicity of the region, characteristics of the measured ground motions, seismic load demands including response spectra, and damage mechanisms, potential causes and classification of observed damage in reinforced concrete buildings.

  15. Refiring bricks at 540ºC: hot masonry and magnetic separation close the brick recycling process

    NARCIS (Netherlands)

    Van der Graaf, A.

    2004-01-01

    For many decades, stony debris from building and demolition sites was reused as road building material. Until recently there was no need to look for other uses for this mixture of concrete and masonry rubble. However, now that our supplies of marl and gravel (two of the three ingredients of mortar a

  16. 砖混教室窗间墙不同构造条件下的破坏特点和抗震性能分析%Failure characteristics and seismic performance analysis of longitudinal wall between windows of brick-concrete masonry classroom buildings with different structural measures

    Institute of Scientific and Technical Information of China (English)

    吴昊; 赵世春; 张蓬勃; 许浒

    2012-01-01

    为了研究砖混教学楼窗间墙中构造柱的截面尺寸和配筋对纵向窗间墙破坏特点和抗震性能的影响,设计了5片缩尺纵墙试件,并通过低周反复加载试验对配置不同尺寸和配筋构造柱的墙体试件的破坏破坏形态、滞回特性、变形能力、刚度退化等进行了分析.结果表明,中柱的截面大小和配筋不改变墙体的破坏形态,各墙体试件均发生剪切破坏,按照规范要求设置构造柱的墙体试件表现出较好的抗震性能,构造柱与砖砌体具有较好的协同工作性能,适当增大构造柱截面尺寸能够显著改善墙体的延性耗能性能、变形能力,主裂缝宽度明显减小;增大中柱的配筋率使其成为RC柱时,尽管墙体试件抗侧刚度和承载力得到提高,但墙体的耗能能力和变形能力均出现降低,中柱与砖墙体的协同工作性能明显变差.因此,适当增大构造柱尺寸对于进一步提高砖混教学楼窗间墙的抗震和抗倒塌能力是有利的.%Five reduced-scale wall specimens were designed in order to investigate the influence of section size and reinforcement ratio of middle column on the failure characteristic and seismic performance of longitudinal wall between windows of brick-concrete school buildings. The failure characteristics, hysteretic behavior, deformability and stiffness degradation of each wall specimen were analyzed respectively. The results indicate that all specimens with different middle columns are characterized by shear failure. The specimen designed in accordance with the current code for seismic design generally exhibits good seismic performance where the structural column works well with brick masonry. Increasing section size of structural column can improve the energy dissipation, deformability and the crack distribution of specimen significantly. RC column decreases the energy dissipation and deformability of wall specimens in the highly nonlinear stage, although it can

  17. Types and Characteristics of Performing Concretes Used in the Constructions Processes Engineering

    Directory of Open Access Journals (Sweden)

    Vladimir Corobceanu

    2005-01-01

    Full Text Available The light concrete industry has a great development at present, due to some technical characteristics that make them highly appreciated. These characteristics are: the reduced apparent density, the capacity of high thermal insulation and high resistance at fire, compared to heavy concretes. These features have a result a type concrete elements (simple, reinforced of prestressed with reduced weight, which are good thermo-insulators and easy to manufacture, etc.

  18. GENERAL REGULARITIES ON NPS CONSTRUCTION CONCRETE CORROSION PROCESSES AND THEIR SIMULATION

    Directory of Open Access Journals (Sweden)

    S. N. Leonovich

    2010-01-01

    Full Text Available Civil engineering material science has accumulated a great amount of scientific data on corrosive processes occurring in the NPS concrete structures (including the Bushehr NPS, Islamic Republic of Iran due to environmental conditions.This practical material creates appropriate prerequisites for generalizations, presentation of results in the form of mathematical models permitting to make calculations on durability of the NPS concrete and reinforced concrete  structures with the required accuracy. 

  19. Collapse Mechanisms Of Masonry Structures

    Science.gov (United States)

    Zuccaro, G.; Rauci, M.

    2008-07-01

    The paper outlines a possible approach to typology recognition, safety check analyses and/or damage measuring taking advantage by a multimedia tool (MEDEA), tracing a guided procedure useful for seismic safety check evaluation and post event macroseismic assessment. A list of the possible collapse mechanisms observed in the post event surveys on masonry structures and a complete abacus of the damages are provided in MEDEA. In this tool a possible combination between a set of damage typologies and each collapse mechanism is supplied in order to improve the homogeneity of the damages interpretation. On the other hand recent researches of one of the author have selected a number of possible typological vulnerability factors of masonry buildings, these are listed in the paper and combined with potential collapse mechanisms to be activated under seismic excitation. The procedure takes place from simple structural behavior models, derived from the Umbria-Marche earthquake observations, and tested after the San Giuliano di Puglia event; it provides the basis either for safety check analyses of the existing buildings or for post-event structural safety assessment and economic damage evaluation. In the paper taking advantage of MEDEA mechanisms analysis, mainly developed for the post event safety check surveyors training, a simple logic path is traced in order to approach the evaluation of the masonry building safety check. The procedure starts from the identification of the typological vulnerability factors to derive the potential collapse mechanisms and their collapse multipliers and finally addresses the simplest and cheapest strengthening techniques to reduce the original vulnerability. The procedure has been introduced in the Guide Lines of the Regione Campania for the professionals in charge of the safety check analyses and the buildings strengthening in application of the national mitigation campaign introduced by the Ordinance of the Central Government n. 3362

  20. Thermal properties of masonry materials for passive-solar design: A state-of-the-art review

    Science.gov (United States)

    Vangeem, M. G.; Fiorato, A. E.

    1983-04-01

    Available test data are summarized, test methods are evaluated and values are recommended for thermal properties of masonry to be used in passive solar design. Values of specific heat, conductivity, and diffusivity are given for concrete and clay brick. Variations of these values with other physical properties such as density, moisture content, and temperature are shown. Variations of data due to different test methods are analyzed. Values of absorptivity and emissivity for concrete and clay brick, and associated test methods are discussed.

  1. Damage to historic brick masonry structures. Masonry damage diagnostic system and damage atlas for evaluation of deterioration

    NARCIS (Netherlands)

    Balen, K. van; Binda, L.; Hees, R.P.J. van; Franke, L.

    1996-01-01

    The aim of the research on brick masonry degradation supported by the D.G. XII is presented. The project is delivering the following: ► Damage Atlas of ancient brick masonry, a book with a description of the types of damage, and their possible causes, in ancient brick masonry structures; ► Masonry D

  2. The Bourgain-Tzafriri conjecture and concrete constructions of non-pavable projections

    CERN Document Server

    Casazza, Peter G; Mixon, Dustin G; Tremain, Janet C

    2010-01-01

    It is known that the Kadison-Singer Problem (KS) and the Paving Conjecture (PC) are equivalent to the Bourgain-Tzafriri Conjecture (BT). Also, it is known that (PC) fails for $2$-paving projections with constant diagonal $1/2$. But the proofs of this fact are existence proofs. We will use variations of the discrete Fourier Transform matrices to construct concrete examples of these projections and projections with constant diagonal $1/r$ which are not $r$-pavable in a very strong sense. In 1989, Bourgain and Tzafriri showed that the class of zero diagonal matrices with small entries (on the order of $\\le 1/log^{1+\\epsilon}n$, for an $n$-dimensional Hilbert space) are {\\em pavable}. It has always been assumed that this result also holds for the BT-Conjecture - although no one formally checked it. We will show that this is not the case. We will show that if the BT-Conjecture is true for vectors with small coefficients (on the order of $\\le C/\\sqrt{n}$) then the BT-Conjecture is true and hence KS and PC are true.

  3. 75 FR 62181 - Annual Materials Report on New Bridge Construction and Bridge Rehabilitation

    Science.gov (United States)

    2010-10-07

    ... the NBI: steel, concrete, pre-stressed concrete, and other. The category ``other'' includes wood, timber, masonry, aluminum, wrought iron, cast iron, and other. Material type is the predominate type...

  4. EI Scale: an environmental impact assessment scale related to the construction materials used in the reinforced concrete

    OpenAIRE

    Gilson Morales; Antonio Edésio Jungles; Sheila Elisa Scheidemantel Klein; Juliana Guarda

    2010-01-01

    This study aimed to create EI Scal, an environmental impact assessment scal, related to construction materials used in the reinforced concrete structure production. The main reason for that was based on the need to classify the environmental impact levels through indicators to assess the damage level process. The scale allowed converting information to estimate the environmental impact caused. Indicators were defined trough the requirements and classification criteria of impact aspects consid...

  5. Composition and leaching of construction and demolition waste: inorganic elements and organic compounds.

    Science.gov (United States)

    Butera, Stefania; Christensen, Thomas H; Astrup, Thomas F

    2014-07-15

    Thirty-three samples of construction and demolition waste collected at 11 recycling facilities in Denmark were characterised in terms of total content and leaching of inorganic elements and presence of the persistent organic pollutants PCBs and PAHs. Samples included (i) "clean" (i.e. unmixed) concrete waste, (ii) mixed masonry and concrete, (iii) asphalt and (iv) freshly cast concrete cores; both old and newly generated construction and demolition waste was included. PCBs and PAHs were detected in all samples, generally in non-critical concentrations. Overall, PAHs were comparable to background levels in urban environments. "Old" and "new" concrete samples indicated different PCB congener profiles and the presence of PCB even in new concrete suggested that background levels in raw materials may be an issue. Significant variability in total content of trace elements, even more pronounced for leaching, was observed indicating that the number of analysed samples may be critical in relation to decisions regarding management and utilisation of the materials. Higher leaching of chromium, sulphate and chloride were observed for masonry-containing and partly carbonated samples, indicating that source segregation and management practices may be important. Generally, leaching was in compliance with available leaching limits, except for selenium, and in some cases chromium, sulphate and antimony. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Ambient Cured Alkali Activated Flyash Masonry Units

    Science.gov (United States)

    Venugopal, K.; Radhakrishna; Sasalatti, Vinod M.

    2016-09-01

    Geopolymers belong to a category of non-conventional and non-Portland cement based cementitious binders which are produced using industrial by products like fly ash and ground granulated blast furnace slag (GGBFS). This paper reports on the development of geopolymer mortars for production of masonry units. The geopolymer mortars were prepared by mixing various by products with manufactured sand and a liquid mixture of sodium silicate and sodium hydroxide solutions. After curing at ambient conditions, the masonry units were tested for strength properties such as water absorption, initial rate of absorption, compression, shear- bond, and stress-strain behaviour etc. It was observed that the flexural strength of the blocks is more than 2 MPa and shear bond strength is more than 0.4MPa. It was found that the properties of geopolymer blocks were superior to the traditional masonry units. Hence they can be recommended for structural masonry.

  7. Design, construction and conditions of the application of unreinforced concrete final lining in conventionally driven tunnels

    Science.gov (United States)

    Faltýnek, Jan; Hořejší, Jiří; Mařík, Libor; Růžička, Pavel

    2017-09-01

    The way to an economic design in the final lining in conventionally driven tunnels lies in structural analysing based on the actually encountered geotechnical conditions. Regarding reinforced concrete structures, many standards and regulations applicable to designing and building structures and taking them over by the client before their commissioning and before the end of the warranty period respectively exist in the Czech Republic. If the local conditions allow it, it is possible to design the final lining as an unreinforced concrete structure. In such a case it is necessary to take the differences into consideration in the structural design and in the possibilities of the lining behaviour and to set criteria for taking over the lining allowing for its use. Setting too stringent criteria for cracking can lead to an increase in the contract price, either because of the necessity for reinforcing the lining or because of the fact that the contractor reduces the risk by incorporating the assumed cost of repairs into the total cost. The paper describes basic differences in the approach to reinforced concrete and unreinforced concrete linings, the possibilities of limiting formation of cracks by means of the concrete mix design, by selection of the technological procedure of the work and the method of curing after stripping. The text contains a comparison of criteria for assessing the surface of an unreinforced concrete lining with criteria in foreign regulations.

  8. Experimental and analytical investigation of the lateral load response of confined masonry walls

    Directory of Open Access Journals (Sweden)

    Hussein Okail

    2016-04-01

    Full Text Available This paper investigates the behavior of confined masonry walls subjected to lateral loads. Six full-scale wall assembles, consisting of a clay masonry panel, two confining columns and a tie beam, were tested under a combination of vertical load and monotonic pushover up to failure. Wall panels had various configurations, namely, solid and perforated walls with window and door openings, variable longitudinal and transverse reinforcement ratios for the confining elements and different brick types, namely, cored clay and solid concrete masonry units. Key experimental results showed that the walls in general experienced a shear failure at the end of the lightly reinforced confining elements after the failure of the diagonal struts formed in the brick wall due to transversal diagonal tension. Stepped bed joint cracks formed in the masonry panel either diagonally or around the perforations. A numerical model was built using the finite element method and was validated in light of the experimental results. The model showed acceptable correlation and was used to conduct a thorough parametric study on various design configurations. The conducted parametric study involved the assessment of the load/displacement response for walls with different aspect ratios, axial load ratios, number of confining elements as well as the size and orientation of perforations. It was found that the strength of the bricks and the number of confining elements play a significant role in increasing the walls’ ultimate resistance and displacement ductility.

  9. Construction of five-piece segment using high-fluidity concrete; Koryudo togo bunkatsu segment no seko jisseki

    Energy Technology Data Exchange (ETDEWEB)

    Suda, Y.; Fukuzawa, I.; Matsunaga, H. [Tokyo Electric Power Co. Inc., Tokyo (Japan)

    1998-09-05

    After reviewing RC segment materials and the number of joints required, a segment of five equal pieces using high-fluidity concrete is employed in conduit construction work (for 500kV transmission lines) near Hommoku Wharf, Kanagawa Prefecture, which is for reduction in the shield tunnel construction cost (segment cost rate approximately 1/3). The use of high-fluidity concrete raises the materials cost a little but the factory overhead, expenditures for fabrication and formwork construction are lowered because some working processes may be dispensed with, such as the processes of compaction by vibration, surface finish, and formwork movement, and because the formwork main body may be simplified in structure. Although the standard tunnel specifications mention a segment consisting of 6 pieces, the 5-piece segment adopted in this construction work lowers the cost approximately 20% thanks to reduction in the numbers of joints between segment pieces and between rings. In the shield tunnelling process, assembly is easier and the construction work is executed without hitches deserving special mention. The new technique is comparable to the conventional ones in terms of quality and process management. Since the number of joints per piece between rings is reduced from the 3 in the conventional method to the 2 in this new method, two core-sensing pins are provided per piece between rings for assuring accuracy and shortening time in assembling. 2 refs., 8 figs., 11 tabs.

  10. Rubble masonry response under cyclic actions: The experience of L’Aquila city (Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Fonti, Roberta, E-mail: roberta.fonti@tum.de; Barthel, Rainer, E-mail: r.barthel@lrz.tu-muenchen.de [TUM University, Chair of Structural Design, Arcisstraße 21, 80333 Munich (Germany); Formisano, Antonio, E-mail: antoform@unina.it [University of Naples “Federico II”, DIST Department, P.le V. Tecchio, 80, 80125 Naples (Italy); Borri, Antonio, E-mail: antonio.borri@unipg.it [University of Perugia, Department of Engineering, Via G. Duranti 95, 06125 Perugia (Italy); Candela, Michele, E-mail: ing.mcandela@libero.it [University of Reggio Calabria, PAU Department, Salita Melissari 1, 89124 Reggio Calabria (Italy)

    2015-12-31

    Several methods of analysis are available in engineering practice to study old masonry constructions. Two commonly used approaches in the field of seismic engineering are global and local analyses. Despite several years of research in this field, the various methodologies suffer from a lack of comprehensive experimental validation. This is mainly due to the difficulty in simulating the many different kinds of masonry and, accordingly, the non-linear response under horizontal actions. This issue can be addressed by examining the local response of isolated panels under monotonic and/or alternate actions. Different testing methodologies are commonly used to identify the local response of old masonry. These range from simplified pull-out tests to sophisticated in-plane monotonic tests. However, there is a lack of both knowledge and critical comparison between experimental validations and numerical simulations. This is mainly due to the difficulties in implementing irregular settings within both simplified and advanced numerical analyses. Similarly, the simulation of degradation effects within laboratory tests is difficult with respect to old masonry in-situ boundary conditions. Numerical models, particularly on rubble masonry, are commonly simplified. They are mainly based on a kinematic chain of rigid blocks able to perform different “modes of damage” of structures subjected to horizontal actions. This paper presents an innovative methodology for testing; its aim is to identify a simplified model for out-of-plane response of rubbleworks with respect to the experimental evidence. The case study of L’Aquila district is discussed.

  11. Rubble masonry response under cyclic actions: The experience of L'Aquila city (Italy)

    Science.gov (United States)

    Fonti, Roberta; Barthel, Rainer; Formisano, Antonio; Borri, Antonio; Candela, Michele

    2015-12-01

    Several methods of analysis are available in engineering practice to study old masonry constructions. Two commonly used approaches in the field of seismic engineering are global and local analyses. Despite several years of research in this field, the various methodologies suffer from a lack of comprehensive experimental validation. This is mainly due to the difficulty in simulating the many different kinds of masonry and, accordingly, the non-linear response under horizontal actions. This issue can be addressed by examining the local response of isolated panels under monotonic and/or alternate actions. Different testing methodologies are commonly used to identify the local response of old masonry. These range from simplified pull-out tests to sophisticated in-plane monotonic tests. However, there is a lack of both knowledge and critical comparison between experimental validations and numerical simulations. This is mainly due to the difficulties in implementing irregular settings within both simplified and advanced numerical analyses. Similarly, the simulation of degradation effects within laboratory tests is difficult with respect to old masonry in-situ boundary conditions. Numerical models, particularly on rubble masonry, are commonly simplified. They are mainly based on a kinematic chain of rigid blocks able to perform different "modes of damage" of structures subjected to horizontal actions. This paper presents an innovative methodology for testing; its aim is to identify a simplified model for out-of-plane response of rubbleworks with respect to the experimental evidence. The case study of L'Aquila district is discussed.

  12. Design and Construction of a 50m Single Span Ultra High Performance Ductile Concrete Composite Road Bridge

    Directory of Open Access Journals (Sweden)

    Voo - Yen Lei

    2012-04-01

    Full Text Available A single span 50m long prestressed road bridge was constructed under Public Works Department in the State of Negeri Sembilan, Malaysia contract recently. The bridge was constructed at a small village, Kampung Linsum, crossing a river, Sungai Linggi. To date, this bridge is the Malaysia first and may also be the world longest composite road bridge which made from ultra-high performance ductile concrete (UHPdC. This paper presents the feature of the UHPdC precast girder; brief in-sight of the manufacturing of the girder; the construction sequence of the bridge; the design method and lastly the environmental impact calculation. The midspan deflections of the bridge at different construction history were compared against the collected field data and it showed that the calculated values generally agree well with the field data.

  13. Construction Costs Assessment of Structural Systems for Low-Rise and Social Welfare Housing

    Directory of Open Access Journals (Sweden)

    Carrillo Julián

    2015-09-01

    Full Text Available A comparative analysis of the costs related to the construction of low-rise, low-cost and social welfare housing was carried out. The study included three of the most commonly used structural systems for low-rise housing in Latin America, such as the traditional system of confined masonry walls, concrete walls conventionally reinforced with welded-wire meshes and concrete walls reinforced with steel fiber. The cost comparison was carried out by budgets analysis, which were performed based on construction quantities, unit prices and particular items for each structural system. It was found in the study that, from an economic point of view, the systems of concrete walls reinforced with welded-wire meshes or steel fibers are more advantageous than confined masonry systems. In addition, the integral comparison of the three structural systems demonstrates that the industrialized system of steel fiber reinforced concrete walls allows obtaining greater advantages of cleaning and sustainability, faster construction, lower cost and a more attractive scenario for builders investing in such projects.

  14. Cut-HDMR-based fully equivalent operational model for analysis of unreinforced masonry structures

    Indian Academy of Sciences (India)

    D Mukherjee; B N Rao; A M Prasad

    2012-10-01

    Mesoscale models are highly competent for understanding behaviour of unreinforced masonry structures. Their only limitation is large computational expense. Fully Equivalent Operational Model forms an equivalent mathematical model to represent a particular phenomenon where explicit relationship between inputs and outputs are unknown. This paper explores the ability of a major variant of High Dimensional Model Representation (HDMR) technique, namely Cut-HDMR, to construct the most efficient Fully Equivalent Operational Model for nonlinear finite element analysis of mesoscale model of an unreinforced masonry structure. Conclusions are reached on various aspects such as, suitability of interpolation schemes and order of Cut-HDMR approximation.

  15. Geometry control of long-span continuous girder concrete bridge during construction through finite element model updating

    Science.gov (United States)

    Wu, Jie; Yan, Quan-sheng; Li, Jian; Hu, Min-yi

    2016-04-01

    In bridge construction, geometry control is critical to ensure that the final constructed bridge has the consistent shape as design. A common method is by predicting the deflections of the bridge during each construction phase through the associated finite element models. Therefore, the cambers of the bridge during different construction phases can be determined beforehand. These finite element models are mostly based on the design drawings and nominal material properties. However, the accuracy of these bridge models can be large due to significant uncertainties of the actual properties of the materials used in construction. Therefore, the predicted cambers may not be accurate to ensure agreement of bridge geometry with design, especially for long-span bridges. In this paper, an improved geometry control method is described, which incorporates finite element (FE) model updating during the construction process based on measured bridge deflections. A method based on the Kriging model and Latin hypercube sampling is proposed to perform the FE model updating due to its simplicity and efficiency. The proposed method has been applied to a long-span continuous girder concrete bridge during its construction. Results show that the method is effective in reducing construction error and ensuring the accuracy of the geometry of the final constructed bridge.

  16. 29 CFR 1926.854 - Removal of walls, masonry sections, and chimneys.

    Science.gov (United States)

    2010-07-01

    ... to work on the top of a wall when weather conditions constitute a hazard. (d) Structural or load... 29 Labor 8 2010-07-01 2010-07-01 false Removal of walls, masonry sections, and chimneys. 1926.854... ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Demolition § 1926...

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

    Directory of Open Access Journals (Sweden)

    Ali, Majid

    2016-03-01

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

  18. Ulexite-galena intermediate-weight concrete as a novel design for overcoming space and weight limitations in the construction of efficient shields against neutrons and photons.

    Science.gov (United States)

    Aghamiri, S M R; Mortazavi, S M J; Razi, Z; Mosleh-Shirazi, M A; Baradaran-Ghahfarokhi, M; Rahmani, F; Faeghi, F

    2013-01-01

    Recently, due to space and weight limitations, scientists have tried to design and produce concrete shields with increased attenuation of radiation but not increased mass density. Over the past years, the authors' had focused on the production of heavy concrete for radiation shielding, but this is the first experience of producing intermediate-weight concrete. In this study, ulexite (hydrated sodium calcium borate hydroxide) and galena (lead ore) have been used for the production of a special intermediate-weight concrete. Shielding properties of this intermediate-weight concrete against photons have been investigated by exposing the samples to narrow and broad beams of gamma rays emitted from a ⁶⁰Co radiotherapy unit. Densities of the intermediate-weight concrete samples ranged 3.64-3.90 g cm⁻³, based on the proportion of the ulexite in the mix design. The narrow-beam half-value layer (HVL) of the ulexite-galena concrete samples for 1.25 MeV ⁶⁰Co gamma rays was 2.84 cm, much less than that of ordinary concrete (6.0 cm). The Monte Carlo (MC) code MCNP4C was also used to model the attenuation of ⁶⁰Co gamma-ray photons and Am-Be neutrons of the ulexite-galena concrete with different thicknesses. The ⁶⁰Co HVL calculated by MCNP simulation was 2.87 cm, indicating a good agreement between experimental measurements and MC simulation. Furthermore, MC-calculated results showed that thick ulexite-galena concrete shields (60-cm thickness) had a 7.22 times (722 %) greater neutron attenuation compared with ordinary concrete. The intermediate-weight ulexite-galena concrete manufactured in this study may have many important applications in the construction of radiation shields with weight limitations such as the swing or sliding doors that are currently used for radiotherapy treatment rooms.

  19. Strengthening masonry infill panels using engineered cementitious composites

    DEFF Research Database (Denmark)

    Dehghani, Ayoub; Fischer, Gregor; Nateghi Alahi, Fariborz

    2015-01-01

    This comprehensive experimental study aims at investigating the behavior of masonry infill panels strengthened by fiber reinforced engineered cementitious composites (ECC). The experimental program included testing of materials, masonry elements and panels. Material tests were carried out first f...

  20. Discussion on the construction technology of reinforced concrete shear wall structure%钢筋混凝土剪力墙结构施工技术

    Institute of Scientific and Technical Information of China (English)

    曾秋

    2013-01-01

    Through the summary of the construction of the reinforced concrete shear wall structure in engineering projects, from the shear wall formwork construction, installation and positioning, reinforced concrete construction quality control, door and window openings to the matters needing attention in the construction and other aspects of the high-rise buildings of reinforced concrete shear wall construction technology control points.%经过对工程项目中钢筋混凝土剪力墙结构的施工总结,从剪力墙的模板工程施工、钢筋的安装和定位、混凝土的施工质量控制、门窗洞口处施工注意事项等方面探讨了高层建筑钢筋混凝土剪力墙结构施工的技术控制要点。

  1. 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…

  2. Seepage and stress analysis of anti-seepage structures constructed with different concrete materials in an RCC gravity dam

    Directory of Open Access Journals (Sweden)

    Ming-chao Li

    2015-10-01

    Full Text Available This study used the finite element method (FEM to analyze the stress field and seepage field of a roller-compacted concrete (RCC dam, with an upstream impervious layer constructed with different types of concrete materials, including three-graded RCC, two-graded RCC, conventional vibrated concrete (CVC, and grout-enriched vibrated RCC (GEVR, corresponding to the design schemes S1 through S4. It also evaluated the anti-seepage performance of the imperious layer in the four design schemes under the normal water level and flood-check level. Stress field analysis of a retaining section and discharge section shows that the maximum tensile stress occurs near the dam heel, the maximum compressive stress occurs near the dam toe, and the stress distributions in the four schemes can satisfy the stress control criteria. Seepage field analysis shows that the uplift pressure heads in schemes S3 and S4 descend rapidly in the anti-seepage region, and that the calculated results of daily seepage flow under the steady seepage condition in these two schemes are about 30% to 50% lower than those in the other two schemes, demonstrating that CVC and GEVR show better anti-seepage performance. The results provide essential parameters such as the uplift pressure head and seepage flow for physical model tests and anti-seepage structure selection in RCC dams.

  3. Comparative analysis of structural concrete quality assurance practices on nine nuclear power plant construction projects. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Willenbrock, J.H.; Thomas, H.R. Jr.; Burati, J.L. Jr.

    1978-06-01

    The basic objective of this research effort was to perform a comparative analysis of the Quality Assurance practices related to the structural concrete phase on nine nuclear power plant projects which are (or have been) under construction in the United States in the past ten years. This analysis identified the response of each Quality Assurance program to the applicable criteria of 10 CFR Part 50, Appendix B as well as to the pertinent regulatory requirements and industry standards. The major emphasis was placed on the construction aspects of the structural concrete phase of each project. The engineering and design aspects were examined whenever they interfaced with the construction aspects. For those aspects of the Quality Assurance system which can be considered managerial in nature (i.e., organizational relationships, types of Quality Assurance programs, corrective action procedures, etc.) an attempt has been made to present the alternative approaches that were identified. For those aspects of the Quality Assurance system which are technical in nature (i.e., the frequency of testing for slump, compressive strength, etc.) an attempt has been made to present a comparative analysis between projects and in relation to the recommended or mandated practices presented in the appropriate industry codes and standards.

  4. Comparative analysis of structural concrete quality assurance practices on three fossil fuel power plant construction projects. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Willenbrock, J.H.; Thomas, H.R. Jr.; Burati, J.L. Jr.

    1978-06-01

    The basic objective of this research effort was to perform a comparative analysis of the Quality Assurance practices related to the structural concrete phase on three fossil fuel power plant projects which are (or have been) under construction in the United States in the past ten years. This analysis identified the response of each Quality Assurance program to criteria similar to those which apply on nuclear power plant projects. The major emphasis was placed on the construction aspects of the structural concrete phase of each project. The engineering and design aspects were examined whenever they interfaced with the construction aspects. For those aspects of the Quality Assurance system which can be considered managerial in nature (i.e., organizational relationships, types of Quality Assurance programs, corrective action procedures, etc.) an attempt has been made to present the alternative approaches that were identified. For those aspects of the Quality Assurance system which are technical in nature (i.e., the frequency of testing for slump, compressive strength, etc.) an attempt has been made to present a comparative analysis between projects and in relation to the recommended or mandated practices presented in the appropriate industry codes and standards.

  5. Self-Compacting Concrete

    OpenAIRE

    Okamura, Hajime; Ouchi, Masahiro

    2003-01-01

    Self-compacting concrete was first developed in 1988 to achieve durable concrete structures. Since then, various investigations have been carried out and this type of concrete has been used in practical structures in Japan, mainly by large construction companies. Investigations for establishing a rational mix-design method and self-compactability testing methods have been carried out from the viewpoint of making self-compacting concrete a standard concrete.

  6. Self-Compacting Concrete

    OpenAIRE

    Okamura, Hajime; Ouchi, Masahiro

    2003-01-01

    Self-compacting concrete was first developed in 1988 to achieve durable concrete structures. Since then, various investigations have been carried out and this type of concrete has been used in practical structures in Japan, mainly by large construction companies. Investigations for establishing a rational mix-design method and self-compactability testing methods have been carried out from the viewpoint of making self-compacting concrete a standard concrete.

  7. Lunar concrete: Prospects and challenges

    Science.gov (United States)

    Khitab, Anwar; Anwar, Waqas; Mehmood, Imran; Kazmi, Syed Minhaj Saleem; Munir, Muhammad Junaid

    2016-02-01

    The possibility of using concrete as a construction material at the Moon surface is considered. Dissimilarities between the Earth and the Moon and their possible effects on concrete are also emphasized. Availability of constituent materials for concrete at lunar surface is addressed. An emphasis is given to two types of materials, namely, hydraulic concrete and sulfur concrete. Hydraulic concrete necessitates the use of water and sulfur concrete makes use of molten sulfur in lieu of cement and water.

  8. NANOMODIFIED CONCRETE

    Directory of Open Access Journals (Sweden)

    B. M. Khroustalev

    2015-01-01

    Full Text Available One of the main directions in construction material science is the development of  next generation concrete that is ultra-dense, high-strength, ultra-porous, high heat efficient, extra corrosion-resistant. Selection of such direction is caused by extreme operational impacts on the concrete, namely: continuously increasing load on the concrete and various dynamics of such loads; the necessity in operation of concrete products in a wide temperature range and their exposure to various chemical and physical effects.The next generation concrete represents high-tech concrete mixtures with additives that takes on and retain the required properties when hardening and being used under any operational conditions. A differential characteristic of the next generation concrete is its complexity that presumes usage of various mineral dispersed components, two- and three fractional fine and coarse aggregates, complex chemical additives, combinations of polymer and iron reinforcement.Design strength and performance properties level of the next generation concrete is achieved by high-quality selection of the composition, proper selection of manufacturing techniques, concrete curing, bringing the quality of concrete items to the required level of technical condition during the operational phase. However, directed formation of its structure is necessary in order to obtain high-tech concrete.Along with the traditional methods for regulation of the next generation concrete structure, modification of concrete while using silica nanoparticles is also considered as a perspective one because the concrete patterning occurs due to introduction of a binder in a mineral matrix. Due to this it is possible to obtain nano-modified materials with completely new properties.The main problem with the creation of nano-modified concrete is a uniform distribution of nano-materials in the volume of the cement matrix which is particularly important in the cases of adding a modifier in

  9. Construction safety program for the National Ignition Facility, Appendix A

    Energy Technology Data Exchange (ETDEWEB)

    Cerruti, S.J.

    1997-06-26

    Topics covered in this appendix include: General Rules-Code of Safe Practices; 2. Personal Protective Equipment; Hazardous Material Control; Traffic Control; Fire Prevention; Sanitation and First Aid; Confined Space Safety Requirements; Ladders and Stairways; Scaffolding and Lift Safety; Machinery, Vehicles, and Heavy Equipment; Welding and Cutting-General; Arc Welding; Oxygen/Acetylene Welding and Cutting; Excavation, Trenching, and Shoring; Fall Protection; Steel Erection; Working With Asbestos; Radiation Safety; Hand Tools; Electrical Safety; Nonelectrical Work Performed Near Exposed High-Voltage Power-Distribution Equipment; Lockout/Tagout Requirements; Rigging; A-Cranes; Housekeeping; Material Handling and Storage; Lead; Concrete and Masonry Construction.

  10. Collapse Modeling of a Masonry Arch Dam Using the Cohesive Interface Elements

    Directory of Open Access Journals (Sweden)

    Jianwen Pan

    2015-01-01

    Full Text Available A finite element (FE approach with zero-thickness cohesive interface elements is presented to simulate collapse of continuum structures. The element removal technique merged with the general contact algorithm is adapted in the FE approach to achieve modeling for a transition from continua to discontinua, that is, fracture, fragmentation, and collapse. Collapse process of Meihua masonry arch dam, which is a famous disaster in dam engineering in China, is simulated and the failure mechanism is studied. The collapse process obtained from the presented procedure coincides with the field observation after the dam failure. The failure of Meihua arch dam can be attributed to reducing shear strength of the peripheral joint between the dam body and the concrete pedestal by daubing a layer of asphalt there. With low sliding resistance strength, the masonry dam body may slide upwards along the peripheral joint under hydrostatic pressure, leading to weakening of the arch action, fracturing, and final collapse of the dam.

  11. a Procedural Solution to Model Roman Masonry Structures

    Science.gov (United States)

    Cappellini, V.; Saleri, R.; Stefani, C.; Nony, N.; De Luca, L.

    2013-07-01

    The paper will describe a new approach based on the development of a procedural modelling methodology for archaeological data representation. This is a custom-designed solution based on the recognition of the rules belonging to the construction methods used in roman times. We have conceived a tool for 3D reconstruction of masonry structures starting from photogrammetric surveying. Our protocol considers different steps. Firstly we have focused on the classification of opus based on the basic interconnections that can lead to a descriptive system used for their unequivocal identification and design. Secondly, we have chosen an automatic, accurate, flexible and open-source photogrammetric pipeline named Pastis Apero Micmac - PAM, developed by IGN (Paris). We have employed it to generate ortho-images from non-oriented images, using a user-friendly interface implemented by CNRS Marseille (France). Thirdly, the masonry elements are created in parametric and interactive way, and finally they are adapted to the photogrammetric data. The presented application, currently under construction, is developed with an open source programming language called Processing, useful for visual, animated or static, 2D or 3D, interactive creations. Using this computer language, a Java environment has been developed. Therefore, even if the procedural modelling reveals an accuracy level inferior to the one obtained by manual modelling (brick by brick), this method can be useful when taking into account the static evaluation on buildings (requiring quantitative aspects) and metric measures for restoration purposes.

  12. Analysis on winter concrete construction technology selecting concept%冬季混凝土施工工艺的选择思路分析

    Institute of Scientific and Technical Information of China (English)

    赵路

    2014-01-01

    According to winter concrete engineering construction technology principles,the paper compares features and application scopes of three concrete construction technologies including sulphur-aluminate early-strength concrete,thermal storage method and frost-resisting admix-ture,and analyzes its construction technology selecting methods by combining with examples,with a view to select rational and scientific con-struction methods.%依据冬季混凝土工程施工的工艺原理,对使用硫铝酸盐早强混凝土、蓄热法、抗冻外加剂法三种混凝土施工工艺的特点及使用范围进行了对比,并结合实例,分析了工艺选择的方法,以选择科学合理的施工工法。

  13. 船闸薄壁衬砌墙混凝土施工工艺%Construction of Thin Concrete Lined Walls for Thre e Gorges Shiplock

    Institute of Scientific and Technical Information of China (English)

    马玉增

    2002-01-01

    With high rock slope in shiplock area, thin reinforced concrete lining walls are constructed for the shiplock system. The construction technology involves much complicated structures in formwork, fr equent interference due to crossover working procedures, tight time schedule, hi gh quality of reinforced concrete and showcase appearance requirements, hidden t roubles affecting construction safety. With above-mentioned factors in considera tion, a single-side-separated sliding formwork technology advanced from past sli ding formwork experiences has been developed and applied successfully. This new technology is beneficial in quick and safe operation, capable to assure best qua lity and appearance of shiplock concrete works, and has filled up the gap in ter ms of construction sliding formwork in our country.

  14. Masonry structures between mechanics and architecture

    CERN Document Server

    Pedemonte, Orietta; Williams, Kim

    2015-01-01

    This book provides an overview of state of the art research in the mechanics of masonry structures. It continues the series Between Mechanics and Architecture, initially launched in 1995 from the collaboration of several renowned scholars, including Edoardo Benvenuto and Patricia Radelet-de Grave.   The contributions in this volume represent the main approaches to the complex topic of masonry structures. In addition to historical studies, the mechanical behavior of masonry arches and structures is studied using different approaches (structural analysis, limit analysis, elastic analysis, plasticity, mathematical approaches, etc.), at times difficult to reconcile, at others intertwined and complementary.   Readers will have the opportunity to compare different theoretical lines of inquiry and thus explore new horizons of research.   Contributions by: Danila Aita Andrea Bacigalupo Riccardo Barsotti Stefano Bennati Antonio Brencich Mario Como Salvatore D’Agostino Luigi Gambarotta Jacques Heyman Santiago Huer...

  15. 大坝加高混凝土施工技术研究综述%Research Overview about the Concrete Construction Technology of Dam Heightening

    Institute of Scientific and Technical Information of China (English)

    周厚贵

    2015-01-01

    在查阅国内外大坝加高混凝土施工资料及工程实践的基础上,阐述了国内外典型混凝土坝在加高施工中针对技术难题所开展的各项研究.从老混凝土体拆除、老混凝土面处理、新老混凝土结合、新混凝土浇筑及加高施工与枢纽运行关系的处理等方面对其研究现状进行了归纳总结,综述了大坝加高混凝土施工技术,有助于建立完善的大坝加高工程施工的理论体系及施工技术体系.%On the basis of engineering practice and consulting concrete construction materials about dam heightening at home and a-broad, various studies carried out for the technical problems in heightening construction of typical concrete dam are elaborated. Re-search status are summarized for several aspects, such as the old concrete body removal, old concrete surface treatment, new and old concrete combination, new concrete pouring,the relationship processing between heightening construction and the hub operation and so on. Furthermore, the concrete construction technology of dam heightening is summarized. This can help to build perfect theoretical sys-tem and construction technology system of dam heightening project construction.

  16. Extending the Season for Concrete Construction and Repair. Phase II - Defining Engineering Parameters

    Science.gov (United States)

    2006-04-01

    18 Tricalcium aluminate 12 7 8 Tetracalcium alumino-ferrite 8 12 9 Fineness (Blaine, m2/kg) 350 350 370 * Data from Mindess and Young (1981...compares favorably to published values for the thermal coefficient of expansion of mortar of between 7 and 12 ppm/°C ( Mindess and Young 1981, p. 526...Prentice- Hall. Mindess , S. and J. F. Young. 1981. Concrete. Englewood Cliffs, New Jersey: Prentice-Hall, Inc. Mironov, S. A. 1977. Theory and

  17. Epoxy asphalt concrete is a perspective material for the construction of roads

    Science.gov (United States)

    Vyrozhemskyi, Valerii; Kopynets, Ivan; Kischynskyi, Sergii; Bidnenko, Nataliia

    2017-09-01

    An effective way to increase the durability of asphalt concrete pavements that are subject to high traffic loads and adverse weather and climatic factors is the use of polymer additives which drastically improve the rheological and physical-mechanical properties of bitumen. The use of thermosetting polymers including epoxy resins for asphalt and bitumen modification is seen as a perspective solution for this issue. Conducted at DerzhdorNDI SE studies have proved high riding qualities of asphalt pavements that contain epoxy resins. When replacing 20-35% of bitumen with epoxy component, a significant improvement in strength characteristics of asphalt pavement is noted, especially at elevated temperatures. Specific feature of epoxy asphalt concrete is its ability to gain strength over a long-term operation. Thus, despite the increased cost of epoxy asphalt concrete, long service life of pavements on its basis (up to 30 years as predicted) ensures a high profitability of using this material, especially on the roads with heavy traffic and severe traffic conditions.

  18. Computer-Aided Construction at Designing Reinforced Concrete Columns as Per Ec

    Directory of Open Access Journals (Sweden)

    Zielińska M.

    2015-02-01

    Full Text Available The article presents the authors’ computer program for designing and dimensioning columns in reinforced concrete structures taking into account phenomena affecting their behaviour and information referring to design as per EC. The computer program was developed with the use of C++ programming language. The program guides the user through particular dimensioning stages: from introducing basic data such as dimensions, concrete class, reinforcing steel class and forces affecting the column, through calculating the creep coefficient taking into account the impact of imperfection depending on the support scheme and also the number of mating members at load shit, buckling length, to generating the interaction curve graph. The final result of calculations provides two dependence points calculated as per methods of nominal stiffness and nominal curvature. The location of those points relative to the limit curve determines whether the column load capacity is assured or has been exceeded. The content of the study describes in detail the operation of the computer program and the methodology and phenomena which are indispensable at designing axially and eccentrically the compressed members of reinforced concrete structures as per the European standards.

  19. EI Scale: an environmental impact assessment scale related to the construction materials used in the reinforced concrete

    Directory of Open Access Journals (Sweden)

    Gilson Morales

    2010-12-01

    Full Text Available This study aimed to create EI Scal, an environmental impact assessment scal, related to construction materials used in the reinforced concrete structure production. The main reason for that was based on the need to classify the environmental impact levels through indicators to assess the damage level process. The scale allowed converting information to estimate the environmental impact caused. Indicators were defined trough the requirements and classification criteria of impact aspects considering the eco-design theory. Moreover, the scale allowed classifying the materials and processes environmental impact through four score categories which resulted in a single final impact score. It was concluded that the EI scale could be cheap, accessible, and relevant tool for environmental impact controlling and reduction, allowing the planning and material specification to minimize the construction negative effects caused in the environment.

  20. Monomaterial ecological buildings, with Mopatel® and Ecopierra® concrete

    Directory of Open Access Journals (Sweden)

    Livia Miron

    2013-09-01

    Full Text Available This paper presents a case study performed on a pilot building from Gainesti, Suceava county. The constructive system used is unique in that it employs a monomaterial, namely ecological concrete of type MOPATEL® or ECOPIERRA®. These types of concrete, created by eng. Petrache Teleman, possess international patents and have received awards in Brussels, but they are not yet used in Romania. These materials can be used integrally to make all the constructive elements of a building – load-bearing elements (floors, beams, pillars, walls as well as the secondary elements of a partly finished building, such as screeds or non-load-bearing masonry. The constructive system also uses ecological mortars which integrally ensure the interior and exterior finishing. The final result is a building practically made from a single type of material, in which the effect of thermal bridges is reduced to a maximum. The MOPATEL and ECOPIERRA types of concrete have a mechanical resistance similar to regular concrete, but they also have superior thermal insulation qualities (between 0.09 and 0.28 W/mK, they are permeable to the transfer of water vapours from the interior to the exterior of the building, and, in certain compositions, they can also be considered waterproof.

  1. Maintaining Indoor Environmental Quality (IEQ) during Construction and Renovation

    Science.gov (United States)

    ... renovation activities. Sources include drywall, plaster, concrete, soil, wood, masonry, flooring, roofing, and ductwork. Non toxic dusts are irritants and can exacerbate lung conditions such as asthma and chronic obstructive lung ...

  2. The evaluation of damage mechanism of unreinforced masonry buildings after Van (2011) and Elazig (2010) Earthquakes

    Science.gov (United States)

    Güney, D.; Aydin, E.; Öztürk, B.

    2015-07-01

    On March 8th, 2010 Karakocan-Elazig earthquake of magnitude 6.0 occurred at a region where masonry and adobe construction is very common. Karakocan-Elazig is located in a high seismicity region on Eastern Anatolian Fault System (EAFS). Due to the earthquake, 42 people were killed and 14’113 buildings were damaged. Another city, Van located at South east of Turkey is hit by earthquakes with M = 7.2 occurred on October 23rd, 2011 at 13:41 (local time), whose epicenter was about 16 km north of Van (Tabanli village) and M = 5.6 on November 9th, 2011 with an epicenter near the town of Edremit, south of Van and caused the loss of life and heavy damages. Both earthquakes killed 644 people and 2608 people were injured. Approximately 10’000 buildings were seriously damaged. There are many traditional types of structures existing in the region hit by earthquakes (both Van and Elazig). These buildings were built as adobe, unreinforced masonry or mixed type. These types of buildings are very common in rural areas (especially south and east) of Turkey because of easy workmanship and cheap construction cost. Many of those traditional type structures experienced serious damages. The use of masonry is very common in some of the world's most hazard-prone regions, such as in Latin America, Africa, the Indian subcontinent and other parts of Asia, the Middle East, and southern Europe. Based on damage and failure mechanism of those buildings, the parameters affecting the seismic performance of those traditional buildings are analyzed in this paper. The foundation type, soil conditions, production method of the masonry blocks, construction method, the geometry of the masonry walls, workmanship quality, existence of wooden beams, type of roof, mortar between adobe blocks are studied in order to understand the reason of damage for these types of buildings.

  3. HOW TO OBTAIN ECONOMICALLY EFFICIENT ASPHALT CONCRETE MIXTURES FOR CONSTRUCTIVE AUTOMOBILE ROAD AND STREET PAVEMENTS

    Directory of Open Access Journals (Sweden)

    V. A. Verenko

    2009-01-01

    Full Text Available The paper describes a methodology for evaluation of technical and economic efficiency of asphalt concrete mixture components. The method allows to perform a directed search for new materials which are used for mixture preparation and it also provides an efficient use of monetary funds. Firstly, it is possible to obtain this result due to optimum price-quality ratio of asphalt mixture which is determined by its service life in a pavement; secondly, it is possible to obtain this result due to  exclusion of errors while selecting components of the asphalt mixture out of the whole range applied presently in the world practice.

  4. Using loose-fill perlite with normal weight precast wall panels to lower the cost, time of construction projects, and to provide an alternative to lightweight concrete

    Science.gov (United States)

    Al kulabi, Ahmed Kamil

    Lightweight concrete has been used in construction because of its properties, such as thermal, and fire resistances although it is more expensive and less available than normal weight concrete. One way to save time, cost, and to provide an alternative to lightweight concrete in construction projects is to reduce the number of installed insulations on precast wall panels and to improve the properties of normal weight concrete panels, respectively. These goals can be achieved by improving the four properties of precast panels, such as thermal resistance, fire resistance, heat capacity, and sound insulation by using perlite as insulation. The main goals of this research are getting buildings constructed or modified in less time and cost by producing superior wall panels and improving the properties of normal weight panels. Superior wall panels are new panels that provide the four properties listed above. Precast panels with different cross sections, concrete type, and different amounts of perlite will be investigated to observe the impact of each factor on the mentioned properties. The cost of each panel will be studied, and analytical methods will be used to find the optimum panel that provides the four mentioned properties with least cost. Moreover, theoretical methods will be applied to calculate the four properties for each panel. The preliminary theoretical calculations approved a good improvement in the four properties. In summary, the four properties of precast panels can be improved, time, and cost of construction can be reduced by using perlite as insulation.

  5. Utilization of crushed clay brick in concrete industry

    Directory of Open Access Journals (Sweden)

    Ali A. Aliabdo

    2014-03-01

    Full Text Available A comprehensive experimental program regarding the use of recycled aggregates produced from demolition of brick buildings is presented. The brick wastes were crushed, sorted and classified into coarse and fine aggregates as well as powder (CBP. The first phase of the research focuses on the effect of incorporating recycled aggregates on physico-mechanical properties of paste, mortar and concrete. Non-traditional tests including X-ray diffraction (XRD, thermo-gravimetric analysis (TGA and micro-structural analysis (MSA were performed. The second phase of the program explores the effect of using recycled aggregates on properties of concrete masonry units. A total of 44 mixtures were utilized throughout the program. Results show cement paste when modified with 25% CBP achieves smaller pore size and lower weight loss under high temperature than reference paste. Furthermore, the use of recycled aggregates reduces the overall unit weight of concrete masonry units. Actually, modified concrete masonry units incorporating recycled aggregates achieve lower unit weight, higher thermal resistance and absorption rate than reference units. Although considerable strength reduction is noticeable by substitution, compressive strength levels meet the Egyptian specifications limitations. Critical replacement ratios are suggested to produce load bearing-concrete masonry units. Based on experimental evidences, it can be stated that the use of recycled aggregate and dust made of clay bricks is promising in many applications where the thermal resistance, cost and environmental aspects are imperative.

  6. Seismic capacity evaluation of unreinforced masonry residential buildings in Albania

    Directory of Open Access Journals (Sweden)

    H. Bilgin

    2012-12-01

    Full Text Available This study evaluates seismic capacity of the unreinforced masonry buildings with the selected template designs constructed per pre-modern code in Albania considering nonlinear behaviour of masonry. Three residential buildings with template designs were selected to represent an important percentage of residential buildings in medium-size cities located in seismic regions of Albania. Selection of template designed buildings and material properties were based on archive and site survey in several cities of Albania. Capacity curves of investigated buildings were determined by pushover analyses conducted in two principal directions. The seismic performances of these buildings have been determined for various earthquake levels. Seismic capacity evaluation was carried out in accordance with FEMA (Federal Emergency Management Agency 440 guidelines. Reasons for building damages in past earthquakes are examined using the results of capacity assessment of investigated buildings. It is concluded that of the residential buildings with the template design, with the exception of one, are far from satisfying required performance criteria. Furthermore, deficiencies and possible solutions to improve the capacity of investigated buildings are discussed.

  7. Properties of wastepaper sludge in geopolymer mortars for masonry applications.

    Science.gov (United States)

    Yan, Shiqin; Sagoe-Crentsil, Kwesi

    2012-12-15

    This paper presents the results of an investigation into the use of wastepaper sludge in geopolymer mortar systems for manufacturing construction products. The investigation was driven by the increasing demand for reuse options in paper-recycling industry. Both fresh and hardened geopolymer mortar properties are evaluated for samples incorporating dry wastepaper sludge, and the results indicate potential end-use benefits in building product manufacture. Addition of wastepaper sludge to geopolymer mortar reduces flow properties, primarily due to dry sludge absorbing water from the binder mix. The average 91-day compressive strength of mortar samples incorporating 2.5 wt% and 10 wt% wastepaper sludge respectively retained 92% and 52% of the reference mortar strength. However, contrary to the normal trend of increasing drying shrinkage with increasing paper sludge addition to Portland cement matrices, the corresponding geopolymer drying shrinkage decreased by 34% and 64%. Equally important, the water absorption of hardened geopolymer mortar decreased with increasing paper sludge content at ambient temperatures, providing good prospects of overall potential for wastepaper sludge incorporation in the production of building and masonry elements. The results indicate that, despite its high moisture absorbance due to the organic matter and residual cellulose fibre content, wastepaper sludge appears compatible with geopolymer chemistry, and hence serves as a potential supplementary additive to geopolymer cementitious masonry products.

  8. Surface Thermal Insulation and Pipe Cooling of Spillways during Concrete Construction Period

    Directory of Open Access Journals (Sweden)

    Wang Zhenhong

    2014-01-01

    Full Text Available Given that spillways adopt a hydraulic thin concrete plate structure, this structure is difficult to protect from cracks. The mechanism of the cracks in spillways shows that temperature stress is the major reason for cracks. Therefore, an effective way of preventing cracks is a timely and reasonable temperature-control program. Studies show that one effective prevention method is surface thermal insulation combined with internal pipe cooling. The major factors influencing temperature control effects are the time of performing thermal insulation and the ways of internal pipe cooling. To solve this problem, a spillway is taken as an example and a three-dimensional finite element program and pipe cooling calculation method are adopted to conduct simulation calculation and analysis on the temperature fields and stress fields of concretes subject to different temperature-control programs. The temperature-control effects are then compared. Optimization results show that timely and reasonable surface thermal insulation and water-flowing mode can ensure good temperature-control and anticrack effects. The method has reference value for similar projects.

  9. Electrokinetic removal of salt from brick masonry

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Pedersen, Anne Juul; Rörig-Dalgaard, Inge

    2006-01-01

    A method to effectively remove salts from masonry is lacking. The present study aims at determining the removal efficiency of salts from bricks in an applied low current electric DC field. At first an investigation on removal of NaCl and Na(NO3)2 from spiked bricks in laboratory scale was conducted...

  10. Electrokinetic removal of salt from brick masonry

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Pedersen, Anne Juul; Rörig-Dalgaard, Inge

    2006-01-01

    A method to effectively remove salts from masonry is lacking. The present study aims at determining the removal efficiency of salts from bricks in an applied low current electric DC field. At first an investigation on removal of NaCl and Na(NO3)2 from spiked bricks in laboratory scale was conducted...

  11. Construction Techniques of Asphalt Concrete Pavement%浅析沥青混凝土路面施工技术

    Institute of Scientific and Technical Information of China (English)

    席晓彬

    2012-01-01

    随着我国公路建设事业的发展,沥青混凝土路面由于具有表面平整、行车舒适、耐磨、噪音小、施工周期短、养护维修简便等优点,无扬尘、无振动,还具有良好的抗滑性,因而被越来越多地应用到公路建设中。因此,只有对施工组织设计以及每道工序严格地控制,才能保证沥青混凝土路面的质量。%With the development of highway construction in China,asphalt concrete pavement is widely used for its advantages of smooth surface,comfortable driving,abrasion resistance,low noise,short construction period and easy maintenance and repair,and its non-dust and non-vibration construction with better slip resistance.Therefore,every procedure in construction and design should be strictly controlled to guarantee the quality of the pavement.

  12. User costs as one of main advantages of precast concrete application in highway construction

    Science.gov (United States)

    Tomek, Radan

    2017-09-01

    Road user cost primarily refer to the monetized components of road (re)construction impacts, such as the user delay costs, vehicle operating costs, crash costs and emission costs. Objective of this paper is to analyze and appraise the advantages and benefits of the innovative prefabrication approach in contrast to traditional cast-in-place construction method. The goal is to reduce these additional costs borne by motorists and the community at-large as a result of road construction activity to their minimum through application of the prefabrication. Assessing two basic possible approaches to highway infrastructure construction - casting the road pavements and structures either in place or precast off the site - it can be concluded that the initial capital investment costs do not vary much. Substantial differences can be recognized when comparing their life-cycle costs and an extent to which their construction process affects the public, environment and the local economy. Prefabrication of any structure component off-site offers major construction time and user cost savings in comparison with the traditional cast-in-place methods of construction. Precast prestressed road pavements’ technology and precasting bridges’ parts and elements offers dramatic increase in durability, while it also substantially decreases construction time and resulting user costs.

  13. 水泥混凝土桥面铺装施工质量控制%Pavement construction quality control of cement concrete bridge deck

    Institute of Scientific and Technical Information of China (English)

    贾志民

    2009-01-01

    Combining with construction practice of the bridge deck pavement, the author introduces the quality control points in the cement concrete bridge deck pavement construction from aspects of hinge joint concrete construction and bridge deck pavement concrete construction, so as to perfect bridge deck pavement construction technology, ensure that the bridge deck concrete pavement layer has design strength, in-tegrity and anti-permeability, anti-crack and anti-impact performance.%结合桥面铺装的施工实践,从铰缝混凝土施工和桥面铺装混凝土施工两方面介绍了水泥混凝土桥面铺装施工中的质量控制要点,以完善桥面铺装施工工艺,保证桥面混凝土铺装层具有设计强度、整体性及抗渗抗裂抗冲击性.

  14. To Discuss the Construction Technology of Building Concrete%探讨建筑中混凝土的施工技术

    Institute of Scientific and Technical Information of China (English)

    初艳鲲

    2013-01-01

    In building construction, the construction technolo-gy of concrete is the key to the quality of the entire project. R-ebar and concrete are important support of engineering load-b-earing, and a large amount and widely used of concrete is an i-ntegral part of the engineering and construction materials. Rei-nforced the concrete construction technology and put the high level of technology into used in construction engineering, whi-ch can effectively improve the quality of projects and shorten the construction period and improve the economic benefits of the project. In this article, the author analysis and explore the construction technology in concrete.%  在建筑工程的施工中,混凝土的施工技术是整个工程质量的关键之处。钢筋与混凝土是工程承重的重要支撑,凝土用量大、用途广,是工程建筑中的不可或缺的材料。加强对混凝土施工技术,将高水平的混凝土施工技术应用在建筑工程项目中,可以有效提高项目质量和缩短工期,提高项目的经济效益。本文对于建筑工程中混凝土施工技术进行了研究和分析。

  15. Concrete Pavement Joint Deterioration

    OpenAIRE

    2016-01-01

    Concrete pavements are an important part of our national infrastructure. In recent years the relatively small number of reported joints deteriorating prematurely in concrete pavements around Indiana has increased. Changes over the past 45 years in INDOT specification, pavement materials, designs and construction practices, and current de-icing materials were examined and related to the durability of concrete at the joints of existing pavements. A survey of concrete pavements across the state ...

  16. An Analysis of Insulated Concrete Forms for use in Sustainable Military Construction

    Science.gov (United States)

    2014-03-27

    homes were constructed using wood framing with rolled insulation batting , and the other two were constructed using ICF blocks. The results of this...energy software. One home used wood framing with rolled insulation batting , and the other used ICFs. Energy simulations were run for a... insulation board, steel framing with rolled insulation batting between the studs, and the continuous layer of interior drywall. The majority of the

  17. Experimental Analysis of Repaired Masonry Elements with Flax-FRCM and PBO-FRCM Composites Subjected to Axial Bending Loads

    Directory of Open Access Journals (Sweden)

    Oscar A. Cevallos

    2015-11-01

    Full Text Available In the construction industry, the use of natural fabrics as a reinforcement for cement-based composites has shown great potential. The use of these sustainable composites to provide strengthening or repair old masonry structures that exhibit structural problems mainly due to a poor tensile strength of the mortar/brick joints is revealed to be a promising area of research. One of the most significant load conditions affecting the mechanical response of masonry structures occurs when axial bending loads are applied on the resistant cross-section. In this study, three different types of masonry elements were built using clay bricks and a lime-based mortar. After 28 days, the samples were subjected to concentric and eccentric compressive loads. In order to produce significant bending effects, the compressive loads were applied with large eccentricity, and a sudden failure characterized the behavior of the unreinforced masonry (URM elements. The tested masonry specimens were repaired using fabric-reinforced cementitious matrix (FRCM composites produced using bi-directional flax and polyparaphenylene benzobisoxazole (PBO fabrics. The mechanical behavior of the URM and repaired samples was compared in terms of load-displacement and moment-curvature responses. Furthermore, the results achieved using flax-FRCM composites were compared with those of using PBO-FRCM composites.

  18. 大体积混凝土冬期施工技术研究%The Study of Mass Concrete Winter Construction Technology Research

    Institute of Scientific and Technical Information of China (English)

    牛兴亮

    2014-01-01

    Large volume concrete construction is completed,due to the cement in concrete hydration reaction to produce a lot of hydration heat,the existence of hydration heat makes the concrete internal temperature changes,leading to the cracks of concrete internal,cause certain influence to the strength and durability of concrete. Usually can use change of concrete,the use of large particle size of gravel and coarse medium sand,for thermal insulation of concrete, the control of temperature and pouring temperature, second vibrating,secondary smoothing method,the background monitoring methods to decrease the cracking of concrete internal.%大体积混凝土施工完成后,由于混凝土内水泥水化反应后产生大量的水化热,使得混凝土内部发生巨大的温差变化,温差变化容易导致混凝土中产生裂缝,对混凝土的强度和耐久性造成一定影响。通常可以采用改变混凝土配合比、使用大粒径石子和粗中砂、对混凝土进行保温、控制出机温度和浇筑温度、二次振捣、二次抹平、后台监测等方法进行控制,以减少混凝土内部裂缝的出现。

  19. 沈阳浑北灌区节水配套改造工程二期项目施工总结%Shenyang Hunbei irrigation water saving Reconstruct Project Phase II construction

    Institute of Scientific and Technical Information of China (English)

    董浩

    2015-01-01

    This paper focuses on Shenyang Hunbei irrigation water saving Reconstruct Project Phase II ,from foundation excavation,masonry mortar rubble masonry retaining wall construction,embankment foundation treatment and reclamation,geomembrane laying,pressure beam,concrete slope,retaining five feet,the con-struction methods,processes and key issues requiring attention are analyzed and discussed.%本文围绕沈阳浑北灌区节水配套改造工程二期项目,从基础开挖、浆砌石挡土墙砌筑施工、堤防基础处理与填筑、土工膜铺设、压梁、混凝土护坡、护脚五个方面,对施工方法、工艺及需要注意的重点问题进行了分析和讨论。

  20. Use of information technologies for energetic portrait construction of cylindrical reinforced concrete shells

    Directory of Open Access Journals (Sweden)

    Kalmykov Oleg

    2017-01-01

    Full Text Available The analysis of strain-stress state of new type of architectural and construction system ‘Monofant’ was examined. The analysis of the advanced graphic, computing software packages was carried out. The possibility of joint applying these packages to the problem of sustainable conjunction study of a rational combination of the geometric parameters of the design-built system “Monofant” was analyzed. From the constructive point of view, the search for the structural element shape that provides a minimum material consumption under desired conditions is of some interest. The approach based on the energy criterion of rationalization was adopted to solve this problem. Fundamentally, new opportunities in the field of building structures optimization are offered with introduction of visual programming complexes adopted for designers (Grasshopper, Dynamo. Applying the described approach to the problem of rationalizing of the constructive system “Monofant” offers the opportunity of constructing, calculating, analyzing and rationalizing of construction that has complex external and internal geometry. An illustration of a possible approach is given in a specific numerical example.

  1. Compressive strength of brick masonry made with weak mortars

    DEFF Research Database (Denmark)

    Pedersen, Erik Steen; Hansen, Klavs Feilberg

    2013-01-01

    The use of weak mortar has a number of advantages (e.g. prevention of expansion joints, environmental issues). However, according to EC6, the strength of masonry vanishes when the compressive strength of the mortar approaches zero. In reality the presence of even unhardened mortar kept in place...... (fm≈6 N/mm2) compression tests of masonry with perforated bricks show that the EC6 expression is not always safe for Danish masonry. This is probably because the tensile strength of the bricks also has an effect on the compressive strength of masonry when the mortar is stronger than weak lime mortar...

  2. Estimation of construction and demolition waste using waste generation rates in Chennai, India.

    Science.gov (United States)

    Ram, V G; Kalidindi, Satyanarayana N

    2017-06-01

    A large amount of construction and demolition waste is being generated owing to rapid urbanisation in Indian cities. A reliable estimate of construction and demolition waste generation is essential to create awareness about this stream of solid waste among the government bodies in India. However, the required data to estimate construction and demolition waste generation in India are unavailable or not explicitly documented. This study proposed an approach to estimate construction and demolition waste generation using waste generation rates and demonstrated it by estimating construction and demolition waste generation in Chennai city. The demolition waste generation rates of primary materials were determined through regression analysis using waste generation data from 45 case studies. Materials, such as wood, electrical wires, doors, windows and reinforcement steel, were found to be salvaged and sold on the secondary market. Concrete and masonry debris were dumped in either landfills or unauthorised places. The total quantity of construction and demolition debris generated in Chennai city in 2013 was estimated to be 1.14 million tonnes. The proportion of masonry debris was found to be 76% of the total quantity of demolition debris. Construction and demolition debris forms about 36% of the total solid waste generated in Chennai city. A gross underestimation of construction and demolition waste generation in some earlier studies in India has also been shown. The methodology proposed could be utilised by government bodies, policymakers and researchers to generate reliable estimates of construction and demolition waste in other developing countries facing similar challenges of limited data availability.

  3. Measure Guideline. Internal Insulation of Masonry Walls

    Energy Technology Data Exchange (ETDEWEB)

    Straube, J. F. [Building Science Corporation (BSC), Somerville, MA (United States); Ueno, K. [Building Science Corporation (BSC), Somerville, MA (United States); Schumacher, C. J. [Building Science Corporation (BSC), Somerville, MA (United States)

    2012-07-01

    This measure guideline provides recommendations for interior insulation assemblies that control interstitial condensation and durability risks; recommendations for acceptable thermal performance are also provided. An illustrated guide of high-risk exterior details (which concentrate bulk water), and recommended remediation details is provided. This is followed by a recommended methodology for risk assessment of a masonry interior insulation project: a series of steps are suggested to assess the risks associated with this retrofit, with greater certainty with added steps.

  4. Measure Guideline: Internal Insulation of Masonry Walls

    Energy Technology Data Exchange (ETDEWEB)

    Straube, J. F.; Ueno, K.; Schumacher, C. J.

    2012-07-01

    This measure guideline provides recommendations for interior insulation assemblies that control interstitial condensation and durability risks; recommendations for acceptable thermal performance are also provided. An illustrated guide of high-risk exterior details (which concentrate bulk water), and recommended remediation details is provided. This is followed by a recommended methodology for risk assessment of a masonry interior insulation project: a series of steps are suggested to assess the risks associated with this retrofit, with greater certainty with added steps.

  5. Thermographic inspection of bond defects in Fiber Reinforced Polymer applied to masonry structures

    Science.gov (United States)

    Masini, N.; Aiello, M. A.; Capozzoli, L.; Vasanelli, E.

    2012-04-01

    Nowadays, externally bonded Fiber Reinforced Polymers (FRP) are extensively used for strengthening and repairing masonry and reinforced concrete existing structures; they have had a rapid spread in the area of rehabilitation for their many advantages over other conventional repair systems, such as lightweight, excellent corrosion and fatigue resistance, high strength, etc. FRP systems applied to masonry or concrete structures are typically installed using a wet-layup technique.The method is susceptible to cause flaws or defects in the bond between the FRP system and the substrate, which may reduce the effectiveness of the reinforcing systems and the correct transfer of load from the structure to the composite. Thus it is of primary importance to detect the presence of defects and to quantify their extension in order to eventually provide correct repair measurements. The IR thermography has been cited by the several guidelines as a good mean to qualitatively evaluate the presence of installation defects and to monitor the reinforcing system with time.The method is non-destructive and does not require contact with the composite or other means except air to detect the reinforcement. Some works in the literature have been published on this topic. Most of the researches aim at using the IR thermography technique to characterize quantitatively the defects in terms of depth, extension and type in order to have an experimental database on defect typology to evaluate the long term performances of the reinforcing system. Nevertheless, most of the works in the literature concerns with FRP applied to concrete structures without considering the case of masonry structures. In the present research artificial bond defects between FRP and the masonry substrate have been reproduced in laboratory and the IR multi temporal thermography technique has been used to detect them. Thermographic analysis has been carried out on two wall samples having limited dimensions (100 x 70 cm) both

  6. Rio 2016 sustainable construction commitments lead to new developments in recycled aggregate concrete

    NARCIS (Netherlands)

    Toledo Filho, R.D.; Koenders, E.A.B.; Pepe, M.; Cordeiro, G.C.; Fairbairn, E.; Martinelli, E.

    2013-01-01

    The Brazilian construction industry is committed to delivering the venues and infrastructure of the Rio 2016 Olympic and Paralympic Games with zero increase in carbon dioxide emissions, reduced consumption of raw materials, increased use of renewable materials and 100% local recycling of

  7. Rio 2016 sustainable construction commitments lead to new developments in recycled aggregate concrete

    NARCIS (Netherlands)

    Toledo Filho, R.D.; Koenders, E.A.B.; Pepe, M.; Cordeiro, G.C.; Fairbairn, E.; Martinelli, E.

    2013-01-01

    The Brazilian construction industry is committed to delivering the venues and infrastructure of the Rio 2016 Olympic and Paralympic Games with zero increase in carbon dioxide emissions, reduced consumption of raw materials, increased use of renewable materials and 100% local recycling of constructio

  8. PIXE, PIGE and NMR study of the masonry of the pyramid of Cheops at Giza

    Energy Technology Data Exchange (ETDEWEB)

    Demortier, Guy E-mail: guy.demortier@fundp.ac.be

    2004-11-01

    The mystery of the construction of the great pyramids of Egypt could be elucidated by physico-chemical measurements on small pieces of the material. In this paper, we give several arguments against the present point of view of most Egyptologists who do not admit another method than hewn blocks. We give several pieces of evidence that the masonry was entirely built by a moulding procedure involving the use of ingredients that were all available in the region of Cairo.

  9. Experimental evaluation of the structural behaviour of adobe masonry structural elements

    OpenAIRE

    Varum, H.; Costa, A.; Pereira, H.; Almeida, J.; Rodrigues, H.; D. Silveira

    2007-01-01

    Rehabilitation and strengthening of existing adobe masonry constructions have been neglected during the last decades. In Aveiro, Portugal, many adobe buildings present an important level of structural damage and, in many cases, are even near to ruin, having the majority a high vulnerability to seismic actions. To face the lack of information concerning the mechanical properties and structural behaviour of adobe elements, it was developed an experimental campaign. The composition and mechanica...

  10. Environmental impact of highway construction and repair materials on surface and ground waters. Case study: crumb rubber asphalt concrete.

    Science.gov (United States)

    Azizian, Mohammad F; Nelson, Peter O; Thayumanavan, Pugazhendhi; Williamson, Kenneth J

    2003-01-01

    The practice of incorporating certain waste products into highway construction and repair materials (CRMs) has become more popular. These practices have prompted the National Academy of Science, National Cooperative Highway Research Program (NCHRP) to research the possible impacts of these CRMs on the quality of surface and ground waters. State department of transportations (DOTs) are currently experimenting with use of ground tire rubber ( crumb rubber) in bituminous construction and as a crack sealer. Crumb rubber asphalt concrete (CR-AC) leachates contain a mixture of organic and metallic contaminants. Benzothiazole and 2(3H)-benzothiazolone (organic compounds used in tire rubber manufacturing) and the metals mercury and aluminum were leached in potentially harmful concentrations (exceeding toxic concentrations for aquatic toxicity tests). CR-AC leachate exhibited moderate to high toxicity for algae ( Selenastrum capriconutum) and moderate toxicity for water fleas ( Daphnia magna). Benzothiazole was readily removed from CR-AC leachate by the environmental processes of soil sorption, volatilization, and biodegradation. Metals, which do not volatilize or photochemically or biologically degrade, were removed from the leachate by soil sorption. Contaminants from CR-AC leachates are thus degraded or retarded in their transport through nearby soils and ground waters.

  11. How Concrete Is Concrete?

    Science.gov (United States)

    Gravemeijer, Koeno

    2011-01-01

    If we want to make something concrete in mathematics education, we are inclined introduce, what we call, "manipulatives", in the form of tactile objects or visual representations. If we want to make something concrete in a everyday-life conversation, we look for an example. In the former, we try to make a concrete model of our own,…

  12. Technology Solutions Case Study: Insulating Concrete Forms

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2012-10-01

    This Pacific Northwest National Laboratory project investigated insulating concrete forms—rigid foam, hollow walls that are filled with concrete for highly insulated, hurricane-resistant construction.

  13. The Effect of Externally Retrofitted Carbon Fiber Reinforced Polymer Composites on the Ductility of Reinforced Concrete Beams

    Science.gov (United States)

    2007-11-02

    Reinforcement Ratios 84 8-5 Ductility Indices 86 5 LIST OF FIGURES FIGURE PAGE 2-1 Failure Modes of Concrete Beams 17 2-2 Composite Jacket Installation...20 2-3 Composite Jacket Application 20 2-4 Four Point Bending Configuration 21 3-1 Stress-Strain Relationship for Concrete 27 3-2 Standard Rebar 28 3...researchers around the world, such as reinforcing and prestressing concrete structures, seismic retrofitting of concrete and unreinforced masonry

  14. Evaluating potential chlorinated methanes degradation mechanisms and treatments in interception trenches filled with concrete-based construction wastes

    Science.gov (United States)

    Rodríguez-Fernandez, Diana; Torrentó, Clara; Rosell, Mònica; Audí-Miró, Carme; Soler, Albert

    2014-05-01

    A complex mixture of chlorinated organic compounds is located in an unconfined carbonated bedrock aquifer with low permeability in a former industrial area next to Barcelona (NE Spain). The site exhibited an especially high complexity due to the presence of multiple contaminant sources, wide variety of pollutants (mainly chlorinated ethenes but also chlorinated methanes) and unknown system of fractures (Palau et al., 2014). Interception trenches were installed in the place of the removed pollution sources and were filled with construction wastes with the aim of retaining and treating the accumulated contaminated recharge water before reaching the aquifer. Recycled concrete-based aggregates from a construction and demolition waste recycling plant were used to maintain alkaline conditions in the water accumulated in the trenches (pH 11.6±0.3) and thus induce chloroform (CF) degradation by alkaline hydrolysis. An efficacy of around 30-40% CF degradation in the interception trenches was calculated from the significant and reproducible CF carbon isotopic fractionation (-53±3o obtained in batch experiments (Torrentó et al., 2014). Surprisingly, although hydrolysis of carbon tetrachloride (CT) is extremely slow, a significant CT carbon isotopic enrichment was also observed in the trenches. The laboratory experiments verified the low capability of concrete to hydrolyze the CT and showed the high adsorption of CT on the concrete particles (73% after 50 days) with invariability in its δ13C values. Therefore, the significant CT isotopic fractionation observed in the interception trenches could point out the occurrence of other degradation processes distinct than alkaline hydrolysis. Geochemical speciation modelling using the code PHREEQC showed that water collected at the trenches is supersaturated with respect to several iron oxy-hydroxides and therefore, CT degradation processes related to these iron minerals cannot be discarded. In addition, the combination of alkaline

  15. Energy Efficiency Improvement and Cost Saving Opportunities for the Concrete Industry

    OpenAIRE

    Kermeli, Katerina; Worrell, E.; Masanet, Eric

    2011-01-01

    The U.S. concrete industry is the main consumer of U.S.-produced cement. The manufacturing of ready mixed concrete accounts for about 75% of the U.S. concrete production following the manufacturing of precast concrete and masonry units. The most significant expenditure is the cost of materials accounting for more than 50% of total concrete production costs - cement only accounts for nearly 24%. In 2009, energy costs of the U.S. concrete industry were over $610 million. Hence, energy efficienc...

  16. Fiber Reinfoced Polymer Used for Flooding Protection of Engineering Structures Made of RC and Brick Masonry

    Directory of Open Access Journals (Sweden)

    Gabriel Oprişan

    2008-01-01

    Full Text Available Urban and rural floods are becoming nowadays a frequent problem to be dealt with, by both the population and the authorities. Floods and flood related natural disasters act against the civil, industrial and agricultural structures by the hydrostatic and hydrodynamic pressures of water. A set of protective solutions based on Fiber Reinforced Polymer (FRP composite materials, for structural elements of buildings subjected to flood loadings, is proposed and analysed. These solutions are achieved by using the hand lay-up forming technique utilizing glass, carbon or aramid fibers fabrics pre-impregnated with thermosetting epoxy, polyester or vynilester resins. The application of these FRP composites is carried out on reinforced concrete columns and beams as well as on brick masonry works aiming to increase in the overall load bearing capacity, especially against horizontal loads. An improved protection against excessive humidity is also envisaged. The Finite Elements Method based LUSAS software was used to simulate a partially flooded structure. The numerical modeling was carried out in both the un-strengthened and strengthened conditions of the structure in order to assess the increasing in load and deformation capacities of the structural elements. Volumetric finite elements were used for modeling the concrete and masonry members.

  17. Application of Bi-axial Warp Knitted Structures in Concrete Constructions

    Institute of Scientific and Technical Information of China (English)

    李炜; 陈南梁

    2001-01-01

    The warp knitted bi-axial directionally oriented structure (D. O. S. ) reinforcement substrates applied to building construction are discussed in comparison to woven fabrics. One of usage barriers of reinforced cement with gloss-grid is its sensitivity to alkali existed in the cement which will lead to the reduction of its service-life. The tests show that the treatment by sol-gel method to protect the composite from alkali corrosion is effective. Then two formulae of sol-gel solution are also recommended here for application.

  18. 某大桥承台大体积混凝土温控分析%Temperature Control of Mass Concrete Construction of Fuping railway bridge

    Institute of Scientific and Technical Information of China (English)

    范倩倩

    2016-01-01

    某大桥26#墩承台施工,采用低热水泥,并掺入矿物、粉煤灰、引气剂和高效减水剂,降低水化热,增强混凝土强度、耐久性;分层浇筑、铺设冷循环水管,增强混凝土散热能力,降低混凝土内部温度;在施工过程严格实行控温保温养护措施,进行实时温度监测,实现了大体积混凝土温度控制的信息化施工,为混凝土保温保湿养护提供依据,为同类工程提供参考价值。%The mass concrete construction of number 26 pile cap of the Bridge makes use of low heat cement , mixed with mineral,fly ash,air-entraining agent,and concrete water-reducer to cut down the hydration heat as well as enhance the concrete strength and durability.Reducing the internal temperature of the concrete by set-ting circulating cooling water pipes and stratified pouring.The implementing of strict temperature control , preservation measures and real-time dynamic temperature monitoring in the working process makes the infor-mation construction of mass concrete temperature control come true.The study provides reference to the heat and humidity preservation of concrete and other similar projects.

  19. An Assessment of the Compressive Strength of Glass Reinforced Plastic Waste Filled Concrete for Potential Applications in Construction

    Directory of Open Access Journals (Sweden)

    Asokan Pappu

    2010-03-01

    Full Text Available

    Efforts were made to recycle Glass reinforced plastic (GRP waste powder in concrete products and assess its compressive strength to comply with British Standards for use in construction applications. More than 90 GRP waste-filled concrete specimens were

  20. ELWIRA "Plants, wood, steel, concrete - a lifecycle as construction materials": University meets school - science meets high school education

    Science.gov (United States)

    Strauss-Sieberth, Alexandra; Strauss, Alfred; Kalny, Gerda; Rauch, Hans Peter; Loiskandl, Willibald

    2016-04-01

    The research project "Plants, wood, steel, concrete - a lifecycle as construction materials" (ELWIRA) is in the framework of the Sparkling Science programme performed by the University of Natural Resources and Life Sciences together with the Billroth Gymnasium in Vienna. The targets of a Sparkling Science project are twofold (a) research and scientific activities should already be transferred in the education methods of schools in order to fascinate high school students for scientific methods and to spark young people's interest in research, and (b) exciting research questions not solved and innovative findings should be addressed. The high school students work together with the scientists on their existing research questions improve the school's profile and the high school student knowledge in the investigated Sparkling Science topic and can lead to a more diverse viewing by the involvement of the high school students. In the project ELWIRA scientists collaborate with the school to quantify and evaluate the properties of classical building materials like concrete and natural materials like plants and woodlogs in terms of their life cycle through the use of different laboratory and field methods. The collaboration with the high school students is structured in workshops, laboratory work and fieldworks. For an efficient coordination/communication, learning and research progress new advanced electronic media like "Moodle classes/courses" have been used and utilized by the high school students with great interest. The Moodle classes are of high importance in the knowledge transfer in the dialogue with the high school students. The research project is structured into four main areas associated with the efficiencies of building materials: (a) the aesthetic feeling of people in terms of the appearance of materials and associated structures will be evaluated by means of jointly developed and collected questionnaires. The analysis, interpretation and evaluation are carried

  1. Multisurface interface model for analysis of masonry structures

    NARCIS (Netherlands)

    Lourenço, P.B.; Rots, J.G.

    1997-01-01

    The performance of an interface elastoplastic constitutive model for the analysis of unreinforced masonry structures is evaluated. Both masonry components are discretized aiming at a rational unit-joint model able to describe cracking, slip, and crushing of the material. The model is formulated in t

  2. Discussion on paving construction technology of asphalt concrete core wall:with construction of Ethiopia asphalt concrete core wall as an example%沥青混凝土心墙铺筑施工技术探讨--以埃塞沥青混凝土心墙施工为例

    Institute of Scientific and Technical Information of China (English)

    谢盛

    2015-01-01

    本文结合 Wolkite 沥青混凝土心墙项目,全程系统地探讨了沥青混凝土心墙施工技术,意在为同类型情况下心墙施工提供参考实例。%Wolkite asphalt concrete core wall project is combined for systematically discussing the construction technology of asphalt concrete core wall in the whole process.Reference example is provided for core wall construction under the same type conditions.

  3. Studies on use of Copper Slag as Replacement Material for River Sand in Building Constructions

    Science.gov (United States)

    Madheswaran, C. K.; Ambily, P. S.; Dattatreya, J. K.; Rajamane, N. P.

    2014-09-01

    This work focuses on the use of copper slag, as a partial replacement of sand for use in cement concrete and building construction. Cement mortar mixtures prepared with fine aggregate made up of different proportions of copper slag and sand were tested for use as masonry mortars and plastering. Three masonry wall panels of dimensions 1 × 1 m were plastered. The studies showed that although copper slag based mortar is suitable for plastering, with the increase in copper slag content, the wastage due to material rebounding from the plastered surfaces increases. It is therefore suggested that the copper slag can be used for plastering of floorings and horizontal up to 50 % by mass of the fine aggregate, and for vertical surfaces, such as, brick/block walls it can be used up to 25 %. In this study on concrete mixtures were prepared with two water cement ratios and different proportions of copper slag ranging from 0 % (for the control mix) to 100 % of fine aggregate. The Concrete mixes were evaluated for workability, density, and compressive strength.

  4. The influence of local mechanisms on large scale seismic vulnerability estimation of masonry building aggregates

    Science.gov (United States)

    Formisano, Antonio; Chieffo, Nicola; Milo, Bartolomeo; Fabbrocino, Francesco

    2016-12-01

    The current paper deals with the seismic vulnerability evaluation of masonry constructions grouped in aggregates through an "ad hoc" quick vulnerability form based on new assessment parameters considering local collapse mechanisms. First, a parametric kinematic analysis on masonry walls with different height (h) / thickness (t) ratios has been developed with the purpose of identifying the collapse load multiplier for activation of the main four first-order failure mechanisms. Subsequently, a form initially conceived for building aggregates suffering second-mode collapse mechanisms, has been expanded on the basis of the achieved results. Tre proposed quick vulnerability technique has been applied to one case study within the territory of Arsita (Teramo, Italy) and, finally, it has been also validated by the comparison of results with those deriving from application of the well-known FaMIVE procedure.

  5. 3D homogenised strength criterion for masonry: Application to drystone retaining walls

    Science.gov (United States)

    Le, Hong Hanh; Garnier, Denis; Colas, Anne-Sophie; Terrade, Benjamin; Morel, Jean-Claude

    2016-10-01

    A 3D strength criterion for masonry is constructed based on yield design theory. Yield design homogenisation provides a rigorous theoretical framework to determine the yield strength properties of a periodic medium, based on the properties of its constituent materials. First, theoretical basis of 2D homogenisation of periodic media, and more particularly its application in the framework of yield design, will be retrieved. Then, 2D principles are extended to exhibit a 3D domain of running-bond masonry. This criterion is finally used to assess the stability of a drystone retaining wall loaded by an axle load, and theoretical results are compared to experimental data. Perspectives on this work are given as a conclusion.

  6. Photoelasticity and DIC as optical techniques for monitoring masonry specimens under mechanical loads

    Science.gov (United States)

    Colla, C.; Gabrielli, E.

    2017-01-01

    To evaluate the complex behaviour of masonry structures under mechanical loads, numerical models are developed and continuously implemented at diverse scales, whilst, from an experimental viewpoint, laboratory standard mechanical tests are usually carried out by instrumenting the specimens via traditional measuring devices. Extracted values collected in the few points where the tools were installed are assumed to represent the behaviour of the whole specimen but this may be quite optimistic or approximate. Optical monitoring techniques may help in overcoming some of these limitations by providing full-field visualization of mechanical parameters. Photoelasticity and the more recent DIC, employed to monitor masonry columns during compression tests are here presented and a lab case study is compared listing procedures, data acquisitions, advantages and limitations. It is shown that the information recorded by traditional measuring tools must be considered limited to the specific instrumented points. Instead, DIC in particular among the optical techniques, is proving both a very precise global and local picture of the masonry performance, opening new horizons towards a deeper knowledge of this complex construction material. The applicability of an innovative DIC procedure to cultural heritage constructions is also discussed.

  7. Review of Japanese recommendations on design and construction of different classes of fiber reinforced concrete and application examples

    DEFF Research Database (Denmark)

    Uchida, Yuichi; Fischer, Gregor; Hishiki, Yoshihiro

    2008-01-01

    Reinforced Cement Composites (HPFRCC) with strain hardening and multiple cracking behavior, and Ultra High-strength Fiber Reinforced concrete (UFC) with increased tensile strength. The recommendations on the design, production, and application of these classes of fiber reinforced concrete have been...

  8. Use of Natural-Fiber Bio-Composites in Construction versus Traditional Solutions: Operational and Embodied Energy Assessment

    Directory of Open Access Journals (Sweden)

    Carmen Galan-Marin

    2016-06-01

    Full Text Available During the last decades natural polymers have become more and more frequent to replace traditional inorganic stabilizers in building materials. The purpose of this research is to establish a comparison between the most conventional building material solutions for load-bearing walls and a type of biomaterial. This comparison will focus on load-bearing walls as used in a widespread type of twentieth century dwelling construction in Europe and still used in developing countries nowadays. To carry out this analysis, the structural and thermal insulation characteristics of different construction solutions are balanced. The tool used for this evaluation is the life cycle assessment throughout the whole lifespan of these buildings. This research aims to examine the environmental performance of each material assessed: fired clay brick masonry walls (BW, concrete block masonry walls (CW, and stabilized soil block masonry walls (SW stabilized with natural fibers and alginates. These conventional and new materials are evaluated from the point of view of both operational and embodied energy.

  9. Use of Natural-Fiber Bio-Composites in Construction versus Traditional Solutions: Operational and Embodied Energy Assessment.

    Science.gov (United States)

    Galan-Marin, Carmen; Rivera-Gomez, Carlos; Garcia-Martinez, Antonio

    2016-06-13

    During the last decades natural polymers have become more and more frequent to replace traditional inorganic stabilizers in building materials. The purpose of this research is to establish a comparison between the most conventional building material solutions for load-bearing walls and a type of biomaterial. This comparison will focus on load-bearing walls as used in a widespread type of twentieth century dwelling construction in Europe and still used in developing countries nowadays. To carry out this analysis, the structural and thermal insulation characteristics of different construction solutions are balanced. The tool used for this evaluation is the life cycle assessment throughout the whole lifespan of these buildings. This research aims to examine the environmental performance of each material assessed: fired clay brick masonry walls (BW), concrete block masonry walls (CW), and stabilized soil block masonry walls (SW) stabilized with natural fibers and alginates. These conventional and new materials are evaluated from the point of view of both operational and embodied energy.

  10. Life-Cycle Evaluation of Concrete Building Construction as a Strategy for Sustainable Cities

    Energy Technology Data Exchange (ETDEWEB)

    Stadel, Alexander [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Drexel Univ., Philadelphia, PA (United States); Gursel, Petek [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Masanet, Eric [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-01-18

    Structural materials in commercial buildings in the United States account for a significant fraction of national energy use, resource consumption, and greenhouse gas (GHG) emissions. Robust decisions for balancing and minimizing these various environmental effects require that structural materials selections follow a life-cycle, systems modeling approach. This report provides a concise overview of the development and use of a new life-cycle assessment (LCA) model for structural materials in U.S. commercial buildings-the Berkeley Lab Building Materials Pathways (B-PATH) model. B-PATH aims to enhance environmental decision-making in the commercial building LCA, design, and planning communities through the following key features: (1) Modeling of discrete technology options in the production, transportation, construction, and end of life processes associated U.S. structural building materials; (2) Modeling of energy supply options for electricity provision and directly combusted fuels across the building life cycle; (3) Comprehensiveness of relevant building mass and energy flows and environmental indicators; (4) Ability to estimate modeling uncertainties through easy creation of different life-cycle technology and energy supply pathways for structural materials; and (5) Encapsulation of the above features in a transparent public use model. The report summarizes literature review findings, methods development, model use, and recommendations for future work in the area of LCA for commercial buildings.

  11. Corrosion-resistant sulfur concretes

    Science.gov (United States)

    McBee, W. C.; Sullivan, T. A.; Jong, B. W.

    1983-04-01

    Sulfur concretes have been developed by the Bureau of Mines as construction materials with physical and mechanical properties that suit them for use in acid and salt corrosive environments where conventional concretes fail. Mixture design methods were established for preparing sulfur concretes using different types of aggregates and recently developed mixed-modified sulfur cements. Bench-scale testing of the sulfur concretes has shown their potential value. Corrosion resistance, strength, and durability of sulfur concrete are superior to those of conventional materials. Field in situ evaluation tests of the sulfur concretes as replacement for conventional concrete materials are in progress in corrosive areas of 24 commercial chemical, fertilizer, and metallurgical plants.

  12. Validation of simple method for determination of penetration of PCB in concrete

    DEFF Research Database (Denmark)

    Gunnarsen, Lars; Witterseh, Thomas; Olesen, Kathrine Birkemark

    2014-01-01

    After extensive use of PCB containing polymeric materials in construction the knowledge about toxicity and biomagnification of PCB increased in the early seventies. This lead in Denmark to a ban on the use of PCB in building materials that was effective from 1 January 1977. Now much later...... an increased focus on indoor health risks caused by previous use of PCB containing building materials has sparked a need for large scale efficient sampling of materials for analysis of PCB content and penetration in materials adjoining the primary sources. Sampling in masonry and concrete is difficult because...... of strength and inhomogeneity of the materials. Much heat and dust may be generated while sampling from these mineral materials. It is furthermore suspected that the heat generation may mobilize the PCB and make the following analysis imprecise. The purpose of this paper...

  13. Effect of Axial Pre-Compression on Lateral Performance of Masonry Under Cyclic Loading

    Directory of Open Access Journals (Sweden)

    Syed HassanFarooq

    2011-10-01

    Full Text Available Strengthening of masonry against seismic events is very essential and getting maximum attention of researchers around the globe. An extensive experimental program was carried out to study the in-plane lateral performance of un-reinforced masonry, strengthened and retrofitted masonry wall panels under lateral cyclic loading. Twenty tests were carried out; four tests under monotonic lateral loading, twelve tests under static cyclic loading and four tests under pure compression. The test results were analyzed in five groups and this paper presents the analysis of group 4, which deals with effect of axial pre-compression on masonry seismic performance. Three single leaf panels with aspect ratio of 0.67 having size 1.65x1.1m were constructed using same material and workmanship. All the three un-reinforced walls were tested under 0, 0.5 and 1.0MPa vertical pre-compression and displacement controlled static cyclic loading. The wall tested under 0.5MPa pre-compression was reference specimen. The key parameters studied were hysterics behavior, peak lateral load, ultimate lateral displacement, energy dissipation, ductility, response factor and damping ratio. It was observed that level of axial pre-compression has significant effect on lateral capacity, failure mode and performance of masonry. In case of zero pre-compression the lateral capacity was very less and wall went into rocking failure at early stages of loading. Increase in pre-compression to 1.0MPa enhanced the lateral capacity by a factor of 1.92 times. After analysis of test results, it is found that pre-compression has significant effect on lateral capacity, failure mode and performance of masonry. In case of zero pre-compression the lateral capacity was very less and wall went into rocking failure at early stages of loading. Increase in pre-compression to 1.0MPa enhanced the lateral capacity by a factor of 1.92 times. After analysis of test results, it is found that pre-compression has very

  14. Comparative study on diagonal equivalent methods of masonry infill panel

    Science.gov (United States)

    Amalia, Aniendhita Rizki; Iranata, Data

    2017-06-01

    Infrastructure construction in earthquake prone area needs good design process, including modeling a structure in a correct way to reduce damages caused by an earthquake. Earthquakes cause many damages e.g. collapsed buildings that are dangerous. An incorrect modeling in design process certainly affects the structure's ability in responding to load, i.e. an earthquake load, and it needs to be paid attention to in order to reduce damages and fatalities. A correct modeling considers every aspect that affects the strength of a building, including stiffness of resisting lateral loads caused by an earthquake. Most of structural analyses still use open frame method that does not consider the effect of stiffness of masonry panel to the stiffness and strength of the whole structure. Effect of masonry panel is usually not included in design process, but the presence of this panel greatly affects behavior of the building in responding to an earthquake. In worst case scenario, it can even cause the building to collapse as what has been reported after great earthquakes worldwide. Modeling a structure with masonry panel as consideration can be performed by designing the panel as compression brace or shell element. In designing masonry panel as a compression brace, there are fourteen methods popular to be used by structure designers formulated by Saneinejad-Hobbs, Holmes, Stafford-Smith, Mainstones, Mainstones-Weeks, Bazan-Meli, Liauw Kwan, Paulay and Priestley, FEMA 356, Durani Luo, Hendry, Al-Chaar, Papia and Chen-Iranata. Every method has its own equation and parameters to use, therefore the model of every method was compared to results of experimental test to see which one gives closer values. Moreover, those methods also need to be compared to the open frame to see if they can result values within limits. Experimental test that was used in comparing all methods was taken from Mehrabi's research (Fig. 1), which was a prototype of a frame in a structure with 0.5 scale and the

  15. 试析路桥施工中钢纤维混凝土的施工技术%Construction technology of steel ifber concrete in the construction of Luqiao

    Institute of Scientific and Technical Information of China (English)

    李强

    2015-01-01

    the steel fiber reinforced concrete construction is an important component of Luqiao engineering construction, the construction quality will have a direct impact on Luqiao construction quality and using effect of therefore, the construction unit must be through a series of technical measures to continuously improve the level of construction technology of steel fiber concrete in construction of Luqiao, to the whole construction quality for Luqiao project to meet the demand, which has an important role in promoting the healthy development of social economy in our country. This paper expatiates on the construction technology of steel fiber concrete in Luqiao in engineering construction, and further discusses the matters needing attention in the application of steel fiber construction technology.%钢纤维混凝土施工是路桥工程施工中的重要组成,其施工质量会对路桥工程施工质量及使用效果产生直接影响,因此,施工单位必须要通过一系列技术措施,来不断提高路桥施工中钢纤维混凝土的施工技术水平,以便于路桥工程的整体施工质量可以满足其使用要求,这对促进我国社会经济健康发展有着重要的作用。本文对路桥工程施工中的钢纤维混凝土施工技术进行详细阐述,并进一步讨论了钢纤维施工技术应用中需要注意的事项。

  16. Inquiry on civil construction technology points of building engineering%建筑工程土建施工技术要点探究

    Institute of Scientific and Technical Information of China (English)

    赵成学

    2015-01-01

    依照建筑工程土建的施工要求,简单的总结了建筑工程土建施工的关键技术要点,主要包括混凝土施工、钢筋施工、砖砌筑施工、防水施工、模板施工五方面内容,以期达到提升建筑工程土建施工技术性能的目的。%According to civil construction demands of building engineering,the paper briefly summarizes critical civil construction technology points of building engineering,which mainly includes concrete construction,steel construction,brick masonry construction,waterproofing construc-tion and template construction,with a view to achieve the goal of improving civil construction technology performance of building engineering.

  17. Drying brick masonry by electro-osmosis

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Rörig-Dalgaard, Inge

    2006-01-01

    When a fine grained, porous medium is applied an electric DC field, transport of matter occurs, and the transport mechanism in focus of the present study is electro-osmosis, which is transport of water. In laboratory it was shown possible to transport water inside a brick and brick/mortar system...... movement of water towards the cathode was seen. Thus the basis for utilizing the electro-osmotic effect for drying brick masonry is present, but proper electrodes still needs to be developed....

  18. Chapter K: Progress in the Evaluation of Alkali-Aggregate Reaction in Concrete Construction in the Pacific Northwest, United States and Canada

    Science.gov (United States)

    Shrimer, Fred H.

    2005-01-01

    The supply of aggregates suitable for use in construction and maintenance of infrastructure in western North America is a continuing concern to the engineering and resources-management community. Steady population growth throughout the region has fueled demand for high-quality aggregates, in the face of rapid depletion of existing aggregate resources and slow and difficult permitting of new sources of traditional aggregate types. In addition to these challenges, the requirement for aggregates to meet various engineering standards continues to increase. In addition to their physical-mechanical properties, other performance characteristics of construction aggregates specifically depend on their mineralogy and texture. These properties can result in deleterious chemical reactions when aggregate is used in concrete mixes. When this chemical reaction-termed 'alkali-aggregate reaction' (AAR)-occurs, it can pose a major problem for concrete structures, reducing their service life and requiring expensive repair or even replacement of the concrete. AAR is thus to be avoided in order to promote the longevity of concrete structures and to ensure that public moneys invested in infrastructure are well spent. Because the AAR phenomenon is directly related to the mineral composition, texture, and petrogenesis of the rock particles that make up aggregates, an understanding of the relation between the geology and the performance of aggregates in concrete is important. In the Pacific Northwest, some aggregates have a moderate to high AAR potential, but many others have no or only a low AAR potential. Overall, AAR is not as widespread or serious a problem in the Pacific Northwest as in other regions of North America. The identification of reactive aggregates in the Pacific Northwest and the accurate prediction of their behavior in concrete continue to present challenges for the assessment and management of geologic resources to the owners and operators of pits and quarries and to the

  19. Natural radioactivity levels and danger ratio in cements, concretes and mortars used in construction; Determinacion de niveles radiactivos naturales e indices de peligrosidad en cementos, hormigones y morteros utilizados en construccion

    Energy Technology Data Exchange (ETDEWEB)

    Meneses, J.; Pacheco, C.; Avila, J. M.; Miro, C.

    2010-07-01

    We have determined the natural radiation level in three types of adhesive cements, five types of concrete and two types of mortars of different strength normally used in the construction field. Of these materials, both concrete and mortars were prepared in our laboratories, cements the contrary were of a commercial nature.

  20. An analysis of the abaca natural fiber in reinforcing concrete composites as a construction material in developing countries

    Energy Technology Data Exchange (ETDEWEB)

    Magdamo, R.V.

    1988-01-01

    This study analyzed the flexural and splitting tensile strengths and the ductility of abaca fiber-reinforced concrete composites. Abaca fibers are natural fibers of vegetable origin from the abaca plant native to the Philippine Islands. The purpose was to investigate how various volume-fractions of the abaca fiber could affect the mechanical properties of the concrete matrix. A concrete design mix containing a volume ratio of 1.0 part Type I Portland cement and 3.0 parts sand was used in the preparation of laboratory test samples. Abaca fibers were 1 to 1.5 inches long and randomly mixed with the concrete at 0.2% and 0.4% volume fractions. The fibers were not chemically treated and no admixtures were used. Samples were cast into concrete cylinders and flexural beams. Standard ASTM procedures in casting of flexural beams and concrete cylinders and the curing of 28-day concrete samples were followed. The center-point loading method of the flexural test and the splitting tensile test was utilized. Addition of abaca fibers decreased the mean flexural and splitting tensile strengths of the concrete matrices. However, ductility of the matrices increased with the addition of abaca fibers at 0.2% and 0.4% volume-fractions. The Scanning Electron Microscope (SEM) micrographs revealed that increasing the fiber volume-fraction influenced the growth rate of dehydration precipitates as CH (calcium hydroxide) crystals. At the 0.2% volume-fraction, smaller density of precipitates grew into large crystals, while at the 0.4% volume-fraction, the dehydration precipitates were much more dense, which were made up of small sized crystals. Abaca fibers in the concrete mix decreased the mean flexural and splitting tensile strengths, increased the modulus of elasticity, improved the ductility, and acted as a medium to slow down and stop the propagation of cracks.

  1. 现浇砼聚苯乙烯BDF柱体施工%The Cast-in-situ Concrete Polystyrene BDF Column Construction

    Institute of Scientific and Technical Information of China (English)

    范海军; 范佳波

    2012-01-01

      现浇混凝土空心楼盖技术是建筑结构领域的一项创新,符合人类的高技术水平的建筑结构体系。本文根据瑞景国际地下车库现浇砼空心楼盖工程对施工现场的管理、BDF 聚苯轻质柱体质量要求和施工技术进行阐述,为类似现浇混凝土空心楼盖施工提供技术参考。%  Cast-in-situ concrete hol ow floor system technol-ogy is an innovation in the field of building structure. It is in line with the human high technology of building structure system.In this paper, the author elaborates construction site management,quality requirements of the BDF polystyrene light column and construction technology about cast-in-situ concre-te hol ow floor engineering of the vista international underg-round garage, in order to provide technical reference for sim-ilar cast-in-place concrete hol ow floor construction.

  2. Valorization of Drinking Water Treatment Sludges as Raw Materials to Produce Concrete and Mortar

    Directory of Open Access Journals (Sweden)

    R. M.R. Zamora

    2008-01-01

    Full Text Available The purpose of this work was to assess the technical feasibility to valorize sludges, generated and stored at the Los Berros drinking water facility (PPLB, as raw material to produce building products (mortar and concrete for the construction industry. The experimental study was divided into three stages: 1 sampling and characterization of PPLB sludges to determine their potential as raw material (sand substitute and supplementary cementing materials to produce mortar and concrete; 2 production and characterization of specimens, using sludge in different weight ratios of mixtures with cement, lime, commercial mortar and plaster to prepare mortars and concretes and 3 comparison of compressive strength and drying contraction values between each specimen and the Mexican criteria to build mortars and concretes. The characterization results of the PPLB sludges showed that these residues could be used as a sand substitute in mortar and concrete formulations, since they were mainly comprised of this material (46.83%. The specimens prepared with a the binary formulations, sludge-cement and sludge-mortar (90-10% and b the ternary formulation, sludge-lime-cement (90-5-5%, gave the best results (ranging from 130 to 150 kg cm-2 of the compressive strength test. The compressive strength values of these formulations were higher than those of equivalent mortar (types I, II and III and cement mixtures (125 kg cm-2 prepared according to the Mexican complementary technical criteria to design and build masonry. These cementing properties exhibited by the PPLB sludges might be associated to their high content of aluminum and silicon oxides, 31.98 and 33.23%, respectively. Thus, calcium silicate (the main carrier strength in hardened cement can be produced from lime hydration of cement with the active silica present in the sludge. Considering all these results, the PPLB sludges present a high feasibility for being valorized as raw materials (supplementary cementing

  3. Mass concrete in the ground floor starts construction and temperature monitoring%地下室底板大体积混凝土施工和温度监控

    Institute of Scientific and Technical Information of China (English)

    林立军

    2012-01-01

    阐述大体积混凝土材料的选用,配合比的确定,混凝土性能的检测。大体积混凝土浇筑体施工阶段温度应力与收缩应力的计算,现场混凝土测温的验证和监控,大体积混凝土施工。%Elaborate the choice of mass concrete material, the match compares to really settle, the examination of concrete function. The mass concrete sprinkles to build the body construction stage temperature in response to the dint and the constringency in response to the calculation of dint, the spot concrete measures the verification and supervision of, mass concrete construction.

  4. 提高仿古建筑混凝土圆柱施工质量%To Improve the Quality of Concrete Column Construction of Pseudo-classic Architecture

    Institute of Scientific and Technical Information of China (English)

    潘峰祖

    2013-01-01

    Through the improvement of the antique building concrete cylindrical model of construction materials and techn-ology, improve the construction quality of concrete cylindrical shape size, perception.%  通过对仿古建筑砼圆柱模型施工材料及工艺的改进,提高砼圆柱外形尺寸、观感施工质量。

  5. How Concrete is Concrete

    OpenAIRE

    2010-01-01

    If we want to make something concrete in mathematics education, we are inclined introduce, what we call, ‘manipulatives’, in the form of tactile objects or visual representations. If we want to make something concrete in a everyday-life conversation, we look for an example. In the former, we try to make a concrete model of our own, abstract, knowledge; in the latter, we try to find an example that the others will be familiar with. This article first looks at the tension between these tw...

  6. 机场水泥混凝土道面施工质量控制技术%Quality Control Technology for Airport Cement Concrete Pavement Construction

    Institute of Scientific and Technical Information of China (English)

    董军; 贡文献

    2011-01-01

    针对机场水泥混凝土道面施工中容易出现掉边掉角、表面网状或环状裂纹、板体断裂和蜂窝麻面等质量通病,根据大面积混凝土铺筑施工的特点和环境因素,综合分析其质量通病产生的原因,并提出相应的施工控制措施,在实践中取得了明显效果,可供水泥混凝土道面施工参考.%For the common quality defects on airport cement concrete pavement such as side or corner peeling,surface pattern crack or annular crack, slab fracture, and voids and pits, according to the characteristics of large area concrete pavement construction and environmental factors, the causes of these quality defects are analyzed and the corresponding control measures are put forward, which have achieved significant effect in practical engineering. These measures can be reference for cement concrete pavement construction.

  7. 土木工程中混凝土施工技术分析%Analysis of the Concrete Construction Technology in Civil Engineering

    Institute of Scientific and Technical Information of China (English)

    王小平

    2013-01-01

    In the building construction process, the choice of materials is extremely strict. The material quality is good or bad is often directly determines the quality of construction wo-rk. The essay analyzes the construction technology of civil en-gineering concrete and summarizes some useful suggestions to improve the quality of construction.%  在建筑工程施工过程中,选用的材料是异常严格的。材料质量好坏往往直接决定了建筑工程的质量。本文对土木工程中混凝土施工技术进行分析,总结了一些提高建筑工程质量的有效建议。

  8. Living with earthquakes - development and usage of earthquake-resistant construction methods in European and Asian Antiquity

    Science.gov (United States)

    Kázmér, Miklós; Major, Balázs; Hariyadi, Agus; Pramumijoyo, Subagyo; Ditto Haryana, Yohanes

    2010-05-01

    Earthquakes are among the most horrible events of nature due to unexpected occurrence, for which no spiritual means are available for protection. The only way of preserving life and property is applying earthquake-resistant construction methods. Ancient Greek architects of public buildings applied steel clamps embedded in lead casing to hold together columns and masonry walls during frequent earthquakes in the Aegean region. Elastic steel provided strength, while plastic lead casing absorbed minor shifts of blocks without fracturing rigid stone. Romans invented concrete and built all sizes of buildings as a single, unflexible unit. Masonry surrounding and decorating concrete core of the wall did not bear load. Concrete resisted minor shaking, yielding only to forces higher than fracture limits. Roman building traditions survived the Dark Ages and 12th century Crusader castles erected in earthquake-prone Syria survive until today in reasonably good condition. Concrete and steel clamping persisted side-by-side in the Roman Empire. Concrete was used for cheap construction as compared to building of masonry. Applying lead-encased steel increased costs, and was avoided whenever possible. Columns of the various forums in Italian Pompeii mostly lack steel fittings despite situated in well-known earthquake-prone area. Whether frequent recurrence of earthquakes in the Naples region was known to inhabitants of Pompeii might be a matter of debate. Seemingly the shock of the AD 62 earthquake was not enough to apply well-known protective engineering methods throughout the reconstruction of the city before the AD 79 volcanic catastrophe. An independent engineering tradition developed on the island of Java (Indonesia). The mortar-less construction technique of 8-9th century Hindu masonry shrines around Yogyakarta would allow scattering of blocks during earthquakes. To prevent dilapidation an intricate mortise-and-tenon system was carved into adjacent faces of blocks. Only the

  9. Experiments on Hybrid Precast Concrete Shear Walls Emulating Monolithic Construction with Different Amounts of Posttensioned Strands and Different Debond Lengths of Grouted Reinforcements

    Directory of Open Access Journals (Sweden)

    Zhangfeng Zhu

    2016-01-01

    Full Text Available This paper proposed a hybrid precast concrete shear wall emulating monolithic construction (HPWEM that utilized grouted vertical connecting reinforcements and unbonded posttensioned high-strength strands across the horizontal joint for the lateral resistance. The grouted reinforcements with predetermined debond length were used to provide strength by tension and energy dissipation by yielding. The posttensioned strands were mainly employed to offer the restoring force to reduce the residual displacement by elastic extension. The overlapping welded closed stirrups improved the confinement property of the restrained concrete, avoiding the brittle failure. Six HPWEM specimens, considering variables including the amounts of strands and the debond lengths of grouted reinforcements, as well as one referenced cast-in-place monolithic wall specimen, were tested under the low-cycle reversed lateral load. The HPWEM specimens were capable of providing strength, stiffness, ductility, and energy dissipation equivalent to that of the monolithic wall specimen under certain variable condition.

  10. Corrosion behaviour of steel rebars embedded in a concrete designed for the construction of an intermediate-level radioactive waste disposal facility

    Science.gov (United States)

    Duffó, G. S.; Arva, E. A.; Schulz, F. M.; Vazquez, D. R.

    2013-07-01

    The National Atomic Energy Commission of the Argentine Republic is developing a nuclear waste disposal management programme that contemplates the design and construction of a facility for the final disposal of intermediate-level radioactive wastes. The repository is based on the use of multiple, independent and redundant barriers. The major components are made in reinforced concrete so, the durability of these structures is an important aspect for the facility integrity. This work presents an investigation performed on an instrumented reinforced concrete prototype specifically designed for this purpose, to study the behaviour of an intermediate level radioactive waste disposal facility from the rebar corrosion point of view. The information obtained will be used for the final design of the facility in order to guarantee a service life more or equal than the foreseen durability for this type of facilities.

  11. Corrosion behaviour of steel rebars embedded in a concrete designed for the construction of an intermediate-level radioactive waste disposal facility

    Directory of Open Access Journals (Sweden)

    Schulz F.M.

    2013-07-01

    Full Text Available The National Atomic Energy Commission of the Argentine Republic is developing a nuclear waste disposal management programme that contemplates the design and construction of a facility for the final disposal of intermediate-level radioactive wastes. The repository is based on the use of multiple, independent and redundant barriers. The major components are made in reinforced concrete so, the durability of these structures is an important aspect for the facility integrity. This work presents an investigation performed on an instrumented reinforced concrete prototype specifically designed for this purpose, to study the behaviour of an intermediate level radioactive waste disposal facility from the rebar corrosion point of view. The information obtained will be used for the final design of the facility in order to guarantee a service life more or equal than the foreseen durability for this type of facilities.

  12. Application of construction waste in insulation composite concrete block%建筑垃圾在混凝土复合保温砌块中的应用

    Institute of Scientific and Technical Information of China (English)

    刘春平; 汤莉

    2014-01-01

    利用建筑垃圾为主要原材料生产混凝土复合保温砌块符合国家节能减排、循环经济和可持续发展的产业政策,具有变废为宝、环保节能的环境效益和社会效益。经检测数据证明,利用建筑垃圾生产的混凝土复合保温砌块各项性能符合有关标准要求。%The insulation composite concrete block is prepared by the construction waste as the main raw material, which accords with the national industrial policy of energy conservation and emissions reduction, recycling economy and sustainable development. The test data show the composite thermal-insulating concrete block meets relevant standards.

  13. Tests and Analysis of the Compressive Performance of an Integrated Masonry Structure of a Brick-Stem-Insulating Layer

    Directory of Open Access Journals (Sweden)

    Suizi Jia

    2016-05-01

    Full Text Available This paper proposes, for low buildings, an integrated wall structure of a brick-stem-insulating layer, which plays a major part in both heat preservation and force bearing. The research team has tested the thermal performance of the structure, the results of which are satisfying. To further study the force-bearing performance, the paper carries out compressive tests of specimens of different structural design, with two types of bricks, i.e., clay and recycled concrete bricks; three types of stems, i.e., square-shaped wood, square-shaped steel pipe and circular steel pipe; and one type of insulating layer, i.e., fly ash masonry blocks. Afterward, the force bearing performance, damage that occurred, compressive deformation and ductility of all of the specimens are compared. On the sideline, the structure is applied in the construction of a pilot residence project, yielding favorable outcomes. The results indicate that in comparison with a brick wall with an insulating layer sandwiched in between, the integrated wall structure of bricks and fly ash blocks is a more preferable choice in terms of compressive performance and ductility. The integrated wall structure of brick-stem-fly ash blocks delivers much better performance to this end. Note that regarding the stem’s contribution to compressive strength, circular steel pipe is highest, followed by square-shaped steel pipe and then square-shaped wood. The compressive performance of the sandwiched blocks surpasses that of the two brick wall pieces combined by a large margin.

  14. Compressive strength of brick masonry made with weak mortars

    DEFF Research Database (Denmark)

    Pedersen, Erik Steen; Hansen, Klavs Feilberg

    2013-01-01

    The use of weak mortar has a number of advantages (e.g. prevention of expansion joints, environmental issues). However, according to EC6, the strength of masonry vanishes when the compressive strength of the mortar approaches zero. In reality the presence of even unhardened mortar kept in place...... in the joint will ensure a certain level of load-carrying capacity. This is due to the interaction between compression in the weak mortar and tension in the adjacent bricks. This paper proposes an expression for the compressive strength of masonry made with weak lime mortars (fm... of masonry depends only on the strength of the bricks. A compression failure in masonry made with weak mortars occurs as a tension failure in the bricks, as they seek to prevent the mortar from being pressed out of the joints. The expression is derived by assuming hydrostatic pressure in the mortar joints...

  15. 房屋建筑混凝土施工技术管控要点论述%Building Concrete Construction Technology Control Key Points

    Institute of Scientific and Technical Information of China (English)

    杨晓楠

    2013-01-01

    随着我国市场经济的不断调整与深化改进,房屋建筑企业迎来其高速发展的黄金时期,人们对房屋安全问题的关注度越来越高,混凝土施工技术的控制也日益受到建筑企业的重视。本文通过对当前房屋建筑现状的全面了解,现从施工规划、实际技术控制以及全局管控三个方面来对混凝土施工技术的管控要点做出浅要论述。%With the continuous adjustment and the deepening improvement of China's market economy, housing construction enterprises ushered in the golden period of high speed develop-pment, people on the housing security problem has been paid more and more at ention, the control of concrete construction technology has also been building enterprises. This paper thro-ugh a comprehensive understanding of the current housing sit-uation makes a shal ow discussion on the control points of co-ncrete construction technology from three aspects of the cons-truction planning, actual technical control and global control.

  16. A Comparative Cradle-to-Gate Life Cycle Assessment of Mid-Rise Office Building Construction Alternatives: Laminated Timber or Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Raymond J. Cole

    2012-07-01

    Full Text Available The objective of this project was to quantify and compare the environmental impacts associated with alternative designs for a typical North American mid-rise office building. Two scenarios were considered; a traditional cast-in-place, reinforced concrete frame and a laminated timber hybrid design, which utilized engineered wood products (cross-laminated timber (CLT and glulam. The boundary of the quantitative analysis was cradle-to-construction site gate and encompassed the structural support system and the building enclosure. Floor plans, elevations, material quantities, and structural loads associated with a five-storey concrete-framed building design were obtained from issued-for-construction drawings. A functionally equivalent, laminated timber hybrid design was conceived, based on Canadian Building Code requirements. Design values for locally produced CLT panels were established from in-house material testing. Primary data collected from a pilot-scale manufacturing facility was used to develop the life cycle inventory for CLT, whereas secondary sources were referenced for other construction materials. The TRACI characterization methodology was employed to translate inventory flows into impact indicators. The results indicated that the laminated timber building design offered a lower environmental impact in 10 of 11 assessment categories. The cradle-to-gate process energy was found to be nearly identical in both design scenarios (3.5 GJ/m2, whereas the cumulative embodied energy (feedstock plus process of construction materials was estimated to be 8.2 and 4.6 GJ/m2 for the timber and concrete designs, respectively; which indicated an increased availability of readily accessible potential energy stored within the building materials of the timber alternative.

  17. Study of the brickwork masonry cracking with a cohesive fracture model

    Directory of Open Access Journals (Sweden)

    Reyes, E.

    2011-09-01

    Full Text Available This paper presents a numerical procedure to simulate the cracking process of the brickwork masonry under tensile/shear loading. The model is an extension of the cohesive model prepared by the authors for concrete, and takes into account the anisotropy of the material. The numerical procedure includes two steps: 1 calculation of the crack path with a linear elastic fracture model, 2 after the crack path is obtained, an interface finite element (using the cohesive fracture model is incorporated into the trajectory. Such a model is then implemented into a commercial code by means of a user subroutine, consequently being contrasted with experimental results. Fracture properties of masonry are independently measured for two directions on the composed masonry, and then input in the numerical model. This numerical procedure accurately predicts the experimental mixed mode fracture records for different orientations of the brick layers on masonry panels.

    Este artículo presenta un modelo de cálculo que permite simular el comportamiento en rotura de la fábrica de ladrillo bajo solicitaciones de tracción y cortante. El modelo extiende el modelo cohesivo formulado por los autores para hormigón, considerando la anisotropía del material. El procedimiento de cálculo consta de dos fases: 1 obtención de la trayectoria de grieta mediante un cálculo elástico lineal, 2 incorporación del modelo cohesivo en la misma mediante elementos de intercara. El modelo se ha implementado en un programa de elementos finitos comercial con una subrutina de usuario y se ha contrastado con los resultados experimentales de los ensayos a escala. Las propiedades mecánicas de la fábrica, en especial las de fractura, se miden con ensayos de caracterización en dos direcciones. Éstas se incorporan al modelo de cálculo para simular los ensayos de fractura en modo mixto, prediciendo los resultados adecuadamente para distintas orientaciones de los tendeles.

  18. Behaviour of masonry structures during the Bhuj earthquake of January 2001

    Indian Academy of Sciences (India)

    K S Jagadish; S Raghunath; K S Nanjunda Rao

    2003-09-01

    A variety of masonry structures suffered damage during the recent Bhuj earthquake. Some of the traditional masonry structures had no earthquake resistant features and suffered considerable damage. This paper attempts to evaluate the behaviour of masonry structures based on the type of masonry used in places like Bhuj, Anjar, Bhachau, Morbi, Samakhyali and several other places. Quite a few masonry buildings had used earthquake resistant features like lintel bands and corner reinforcements. The cracking and failure patterns of such buildings have also been examined. The paper concludes with a discussion on the relevance of the current codal provisions for earthquake resistance of masonry structures and the direction of further research in the area.

  19. Experimental Evaluation of Lightweight AAC Masonry Wall Prisms with Ferrocement Layers in Compression and Flexure

    KAUST Repository

    Abdel Mooty, Mohamed

    2012-05-01

    An experimental program is designed to evaluate the performance of lightweight autoclaved aerated concrete masonry wall strengthened using ferrocement layers, in a sandwich structure, under in-plane compression and out-of-plane bending. The 25 mm thick ferrocement mortar is reinforced with steel welded wire mesh of 1 mm diameters at 15 mm spacing. Different types of shear connectors are used to evaluate their effect on failure loads. The effect of different design parameters on the wall strength are considered including wall thickness, mortar strength, and type and distribution of shear connectors. A total of 20 prisms are tested in compression and 5 prisms are tested under bending. The proposed ferrocement strengthening technique is easy to apply on existing wall system and results in significant strength and stiffness enhancement of the tested wall specimens. © (2012) Trans Tech Publications.

  20. Building America Case Study: Retrofit Measure for Embedded Wood Members in Insulated Mass Masonry Walls, Lawrence, Massachusetts

    Energy Technology Data Exchange (ETDEWEB)

    2015-10-01

    ?There are many existing buildings with load-bearing mass masonry walls, whose energy performance could be improved with the retrofit of insulation. However, adding insulation to the interior side of walls of such masonry buildings in cold (and wet) climates may cause performance and durability problems. Some concerns, such as condensation and freeze-thaw have known solutions. But wood members embedded in the masonry structure will be colder (and potentially wetter) after an interior insulation retrofit. Moisture content and relative humidity were monitored at joist ends in historic mass brick masonry walls retrofitted with interior insulation in a cold climate (Zone 5A); data were collected from 2012-2015. Eleven joist ends were monitored in all four orientations. One limitation of these results is that the renovation is still ongoing, with limited wintertime construction heating and no permanent occupancy to date. Measurements show that many joists ends remain at high moisture contents, especially at north- and east-facing orientations, with constant 100 percent RH conditions at the worst cases. These high moisture levels are not conducive for wood durability, but no evidence for actual structural damage has been observed. Insulated vs. non-insulated joist pockets do not show large differences. South facing joists have safe (10-15 percent) moisture contents. Given the uncertainty pointed out by research, definitive guidance on the vulnerability of embedded wood members is difficult to formulate. In high-risk situations, or when a very conservative approach is warranted, the embedded wood member condition can be eliminated entirely, supporting the joist ends outside of the masonry pocket.

  1. 谈滑模施工在混凝土结构仓体中的应用%On application of slipform construction in bunker of concrete structure

    Institute of Scientific and Technical Information of China (English)

    石芥欣

    2012-01-01

    The study briefly indicates the definition of slipform construction, sums up the advantages of the climbing form consgtruction, intro- duces the application of the application of slipform construction in bunker of concrete structure, and sums up the process for the slipform construction and its technical points, so as to provide some direction for the spreading of the slipform craft.%简单叙述了滑模施工的含义,归纳了滑升模板施工的优点,详细介绍了滑模施工在混凝土仓体结构中的应用,同时总结了滑模施工过程及技术要点,为滑模工艺的推广应用提供了指导。

  2. Cold Weather Construction Materials. Part 2. Regulated-Set Cement for Cold Weather Concreting. Field Validation of Laboratory Results.

    Science.gov (United States)

    1981-09-01

    been used by the civilian sec- tor for a number of years in such activities as highway patching, slip- form tunnel liners, and cast-in-place roof...for this minimum needs to be verified. Once known, this will also dictate the earliest times at which formwork or concrete protection could be removed

  3. Labour-based construction, testing and monitoring of proof-of-concept ultrathin continuously reinforced concrete pavement technology demonstrators

    CSIR Research Space (South Africa)

    Dlamini, N

    2011-09-01

    Full Text Available presentation to the RRA board of directors that outlined the advantages of Ultrathin Continuously Reinforced Concrete Pavements (UTCRCP). From this presentation the board initiated a meeting between the members of the RRA namely SIRDC, CSIR and BOTEC. Aurecon...

  4. Characterization and Degradation of Masonry Mortar in Historic Brick Structures

    Directory of Open Access Journals (Sweden)

    Denis A. Brosnan

    2014-01-01

    Full Text Available This study characterized mortars from a masonry fortification in Charleston, South Carolina (USA, harbor where construction was during the period 1839–1860. This location for analysis was interesting because of the sea water impingement on the structure. The study was included as part of an overall structural assessment with restoration as an objective. The mortars were found to be cement, lime, and sand mixtures in proportions similar to ones expected from the historic literature, that is, one part binder to two parts of sand. The binder was found to be American natural cement, a substance analogous to the European Roman cement. The results suggest that the thermal history of the cement during manufacturing affected setting rate explaining why the cements were considered as variable during the mid-to-late 1800s. Fine pores were found in mortars exposed to sea water resulting from corrosion. Contemporary natural cement was shown to release calcium in aqueous solution. While this release of calcium is necessary for setting in natural and Portland cements, excessive calcium solution, as exacerbated by sea water contact and repointing with Portland cement mortars, was shown to result in brick scaling or decay through cryptoflorescence.

  5. Quality Assessment of Mixed and Ceramic Recycled Aggregates from Construction and Demolition Wastes in the Concrete Manufacture According to the Spanish Standard

    Directory of Open Access Journals (Sweden)

    Desirée Rodríguez-Robles

    2014-08-01

    Full Text Available Construction and demolition waste (CDW constitutes an increasingly significant problem in society due to the volume generated, rendering sustainable management and disposal problematic. The aim of this study is to identify a possible reuse option in the concrete manufacturing for recycled aggregates with a significant ceramic content: mixed recycled aggregates (MixRA and ceramic recycled aggregates (CerRA. In order to do so, several tests are conducted in accordance with the Spanish Code on Structural Concrete (EHE-08 to determine the composition in weight and physic-mechanical characteristics (particle size distributions, fine content, sand equivalent, density, water absorption, flakiness index, and resistance to fragmentation of the samples for the partial inclusion of the recycled aggregates in concrete mixes. The results of these tests clearly support the hypothesis that this type of material may be suitable for such partial replacements if simple pretreatment is carried out. Furthermore, this measure of reuse is in line with European, national, and regional policies on sustainable development, and presents a solution to the environmental problem caused by the generation of CDW.

  6. The construction and crack control of floor heating concrete ground%地暖混凝土地面施工和裂缝控制

    Institute of Scientific and Technical Information of China (English)

    郭运勇; 刘国辉; 岳钊; 曹霞

    2015-01-01

    Through the analysis and summary on the construction procedure and process of a engineering floor heating,this paper summarized the causes,control measures etc. of floor heating concrete ground cracks,so as to effectively control the floor heating ground cracks.%通过对某工程地暖工程施工工序和工艺进行分析和归纳,总结了地暖混凝土地面裂缝的产生原因、控制措施等,以有效控制地暖地面产生裂缝。

  7. Experimental Investigation on Flexural Performance of Masonry Walls Reinforced with GFRP

    Institute of Scientific and Technical Information of China (English)

    LIU Jifu; LIU Ming; SONG Yupu

    2007-01-01

    This paper presents the results of a test program for flexure reinforcing characteristics of gless fiber-rein forced polymer(GFRP) sheets bonded to masonry beams. A total of eight specimens subjected to monotonic four-point bending were tested up to failure. These specimens were constructed with two different bond patterns. Six of these specimens were reinforced by using GFRP sheets prior to testing, and the remaining two were not reinforced. The test results indicate a significant increase in both load-bearing capacity and ductile performance of the reinforced walls over the unreinforced ones.

  8. 襄樊汉江三桥主墩承台大体积混凝土施工技术%Large Volume Concrete Construction Technology of Hanjiang the Third Bridge Main Pier Pile Cap in Xiangfan

    Institute of Scientific and Technical Information of China (English)

    吴刚; 蒲赞全; 钟启凯; 刘开扬

    2011-01-01

    Based on the large volume pile cap construction of Hanjiang the Third Bridge main pier in Xiangfan,the construction technology of the large volume pile cap is analyzed. , including cofferdam construction of steel sheet pile, bottom sealing of underwater concrete. A series of measures from concrete raw material to concrete pouring are taked to prevent exorbitant hydration temperature in mass concrete causing concrete crack, including mix design of low hydration heat concrete, temperature control calculation of concrete, field temperature control measures of mass concrete, temperature monitoring during construction. Thus,pile cap construction is completed successfully.%结合襄樊汉江三桥主墩大体积承台施工,分析了大体积承台施工技术,包括:钢板桩围堰施工,水下混凝土封底.为防止大体积混凝土在水化过程中结构内部产生过高的水化热温度,致使结构产生有害裂缝,从混凝土原材料到混凝土浇筑施工采取了一系列有效的技术控制措施,包括低水化热混凝土配合比设计、混凝土温控计算、大体积混凝土温度现场控制措施,以及施工过程中的温度监测,从而使得承台施工得以顺利完成.

  9. NVENTIONS IN THE NANOTECHNOLOGICAL AREA PROVIDE INCREASED RESISTANCE OF CONSTRUCTION MATERIALS AND PRODUCTS TO OPERATIONAL LOAD

    Directory of Open Access Journals (Sweden)

    VLASOV Vladimir Alexeevich

    2013-12-01

    Full Text Available The invention «Dispersion of Carbon Nanotubes (RU 2494961» can be used in production of modifying additives for construction materials. Dispersion of carbon nanotubes contains, mass %: carbon nanotubes 1–20; surface active agent – sodium chloride of sulfonated derived naphthalene 1–20; fumed silica 5–15; water – the rest. Dispersion can additionally contain ethylene glycol as antifreeze. Dispersion is steady in storage, it is soluble in water, provides increased strength of construction materials. Invention «Building Structures Reinforcement Composition (RU 2493337» can beused in construction to reinforce concrete, brick and masonry structures. Composition contains glass or basalt roving taken in quantity 90÷100 parts by weight, soaked in polymer binder based on epoxy taken in quantity 0,001÷1,5 parts by weight. This invention provides high resistance to operational load.

  10. Cellular Concrete Bricks with Recycled Expanded Polystyrene Aggregate

    OpenAIRE

    Juan Bosco Hernández-Zaragoza; Teresa López-Lara; Jaime Horta-Rangel; Carlos López-Cajún; Eduardo Rojas-González; García-Rodríguez, F. J.; Jorge Adue

    2013-01-01

    Cellular concrete bricks were obtained by using a lightweight mortar with recycled expanded polystyrene aggregate instead of sandy materials. After determining the block properties (absorption, compressive strength, and tensile stresses), it was found that this brick meets the requirements of the masonry standards used in Mexico. The obtained material is lighter than the commercial ones, which facilitates their rapid elaboration, quality control, and transportation. It is less permeable, whic...

  11. Impact resistance performance of green construction material using light weight oil palm shells reinforced bamboo concrete slab

    Science.gov (United States)

    Muda, Z. C.; Usman, F.; Beddu, S.; Alam, M. A.; Thiruchelvam, S.; Sidek, L. M.; Basri, H.; Saadi, S.

    2013-06-01

    This paper investigate the performance of lightweight oil palm shells (OPS) concrete with varied bamboo reinforcement content for the concrete slab of 300mm x 300mm size reinforced with different thickness subjected to low impact projectile test. A self-fabricated drop-weight impact test rig with a steel ball weight of 1.2 kg drop at 1 m height has been used in this research work. The main variables for the study is to find the relationship of the impact resistance against the amount of bamboo reinforcement and slab thickness. A linear relationship has been established between first and ultimate crack resistance against bamboo diameters and slab thickness by the experiment. The linear relationship has also been established between the service (first) crack and ultimate crack resistance against the bamboo reinforcement diameter for a constant spacing for various slab thickness using 0.45 OPS and 0.6 OPS bamboo reinforced concrete. The increment in bamboo diameter has more effect on the first crack resistance than the ultimate crack resistance. The linear relationship has also been established between the service (first) crack and ultimate crack resistance against the various slab thickness. Increment in slab thickness of the slab has more effect on the crack resistance as compare to the increment in the diameter of the bamboo reinforcement.

  12. Measure Guideline: Deep Energy Enclosure Retrofit for Interior Insulation of Masonry Walls

    Energy Technology Data Exchange (ETDEWEB)

    Musunuru, S. [Building Science Corporation, Westford, MA (United States); Pettit, B. [Building Science Corporation, Westford, MA (United States)

    2015-04-01

    This Measure Guideline describes a deep energy enclosure retrofit (DEER) solution for insulating mass masonry buildings from the interior. It describes the retrofit assembly, technical details, and installation sequence for retrofitting masonry walls. Interior insulation of masonry retrofits has the potential to adversely affect the durability of the wall; this document includes a review of decision criteria pertinent to retrofitting masonry walls from the interior and the possible risk of freeze-thaw damage.

  13. Measure Guideline. Deep Energy Enclosure Retrofit for Interior Insulation of Masonry Walls

    Energy Technology Data Exchange (ETDEWEB)

    Musunuru, S. [Building Science Corporation, Westford, MA (United States); Pettit, B. [Building Science Corporation, Westford, MA (United States)

    2015-04-30

    This Measure Guideline describes a deep energy enclosure retrofit solution for insulating mass masonry buildings from the interior. It describes the retrofit assembly, technical details, and installation sequence for retrofitting masonry walls. Interior insulation of masonry retrofits might adversely affect the durability of the wall. This guideline includes a review of decision criteria pertinent to retrofitting masonry walls from the interior and the possible risk of freeze-thaw damage.

  14. Structural Precast Concrete Handbook

    DEFF Research Database (Denmark)

    Kjærbye, Per Oluf H

    Structural concept for precast concrete systems. Design og precast reinforced concrete components. Design of precast concrete connections. Illustrations on design of precast concrete buildings. Precast concrete assembly....

  15. Possibilities of modeling masonry as a composite softening material: Interface modeling and anisotropic continuum modeling

    NARCIS (Netherlands)

    Lourenço, P.B.; Rots, J.G.

    1998-01-01

    Results of using recently developed material models for the analysis of masonry structures are shown. Both interface modeling, in which masonry components (units and joints) are represented, as continuum modeling, in which masonry is represented as a homogeneous continuum, are addressed. It is shown

  16. Basic Hand Tools for Bricklaying and Cement Masonry [and] Basic Hand Tools of the Carpenter.

    Science.gov (United States)

    Texas A and M Univ., College Station. Vocational Instructional Services.

    Intended for student use, this unit discusses and illustrates the tools used in brick and masonry and carpentry. Contents of the brick and masonry section include informative materials on bricklaying tools (brick trowels, joint tools, levels, squares, line and accessories, rules, hammers and chisels, tool kits) and cement masonry tools (tampers,…

  17. Mitigation of Blast Effects on Aluminum Foam Protected Masonry Walls

    Institute of Scientific and Technical Information of China (English)

    SU Yu; WU Chengqing; GRIFFITH Mike

    2008-01-01

    Terrorist attacks using improvised explosive devices (lED) can result in unreinforced masonry (URM) wall collapse.Protecting URM wall from lED attack is very complicated.An effective solution to mitigate blast effects on URM wall is to retrofit URM walls with metallic foam sheets to absorb blast energy.However,mitigation of blast effects on metallic foam protected URM walls is currently in their infancy in the world.In this palaer,numerical models are used to simulate the performance of aluminum foam protected URM walls subjected to blast loads.A distinctive model,in which mortar and brick units of masonry are discritized individually,is used to model the performance of masonry and the contact between the masonry and steel face-sheet of aluminum foam is modelled using the interface element model.The aluminum foam is modelled by a nonlinear elastoplastic material model.The material models for masonry,aluminum foam and interface are then coded into a finite element program LS-DYNA3D to perform the numerical calculations of response and damage of aluminum foam protected URM walls under airblast loads.Discussion is made on the effectiveness of the aluminum foam protected system for URM wall against blast loads.

  18. Calibration under uncertainty for finite element models of masonry monuments

    Energy Technology Data Exchange (ETDEWEB)

    Atamturktur, Sezer,; Hemez, Francois,; Unal, Cetin

    2010-02-01

    Historical unreinforced masonry buildings often include features such as load bearing unreinforced masonry vaults and their supporting framework of piers, fill, buttresses, and walls. The masonry vaults of such buildings are among the most vulnerable structural components and certainly among the most challenging to analyze. The versatility of finite element (FE) analyses in incorporating various constitutive laws, as well as practically all geometric configurations, has resulted in the widespread use of the FE method for the analysis of complex unreinforced masonry structures over the last three decades. However, an FE model is only as accurate as its input parameters, and there are two fundamental challenges while defining FE model input parameters: (1) material properties and (2) support conditions. The difficulties in defining these two aspects of the FE model arise from the lack of knowledge in the common engineering understanding of masonry behavior. As a result, engineers are unable to define these FE model input parameters with certainty, and, inevitably, uncertainties are introduced to the FE model.

  19. Self-compacting concrete (SCC)

    DEFF Research Database (Denmark)

    Geiker, Mette Rica

    2008-01-01

    In many aspects Self-Compacting Concrete (SCC, “Self-Consolidating Concrete” in North America) can be considered the concrete of the future. SCC is a family of tailored concretes with special engineered properties in the fresh state. SCC flows into the formwork and around even complicated...... reinforcement arrangements under its own weight. Thus, SCC is not vibrated like conventional concrete. This drastically improves the working environment during construction, the productivity, and potentially improves the homogeneity and quality of the concrete. In addition SCC provides larger architectural...

  20. Pervious Concrete

    OpenAIRE

    2012-01-01

    Pervious concrete is a type of concrete with little or no fines which give a large void. This enables high permeability and because of this it enables water to percolate through the concrete. Pervious concrete have been used in many years both as pavement material and on several other applications in the U.S and in other countries in Western Europe. In Norway pervious concrete is not currently in use. This thesis aims to investigate if pervious concrete can withstand the harsh Norwegian clima...

  1. Performance of Waterless Concrete

    Science.gov (United States)

    Toutanji, Houssam; Evans, Steve; Grugel, Richard N.

    2010-01-01

    The development of permanent lunar bases is constrained by performance of construction materials and availability of in-situ resources. Concrete seems a suitable construction material for the lunar environment, but water, one of its major components, is an extremely scarce resource on the Moon. This study explores an alternative to hydraulic concrete by replacing the binding mix of concrete (cement and water) with sulfur. Sulfur is a volatile element on the lunar surface that can be extracted from lunar soils by heating. Sulfur concrete mixes were prepared to investigate the effect of extreme environmental conditions on the properties of sulfur concrete. A hypervelocity impact test was conducted, having as its target a 5-cm cubic sample of sulfur concrete. This item consisted of JSC-1 lunar regolith simulant (65%) and sulfur (35%). The sample was placed in the MSFC Impact Test Facility s Micro Light Gas Gun target chamber, and was struck by a 1-mm diameter (1.4e-03 g) aluminum projectile at 5.85 km/s. In addition, HZTERN code, provided by NASA was used to study the effectiveness of sulfur concrete when subjected to space radiation.

  2. Linear Shrinkage Behaviour of Compacted Loam Masonry Blocks

    Directory of Open Access Journals (Sweden)

    NAWAB ALI LAKHO

    2017-04-01

    Full Text Available Walls of wet loam, used in earthen houses, generally experience more shrinkage which results in cracks and less compressive strength. This paper presents a technique of producing loam masonry blocks that are compacted in drained state during casting process in order to minimize shrinkage. For this purpose, loam masonry blocks were cast and compacted at a pressure of 6 MPa and then dried in shade by covering them in plastic sheet. The results show that linear shrinkage of 2% occurred which is smaller when compared to un-compacted wet loam walls. This implies that the loam masonry blocks compacted in drained state is expected to perform better than un-compacted wet loam walls.

  3. Salt Induced Decay of Masonry and Electrokinetic Repair

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Rörig-Dalgaard, Inge

    from brick masonry and also how much the removal rate can be increased by application of the electric field compared to diffusion alone. Some main differences occur between electrokinetic remediation of heavy metal polluted soil and electrokinetic removal of salts from brick masonry. The ions...... of interest in the brick are not adsorbed to a high extent, as it is often the case with heavy metals in soils. Bricks are made from baked clay, however during the baking process the cation exchange capacity of the clay is strongly decreased which affect the electric conductivity. The electric conductivity...... in brick depending on its water content and salts may be precipitated on the outer wall or concentrated under paint layers covering the surface of the brick. Different types of damage may appear in masonry walls due to these concentrating phenomena. Bricks themselves can be destroyed and the mortar can...

  4. Humidity control in the inspection of masonry structures

    Directory of Open Access Journals (Sweden)

    A.V. Ulybin

    2013-11-01

    Full Text Available The problems of wetting of masonry structures were considered: its causes, consequences and methods of humidity control. The classification of destructions that occur in the masonry as a result of its moistening was given. Destruction processes under wetting of different origin were briefly described. The experimentally ascertained impact of humidity on the strength of different kinds of brick was presented. The influence of this factor is often missed in the material testing and analysis of structures. The comparison between different methods of moisture control was given. A technique for measuring the moisture using the calcium carbide method was pictured; this method is little known in Russia. The advantages and disadvantages of non-destructive methods were discussed. Special attention was paid to the definition of errors in electrical control methods, occurring due to existence of salts in the masonry. The recommendations for combined use of different methods of humidity control were given.

  5. EXPERIMENTAL STUDY OF COMPRESSIVE STRENGTH OF THE NEW COMPOSITE BLOCK MASONRY%新型复合砌块砌体结构抗压强度试验研究

    Institute of Scientific and Technical Information of China (English)

    夏多田; 何明胜; 唐艳娟; 付小建; 石磊巍

    2014-01-01

    保温砌模轻质混凝土空心砌块混合生土复合墙体结构是由聚苯乙烯颗粒( EPS)混合土为内芯、轻质陶粒混凝土砌块为外模组成的一种新型复合砌块砌体结构形式,具有保温、抗震和整体好的特性,非常适合村镇低层建筑。考虑不同的内芯材料强度和不同的砌筑砂浆强度,对9组复合砌块砌体抗压试件进行试验研究,分析内芯强度和砂浆强度对复合砌块砌体抗压强度的影响。试验结果表明:内芯材料强度对复合砌体抗压强度贡献最大,影响显著;砂浆强度对复合砌体抗压强度影响较小;空心砌块砌体的抗压强度明显低于复合砌块砌体的抗压强度。%The composite masonry of thermal-insulating lightweight concrete hollow block is a new type of structure with composite polystyrene ( EPS) soil as its inner core and the lightweight ceramsite concrete block as its external mould, because it makes the heat preservation and anti-seismic and integrity as a whole , suitable for buildings in village and town .Considering the different strength of filling materials and different strength of masonry mortar , compressive strength of 9 group specimens of composite block masonry was tested , analyzed the effects of different inner core strength and different mortar strength on the compressive strength of composite block masonry .The test results show that the inner core strength has the largest contribution to the compressive strength of composite masonry , whose influence is significant; mortar strength has weak effect on compressive strength of composite masonry; the compressive strength of hollow block masonry is markedly lower than that of composite block masonry .

  6. 防辐射大体积重晶石混凝土施工技术%Construction Technology of Large-volume Radiation Proof Barite Concrete

    Institute of Scientific and Technical Information of China (English)

    肖方平; 郄嘉琳; 张海静

    2016-01-01

    In the hospital, the operation of linear, cyclotron and other equipment can bring the Gamma rays and neutron flow with strong penetration ability. Effective shielding measures should be taken to avoid harm to human body. Compared to other radiation proof materials, barite concrete has low construction difficulty, low cost, good quality of anti radiation and other advantages. And it has been widely used in the hospital project. This paper introduces the key points of construction engineering of barite concrete in Xiamen Hospital of Zhongshan Hospital Affiliated to Fudan University. The results show that the construction method has good reliability, and can be used for reference for other related projects.%医院中直线、回旋加速器等设备在运行过程中会产生穿透能力极强的γ射线和中子流,需要采取有效的屏蔽措施,以免对人体产生危害。重晶石混凝土相比于其它防辐射材料,具有施工难度低、成本低、防辐射质量好等优点,在医院工程中得到了广泛的使用。本文介绍了复旦大学附属中山医院厦门医院工程重晶石混凝土的施工要点,结果表明本施工方法具有较好的可靠性,亦可为其他相关工程借鉴使用。

  7. Engineering properties of cement mortar with pond ash in South Korea as construction materials: from waste to concrete

    Science.gov (United States)

    Jung, Sang; Kwon, Seung-Jun

    2013-09-01

    Among the wastes from coal combustion product, only fly ash is widely used for mineral mixture in concrete for its various advantages. However the other wastes including bottom ash, so called PA (pond ash) are limitedly reused for reclamation. In this paper, the engineering properties of domestic pond ash which has been used for reclamation are experimentally studied. For this, two reclamation sites (DH and TA) in South Korea are selected, and two domestic PAs are obtained. Cement mortar with two different w/c (water to cement) ratios and 3 different replacement ratios (0%, 30%, and 60%) of sand are prepared for the tests. For workability and physical properties of PA cement mortar, several tests like flow, setting time, and compressive strength are evaluated. Several durability tests including porosity measuring, freezing and thawing, chloride migration, and accelerated carbonation are also performed. Through the tests, PA (especially from DH area) in surface saturated condition is evaluated to have internal curing action which leads to reasonable strength development and durability performances. The results show a potential applicability of PA to concrete aggregate, which can reduce consuming natural resources and lead to active reutilization of coal product waste.

  8. Large-span tunnel construction of clay layer%粘土层大跨度隧道施工

    Institute of Scientific and Technical Information of China (English)

    段杰

    2014-01-01

    Combining with engineering example, the thesis studies large-span tunnel construction technology of clay layer, mainly explores barrel construction technology, and introduces barrel support, spaying concrete and barrel masonry and other points, and analyzes waterproofing and drainage measures of barrel entrance and major barrel, which has accumulated experience for similar engineering construction.%结合工程实例,对粘土层大跨度隧道施工技术进行了研究,着重探讨了洞身的施工工艺,对洞身支护、喷射混凝土、洞身衬砌等环节作了详细介绍,并分析了洞口与正洞的防排水措施,为同类工程的施工积累了经验。

  9. Basic Deformation Parameters of Solid Clay Bricks and Small Masonry Walls

    Directory of Open Access Journals (Sweden)

    P. Bouška

    2000-01-01

    Full Text Available The basic mechanical properties of clay brick masonry and its components were experimentally investigated in the laboratories of the Klokner Institute. The test specimens of masonry materials and the relevant mechanical properties have been identified in solid clay bricks and cement-lime mortar. The aim of the research activity was to study both the deformability of the prevailing type of clay masonry in the existing buildings, i.e. the masonry made from the solid clay units and the lime-cement mortar, and the most important mechanical properties of masonry components.

  10. Initiation of Failure for Masonry Subject to In-Plane Loads through Micromechanics

    Directory of Open Access Journals (Sweden)

    V. P. Berardi

    2016-01-01

    Full Text Available A micromechanical procedure is used in order to evaluate the initiation of damage and failure of masonry with in-plane loads. Masonry material is viewed as a composite with periodic microstructure and, therefore, a unit cell with suitable boundary conditions is assumed as a representative volume element of the masonry. The finite element method is used to determine the average stress on the unit cell corresponding to a given average strain prescribed on the unit cell. Finally, critical curves representing the initiation of damage and failure in both clay brick masonry and adobe masonry are provided.

  11. Constructing an Innovative Base-Isolation System under Masonry Structures

    OpenAIRE

    Zeeshan, Badar-Ul-Ali

    2014-01-01

    Seismic up-gradation of existing buildings is a very challenging task, as it requires us to consider historical and economical aspects of building. While proposing a seismic-retrofit scheme for a historical building, one should keep in mind that it should be compatible with existing materials, be least intrusive, monitorable and removable. A novel base-isolation technique has been proposed for the up-gradation of existing buildings against seismic actions which does not involve any alteration...

  12. 陕西科技信息大厦钢管混凝土施工%CONSTRUCTION OF STEEL TUBE ENCASED CONCRETE COLUMN FOR SHAANXI SCIENCE AND TECHNOLOGY INFORMATION TOWER BUILDING

    Institute of Scientific and Technical Information of China (English)

    梁睿鑫

    2001-01-01

    This paper introduces the structural characteristics, jobpractice and quality requirements of the steel tube encased concrete column for Shaanxi Science and Technology Information Tower Building, which includs the fabrication and erection of the steel tube column, embedment of the base plate, construction of the compensated contracting concrete, slump control, pouring concrete from a high position and vibration as well as the inspection method of the quality of the steel tube encased concrete column.%介绍陕西科技信息大厦钢管混凝土柱结构特点、施工工艺和质量要求,包括钢管柱制作、安装、底座埋设、补偿收缩混凝土施工、坍落度调整、高位抛落并振捣的方法及钢管混凝土柱质量检查方法.

  13. The Construction of Large-Bulk Concrete Baseboard of High-rising Building’s Basement%论高层建筑地下室底板大体积混凝土施工

    Institute of Scientific and Technical Information of China (English)

    覃勤怀

    2012-01-01

      文章从施工现场的平面布置、劳动力的组织、施工的技术准备及砼的运输、浇筑、养护、测温、保温等方面介绍了大体积混凝土的施工方法及控制要点。%  The paper introduces the construction methods and controlling key points of large-bulk concrete baseboard, in the aspects of floor plan layout of construction site, organizing labour force, technical preparation and concrete transportation, pouring, maintenance, temperature testing, and heat preservation.

  14. 大体积承台混凝土配合比设计及工程应用%Design and Construction Application of Large Volume Cap Concrete

    Institute of Scientific and Technical Information of China (English)

    孙宏图

    2016-01-01

    针对东明黄河公路大桥主桥主墩承台混凝土的特点,通过掺加大掺量复合矿物掺合料、细集料采用机制砂及掺加聚羧酸缓凝高效减水剂的方案,配制出密实性好、水化热低、抗裂性能好的大体积混凝土。同时,结合科学的施工措施,有效防止了大体积承台温度裂缝的产生。%Aimed at the characteristics of the main pier pile concrete of the main bridge of Dongming Yellow River Highway Bridge, the mass concrete with good compactness, low hydration heat, good crack resistance is made by the plan of mixing lots of composite mineral admixture, using machine-made sand as fine aggregate and adding polycarboxylic acid retarded high efficiency water reducing agent. At the same time, the large volume cap temperature cracks are effectively prevented by the scientific construction measures.

  15. The concrete construction technology of a residential building in western Guangxi%桂西某住宅楼混凝土施工技术

    Institute of Scientific and Technical Information of China (English)

    黄海洪

    2013-01-01

    底板与内墙水平施工缝采用平口形式。为了保证内墙浇筑在底板处不漏浆,浇筑底板时要用4m刮杠赶平。合墙模前剔除根部松动石子,清扫干净。浇筑内墙前,用布料器铺30mm砂浆。考虑外墙为抗渗混凝土,在剔除时要及时检查剔除部位,如果剔至30mm仍有>20mm气泡或松散石子,则须继续向下剔,直到剔至密实混凝土为止。%Using flat form for horizontal construction joints and interior floor, in order to ensure interior pouring slurry does not leak at the bottom, use 4m scrape bars to scratch when pouring floor, excluding the roots loose gravel before closing wall formwork, cleaning. Before pouring walls, lay 30mm mortar with distributor. Consider that the wall is impermeability of concrete. Check the removed parts in a timely manner when excluded. If the tick is still to 30mm>20mm bubbles or loose gravel, then continued downward tick, until tick to compacting concrete.

  16. On quality control of large area wearable concrete ground construction%大面积耐磨混凝土地面施工质量控制

    Institute of Scientific and Technical Information of China (English)

    张建军

    2012-01-01

    针对某工程地下车库大面积耐磨地面表面平整度、光洁度、耐磨度等指标的要求,对影响该车库大面积耐磨混凝土地面质量的原因进行分析,提出了保证大面积耐磨混凝土质量的控制措施,避免了中间环节可能造成的影响,使大面积地面施工一次成优。%According to the requirements of the underground garage of some project on the smoothness,the finish,and the wearability of the large area wearable surface,the paper analyzes the reasons for influencing the large wearable concrete surface quality of the garage,and points out some quality control measures for the large area wearable concrete,so as to avoid the possible influence in the middle step and make the large area ground construction be optimal in the first time.

  17. Structural Precast Concrete Handbook

    DEFF Research Database (Denmark)

    Kjærbye, Per Oluf H

    Structural concept for precast concrete systems. Design og precast reinforced concrete components. Design of precast concrete connections. Illustrations on design of precast concrete buildings. Precast concrete assembly.......Structural concept for precast concrete systems. Design og precast reinforced concrete components. Design of precast concrete connections. Illustrations on design of precast concrete buildings. Precast concrete assembly....

  18. 自升式布料机在超高层双连体核心筒混凝土施工中的应用%Application of the Self-elevating Concrete Spreader in Concrete Construction of Double-connected Core Tubes for High-rise Building

    Institute of Scientific and Technical Information of China (English)

    高振洲

    2011-01-01

    The reasonable concrete construction process is decided based on actual situation of HNA International Mansion. Self-elevating concrete spreader distribute materials on the work face to improve the efficiency and quality of concrete transportation. The fixation requirement of spreader to concrete structure is put forward. The installation process and jacking up steps are introduced. The attentions of pump pipe laying, concrete pouring and spreader washing are introduced. The construction safety is guaranteed and construction cost is saved by using the spreader.%结合海控国际广场实际情况,确定了合理的混凝土施工工艺.采用自升式布料机置于结构工作面进行布料,大大提高了混凝土作业的效率和质量.同时指出了布料机附着固定对混凝土结构的要求,介绍了布料机的安装流程及顶升步骤.指出混凝土泵管的敷设,混凝土浇筑及布料机清洗过程中的注意事项.该技术的应用保证了施工安全且降低了施工成本.

  19. Effective way to reconstruct arch bridges using concrete walls and transverse strands

    Science.gov (United States)

    Klusáček, Ladislav; Pěkník, Robin; Nečas, Radim

    2017-09-01

    There are more than 500 masonry arch bridges in the Czech Road system and about 2500 in the Czech Railway system. Many of them are cracked in the longitudinal (span) direction. The barrel vaults are separated by the cracks into partial masonry arches without load bearing connection in transverse direction. These constructions are about 150 years old and they are also too narrow for the current road system. This paper presents a strengthening method for masonry arch bridges using transverse post-tensioning. This method is very useful not only for strengthening in the transverse direction, but widening of masonry arches can be taken as secondary effect especially in case of road bridges. Several bridges were successfully repaired with the use of this system which seems to be effective and reliable.

  20. Concrete Hinges

    DEFF Research Database (Denmark)

    Halding, Philip Skov; Hertz, Kristian Dahl; Schmidt, Jacob Wittrup

    2014-01-01

    In the first part of the 20th century concrete hinges developed by Freyssinet and Mesnager were widely tested and implemented in concrete structures. The concrete hinges were used a great deal in closed-spandrel arch bridges. Since such a bridge type has not been competitive for the past 40 years......, the research in concrete hinges has not evolved significantly in that period. But introducing a new state-of-the-art concrete arch bridge solution (Pearl-Chain arches invented at the Technical University of Denmark) creates a necessity of a concrete hinge research based on modern standards. Back when research...... in concrete hinges was more common different designs were proposed for the geometry and reinforcement. Previous research focused on fatigue, multi-axial stresses around the hinge throat, and the relation between rotation- and moment. But many different test-setups were proposed by different researchers...

  1. Discuss the Application of High Performance Concretes in Road and Bridge Construction%高性能混凝土在路桥施工中的应用论述

    Institute of Scientific and Technical Information of China (English)

    杨生朋

    2014-01-01

    High performance concrete has very good plasticity, durability and strength, which has been widely used in water conservancy construction and transportation, etc. This paper mainly introduces the requirement of different raw materials for high performance concrete, and explores the application of high performance concretes in road and bridge construction.%高性能混凝土具有非常好的可塑性、耐久性以及强度,现已被广泛地应用于水利、建筑以及交通等领域中。本文说明了高性能混凝土对不同原材料的要求,并探究了在公路工程以及桥梁工程项目中高性能混凝土的具体应用。

  2. On construction of cast-in-place concrete hollow plate of newly-built wards of some hospital%谈某医院新建病房现浇混凝土空心板的施工

    Institute of Scientific and Technical Information of China (English)

    宋白平

    2015-01-01

    The paper introduces the main construction craft of the cast-in-place concrete hollow plate of newly-built ward at some hospital,illus-trates the construction precautions and quality control measures in the pipeline allocation,thin-wall hollow plate positioning,and concrete grou-ting,and points out the cast-in-place concrete hollow plate is economical,environment-friendly and energy-saving.%介绍了某医院新建病房现浇混凝土空心板的主要施工工艺,阐述了管线布置、薄壁空心板定位、混凝土浇筑等施工注意事项及质量控制措施,指出现浇混凝土空心板具有经济、环保、节能等优势。

  3. Seismic Analysis of Historic Masonry Buildings: The Vicarious Palace in Pescia (Italy

    Directory of Open Access Journals (Sweden)

    Luciano Galano

    2012-04-01

    Full Text Available Recent Italian earthquakes have underlined the need for wide monitoring and safety assessment of architectonical heritage. This has emerged also from requirements of the new Italian Technical Recommendations for buildings. Within this subject the paper investigates the seismic vulnerability of a specific monumental masonry building: the Vicarious Palace (Palazzo del Vicario in Pescia, a small town near Florence. The structural behavior of the Palace was investigated using a finite element model in which the non-linearities of the masonry were considered by proper constitutive assumptions. The seismic behavior was evaluated by the pushover method, according to the Italian Technical Recommendations. The results were compared with the ones obtained by a simplified approach based on the kinematic theorem of limit analysis. Comparisons of the expected seismic demand vs the seismic capacity of the Palace confirm the weakness of this type of building to suffer extensive damage under earthquakes, as frequently observed in similar construction typologies. Additionally, the comprehension of the structural behavior under seismic loading allows the identification of a proper retrofitting strategy.

  4. Improving Resistance of Masonry Structures to Tsunami Loading

    Science.gov (United States)

    Revanth, D.; Akshay, Baheti; Nayak, Sanket; Dutta, Sekhar Chandra

    2016-06-01

    The Asian tsunami of 26th December, 2004 took the lives of 2,20,000 people and devastated coastal structures, including many thousands of brick-built homes. Many economically backward people who have made their homes in non-engineered masonry lost their shelters. Though very high waves of tsunami cannot be resisted, waves comparable to the height of the masonry structures can be tolerated by these structures by implementing simple design techniques which are cost effective and can be implemented without any modern equipment. The present study throws light on the issues related to effect of brick orientation, number of openings, orientation and shape of the structures with respect to possible direction of wave movement and effect of support conditions upon the performance of masonry structures subjected to tsunami loading. It has also been noticed that boundary walls acts as a barrier to reduce the effect on the actual structures. In this context, this study may be helpful in framing design guidelines for improving the performance of non-engineered masonry structures under tsunami loading.

  5. Confusing cracks and difficult deformations: Interpreting structural damage in masonry

    NARCIS (Netherlands)

    De Vent, I.; Rots, J.G.; Van Hees, R.P.J.; Hobbelman, G.J.

    2012-01-01

    Cracks and deformatiçns in masonry are common phenomena in historical buildings. If they are interpreted correctly, they can be an extremely valuable source çf informatiçn on the load history of the premises. Nevertheless, this interpretation is not always as obvious as one may think. In the framewo

  6. Characterization of materials formed by rice husk for construction

    Science.gov (United States)

    Portillo-Rodríguez, A. M.

    2013-11-01

    This review article delves into the use of agro-industrial wastes, which in construction field provides alternatives for environmental problems with the use of them. This fact enables development and lower costs for new options in the brick, cluster, mortar and concrete industry, what represents benefits for environment, housing and generally everything related to construction, looking for sustainability. For that reason a literature review is made to support the theme focusing on the use of rice husk in its natural, ground or ash state for manufacturing elements with clay masonry, precast and optimization of concrete and mortars. The technique used is based on scientific articles and researches found in reliable databases that were analyzed and integrated into a synthesized structure, which summarized the objectives, analysis processes, the physical and mechanical properties and finally the results. The conclusions are focused on potentiality of elements production in the construction development based on the high effectiveness like thermal insulation, low density and various benefits offered by high silica content pozzolanic properties, etc.

  7. New Frontiers on Seismic Modeling of Masonry Structures

    Directory of Open Access Journals (Sweden)

    Salvatore Caddemi

    2017-07-01

    Full Text Available An accurate evaluation of the non-linear behavior of masonry structural elements in existing buildings still represents a complex issue that rigorously requires non-linear finite element strategies difficult to apply to real large structures. Nevertheless, for the static and seismic assessment of existing structures, involving the contribution of masonry materials, engineers need reliable and efficient numerical tools, whose complexity and computational demand should be suitable for practical purposes. For these reasons, the formulation and the validation of simplified numerical strategies represent a very important issue in masonry computational research. In this paper, an innovative macroelement approach, developed by the authors in the last decade, is presented. The proposed macroelement formulation is based on different, plane and spatial, macroelements for the simulation of both the in-plane and out-of-plane behavior of masonry structures also in presence of masonry elements with curved geometry. The mechanical response of the adopted macroelement is governed by non-linear zero-thickness interfaces, whose calibration follows a straightforward fiber discretization, and the non-linear internal shear deformability is ruled by equivalence with a corresponding geometrically consistent homogenized medium. The approach can be considered as “parsimonious” since the kinematics of the adopted elements is controlled by very few degrees of freedom, if compared to a corresponding discretization performed by using non-linear finite element method strategies. This innovative discrete element strategy has been implemented in two user-oriented software codes 3DMacro (Caliò et al., 2012b and HiStrA (Historical Structures Analysis (Caliò et al., 2015, which simplify the modeling of buildings and historical structures by means of several wizard generation tools and input/output facilities. The proposed approach, that represents a powerful tool for the

  8. Probabilistic seismic vulnerability and risk assessment of stone masonry structures

    Science.gov (United States)

    Abo El Ezz, Ahmad

    Earthquakes represent major natural hazards that regularly impact the built environment in seismic prone areas worldwide and cause considerable social and economic losses. The high losses incurred following the past destructive earthquakes promoted the need for assessment of the seismic vulnerability and risk of the existing buildings. Many historic buildings in the old urban centers in Eastern Canada such as Old Quebec City are built of stone masonry and represent un-measurable architectural and cultural heritage. These buildings were built to resist gravity loads only and generally offer poor resistance to lateral seismic loads. Seismic vulnerability assessment of stone masonry buildings is therefore the first necessary step in developing seismic retrofitting and pre-disaster mitigation plans. The objective of this study is to develop a set of probability-based analytical tools for efficient seismic vulnerability and uncertainty analysis of stone masonry buildings. A simplified probabilistic analytical methodology for vulnerability modelling of stone masonry building with systematic treatment of uncertainties throughout the modelling process is developed in the first part of this study. Building capacity curves are developed using a simplified mechanical model. A displacement based procedure is used to develop damage state fragility functions in terms of spectral displacement response based on drift thresholds of stone masonry walls. A simplified probabilistic seismic demand analysis is proposed to capture the combined uncertainty in capacity and demand on fragility functions. In the second part, a robust analytical procedure for the development of seismic hazard compatible fragility and vulnerability functions is proposed. The results are given by sets of seismic hazard compatible vulnerability functions in terms of structure-independent intensity measure (e.g. spectral acceleration) that can be used for seismic risk analysis. The procedure is very efficient for

  9. New Ideas for School Construction.

    Science.gov (United States)

    Producers' Council, Inc., Washington, DC.

    Present educators, architects, engineers, and building product manufacturers with a medium of common interest for discussion of mutual school construction problems, objectives, needs, ideas, capabilities and limitations. Contents include--(1) modern wood construction, (2) school room in a steel mill, (3) masonry in new school design, (4) the…

  10. Life Cycle Assessment of Concrete

    Energy Technology Data Exchange (ETDEWEB)

    Sjunnesson, Jeannette

    2005-09-15

    This is an environmental study on concrete that follows the standard protocol of life cycle assessment (LCA). The study is done for two types of concrete, ordinary and frost-resistant concrete, and has an extra focus on the superplasticizers used as admixtures. The utilization phase is not included in this study since the type of construction for which the concrete is used is not defined and the concrete is assumed to be inert during this phase. The results show that it is the production of the raw material and the transports involved in the life cycle of concrete that are the main contributors to the total environmental load. The one single step in the raw material production that has the highest impact is the production of cement. Within the transportation operations the transportation of concrete is the largest contributor, followed by the transportation of the cement. The environmental impact of frost-resistant concrete is between 24-41 % higher than that of ordinary concrete due to its higher content of cement. Superplasticizers contribute with approximately 0.4-10.4 % of the total environmental impact of concrete, the least to the global warming potential (GWP) and the most to the photochemical ozone creation potential (POCP). Also the toxicity of the superplasticizers is investigated and the conclusion is that the low amount of leakage of superplasticizers from concrete leads to a low risk for the environment and for humans.

  11. The Concrete Construction Technology of Basement Floor in High-rise Building%高层建筑地下室底板混凝土施工技术

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    The concrete pouring of high-rise building baseme-nt floor is important and difficult in construction, so the quality control is extremely important, which involves the control me-asures of large volume concrete construction and impervious concrete construction, and the technical measures of the behind pouring belt concrete. In this article, the author combines with work practice, and discusses the construction technology of basement floor to provide reference for future projects.%  高层建筑地下室底板混凝土浇筑是施工中的重点也是难点,做好质量控制极为重要。其中,涉及到大体积混凝土施工的控制措施、抗渗混凝士施工控制措施及后浇带混凝土施工技术措施等。本文结合笔者的工作实践,论述了地下室底板施工技术,为日后此类工程提供了参考。

  12. Application of Super Absorbent Polymers (SAP) in Concrete Construction State-of-the-Art Report Prepared by Technical Committee 225-SAP

    CERN Document Server

    Reinhardt, Hans-Wolf

    2012-01-01

    This is the state-of-the-art report prepared by the RILEM TC “Application of Super Absorbent Polymers (SAP) in concrete construction”. It gives a comprehensive overview of the properties of SAP, specific water absorption and desorption behaviour of SAP in fresh and hardening concrete, effects of the SAP addition on rheological properties of fresh concrete, changes of cement paste microstructure and mechanical properties of concrete. Furthermore, the key advantages of using SAP are described in detail: the ability of this material to act as an internal curing agent to mitigate autogenous shrinkage of high-performance concrete, the possibility to use SAP as an alternative to air-entrainment agents in order to increase the frost resistance of concrete, and finally, the benefit of steering the rheology of fresh cement-based materials. The final chapter describes the first existing and numerous prospective applications for this new concrete additive.

  13. Full scale model experiment of fair- faced concrete construction for Hongkong- Zhuhai- Macao Bridge%港珠澳大桥清水混凝土施工足尺模型试验研究

    Institute of Scientific and Technical Information of China (English)

    孔令磊; 杨润来; 江宪权

    2016-01-01

    为提升整体景观效果,港珠澳大桥岛上段隧道敞开段墙身、挡浪墙及岛上房建采用清水混凝土工艺。由于清水混凝土在国内应用不多,缺乏施工经验,为确保施工品质及工程目标实现,针对清水混凝土施工技术及影响观感的各环节,在现场开展系统的足尺模型试验。通过系统试验,掌握了施工过程中的各项参数,并形成量化指标,以指导现场施工。%In order to enhance the overall landscape effect, fair-faced concrete was used on tunnel walls, wave walls and the buildings on the artificial islands of Hongkong-Zhuhai-Macao Bridge. As fair-faced concrete was not much used in China, the builders had no much experience in construction of the fair-faced concrete.In order to ensure the quality of concrete construction and the project goals, systematic full-scale model testing was carried out on site to assess and ascertain the technology for fair faced concrete construction and various links affecting the external appearance. Through the systematic full scale model tests, various parameters in the process of construction were achieved and transformed into quantitative indicators to guide the construction on site.

  14. 多孔贫混凝土配合比设计及施工技术研究%Investigations with construction technology and mix proportion design of the lean concrete

    Institute of Scientific and Technical Information of China (English)

    姜波; 张卫芳; 张彤

    2015-01-01

    对多孔贫混凝土的配合比设计方法及施工技术进行了研究,提出了适合机场建设的贫混凝土配合比设计方案,并进行了算例应用. 结合工程实例,给出了贫混凝土基层道面的施工流程. 在现场试验的基础上,对多孔贫混凝土基层的施工工艺,包括拌和工艺、成型工艺和养护工艺3个方面进行了深入的研究,提出了适用于多孔贫混凝土的拌和时间,建议多孔贫混凝土采用振动成型和洒水养护.%The design method of mix proportion and construction technology of the lean concrete were investigated. The design method of mix proportion of the lean concrete suitable for airport concrete was proposed and used in a calculation example. Combined with an engineering example,the construction process of lean concrete base was given. On the basis of field experiment, the deep studies on construction technique such as mix technique,molding technique and curing technique were carried out. Finally,the mix time suitable for lean concrete was proposed. The vibration molding and sprinkling curing are suitable for the lean concrete.

  15. Design and Construction Defects Analysis of Ordinary Steel Bar in Reinforced Concrete Structure%钢筋工程设计及施工缺陷分析

    Institute of Scientific and Technical Information of China (English)

    王芳

    2011-01-01

    钢筋混凝土工程包括钢筋、模板、混凝土三部分,而钢筋工程的设计及施工优劣直接影响混凝土结构的质量.通过对钢筋工程在结构主次梁的连接、框架柱与梁及剪力墙的连接、梁与板的连接、柱子纵向钢筋的加工、现浇板负筋的绑扎等部位的设计及施工缺陷分析,提出了相应的解决对策,供设计和施工人员参考.%Reinforced concrete works include reinforcement works, forwork, concretework three parts, but advantages and disadvantages of design and construction of reinforcement works will directly affect the quality of concrete structures. Some aspects are demonstrated that include the join of main beam and secondary beam, the join of frame column and beam, the join of frame and shear wall, the join of beam and board, the processing of lengthways steel bar in column, the colligation of negative reinforcement in casting board and other problems easily ignored on reinforcing steel bar project, and the corresponding measures are presented to the problems listed above. It is expected to give a reference to the colleagues working in the civil engineering and to bring new academic exchanges with others.

  16. The extreme wave interaction with the constructions of the breakwaters including the damping chamber that was filled up with the stones and concrete units

    Science.gov (United States)

    Maximov, Vasily; Nudner, Igor; Revyakin, Alexei

    2010-05-01

    The eight types of the breakwaters constructions including the damping chamber were experimentally studied. The damping chamber has the infilling with the stones, with the concrete units, or with the combinations of the stones and units. The back wall of the damping chamber was impermeable. The construction varies by the volume and by the type of the infilling. The experiments to specify the pressure at the internal walls of the damping chamber, the reflected wave height, and the wave height at the front wall were performed at the hydro flume. This flume has the following dimensions: 43 m length, 0.7 m width, and 1.2 m height. The periodic waves were produced by the shield-type wavemaker. We vary in this research the periods of the waves over the range 0.8 s to 1.64 s, and the wave height over the range 10 cm to 24 cm. The analysis revealed the most improved structure possessing the good wave-protective features.

  17. 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. 

  18. A masonry heater, a large thermal flywheel and constant temperatures : the winter of 1996/1997 of the Alberta Sustainable Home/Office

    Energy Technology Data Exchange (ETDEWEB)

    Ostrowski, J.; Fofonoff, B.

    1997-07-01

    A masonry heater using scrapwood and firewood as the only source of back-up heat in this 1820 sq ft single-family live-in demonstration home/office, was described. The heater also contributed significantly to the thermal flywheel of the house. Together with other forms of thermal mass within the building (concrete slab, wood studs, drywall, tiles, furniture, plants, etc), the masonry heater was sufficient to see the occupants through the severe and long winter of 1996/97 with comfortable indoor temperatures. The masonry heater is located near the center of the house with a sunny view towards the south. On sunny winter days it operates as a passive solar heat sink, with the sun charging up the brick face by about five degrees C. In the evening, a 40 pound load of scrap and firewood will take about 1.25 hours to penetrate through the refractory interior core and brick exterior. This provides a cosy fireplace for the occupants, while storing heat in its mass for slow release during the next 1.5 to 3 days. It heats water for storage in the hot water tank. During the period of September 1996 to May 1997 one cord of wood was burned, which is about 12 per cent of the energy pumped into the average single family home in Calgary during the same period. Experience to-date suggests that the masonry heater performs very well as a back-up heater, maintaining an ambient temperature of about 20 degrees C throughout the winter. Some flat plate solar collectors might be necessary to provide for radiant floor heating of the mass since floor temperatures were lower than most occupants found comfortable.

  19. Radon penetration of concrete slab cracks, joints, pipe penetrations, and sealants.

    Science.gov (United States)

    Nielson, K K; Rogers, V C; Holt, R B; Pugh, T D; Grondzik, W A; de Meijer, R J

    1997-10-01

    Radon movement through 12 test slabs with different cracks, pipe penetrations, cold joints, masonry blocks, sealants, and tensile stresses characterized the importance of these anomalous structural domains. Diffusive and advective radon transport were measured with steady-state air pressure differences controlled throughout the deltaP = 0 to 60 Pa range. Diffusion coefficients (deltaP = 0) initially averaged 6.5 x 10(-8) m2 s(-1) among nine slabs with only 8% standard deviation, but increased due to drying by 0.16% per day over a 2-y period to an average of 2.0 x 10(-7) m2 s(-1). An asphalt coating reduced diffusion sixfold but an acrylic surface sealant had no effect. Diffusion was 42 times higher in solid masonry blocks than in concrete and was not affected by small cracks. Advective transport (deltaP permeability), pipe penetrations, and caulked gaps, but was significant for cracks, disturbed pipe penetrations, cold joints, masonry blocks, and concrete under tensile stress. Crack areas calculated to be as small as 10(-7) m2 significantly increased radon advection. Algebraic expressions predict air velocity and effective crack width from enhanced radon transport and air pressures. Masonry blocks, open cracks, and slab cold joints enhance radon penetration but stressed slabs, undisturbed pipe penetrations, and sealed cracks may not.

  20. Precast Concrete Pavements

    Science.gov (United States)

    1981-11-01

    Gorsuch 1962, Kruse 1966, Jacoby 1967, and Hargett 1970). The final slab design used in construction is shown in Figure 2. These slabs were 6 ft wide, 24...Experiment Station, CE, Vicksburg, Miss. Gorsuch , R. F. 1962. "Preliminary Investigation of Precast Prestressed Concrete Pavements," MS Thesis, South Dakota

  1. Construction of fair- faced concrete for open tunnel of the west artificial island of Hongkong- Zhuhai- Macao Bridge%港珠澳大桥西人工岛敞开段隧道清水混凝土施工

    Institute of Scientific and Technical Information of China (English)

    刘昊槟; 孟令月; 贾紫阳

    2016-01-01

    In order to improve the landscape effect at the entrance of HZMB tunnel, fair-faced concrete is used. Based on the conditions for fair-faced concrete construction at the entrance of HZMB tunnel and by way of determination of the construction scheme and working process and the optimization of the construction technology, the level of fair-faced concrete construction was improved steadily. With the use of high-efficiency and high quality formwork, high-frequency vibrators and high performance concrete, the apparent quality of the fair-faced concrete was significantly improved and such defects as grout leakage, bubbles and pitted surfaces were also avoided.%为提升港珠澳大桥隧道口部整体景观效果,敞开段隧道外露面均采用饰面清水混凝土施工工艺。结合敞开段隧道清水混凝土施工条件,通过确定方案、固定工序、优化工艺等过程,稳步提高清水混凝土施工水平。在施工过程中采用高效高品质模板系统、高频振捣棒及稳定性高的混凝土,有效提高了清水混凝土表观质量,同时避免了混凝土的漏浆、气泡、麻面等缺陷。

  2. Stress State Analysis and Failure Mechanisms of Masonry Columns Reinforced with FRP under Concentric Compressive Load

    Directory of Open Access Journals (Sweden)

    Jiří Witzany

    2016-04-01

    Full Text Available The strengthening and stabilization of damaged compressed masonry columns with composites based on fabrics of high-strength fibers and epoxy resin, or polymer-modified cement mixtures, belongs to novel, partially non-invasive and reversible progressive methods. The stabilizing and reinforcing effect of these fabrics significantly applies to masonry structures under concentric compressive loading whose failure mechanism is characterized by the appearance and development of vertical tensile cracks accompanied by an increase in horizontal masonry strain. During the appearance of micro and hairline cracks (10−3 to 10−1 mm, the effect of non-pre-stressed wrapping composite is very small. The favorable effect of passive wrapping is only intensively manifested after the appearance of cracks (10−1 mm and bigger at higher loading levels. In the case of “optimum” reinforcement of a masonry column, the experimental research showed an increase in vertical displacements δy (up to 247%, horizontal displacements δx (up to 742% and ultimate load-bearing capacity (up to 136% compared to the values reached in unreinforced masonry columns. In the case of masonry structures in which no intensive “bed joint filler–masonry unit” interaction occurs, e.g., in regular coursed masonry with little differences in the mechanical characteristics of masonry units and the binder, the reinforcing effect of the fabric applies only partially.

  3. Monitoring historical masonry structures with operational modal analysis: Two case studies

    Science.gov (United States)

    Ramos, L. F.; Marques, L.; Lourenço, P. B.; De Roeck, G.; Campos-Costa, A.; Roque, J.

    2010-07-01

    The paper addresses two complex case studies of modal and structural identification of monuments in Portugal: the Clock Tower of Mogadouro and the Church of Jerónimos Monastery, in Lisbon. These are being monitored by University of Minho with vibration, temperature and relative air humidity sensors. Operational modal analysis is being used to estimate the modal parameters, followed by statistical analysis to evaluate the environmental effects on the dynamic response. The aim is to explore damage assessment in masonry structures at an early stage by vibration signatures, as a part of a health monitoring process that helps in the preservation of historical constructions. The paper presents the necessary preliminary dynamic analysis steps before the monitoring task, which includes installation of the monitoring system, system identification and subsequent FE model updating analysis, automatic modal identification and investigation of the influence of the environment on the identified modal parameters.

  4. Post-cracking behavior of blocks, prisms, and small concrete walls reinforced with plant fiber

    Directory of Open Access Journals (Sweden)

    I. I. Soto

    Full Text Available Structural masonry using concrete blocks promotes the rationalization of construction projects, lowering the final cost of a building through the elimination of forms and the reduction of the consumption of reinforcement bars. Moreover, production of a block containing a combination of concrete and vegetable fiber sisal results in a unit with properties such as mechanical strength, stiffness, flexibility, ability to absorb energy, and post-cracking behavior that are comparable to those of a block produced with plain concrete. Herein are reported the results of a study on the post-cracking behavior of blocks, prisms, and small walls reinforced with sisal fibers (lengths of 20 mm and 40 mm added at volume fractions of 0.5% and 1%. Tests were performed to characterize the fibers and blocks and to determine the compressive strength of the units, prisms, and small walls. The deformation modulus of the elements was calculated and the stress-strain curves were plotted to gain a better understanding of the values obtained. The compression test results for the small walls reinforced with fibers were similar to those of the reference walls and better than the blocks and prisms with added fibers, which had resistances lower than those of the corresponding conventional materials. All elements prepared with the addition of sisal exhibited an increase in the deformation capacity (conferred by the fibers, which was observed in the stress-strain curves. The failure mode of the reference elements was characterized by an abrupt fracture, whereas the reinforced elements underwent ductile breakage. This result was because of the presence of the fibers, which remained attached to the faces of the cracks via adhesion to the cement matrix, thus preventing loss of continuity in the material. Therefore, the cement/plant fiber composites are advantageous in terms of their ductility and ability to resist further damage after cracking.

  5. Utilization of concrete as a construction material in the concept of Radioactive Waste Storage in Slovak Republic

    Directory of Open Access Journals (Sweden)

    Igor Hudoba

    2007-01-01

    Full Text Available The nuclear power energy for the production of electricity seems to be, along with the alterantive ways like the wind, solar and geothermal energy, the only possibility how to cover the increasing needs for the energy in the human population. The adoption of nuclear power energy concept for the production of electricity is always a hot topic of discussion not only on the professional, but also on the political level. The join of problem of the electricity production in nuclear power plants is the disposal and storing of radioactive waste. The increasing amount of low and medium radioactive waste needs a serious concept of a long term policy in the radioactive waste management. In general, a period of 300 years is a minimum time span in which the storing facilities have to guarantie the safety of human population and environment against radiation and radiation-chemical danger. A correct design of the storage place for the radioactive waste is a challenge for experts in the fields of material science, geoscience, construction etc. This paper is dealing with the basic information about the concept, material and construction basis of the low a medium radioactive waste storage in Slovak Republic.

  6. Internal insulation applied in heritage multi-storey buildings with wooden beams embedded in solid masonry brick facades

    DEFF Research Database (Denmark)

    Harrestrup, Maria; Svendsen, Svend

    2016-01-01

    The use of internal insulation is investigated in a heritage building block with wooden beam construction and masonry brick walls as part of an energy renovation. Measurements were carried out and compared to results from a hygrothermal simulation model. The risk of mould growth in the wooden beams...... and in the interface between the insulation and the brick wall was evaluated. Three different insulation strategies for applying internal insulation were investigated: 1) insulation applied on the entire interior facade; 2) 200 mm gap in the insulation above the floor; and 3) 200 mm gap in the insulation both above...

  7. Application of small hollow concrete blocks in earth-rock dam drainage body%小型空心砼砌块在土石坝排水体中的应用

    Institute of Scientific and Technical Information of China (English)

    宁杨

    2012-01-01

      根据土石坝排水体除险加固设计实践,借鉴砌体结构设计相关成果,论述了合理引进混凝土小型空心砌块,对土石坝排水体出水面进行优化设计的方法,使得坝体排水更通畅,施工更方便,外观更整齐漂亮。%  According to reinforcement design practice and masonry structural design achievements, small hollow concrete blocks were applied at the outflow surface of earth-rock dam drainage body, rendering more smooth drain⁃age, more convenient construction, more even and beautiful appearance.

  8. C50自密实钢管混凝土施工技术研究与应用%Construction technology research and application of C50 self-compacting steel tube-confined concrete

    Institute of Scientific and Technical Information of China (English)

    张海霞; 崔鑫; 王龙志; 李金龙; 范兆付

    2016-01-01

    南水北调工程河南庞村钢管混凝土无推力系杆拱桥项目设计采用C50高强、微膨胀、自密实混凝土灌注施工,混凝土灌注施工工艺为顶升法。通过优选骨料级配、使用微膨胀剂、高效减水剂等措施优化混凝土配合比,制备出性能参数符合顶升法施工要求的C50自密实钢管混凝土。混凝土灌注施工中,通过控制混凝土生产和运输,保证混凝土的连续灌注;通过清洗钢管、预灌砂浆、灌注节奏的控制,保证了混凝土与钢管的黏结与饱满;通过覆盖湿润的养护布连续养护14 d,保证了钢管混凝土的强度的顺利发展,通过以上措施的综合应用,经敲击法检验,混凝土于钢管内黏结牢靠、无缺陷、强度发展正常。%Pang village steel tube-confined concrete without thrust tied arch bridge project in Henan of South to North Water Diversion Project design pouring construction by using the C50 high strength,micro expansive,self-compacting concrete,the construction tech-nology of concrete pouring for lift-up method. Through optimizing aggregate gradation,using micro expansive agent and superplastici-zer and other measures to optimize mix of concrete,prepared C50 self-compacting steel tube-confined concrete,whose performance parameters meet the requirements of the lift-up method construction. In concrete pouring construction,through the control of concrete production and transportation to guarantee continuous pouring concrete. Through cleaning pipe,pre-pouring mortar,controlling perfu-sion rhythm to ensure the bond between concrete and steel tube with full. Through covering wet curing cloth and continuous curing 14 d to guarantee the smooth development of the strength of the steel tube-confined concrete. Through the integrated application of the a-bove measures,the concrete in steel tube bonds solid,no defects,strength normal development by the percussion method testing.

  9. 无梁现浇混凝土GBF管空心楼盖施工技术例析%Case study of construction technology of concrete hollow floor without beam and cast in situ

    Institute of Scientific and Technical Information of China (English)

    张俊; 何松泉; 李昌贤

    2009-01-01

    GBF concrete hollow floor without beam is a new type structure with low weight and high rigidity,the architecture function of this floor is good and fit for cast in situ,while its price is low.Keeping the GBF tube from moving or floating and ensuring the concrete quality below the tube are the difficulties of construction for the floor.In the construction of the case given,a special fixing set is designed to ensure the quality of hollow floor,in the mean time,concrete is cast by two steps, by these measures, the quality of GBF concrete hollow floor without beam is ensured.%无梁现浇混凝土GBF管空心楼盖具有自重小、刚度大、建筑使用功能好、施工便捷以及综合造价低等优点,该新型楼盖的施工重点是确保GBF管在混凝土浇筑时不发生移位和上浮,以及防止管底混凝土产生蜂窝孔洞.采用专门设计的"云梯状"定位钢筋和混凝土分步浇筑等措施,成功克服了GBF管空心楼盖的施工难点,保证了整个工程的施工质量.

  10. Construction Technology of an Arc Large Cross-section with Step-type Concrete Stand%某弧形大截面台阶式混凝土观众台施工技术

    Institute of Scientific and Technical Information of China (English)

    彭三阳; 王富奎; 雷通洲

    2012-01-01

    Construction technology of an arc large cross-section with step-type concrete stand is showed as an example. According to its difficulties as site setting .big structural section size and span, complicated structure,and concrete static pressure box setting etc, some technical measures, tangent offset method for site setting and last setting of concrete static pressure box, etc, are adopted. Consequently, the implementation of the measures reduce construction difficulties,shorten the given period, and realize engineering effect of bare concrete.%以某会议中心弧形大截面台阶式混凝土观众台为实例,针对弧形大截面台阶式混凝土看台施工中存在的弧形看台放线定位、结构截面尺寸大、跨度大、结构复杂以及下部设有混凝土静压箱等难点,采取了切线支距法放线、后施工静压箱底板等技术措施,降低了施工难度,缩短了预计工期,达到了清水混凝土的工程效果.

  11. Visual Quality Control Techniques Used to Concrete Pylon Column Construction%混凝土塔柱施工外观质量控制技术

    Institute of Scientific and Technical Information of China (English)

    韦理仁; 张家伦; 陈新

    2016-01-01

    To improve the visual quality of concrete pylon columns of urban bridges ,the con‐struction of the pylon columns of Jiangshun Bridge was cited as an example ,to study the key visual quality control techniques used during the pylon column construction .The formwork was rational‐ly divided according to the structural characteristics of the pylon columns ,the joints between every two divisions adopts tongue‐and‐groove joints ,and the connection of the arc‐chamfered steel form‐work and the timber formwork was optimized .The WISA plate and the I‐shaped timber back ribs were connected by nails driven from the opposite side .Besides the tie rods ,there are embedded climbing cones and fining twisted steel bars installed at the base opening of the formwork ,aiming to gain the twofold tightening effect .A testing block of the pylon saddle was prepared ,comparison was made among different mold release agents ,and the salad oil was finally chosen as the release agent .During the construction of the pylon column concrete ,the timbers with length equal to the thickness of the pylon column walls were used as inner shoring ,to ensure the width of the form‐work top opening .The horizontal nails in the construction joints at the top opening of the form‐work were backed by through‐length battens to control flatness .A pump washing cycling system was designed for the ordered draining of waste water .By taking the aforementioned measures ,the pylon columns of the Jiangshun Bridge were constructed to be solid columns with pleasing sur‐f aces .%为提高城市桥梁混凝土塔柱的外观质量,以江顺大桥桥塔塔柱施工为例,对塔柱施工中混凝土外观质量控制的关键技术进行研究。结合塔柱结构特点合理进行模板分块,分块拼缝采用企口缝形式,并对圆弧倒角钢模与木模的连接进行优化处理;W IS A面板与木工字背肋的连接采用反面打钉的连接方式;模板底口除了设置拉杆

  12. 汉阳河特大桥自密实微膨胀混凝土的制备及其施工工艺%Preparation and Construction Technology of Self-compacting Expansive Concrete for Hanyang River Bridge

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    This paper prepared the C50 self compacting and micro expansional concrete by using P·O 42.5 cement, high-performance expansive agent,local raw aggregate and adding fly ash II,silica fume mineral admixtures.It was suc-cessfully applied into the construction of Hanyang River steel tube arch bridge in Wufeng County,Yichang City.The engineering application showed that:the concrete with proposed construction mixture proportion met the standard and construct requirements;the appropriate amount of expansive agent compensated the shrinkage degree of concrete;the viscosity and fluidity of the concrete was significantly improved by adding tackifier constituents and air entraining com-ponents in admixture.The construction was carried out successfully with lift pumping construction technology.%以Ⅱ级粉煤灰和硅灰作为矿物掺和料,利用当地砂石原材料、P·O 42.5水泥和 HCSA 高性能膨胀剂,制备出了 C50自密实补偿收缩混凝土,并应用于宜昌五峰汉阳河特大桥钢管拱桥中。工程应用表明:制备出的混凝土满足标准和施工要求,适当掺量的膨胀剂可以补偿混凝土收缩,外加剂中增粘组分及引气组分可明显提升混凝土的黏聚性和流动性,通过采用泵送顶升现场施工工艺成功对宜昌五峰汉阳河特大桥进行了施工。

  13. Structural recycled concrete: utilization of recycled aggregate from construction and demolition wastes; Hormigon reciclado estructural: utilizacion de arido reciclado procedente de escombros de hormigon

    Energy Technology Data Exchange (ETDEWEB)

    Alaejos Gutierrez, P.; Sanchez de Juan, M.

    2015-07-01

    This paper aims to present the main results of CEDEX research works concerning the use of recycled aggregates for structural concretes. By way of conclusion, recommendations on the requirements of the recycled aggregates have been established, providing information about the influence of these aggregates on the properties of structural concrete. (Author)

  14. Finite element analyses of continuous filament ties for masonry applications : final report for the Arquin Corporation.

    Energy Technology Data Exchange (ETDEWEB)

    Quinones, Armando, Sr. (Arquin Corporation, La Luz, NM); Bibeau, Tiffany A.; Ho, Clifford Kuofei

    2008-08-01

    Finite-element analyses were performed to simulate the response of a hypothetical vertical masonry wall subject to different lateral loads with and without continuous horizontal filament ties laid between rows of concrete blocks. A static loading analysis and cost comparison were also performed to evaluate optimal materials and designs for the spacers affixed to the filaments. Results showed that polypropylene, ABS, and polyethylene (high density) were suitable materials for the spacers based on performance and cost, and the short T-spacer design was optimal based on its performance and functionality. Simulations of vertical walls subject to static loads representing 100 mph winds (0.2 psi) and a seismic event (0.66 psi) showed that the simulated walls performed similarly and adequately when subject to these loads with and without the ties. Additional simulations and tests are required to assess the performance of actual walls with and without the ties under greater loads and more realistic conditions (e.g., cracks, non-linear response).

  15. Statistical analysis of concrete quality testing results

    Directory of Open Access Journals (Sweden)

    Jevtić Dragica

    2014-01-01

    Full Text Available This paper statistically investigates the testing results of compressive strength and density of control concrete specimens tested in the Laboratory for materials, Faculty of Civil Engineering, University of Belgrade, during 2012. The total number of 4420 concrete specimens were tested, which were sampled on different locations - either on concrete production site (concrete plant, or concrete placement location (construction site. To be exact, these samples were made of concrete which was produced on 15 concrete plants, i.e. placed in at 50 different reinforced concrete structures, built during 2012 by 22 different contractors. It is a known fact that the achieved values of concrete compressive strength are very important, both for quality and durability assessment of concrete inside the structural elements, as well as for calculation of their load-bearing capacity limit. Together with the compressive strength testing results, the data concerning requested (designed concrete class, matching between the designed and the achieved concrete quality, concrete density values and frequency of execution of concrete works during 2012 were analyzed.

  16. 76 FR 34890 - Track Safety Standards; Concrete Crossties

    Science.gov (United States)

    2011-06-15

    ... Federal Railroad Administration 49 CFR Part 213 RIN 2130-AC01 Track Safety Standards; Concrete Crossties... mandates specific requirements for effective concrete crossties, for rail fastening systems connected to concrete crossties, and for automated inspections of track constructed with concrete crossties. The Track...

  17. 76 FR 55819 - Track Safety Standards; Concrete Crossties

    Science.gov (United States)

    2011-09-09

    ... Federal Railroad Administration 49 CFR Part 213 RIN 2130-AC35 Track Safety Standards; Concrete Crossties... concrete crossties, for rail fastening systems connected to concrete crossties, and for automated inspections of track constructed with concrete crossties. This document amends and clarifies the final rule...

  18. Briefing Construction Technologies and Application of CBM Internal Mold Cast-in-Situ Concrete Hollow Floor%浅谈CBM内模现浇混凝土空心楼盖施工技术及应用

    Institute of Scientific and Technical Information of China (English)

    李新革

    2015-01-01

    文章结合工程实例,介绍CBM内模现浇混凝土空心楼盖的构造、施工方法及应用效果,提出现浇混凝土空心楼盖中内模抗浮装置及其施工方法,可有效解决因内模带动楼板钢筋上浮而影响结构质量安全的难题。%Combining engineering cases, this paper introduces structure, construction method and application results of CBM internal mold cast-in-situ concrete hollow floor, proposes internal mold anti-floating devices in cast-in-situ concrete hollow floor and its construction method that can effectively solve the problem that internal mold drives lfoor bars to rise so as to inlfuence the structure quality.

  19. Installation and Operation of Concrete Spreader in the Construction of Nuozhadu Hydropower Station%糯扎渡水电站施工中布料机的安装与运行

    Institute of Scientific and Technical Information of China (English)

    王玉; 王相森; 张雅东

    2012-01-01

    The concrete spreader is successfully used in the concrete construction of underground powerhouse of Nuozhadu Hydmpower Station, and ensures the rapid and civil construction. The installation, commissioning, operation and dismantling procedures are introduced herein, and the precautions on operation, maintenance and safety are also proposed.%糯扎渡水电站地下厂房混凝土施工中,成功使用布料机进行混凝土浇筑,实现了快速施工和文明施工的双重目标.介绍了布料机的安装、调试、运行与拆除程序,以及操作、维护、保养和安全等方面的注意事项.

  20. The Comprehensive Research on the Industrial Plant Construction Technology of Large Area Concrete Ground Floor%工业厂房大面积混凝土地坪施工技术综合研究

    Institute of Scientific and Technical Information of China (English)

    李明

    2014-01-01

    With the continuous development of modern ind-ustry and the continuous optimization of production techno-logy, d large area concrete ground floors are widely used in industrial workshop floor of construction engineering. This ar-ticle combines with engineering example, carries on the comp-rehensive study to the industrial plant construction technology of large area concrete ground floors to provide reference for readers.%随着现代化工业的不断发展和生产工艺的不断优化,大面积混凝土地坪越来越广泛地被应用于工业厂房地坪施工工程中。本文结合工程实例,对工业厂房大面积混凝土地坪施工技术进行了综合研究,以供读者参考。

  1. 综述路桥施工技术中钢纤维混凝土技术的使用%The Technology of Steel Fiber Reinforced Concrete in Road and Bridge Construction

    Institute of Scientific and Technical Information of China (English)

    邓强

    2014-01-01

    对于路桥施工而言,混凝土质量对于路桥结构的强度与力学性能有着直接的影响。将钢纤维混凝土技术应用在路桥施工中,能够提升施工质量的安全性与可靠性,这对路桥工程的良性发展有着十分积极的效用。%The quality of concrete has a direct effect on the strength and mechanical property of road and bridge structure. Applying the technology of steel fiber reinforced concrete in road bridge construction can effectively improve the safety and reliability of the construction quality, which has a very positive effect on the development of road and bridge engineering.

  2. Design of Pervious Concrete Pavement and Constructed Wetland System for Rainwater Collection and Treatment%透水混凝土路面/人工湿地雨水收集处理系统的设计

    Institute of Scientific and Technical Information of China (English)

    吴文伶; 宋中南; 石云兴; 罗兰; 王珂; 戢文占; 张涛; 冯建华; 李艳稳

    2011-01-01

    Pervious concrete pavement for rainwater collection and constructed wetland for rainwater treatment are used in a rainwater collection and utilization project in Lisui town of Shunyi District, Beijing City. The design methods of pervious concrete pavement, detention tank and constructed wetland are introduced. Furthermore, the technology advantages, process flow and structure design are discussed.%北京市顺义区李遂镇某雨水收集利用工程采用透水混凝土路面收集雨水并应用人工湿地进行雨水处理,详细介绍了透水混凝土路面、调节池、人工湿地的设计方法,并对该技术的优势、工艺流程、结构设计等进行了详细探讨.

  3. Photocatalyticpaving concrete

    OpenAIRE

    2014-01-01

    Today bituminous concrete is a conventional paving material. Among its advantages one can name dustlessness and noiselessness, fine wear (up to 1 mm a year) and fine maintainability. As the main disadvantages of this material one can name high slipperiness under humidification, low durability and weather resistance. Besides that, during placement of the bituminous concrete a lot of different air pollutants are emitted, which are harmful for environment and human’s health (they are listed in t...

  4. 核电站高性能大体积混凝土配制与施工技术%Preparation and Construction Technology of Nuclear Power Plant High-Performance Mass Concrete

    Institute of Scientific and Technical Information of China (English)

    王辉诚; 陈立胜; 吕光晔

    2011-01-01

    The paper introduces the technical specifications and requirements on the mass concrete for the reactor plant of CPR1000 + nuclear power plant in detail. Taking the A, B, and C layer overall placing of Unit 3 reactor plant (3R.X) in Yangjiang nuclear power plant as an example, the reasonable concrete mix through experimental studies significantly improve the concrete performance and solve the durability problems of CPR100(H mass concrete. Through the quality control of mass concrete such as mold-into temperature control and conservation measures, the temperature cracks and other issues in mass concrete construction are solved.%详细介绍了CPR1000+核电厂反应堆厂房筏基混凝土技术规格书要求.以阳江核电厂3#机组反应堆厂房(3RX)筏基A、B、C层混凝土整体浇筑为例,通过实验研究,确定了混凝土的合理配比,显著改善了混凝土各项性能,解决了CPR1000+大体积混凝土耐久性问题.通过人模温度控制、养护措施控制等大体积混凝土施工质量控制措施,解决了大体积混凝土施工中温度裂缝等问题.

  5. The influence of recycled concrete aggregates in pervious concrete

    Directory of Open Access Journals (Sweden)

    L. M. TAVARES

    Full Text Available The expansion of urban areas under constant changes in the hydrological cycle directly affects the drainage of rainwater. The problems of urban drainage become major engineering problems to be solved in order to avoid negative consequences for local populations. Another urban problem is the excessive production of construction and demolition waste (CDW, in which , even with a increasingly policy of waste management , have been an end up being thrown in inappropriate disposal sites. Alternatively aiming to a minimization of the problems presented, we propose the study of permeable concrete using recycled concrete aggregate. In this study, there were evaluated the performance of concrete by means of permeability, consistency, strength, and interface conditions of the materials . Satisfactory relationships of resistance/permeability of concrete with recycled aggregate in relation to the concrete with natural aggregates was obtained, showing their best potential.

  6. Photocatalyticpaving concrete

    Directory of Open Access Journals (Sweden)

    Lyapidevskaya Ol'ga Borisovna

    2014-02-01

    Full Text Available Today bituminous concrete is a conventional paving material. Among its advantages one can name dustlessness and noiselessness, fine wear (up to 1 mm a year and fine maintainability. As the main disadvantages of this material one can name high slipperiness under humidification, low durability and weather resistance. Besides that, during placement of the bituminous concrete a lot of different air pollutants are emitted, which are harmful for environment and human’s health (they are listed in the paper according to the US Environmental Protection Agency materials. As an alternative, one can use cement-concrete pavement, which is in many ways more efficient than the bituminous concrete. It is proposed to enhance environmental performance of the cement-concrete pavement via usage of photocatalysis. The mechanism of different photocatalytic reactions is described in the paper, namely heterogeneous and homogeneous photocatalysis, photo-induces, photoactivated catalysis and catalytical photoreactions. It is pro-posed to use heterogeneous photocatalysis with titanium dioxide as a photocatalyst. The mechanism of photo oxidation of air contaminants, with the usage of titanium dioxide is2described. The paper sets problems, connected with the sensibilization of TiOto thevisible light (it is proposed to use titanium dioxide, doped with the atoms of certain elements to increase its sensibility to the visible light and with the development of a new photocatalytic paving concrete, which will meet the requirements, specified for paving in the climatic and traffic conditions of the Russian Federation.

  7. 三维渐变大断面洞室混凝土衬砌施工技术探讨%Discussion on concrete lining construction technology of large cavern with gradual cross-section

    Institute of Scientific and Technical Information of China (English)

    陈松

    2014-01-01

    The-expanding-section-of-tailrace-tunnel-of-underground-powerhouse-in-Laxiwa-Hydropower-Station-is-a-3D-structure-with-gradually-changed-cross--section,-and-the-cavern-section-is-large-with-complicated-curved-surface-,-resulting-in-high-techni-cal-requirement-for-formwork-design-and-planning-,-as-well-as-difficult-construction-of-concrete-lining-.In-view-of-the-concrete-lin-ing-construction-of-the-expanding-section-,-this-paper-briefly-introduces-some-construction-technologies-such-as-construction-proce--dure,-formwork-planning-,-bent-erection-and-concrete-lining-,-and-the-coring-test-result-reveals-that-the-internal-structural-strength-of-concrete-can-meet-the-relevant-requirements-.The-research-achievements-can-provide-reference-for-similar-projects-.%拉西瓦水电站地下厂房尾水扩散段为三维渐变结构,洞室断面大,曲面变化复杂,模板设计及配置技术含量高,混凝土衬砌施工难度大。以该水电站尾水扩散段混凝土衬砌施工为例,对施工程序、模板配置、排架搭设和混凝土衬砌等施工技术作了简要介绍,同时通过取芯检验显示,混凝土内部结构强度符合要求。相关成果可为以后同类工程施工提供经验借鉴。

  8. STUDIES ON DURABILITY OF WASTE RUBBER MIXED CONCRETE

    OpenAIRE

    Aritra Mandal*1, Kushal Chakraborty2 & Atanu Samanta3

    2017-01-01

    Concrete is one of the most widely used construction material in the world. The construction industries are looking for making concrete more “greener” by reducing its ecological effects on environment and they are in need of finding cost effective materials for increasing the strength of concrete structures. Cement and aggregate, which are the important constituents used in concrete production, are then vital materials needed for the construction industry. This inevitably led to a continuous ...

  9. Results of lichenometric dating of masonry in the outskirts of Kandalaksha city (Russia, Murmansk region

    Directory of Open Access Journals (Sweden)

    Melekhin Alexey

    2014-11-01

    Full Text Available The lichenometric dating of masonry in the area of Kandalaksha city was carried out. For more accurate dating, the reference sites with known age (70 years were laid in Pechenga district (Murmansk region. According to our calculations, the age of masonry was in the range of 60 to 80 years, that is consistent with dendrochronology data (75 years.

  10. Update to UFC 3-340-02 for Blast Resistant Design of Masonry Components

    Science.gov (United States)

    2010-07-01

    shear force resisted by masonry (lb) Vso = out-of-plane shear force resisted by shear reinforcement (lb) Vmi = in-plane shear force resisted by...plane shear force resisted by masonry (lb) Vso = out-of-plane shear force resisted by shear reinforcement (lb) Vmi = in-plane shear force

  11. 空分装置中冷箱基础珠光砂混凝土冬季施工%Perlite concrete winter construction of cold case foundation in air separation facility

    Institute of Scientific and Technical Information of China (English)

    袁江城

    2012-01-01

    结合具体工程实例及珠光砂混凝土施工流程,阐述了珠光砂混凝土在冬季施工的技术要点,并经过试验及实测数据,计算确定了搅拌水的温度,采用经济性良好、可行性强的热水搅拌措施提高拌合物的温度,从而保证珠光砂混凝土的施工质量。%Integrating with specific engineering case and perlite concrete construction procedure,it describes the technological points of perlite concrete winter construction.Through experiments and actual survey data,it calculates and determines the mixing water temperature,and adopts economic and feasible hot water mixing measures to improve the mixture temperature,so as to guarantee the construction quality of perlite concrete.

  12. Self-Placing Concrete

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    Certain concrete pours have areas where the congestion of reinforcing bars make placement of concrete almost impossible. Using conventional placing and vibration techniques, the resulting concrete can have considerable honeycombing due to the development of voids. Self-placing concrete is a possible solution to the problem. Also known as self-compactable concrete, self-consolidating concrete, flowable concrete, and non-vibration concrete. These concretes eliminate the need for vibration in a ...

  13. HYDRAULIC CONCRETE COMPOSITION AND PROPERTIES CONTROL SYSTEM

    Directory of Open Access Journals (Sweden)

    O. M. Pshinko

    2015-08-01

    consistency and required concrete strength, which allows to optimize the concrete composition by any optimality criterion, depending on the operation conditions. Practical value. Using the developed method will expand its functionality when applied in the form of the composition calculation computer program for the construction and repair of surface and underwater structures. The use of physico-analytical method at production site will simultaneously solve the economic problems of construction and maintenance cost reduction, component saving and ensure obtaining the concrete with the set properties for specific operation conditions of transport engineering structures.

  14. Self-compacting concrete (SCC)

    DEFF Research Database (Denmark)

    Geiker, Mette Rica

    2008-01-01

    In many aspects Self-Compacting Concrete (SCC, “Self-Consolidating Concrete” in North America) can be considered the concrete of the future. SCC is a family of tailored concretes with special engineered properties in the fresh state. SCC flows into the formwork and around even complicated...... reinforcement arrangements under its own weight. Thus, SCC is not vibrated like conventional concrete. This drastically improves the working environment during construction, the productivity, and potentially improves the homogeneity and quality of the concrete. In addition SCC provides larger architectural...... freedom in structural design. The present Chapter describes selected properties of SCC. The properties and use of SCC are illustrated through a few case histories and future trends are briefly described. The Chapter concludes with a list of sources of further information....

  15. Influence of structural parameters of the masonry on effective elastic properties and strength

    Directory of Open Access Journals (Sweden)

    А.I. Grishchenko

    2014-08-01

    Full Text Available Two phase masonry model, which contains elastic mortar and elastic bricks, is analyzed numerically in order to evaluate sensitivity of effective elastic moduli and strength properties to a deviation in the masonry structural parameters. Different methods of masonry homogenization are studied. Effective elastic moduli of the masonry representative volume element are obtained by means of direct finite element simulation and homogenization procedure. Influence of variation in the heterogeneous material microstructure characteristics (influence of brick aspect ratio and orientation angle on the local stress-strain state and mechanical properties of the representative volume element of the composite considered is analyzed. Mechanical properties obtained by direct finite element modeling and other methods in various literary sources are compared. These studies are relevant for the design of composite materials with a structure similar to masonry.

  16. Assessment of the mechanical properties of brick masonry by a flat-jack method

    Directory of Open Access Journals (Sweden)

    S.V. Zubkov

    2015-12-01

    Full Text Available The modern Russian methods for defining the mechanical characteristics of brick masonry are based on finding the strength of masonry components (brick and mortar. After getting the results of laboratory tests of components, mechanical characteristics of masonry are calculated using empirical formulae. Those formulae, however, cannot take into consideration the presence of damages and other factors. Obtaining the characteristics (strength and deformation by a direct flat-jack test of masonry fragments on-site looks promising. A widespread use of FEM requires setting accurate deformation features for modeling domes, arches and thin brick outside layer in multilayer walls. Also accurate deformation characteristics are used for calculating temperature loads. The paper gives the results of practical use for the masonry deformation research by the flat-jack test method. The correlation factors are defined and rigidness coefficients of flat-jacks are obtained in the study.

  17. The use of ultrasonic pulse velocity tests for the diagnosis of ancient masonries: the influence of the applied load

    Science.gov (United States)

    Leucci, Giovanni; Vasanelli, Emilia; Calia, Angela; Micelli, Francesco; Aiello, Maria Antonietta

    2014-05-01

    Sophisticated non destructive techniques for the diagnosis of existing masonry structures have been developed and improved throughout the years, such as ground penetrating radar, thermography, sonic and ultrasonic tomography, laser scanner survey, etc.: by using an integrated approach it is possible to reconstruct the morphology of the masonry walls, to detect the presence of cracks and voids, achieving an accurate and reliable diagnosis of the construction, which is the basis for the restoration design. The ultrasonic pulse velocity (UPV) method can be conveniently used to check the quality of stones, but it can be used also for material characterization. Both the intrinsic characteristic of the stone (porosity, grain size, anisotropy, etc.) and the external factors (humidity, stress, temperature, presence of cracks) may affect the elastic wave propagation, thus in order to correctly estimate the ultrasonic behaviour of the material investigated it is important to know in what manner and how much the variation of the experimental conditions may modify the characteristics of the waves being measured. This aspect is of crucial importance when in situ measurements are made. In this work the influence of the applied load on UPV results has been investigated. In particular, the research has been carried out on ashlars and on sample masonry panels made of lime mortar joints and Lecce stone, a soft calcarenitic stone traditionally used in the Lecce district, South of Italy. The presence of load strongly influenced the UPV measures, due to the particular microstructural characteristic of the stone. The work aim at quantify this influence in order to correctly interpret in situ measurements.

  18. Application of PDCA in Construction of Premixed Concrete Wear-resisting Floor%论PDCA在预拌混凝土耐磨地坪施工的应用

    Institute of Scientific and Technical Information of China (English)

    张静

    2014-01-01

    文章主要论述了PDCA循环管理方法在预拌混凝土耐磨地坪施工中的应用,探讨运用PDCA循环管理方法,如何解决耐磨地坪施工中的问题。%This paper mainly discusses the application and method of PDCA circulation management in construction of pre-mixed concrete wear-resisting floor and how to solve the problem of wear-resisting floor construction.

  19. Mechanical characterization of fiber reinforced Polymer Concrete

    Directory of Open Access Journals (Sweden)

    João Marciano Laredo dos Reis

    2005-09-01

    Full Text Available A comparative study between epoxy Polymer Concrete plain, reinforced with carbon and glass fibers and commercial concrete mixes was made. The fibers are 6 mm long and the fiber content was 2% and 1%, respectively, in mass. Compressive tests were performed at room temperature and load vs. displacement curves were plotted up to failure. The carbon and glass fibers reinforcement were randomly dispersed into the matrix of polymer concrete. An increase in compressive properties was observed as function of reinforcement. The comparison also showed that Polymer Concrete, plain and reinforced, has a better performance than regular market concrete, suggesting that PC is a reliable alternative for construction industry.

  20. 小湾水电站水垫塘抗冲耐磨混凝土施工%Construction of Scour Resistant Concrete for Water Cushion Pool in Xiaowan Hydropower Station

    Institute of Scientific and Technical Information of China (English)

    张捍平

    2013-01-01

      针对小湾水电站坝后水垫塘抗冲耐磨混凝土施工,工程量大,设计标号高,水胶比小,外掺材料多,跨高温、雨季,且抗冲耐磨混凝土粘稠性强,易发干发白、产生干缩裂缝,混凝土振捣困难,抹面平整度难以控制等特点,提出了混凝土配合比优化设计,混凝土拌和,过流面表面不平整处理,早期塑性干缩预防,后期收缩裂缝、温度裂缝预防,雨季施工防雨等措施,保证了施工质量和进度,取得了良好的社会经济效益。%Some difficulties has been encountered in the scour resistant concrete construction of water cushion pool in Xiaowan Hydropower Station: large construction quantity with high design grade , small ratio of water and gel , many mixed materials, high-temperature rainy season , thick abrasion-resistant concrete easy to dry and white which leads to dry shrinkage crack , difficult concrete vibrator and uneven surface .Measures such as optimization design , concrete mix-ing, flow surface roughness treatment , plastic shrinkage prevention in early stage , shrinking and temperature cracks pre-vention in later stage , rain proof in rainy season are proposed in order to ensure construction quality and progress and to achieve good social and economic benefits .

  1. Winter Concrete Construction Technology of Electric Energy Heating and Warm Shed Storage Heat in Plateau%电能加热暖棚蓄热法高原冬季混凝土施工技术

    Institute of Scientific and Technical Information of China (English)

    陈新泉

    2013-01-01

    为了满足高原严寒地区水利水电援建项目抢工期的需要,西藏旁多水利枢纽工程的发电厂房工程采用电能加热、暖棚蓄热的冬季混凝土施工方法,取得了良好社会、经济、质量和进度效益.该方法具有热效率高、操作简便、质量可靠、节能环保等优点,是适合高原特点的冬季混凝土施工方法,可以在类似工程推广应用.%In order to meet the requirement of emergency construction period for water conservancy and hydropower assistance construction project in the plateau and severe cold area,the powerhouse was constructed with winter concrete construction method of electric energy heating and warm shed storage heat in Tibet Pangduo key water-control project,which obtained good society,economy,quality and progress benefit.This method are with high thermal efficiency,easy operation,reliable quality,saving energy and protecting environment etc.advantages.It's winter concrete construction method that is suitable for plateau feature,it can be spread used in the similar projects.

  2. Study Concerning Characterization of Some Recycled Concrete Aggregates

    Directory of Open Access Journals (Sweden)

    Robu Ion

    2016-03-01

    Full Text Available Using recycled concrete aggregates (RCA is a matter of high priority in the construction industry worldwide. In countries like the Netherlands, Denmark, Germany, USA, Japan, France recycled concrete aggregates obtained from demolition are valorized up to 90%, mainly for road construction and less in the manufacture of new concrete.

  3. Cellular fiber–reinforced concrete

    OpenAIRE

    Isachenko S.; Kodzoev M.

    2016-01-01

    Methods disperse reinforcement of concrete matrix using polypropylene, glass, basalt and metal fibers allows to make the construction of complex configuration, solve the problem of frost products. Dispersed reinforcement reduces the overall weight of the structures. The fiber replaces the secondary reinforcement, reducing the volume of use of structural steel reinforcement. Cellular Fiber concretes are characterized by high-performance properties, especially increased bending strength and...

  4. Description of Construction of Roller Compaction Concrete Dam on Left Bank, Jinghong Hydropower Project%景洪水电站左岸碾压混凝土大坝施工综述

    Institute of Scientific and Technical Information of China (English)

    胡海涛; 刘刚; 罗永红

    2013-01-01

    景洪水电站大坝为全断面碾压混凝土重力坝,位于澜沧江流域低热河谷区,高温多雨,每年高气温施工时间长达7~8个月,大坝混凝土温度控制要求严格,措施复杂。同时电站工程量大,施工强度高,常态混凝土、碾压混凝土施工及坝内压力钢管安装施工干扰大,施工难度高。文章结合景洪水电站现场施工实际,全面介绍了大坝混凝土施工方案、原材料与混凝土配合比、温控措施、新材料与新工艺。%The dam of Jinghong Hydropower Project, a RCC gravity one at full section, is located in the lower and hot valley of the Lang-cangjiang river catchment where the temperature is high and it rains often.The construction period at high temperature each year lasts 7~8 months.Therefore, the temperature of the dam concrete is strictly required to control.Measures for the temperature control are com-plicated.Meanwhile, the project work is in a large quantity and the construction strength is high.Construction of normal concrete, RCC and installation of penstocks in the dam are interfered largely.So, the construction difficulties are so high.In the paper, scheme for dam concrete construction, raw materials, concrete mix ratio, temperature control measures, new materials and new technology are totally in-troduced in combination of the site construction practice of Jinghong Hydropower Project.The project construction speed is called Jinghong Speed and the project is awarded the First Prize-winning one of Yunnan Province.

  5. The Application of Concrete in Human History and Development in the Modern World

    Institute of Scientific and Technical Information of China (English)

    杨琳; 韩超

    2012-01-01

    Looking at the five-thousand-year history of mankind,humans developed a series of technology of building environment,i.e.civil engineering. If we say the development of civil engineering is an epitome of the glorious civilisation,the discovery and enhance of material proclaim the developing civil engineering.People have found many sorts of traditional materials (soil,timber,masonry) and modern materials (concrete,glass,fibre,polymer).Among these,concrete as composite material played the greatest role in engineering over the last two hundred years.

  6. Application of Concrete Laser Leveler in Construction of SATEC Textile Factory Floor%混凝土激光整平机在SATEC纺织厂工程施工中应用

    Institute of Scientific and Technical Information of China (English)

    覃晓航

    2014-01-01

    ∶SATEC纺织厂的大面积混凝土地面施工,采用欧盟标准,地面平整度控制要求高。通过采用先进的混凝土激光整平机设备,解决了厂房大面积地面施工存在的分块小、效率低、平整度差等问题,达到了超地坪质量要求,经济效益和社会效益显著。%High flatness is required during the construction of large area concrete floor for SATEC textile factory so as to cater for EU standards. The problems, those may be encountered during large area concrete floor construction, like small block, low efficiency, poor flatness etc., are well solved through using advanced concrete laser leveler, which meets the quality requirements on super-flat floor and gets good economic and social benefits.

  7. 解析混凝土空心楼盖施工质量控制要点%Analysis of the Construction Quality Control Essentials of Concrete Hollow Floor

    Institute of Scientific and Technical Information of China (English)

    吴长龙

    2014-01-01

    In recent years, due to various reasons, the quality of concrete hol ow floor construction is poor, which is difficult to provide safe working living environment for people. This paper carries on analysis of the concrete hol ow floor, and finds the reasons that affect the quality, explores the effective methods to improve the quality of concrete hol ow floor construction, in order to improve the quality of the buildings.%近年来,由于各方面的原因,导致混凝土空心楼盖的施工质量较差,难以为人们提供安全的工作生活环境。本文对混凝土空心楼盖进行了分析,并寻找影响其质量的原因,探讨提高混凝土空心楼盖施工质量的有效方法,以期能够提高建筑物的品质。

  8. Development of Electrode Units for Electrokinetic Desalination of Masonry and Pilot Scale Test at Three locations for Removal of Chlorides

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Christensen, Iben Vernegren; Skibsted, Gry

    2010-01-01

    Electrode units for electrokinetic desalination of masonry has been developed and tested in pilot scale at three different locations. The units are formed as casings with a metallic mesh electrode, and carbonate rich clay to buffer the acid produced at the anode. The case has an extra loose bottom...... which allows continuous pressure between clay and masonry so good electrical contact is remained. The electrode units were tested at three different locations, two on baked brick masonry (inside in a heated room and outside on a masonry with severe plaster peeling) and the third pilot scale experiment...... was conducted outside on a limestone masonry. The duration of the experiments was 4-8 month. Chloride concentrations were measured in drilling powder from the masonry before and after experiments. In all three masonries, the average concentrations decreased. The transport numbers for chloride was between 0...

  9. Metrology Needs for Predicting Concrete Pumpability

    Directory of Open Access Journals (Sweden)

    Myoungsung Choi

    2015-01-01

    Full Text Available With the increasing use of pumping to place concrete, the development and refinement of the industry practice to ensure successful concrete pumping are becoming important needs for the concrete construction industry. To date, research on concrete pumping has been largely limited to a few theses and research papers. The major obstacle to conduct research on concrete pumping is that it requires heavy equipment and large amounts of materials. Thus, developing realistic and simple measurement techniques and prediction tools is a financial and logistical challenge that is out of reach for small research labs and many private companies in the concrete construction industry. Moreover, because concrete pumping involves the flow of a complex fluid under pressure in a pipe, predicting its flow necessitates detailed knowledge of the rheological properties of concrete, which requires new measurement science. This paper summarizes the technical challenges associated with concrete pumping and the development in concrete pumping that have been published in the technical literature and identifies future research needed for the industry to develop best practices for ensuring successful concrete pumping in the field.

  10. Excavation-caused extra deformation of existing masonry residence in soft soil region

    Science.gov (United States)

    Tang, Y.; Franceschelli, S.

    2017-04-01

    Growing need for construction of infrastructures and buildings in fast urbanization process creates challenges of interaction between buildings under construction and adjacent existing buildings. This paper presents the mitigation of contradiction between two parties who are involved the interaction using civil engineering techniques. Through the in-depth analysis of the results of monitoring surveys and enhanced accuracy and reliability of surveys, a better understanding of the behavior of deformable buildings is achieved. Combination with the original construction documents, the two parties agree that both of them are responsible for building damages and a better understanding for the rehabilitation of the existing buildings is focused on. Two cases studies are used to demonstrate and describe the importance of better understanding of the behavior of existing buildings and their rehabilitations. The objective of this study is to insight into mechanisms of soil-structure interaction for buildings adjacent to deep excavations, which can result in a damage in existing masonry residence, and to take the optimized measures to make deep excavations safety and economic and adjacent buildings keep good serviceability in urban areas with soft soil conditions.

  11. Historic Concrete: From Concrete Repair to Concrete Conservation

    NARCIS (Netherlands)

    Heinemann, H.A.

    2013-01-01

    Concrete like materials were already applied during the Roman Empire. After the decline of the Roman Empire, a wide scale application of concrete only reappeared in the 19th century. Here lies also the origin of modern (reinforced) concrete. Since then, both concrete application and composition have

  12. Mechanical DT and NDT: characterisation of building stones and research of correlation for in situ analysis of ancient masonries

    Science.gov (United States)

    Vasanelli, E.; Calia, A.; Aiello, M. A.; Sileo, M.; Leucci, G.

    2012-04-01

    Restoration works of the historical-architectural built heritage move from the typological and mechanical qualification of the buildings. Minimum destructive impact is required in preliminary diagnostic studies for the interventions, as it is possible. The use of the undestructive and non-invasive diagnostic techniques has always advantages in the activities on pre-existing buildings, in terms of sustainability; moreover, it is a need with respect to the conservation constraints when we act on the historical-architectural heritage. This work deals with destructive and non-destructive tests for the mechanical characterisation of some traditional soft stones, used as building materials in the Southern Italy; it is a part of a larger activity devoted to set up non-invasive diagnostic procedures for the mechanical analysis and qualification of ancient masonries. The laboratory experimental activity is based on the use of mechanical compressive tests, ultrasonic and Schmidt-Hammer tests, and the research of correlation between the results obtained by these crossed tests. It is aimed to verify the effectiveness and/or to point out critical aspects and limits of the above mentioned non-destructive tests - already applied in the field of the concrete and compact stones - with reference to the characterisation of the soft stones. The research of correlations between the results of destructive and non destructive tests has the final aim to reduce the use of destructive analyses on the masonries, by acquiring substitutive information derivable from performing NDT in laboratory, as well as in situ conditions. Finally, data gathered by the mechanical characterisation give reference values for the evaluation and control of the effectiveness of restoration interventions and their monitoring. This activity is carried out in an interdisciplinary way within the AITECH network (Applied Innovation Technologies for Diagnosis and Conservation of Built Heritage), a regional research

  13. Toward Development of Self-Compacting No-Slump Concrete Mixtures

    NARCIS (Netherlands)

    Hoornahad, H.

    2014-01-01

    No-slump concrete (NSLC) is one of the commercial types of concrete that is known as a type of concrete with almost zero flowability. No-slump concrete is normally used for typical applications, like pavements construction and massive dam structures. The specific feature of a no-slump concrete is it

  14. 水泥混凝土路面快速薄层修补设计与施工方法%Rapid thin-layer mending design and construction methods of cement concrete pavement

    Institute of Scientific and Technical Information of China (English)

    谢子荣

    2015-01-01

    The paper introduces the development conditions of rapid thin-layer mending material of cement concrete pavement,analyzes strengthe-ning design of rapid thin-layer mending structure of cement concrete pavement and recovering pavement function design,and explores its applica-bility construction strategies,so as to achieve good mending effect.%介绍了水泥混凝土路面快速薄层修补材料的发展状况,对水泥混凝土路面快速薄层修补结构补强设计与恢复路面功能设计进行了分析,探讨了其实用性的施工策略,以收到良好的修补效果。

  15. Resistance of Concrete Masonry Walls With Membrane Catcher Systems Subjected to Blast Loading

    Science.gov (United States)

    2010-12-01

    effectiveness of systems comprised of polymers, composites, geotextiles , and thin steel and aluminum sheets has been researched extensively over the past...secondary debris resulting from blast pressure, and the effectiveness of systems comprising polymers, composites, geotextiles , and thin steel and aluminum...wall structure undergoes large transient displacements. Initially, relatively stiff composite laminates and geotextiles were investigated, including

  16. Designing concrete for durability

    Directory of Open Access Journals (Sweden)

    Boyd, A. J.

    2001-12-01

    Full Text Available Some of the factors affecting the durability of modern concrete structures are discussed, with an emphasis on the problems caused by modern portland cements. This is followed by a description of some concrete durability issues of current interest, such as plastic shrinkage, seawater attack, and sulfate attack. The strategies for testing for durability are also discussed. It is concluded that, to produce durable concretes, a holistic approach to concrete construction must be adopted.

    Se discuten algunos de los factores que influyen en la durabilidad de las estructuras de hormigón modernas, haciendo énfasis en los problemas causados por el cemento Portland. A esto sigue una descripción de algunas cuestiones de interés general de la durabilidad del hormigón tales como la retracción plástica, el ataque por agua de mar y el ataque por sulfatos. Se discuten también las estrategias de los ensayos de durabilidad. Se concluye que para producir hormigones durables se debe adoptar un enfoque holístico de la construcción con hormigón.

  17. Retrofit of a Multifamily Mass Masonry Building in New England

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, K.; Kerrigan, P.; Wytrykowska, H.; Van Straaten, R.

    2013-08-01

    Merrimack Valley Habitat for Humanity (MVHfH) has partnered with Building Science Corporation to provide high performance affordable housing for 10 families in the retrofit of an existing brick building (a former convent) into condominiums. The research performed for this project provides information regarding advanced retrofit packages for multi-family masonry buildings in Cold climates. In particular, this project demonstrates safe, durable, and cost-effective solutions that will potentially benefit millions of multi-family brick buildings throughout the East Coast and Midwest (Cold climates). The retrofit packages provide insight on the opportunities for and constraints on retrofitting multifamily buildings with ambitious energy performance goals but a limited budget. The condominium conversion project will contribute to several areas of research on enclosures, space conditioning, and water heating. Enclosure items include insulation of mass masonry building on the interior, airtightness of these types of retrofits, multi-unit building compartmentalization, window selection, and roof insulation strategies. Mechanical system items include combined hydronic and space heating systems with hydronic distribution in small (low load) units, and ventilation system retrofits for multifamily buildings.

  18. 矿区建设预拌泵送混凝土结构裂缝的控制对策研究%Countermeasures to Control Cracks in Ready-mixed Pumping Concrete Structure in Mine Construction

    Institute of Scientific and Technical Information of China (English)

    张长友

    2013-01-01

      矿区基本建设中泵送混凝土在现浇结构中广泛应用后,早期出现裂缝问题成为关注的焦点。文章针对矿区建设预拌泵送混凝土施工的特点,分析了产生裂缝的原因,并从原材料和施工技术的角度提出了防治预拌泵送混凝土结构裂缝的对策,对矿区建设施工中预测控制裂缝起到一定的指导作用。%  In the mine construction, pumping concrete is widely used in the cast-in-place structure, following with the cracks problem in the early stage as focus. In this paper, the characteristics of ready-mixed pumping concrete construction and reasons for the cracks are discussed. Moreover, the coutermesures are put forward from the point of view of raw materials and construction techniques. This will play a guiding role to predicate and control cracks in the mine construction

  19. FACTORS PROVIDING THE STRENGHT AND DURABILITY OF CONCRETE

    Directory of Open Access Journals (Sweden)

    Bahattin KÜÇÜK

    2000-01-01

    Full Text Available In this study, it has been stated that the project strenght of concrete structures assumed in static and reinforced concrete calculations should also be provided for the concrete produced in construction sites. The effective factors for the production of high quality concrete are explained by interpreting previously made experimantal studies. In this way, by giving preference to scientific studies, engineers, architects, contractors and subcontractors in construction sector are provided to gain practical experience.

  20. 王希鲁节制闸钢筋混凝土底板施工中的温度与浇筑时间控制%Wang Xi Lu Sluice Floor Construction of Reinforced Concrete Pouring Time and Temperature Control

    Institute of Scientific and Technical Information of China (English)

    刘洁

    2012-01-01

    Wangxilu sluice minimum thickness reinforced concrete floor 1.5 m,the amount of time pouring concrete works 525 m3,it is a large volume of concrete.To ensure that the gate does not produce concrete floor construction cold joints and cracks in the temperature,the construction of the temperature and pouring time were strictly controlled to obtain good construction results.%王希鲁节制闸钢筋混凝土底板最小厚度1.5 m,一次浇筑混凝土工程量525 m3,属大体积混凝土。为确保闸底板混凝土不产生施工冷缝和温度裂缝,施工中对温度和浇筑时间进行了严格控制,取得了较好的施工效果。

  1. A Report of Contemporary Rammed Earth Construction and Research in North America

    Directory of Open Access Journals (Sweden)

    Arno Schmidt

    2013-01-01

    Full Text Available Contemporary stabilized rammed earth (SRE draws upon traditional rammed earth (RE methods and materials, often incorporating reinforcing steel and rigid insulation, enhancing the structural and energy performance of the walls while satisfying building codes. SRE structures are typically engineered by licensed Structural Engineers using the Concrete Building Code or the Masonry Building Code. The construction process of SRE creates structural walls of relatively high compressive strength appropriate for a broad range of heating and cooling climates. The incorporation of rigid insulation creates a high mass interior wythe that is thermally separated from the exterior, resulting in improved thermal performance. Modular aluminum reinforced formwork allows walls to be built without the use of through ties, common in concrete construction. The North American Rammed Earth Builders Association (NAREBA collaborated with Unisol Engineering Ltd. and the British Columbia Institute of Technology (BCIT on a battery of tests to obtain preliminary data to be used in support of engineering design. The tests included compressive strength comparisons, pull out rebar testing of both horizontally and vertically placed steel, simple beam tests, and the deflection of two composite wall columns with an insulation core and two types of reinforcing steel connections between the RE wythes.

  2. Description of Concrete Durability Damage Process

    Institute of Scientific and Technical Information of China (English)

    CHEN Yueshun; WEI Jun; ZHAO Xiaolong

    2006-01-01

    Based on the damage mechanics, the concrete damage grade of relative stable environment in measurable spatial is constructed in this paper, and the concrete damage evolving model and corresponding failure rule is constructed based on the damage grade fore-defined. Therefore, the concrete health status and the residual life-span can be assessed according to the measured damage grade. It is propitious to drive the development of concrete durability assessment and life-span forecast. Its feasibility of concrcte damage process description and health assessment is validated with the example in this paper, in which the damage state is described with the ultrasound velocity attenuation, and the freeze-thaw process is regarded as the concrete durability degradation influencing factor to reflect the concrete durability degradation process.

  3. Analysis and treatment of common problems in design and construction of concrete pile foundation%混凝土桩基设计与施工常见问题分析与处理

    Institute of Scientific and Technical Information of China (English)

    潘志芳

    2016-01-01

    From the Pile foundation selection and construction craft,the PaPer introduces the common Problems in the reinforced concrete Pile foundation design,exPlores the selection PrinciPle for the Pile hammer in the Pile foundation construction,and illustrates the reasons and treat-ment measures for the Pile foundation cracks,so as to accumulate exPerience for the design and construction of the Pile foundation.%从桩基选型与施工工艺两方面,介绍了钢筋混凝土桩基设计中常见的问题,探讨了桩基施工中桩锤的选择原则,并阐述了桩基裂缝的产生原因及处理措施,为桩基的设计与施工积累了经验。

  4. 谈煤仓仓顶板混凝土结构模板支撑体系的施工%On construction of support system in bin roof plate concrete structure models of coal bunkers

    Institute of Scientific and Technical Information of China (English)

    孙萍

    2011-01-01

    According to the engineering examples,the paper sums up the construction craft of the support system in bin roof plate concrete structure models of coal bunkers,points out the technical requirements,and provides the construction safety measure,so as to improve the construction methods of the bin roof plate support models and enhance the application of the craft.%通过列举工程实例,总结了煤仓仓顶板混凝土结构模板支撑体系的施工工艺,提出了技术要求,并给出施工安全措施,从而完善仓顶高支模施工方法,同时进一步推广该工艺的应用。

  5. U 型现浇配筋混凝土薄壁空心装饰柱施工技术%On construction technique of U-shaped cast-in-place reinforced concrete thin-wall hollow decoration columns

    Institute of Scientific and Technical Information of China (English)

    姚国荣

    2015-01-01

    The paper describes the craft features for the U-shaped cast-in-place reinforced concrete thin-wall hollow decoration columns,illus-trates the construction craft procedure and material requirements by combining with its construction craft principle,and researches the construc-tion quality,safety and environment protection control measures,so as to achieve better economic and social benefits.%描述了 U 型现浇配筋混凝土薄壁空心装饰柱施工的工艺特点,结合其施工工艺原理,阐述了施工工艺流程及材料要求,并对施工质量、安全、环保控制措施进行了研究,以取得良好的经济、社会效益。

  6. 配筋砌体墙混凝土框架内力分析与裂缝模拟%Internal force analysis and fracture simulation of RC frame with hybrid masonry wall

    Institute of Scientific and Technical Information of China (English)

    姜俊铭

    2014-01-01

    利用有限元方法,对空框架、空心砌体墙框架、实心砌体墙框架、配筋砌体墙框架四种有限元模型进行对比分析,结果显示:空心砌块、实心砌块、配筋砌块的加入显著提高了混凝土框架结构的极限承载力,而降低了结构的延性,改变了结构的破坏形式。%In this paper,four finite element models are analyzed in contrast by using the finite element method,which include the empty frame, hollow masonry wall frame,solid masonry wall frame,and reinforced masonry wall frame. The results show that the hollow block,solid block and reinforced block can significantly improve the ultimate bearing capacity of reinforced concrete frame,while the ductility of the structure can be re-duced,and the failure form structure can be changed.

  7. The design, construction and first-phase heavy vehicle simulator testing results on full scale ultra-thin reinforced concrete test sections at Rayton, South Africa

    CSIR Research Space (South Africa)

    Du Plessis, L

    2016-09-01

    Full Text Available Ultra-Thin Reinforced Concrete Pavements (UTRCP) are successfully being used in residential streets and low-volume road applications in South Africa. Due to its popularity in this domain the Gauteng Provincial Department of Roads and Transport...

  8. High Performance Concrete

    OpenAIRE

    Traian Oneţ

    2009-01-01

    The paper presents the last studies and researches accomplished in Cluj-Napoca related to high performance concrete, high strength concrete and self compacting concrete. The purpose of this paper is to raid upon the advantages and inconveniences when a particular concrete type is used. Two concrete recipes are presented, namely for the concrete used in rigid pavement for roads and another one for self-compacting concrete.

  9. High Performance Concrete

    Directory of Open Access Journals (Sweden)

    Traian Oneţ

    2009-01-01

    Full Text Available The paper presents the last studies and researches accomplished in Cluj-Napoca related to high performance concrete, high strength concrete and self compacting concrete. The purpose of this paper is to raid upon the advantages and inconveniences when a particular concrete type is used. Two concrete recipes are presented, namely for the concrete used in rigid pavement for roads and another one for self-compacting concrete.

  10. APPLICATION OF COMPOSITE STEEL-CONCRETE BEAM WITH TEMPORARY SUPPORT UNDER CONSTRUCTION IN SOME PROJECT%组合梁临时支撑在某工程中的应用

    Institute of Scientific and Technical Information of China (English)

    钱承中

    2013-01-01

    结合工程实例,对钢-混凝土组合简支梁在施工阶段临时支撑的设置进行研究,讨论了在不同支承工况下钢-混凝土组合梁的挠度验算,最终得到支撑布置的最优方案,既满足了钢梁挠度的要求,又使支撑数量最为经济.%In this paper, the research of the application of composite steel-concrete beam with temporary supports under construction in some project are studied. The comparison of composite steel-concrete beam deflections with different arrangements of temporary supports are discussed. At last gain the most effective method to set the temporary supports, not only meeting the deflection requirements of the composite steel-concrete beam but also getting the most economical method to arrange temporary supports.

  11. 小湾水电站泄洪洞抗冲耐磨混凝土施工综述%Construction of Abrasion-resistant Concrete for the spillway Tunnel of Xiaowan Hydropower Station

    Institute of Scientific and Technical Information of China (English)

    李众; 罗毅; 李然; 字林

    2011-01-01

    As the high head, high velocity and large flow of flood discharge, the concrete of spillway tunnel in Xiaowan Hydropower Station is easy to be damaged by cavitation. By reasonable pouring, mix proportion optimizing, effective temperature control and reasonable curing, the concrete quality of spillway tunnel is guaranteed and no crack found. The successful concrete construction and quality control provides guarantees on reducing surface cavitation and increasing abrasion-resistance capacity.%小湾水电站泄洪洞在泄洪时具有高水头、高流速、泄量大的特点,对混凝土冲刷力强,容易产生空蚀破坏.通过合理选择浇筑措施、优选配合比、有效的温度控制以及合理的养护,目前,泄洪洞各方面质量均满足要求,且未发现裂缝.泄洪洞抗冲耐磨混凝土施工及质量控制的成功,为减小泄洪洞过流面空蚀和抗冲耐磨提供了保障.

  12. The Gravel Construction Technology and Quality Control of Cement Concrete Pavement%水泥混凝土路面碎石化施工工艺及质量控制

    Institute of Scientific and Technical Information of China (English)

    王方河

    2013-01-01

    The technology of rubblization is an important me-ans to overhaul of cement concrete pavement, which broke the cement concrete pavement into smal interlocking particles to provide ideal primary for the new asphalt concrete overlay. In this article, the author bases on the example of rebuild project of G312 Luan, and talk about some ideas on the gravel constr-uction technology and quality control.%  碎石化技术是水泥混凝土路面大修改造的重要手段,该技术通过将水泥混凝土路面破碎成小粒径嵌挤颗粒,从而为新的沥青混凝土加铺层提供理想的基层。本文主要结合G312六安段改建工程的实际情况,对碎石化施工工艺及质量控制谈一点心得。

  13. Concrete spirituality

    OpenAIRE

    2014-01-01

    This article reflects on a number of liturgical innovations in the worship of Melodi ya Tshwane, an inner-city congregation of the Uniting Reformed Church in Southern Africa (URCSA). The focus of the innovations was to implement the understanding of justice in Article 4 of the Confession of Belhar, a confessional standard of the URCSA. The basic contention of the article is that well designed liturgies that facilitate experiences of beauty can nurture a concrete spirituality to mobilise urba...

  14. The Construction Technology and Quality Control of Hot Mix Asphalt Concrete Pavement%热拌沥青混凝土路面施工工艺及质量控制

    Institute of Scientific and Technical Information of China (English)

    卢宪法

    2014-01-01

    热拌沥青混凝土作为公路路面施工的重要组成部分,其选材、施工工艺、质量控制等流程对公路的建成性能都具有决定性的影响。笔者结合近年来的学习工作经验,主要从材料、沥青混凝土的配比、施工工艺、质量控制几个方面作简要阐述。%Hot mix asphalt concrete as an important part of highway pavement construction, the material selection, constr-uction technology and quality control hasa decisive influence on the process of highway completed performance. The author combines with work experience in recent years to elaborate from several aspects of material, the ratio of asphalt concrete, construction technology, and quality control, etc.

  15. 三洋港枢纽工程钢筋混凝土地下连续墙施工%Reinforced concrete diaphragm wall construction of Three Ocean Port hub project

    Institute of Scientific and Technical Information of China (English)

    孟仁富; 秦立建; 邱雪峰

    2012-01-01

    Introdcuing reinforced concrete diaphragm wall construction technology of Three Ocean Port hub project, New Shuhe treatment project under coastal complicated geological conditions, and elaborating the key process quality control measurement. The practice has proved that rein- forced concrete diaphragm wall construction technology which used by the project is suited for large range of coastal groundwater and complicated conditions of soil. Meanwhile, this kind of techonology can be used to maintain the stability of surface mining effectively, provide a reference for those similar construction projects.%介绍了新沭河治理工程三洋港枢纽工程沿海复杂地质条件下钢筋混凝土地下连续墙施工技术,并详细阐述了其关键工序质量控制措施,实践证明本工程采用钢筋混凝土地连墙施工工艺适用于沿海地下水变化范围大、土质复杂条件,同时可有效地保持挖掘面的稳定,可为类似工程施工提供借鉴。

  16. Experimental study of masonry wall exposed to blast loading

    Directory of Open Access Journals (Sweden)

    Ahmad, S.

    2014-03-01

    Full Text Available The challenge of protecting the nation against the attack of terrorism has raised the importance to explore the understanding of building materials against the explosion. Unlike most of the building materials, brick masonry materials offer relatively small resistance against blast loading. In this research, a brick masonry wall was exposed to varying blast load at different scaled distances. Six tests with different amounts of explosives at various distances were carried out. Pressure time history, acceleration time history and strain at specific location were measured. The parameters measured from experimental pressure time history and acceleration time history is compared with those determined by ConWep to establish the correlations between experimental determined records and ConWep values. The experimental results were also compared with some researchers. These correlations may assist in understanding the behaviour of masonry structures subjected to explosive loading.Con el reto que supone proteger a la nación contra atentados terroristas se ha visto acrecentada la importancia de conocer el comportamiento de materiales de construcción cuando se someten a una carga explosiva. Al contrario de la mayoría de los materiales, las fábricas de ladrillo ofrecen poca resistencia a dichas cargas. En el presente trabajo, se estudió el comportamiento de una fábrica de ladrillo ante cargas explosivas colocadas a diferentes distancias del muro. Se realizaron seis pruebas con explosivos de potencias distintas y a diferentes distancias. Se trazaron las curvas presión-tiempo y aceleración-tiempo, midiéndose asimismo la deformación en un punto concreto. Los valores experimentales de las curvas presión-tiempo y aceleración-tiempo se compararon con los que se calcularon con la ayuda de la aplicación informática ConWep a fin de establecer las correlaciones entre ambos conjuntos de resultados. También se compararon los resultados experimentales

  17. Energy Efficiency Improvement and Cost Saving Oportunities for the Concrete Industry

    Energy Technology Data Exchange (ETDEWEB)

    Kermeli, Katerina; Worrell, Ernst; Masanet, Eric

    2011-12-01

    The U.S. concrete industry is the main consumer of U.S.-produced cement. The manufacturing of ready mixed concrete accounts for more than 75% of the U.S. concrete production following the manufacturing of precast concrete and masonry units. The most significant expenditure is the cost of materials accounting for more than 50% of total concrete production costs - cement only accounts for nearly 24%. In 2009, energy costs of the U.S. concrete industry were over $610 million. Hence, energy efficiency improvements along with efficient use of materials without negatively affecting product quality and yield, especially in times of increased fuel and material costs, can significantly reduce production costs and increase competitiveness. The Energy Guide starts with an overview of the U.S. concrete industry’s structure and energy use, a description of the various manufacturing processes, and identification of the major energy consuming areas in the different industry segments. This is followed by a description of general and process related energy- and cost-efficiency measures applicable to the concrete industry. Specific energy and cost savings and a typical payback period are included based on literature and case studies, when available. The Energy Guide intends to provide information on cost reduction opportunities to energy and plant managers in the U.S. concrete industry. Every cost saving opportunity should be assessed carefully prior to implementation in individual plants, as the economics and the potential energy and material savings may differ.

  18. Technology Solutions Case Study: Retrofit Measures for Embedded Wood Members in Insulated Mass Masonry Walls

    Energy Technology Data Exchange (ETDEWEB)

    K. Ueno

    2015-10-01

    In this project, the Building Science Corporation team studied a historic brick building in Lawrence, Massachusetts, which is being renovated into 10 condominium units and adding insulation to the interior side of walls of such masonry buildings.

  19. Features of the Masonry Structure Calculation with Vertical Ring Beams based on the European Standards

    Directory of Open Access Journals (Sweden)

    Zejak Danijela

    2016-01-01

    Full Text Available The design of masonry structures should remain a combination of traditional and modern knowledge. The Eurocodes in the field of the design of earthquake-resistant masonry structures, carry mostly acceptable and expected recommendations and requirements. This paper shows that they contain less acceptable principles, which require further experimental and analytical studies. Particularly it should be noted that Eurocode knows only a shearing mechanism by the horizontal coupling, although during the seismic load, the fracture usually occurs due to exceeding the main tensile stress, which manifests by opening diagonal cracks. The mechanism of the horizontal shearing by Eurocode is treated as critical for the seismic resistance of most masonry buildings, thus the masonry structure is attributed as sufficiently secure, although its actual seismic resistance would be far below from the required.

  20. Analyses of Concrete Structures Exposed to Fire

    DEFF Research Database (Denmark)

    Hertz, Kristian

    The text book contains the data and methods necessary for fire safety design of concrete constructions. The methods relate to standard fire as well as to any time of any other fire course.Material data are presented for concretes exposed to fire, and calculation methods are given for the ultimate...

  1. Dual-durometer soft suction foot robot for concrete inspection

    Science.gov (United States)

    Huston, Dryver; Burns, Dylan; Gardner-Morse, John; Montane, Paul; Angola, Enrique

    2014-03-01

    Climbing on concrete, masonry and brick with automated machines is difficult due to the uneven surfaces that prevent getting a good grip. This paper describes developments in using dual-durometer pneumatic suction feet for gripping onto concrete surfaces as part of a multi-legged robotic climbing system for inspecting concrete structures with vertical walls. The dual durometer technique presents a compliant suction tip to the concrete thereby producing a good seal against an irregular surface, and stiff component to deliver the structural rigidity needed for walking and climbing. Individually actuated pneumatic Venturi vacuum generators provide the suction from positive pneumatic pressure in a manner that is robust against leaks that cause the systemic vacuum collapse that can plague other vacuum configurations. The feet are attached to a six-legged robot that with a nominal floor walking capability and gait. Climbing a wall requires modification to leg actuation and gait, along with suction feet. System design, integration, concrete wall climbing performance and sensor deployment in the form of a lightweight ground penetrating radar system are presented.

  2. Suitable Friction Sliding Materials for Base Isolation of Masonry Buildings

    Directory of Open Access Journals (Sweden)

    Radhikesh P. Nanda

    2012-01-01

    Full Text Available A feasibility study of friction base isolation system for seismic protection has been performed. Four different sliding interfaces, namely, green marble/High Density Poly Ethylene (HDPE, green marble/green marble, green marble/geosynthetic, and green marble/ rubber layers have been studied through experimental and analytical investigations. The experimental investigations show that the coefficient of friction values of these interfaces lies in the desirable range for seismic protection, i.e., 0.05 to 0.15. The analytical investigation reveals that most of these sliding interfaces are effective in reducing spectral accelerations up to 50% and the sliding displacement is restricted within plinth projection of 75 mm (3 in. Green marble and geosynthetic are found to be better alternatives for use in friction isolation system with equal effectiveness of energy dissipation and limiting the earthquake energy transmission to super structure during strong earthquake leading to a low cost, durable solution for earthquake protection of masonry buildings.

  3. Electrochemical removal of salts from masonry - Experiences from pilot scale

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Rörig-Dalgaard, Inge; Villumsen, Arne

    2008-01-01

    A pilot experiment with newly developed electrodes was tested for removal of contaminating salts from brick masonry where plaster peeling was a problem. A high concentration of sulfate was found at the height where the paint peeling was most pronounced. The concentrations of chloride and nitrate...... were smaller, though in dangerous concentrations at some points. In the applied electric field, chloride and nitrate were efficiently removed. Sulfate, on the other hand, was less mobile, due to lower solubility of sulphate salts and thus lower percentage in ionic form and mobile for electromigration....... The mean concentration of sulfate was decreased from 0.68 wt% to 0.46 wt% during the approx. 4 months of treatment. The removal rate for sulphate did not decrease significantly during the treatment period and it is expected that reduction in sulphate concentration could continue over longer duration...

  4. Static analysis of masonry kilns built with fictile tubules bricks

    Science.gov (United States)

    Olivito, Renato S.; Scuro, Carmelo; Codispoti, Rosamaria

    2016-12-01

    Industrial archeology is a branch that studies all the testimony (tangible and intangible, direct and indirect) related to the process of industrialization since its origins. This technical field is based on an interdisciplinary approach, it has the task of deepening the story, understanding the technological development made by man over the centuries. The present work focused attention on the study and analysis of a masonry kiln, built with the technique of hollow clay fictile tubules. The study, in particular, has been carried out analyzing the stress state caused by the wind on the structure. The kiln is constituted by a particular geometric configuration that develops in height due to the presence of chimney over the dome.

  5. Stereovision vibration measurement test of a masonry building model

    Science.gov (United States)

    Shan, Baohua; Gao, Yunli; Shen, Yu

    2016-04-01

    To monitor 3D deformations of structural vibration response, a stereovision-based 3D deformation measurement method is proposed in paper. The world coordinate system is established on structural surface, and 3D displacement equations of structural vibration response are acquired through coordinate transformation. The algorithms of edge detection, center fitting and matching constraint are developed for circular target. A shaking table test of a masonry building model under Taft and El Centro earthquake at different acceleration peak is performed in lab, 3D displacement time histories of the model are acquired by the integrated stereovision measurement system. In-plane displacement curves obtained by two methods show good agreement, this suggests that the proposed method is reliable for monitoring structural vibration response. Out-of-plane displacement curves indicate that the proposed method is feasible and useful for monitoring 3D deformations of vibration response.

  6. Research on Techniques for Construction of Half-wet Sprayed Concrete in ClassⅢ Hard Rock Tunnels%Ⅲ级硬质岩隧道半喷混凝土施工技术研究

    Institute of Scientific and Technical Information of China (English)

    李伟坚; 郭军; 宋从军

    2015-01-01

    就特长隧道而言,Ⅲ级围岩比例较大,其已成为制约工期、实现快速施工的关键。以广东省博深高速公路石鼓隧道为依托,探讨3车道大断面特长公路隧道独头掘进条件下Ⅲ级围岩快速施工方法,对半喷混凝土施工技术条件下的围岩稳定性、支护强度与承载力进行系统分析,并采用三维计算进行论证。研究表明:Ⅲ级围岩采用半喷混凝土施工技术完全可行。%As for extralong tunnels,class III wall rock accounts for large proportion and has become the key to restrict construction period and achieve rapid construction. Dependent on Shigu Tunnel on Guangdong Boluo -Shenzhen Expressway,this paper probes into the methods for rapid construction of class III wall rock of 3-lane large-section extralong highway tunnels under the blind heading conditions, systematically analyzes stability,support strength and bearing capacity of wall rock under the technical condition of construction with half-wet sprayed concrete,and demonstrates with 3D calculation.The research shows that the half-wet sprayed concrete construction technique adopted for class III wall rock is fully feasible.

  7. Challenges in treating earthen construction materials as unsaturated soils

    Directory of Open Access Journals (Sweden)

    Augarde Charles E.

    2016-01-01

    Full Text Available Earthen construction is a loosely defined term covering both the materials and methods for creating structural components from mixtures of subsoil, often with the addition of chemical or mechanical stabilisers. There is evidence of Man creating earthen structures for thousands of years, and there are many world heritage sites containing earthen structures, some of which present issues in terms of conservation. In some parts of the world there is a growing market for new-build earthen structures and a key issue here is the lack of design codes. Since these materials are composed mainly of particulates and water it is natural to regard them as geotechnical in nature, where friction and the presence of water have a key influence on material properties, however until very recently this was not the case, with earthen construction materials regarded as weak concrete or masonry. In this paper we examine these opposing views and discuss the issues associated with regarding these materials as unsaturated soils. The paper is illustrated with outcomes from research at Durham University carried out over the past ten years.

  8. Aspects of alteration of masonry historical buildings without ring beam of floor slabs

    Directory of Open Access Journals (Sweden)

    Ryszard Chmielewski

    2016-12-01

    Full Text Available Some problems of alteration for building structures of a conventional masonry for which working lifetime is approaching or has exceeded the expected design life are presented. In the course of these works, non-bearing masonry walls are often removed and as a result significant damages to supporting structures are often made, and in extreme cases even building collapses. Building surveyors who prepare a structural appraisal for technical reports of damaged masonry structures, as a solution to the problem, recommend sometimes to make only surface reinforcement of damaged walls. The question of significant change in the load distribution in alteration for buildings of conventional design is complex and in some cases above the recommended surface repairs may not be sufficient to ensure structural reliability or the safety of buildings exploitation. The paper proposes a scope of evaluation and structural analysis of a building, which allows to properly determine the range of the existing threats, and on this basis to carry out adequate repair of damaged masonry structures, including structural strengthening.[b]Keywords:[/b] masonry structures, buildings without ring beam of floor slabs, damages of masonry walls, structural failures and collapses

  9. On the Design of a Reinforced Concrete Pipe for a Heat Supply Tunnel Constructed by Pipe Jacking%顶管法热力隧道钢筋混凝土管设计研究

    Institute of Scientific and Technical Information of China (English)

    董淑棉

    2013-01-01

    Mechanical pipe jacking construction technology is characterized by many advantages,such as fast construction,high automation,safety,reliability,and less impact on surroundings; it is therefore of great importance in the construction of heat supply tunnels.During the operation phase,a heat supply tunnel will be subjected to a high environmental temperature and internal forces of constant thrust,guiding thrust,and so on.This paper analyzes the deformation and mechanical state of the mechanically jacked reinforced concrete pipe for a heat supply tunnel in different temperatures by means of field testing and theoretical calculation.The results were verified by engineering practice.Additionally,it summarizes how the design and calculation method for reinforced concrete pipes are applicable to heat supply engineering.Finally,it concludes that the calculation results for the structural design of the reinforced concrete pipe in a jacked heat supply tunnel are similar to the test results with more safety redundancy,provided that a reduction method for the concrete strength and elastic modulus is used.%机械顶管施工技术具有施工速度快、自动化程度高、安全可靠、对周围环境影响小等优点,将顶管技术用于热力隧道施工中,具有重要意义.热力隧道在运行过程中,存在较高的环境温度,有固定推力、导向推力等内作用力.文章通过现场试验和理论计算,研究分析了热力机械钢筋混凝土顶管在不同温度工况下的变形和力学状态,并通过工程实践进行了验证;总结出了适用于热力工程的钢筋混凝土管的设计计算方法.分析结果表明,采取混凝土强度值及弹性模量折减的方法进行顶管法热力隧道钢筋混凝土管的结构设计,其计算与试验结果较为接近,更偏于安全.

  10. Construction and design of cold-formed steel joists concrete composite floor%冷弯薄壁型钢-混凝土组合楼盖构造与设计

    Institute of Scientific and Technical Information of China (English)

    贾子文; 周绪红; 刘永健

    2013-01-01

    冷弯薄壁型钢-混凝土组合楼盖作为一种新型楼盖结构形式,需要从受力性能和构造方式方面进行更多的研究和认识.针对冷弯薄壁型钢-混凝土组合楼盖的构造特点,从基本构件、紧固件、压型钢板与楼盖梁连接、楼盖梁腹板开孔、支座加劲件、梁与柱的安装、楼盖梁布置及支撑系统等方面,对其构造进行了详细阐述.最后,提出了冷弯薄壁型钢-混凝土组合楼盖的简化模型——T形组合梁的实用计算公式,以供工程设计参考和借鉴.%The mechanical performance and construction method of cold-formed steel joists concrete composite floor,which is a new floor structure system,should be more carefully studied.According to the structural characteristics of cold-formed steel joists concrete composite floor,from basic components,fasteners,connection between profiled steel sheet and floor joists,holes on the web of floor joists,stiffeners of support saddle,installation method of beam and column,arrangement of floor joists,to bracing system and other aspects,the constructions were elaborated.Practical calculation formula of Tshaped composite beam,which is the simplified model of cold-formed steel joists concrete composite floor,was put forward,some research results were supplemented for reference in project design.

  11. Temperature crack prediction in the construction period of a concrete outer tank for LNG storage%大型液化天然气储罐混凝土外罐施工期间温度裂缝预测

    Institute of Scientific and Technical Information of China (English)

    翟希梅; 王恒; 周庆生; 范峰

    2013-01-01

    以160000 m3大型预应力液化天然气(LNG)全容罐混凝土外罐为研究对象,在利用ANSYS软件建立精细化LNG储罐混凝土外罐有限元模型的基础上,按实际结构施工顺序与时间,模拟了LNG储罐混凝土外罐全部混凝土浇筑过程,获得了在变温条件下,由水化热作用产生的混凝土外罐早期温度场分布;在考虑混凝土收缩和徐变的条件下,采用增量法计算了混凝土外罐的早期温度应力,确定了随时间及配筋率变化的混凝土早期抗拉强度,进而对LNG储罐混凝土外罐施工阶段的裂缝发育特征及分布规律进行了预测.结果表明,混凝土收缩对温度应力影响显著,在150 d的模拟时间段内结构温度应力呈现持续增长状态;第1浇筑段的LNG外罐温度应力明显大于其他浇筑段的温度应力,且该浇筑段的罐壁在模拟期内将产生竖向裂缝,扶壁柱处将产生局部环向裂缝.该结论可为同类工程施工建造开展相应的抗裂措施提供依据.%A fine finite element model for a 160000 m3 LNG concrete tank with reasonable element types and mesh dimension was established using the finite element software (ANSYS) to simulate the actual construction process of the concrete tank.The temperature field distribution under the load of hydration heat was determined in thermal variation conditions.Considering the influence of concrete shrinkage and creep,the early thermal stress under temperature load was figured out with an incremental method,and the early tensile strength of concrete along with the reinforcement ratio and time was determined.Moreover,concrete crack growth characters and distributional rules of the LNG concrete tank were predicted by comparing thermal stress with the early tensile strength.The results showed that the concrete shrinkage has a significant effect on thermal stress,and the thermal stress of structures continues increasing during a 150-days simulation period.The thermal stress of

  12. Environmental impact of concrete use in the Dutch construction industry. Status quo and assessment of improvement options; Milieu-impact van betongebruik in de Nederlandse bouw. Status quo en toetsing van verbeteropties

    Energy Technology Data Exchange (ETDEWEB)

    Bijleveld, M.; Bergsma, G.; Van Lieshout, M.

    2013-04-15

    At the end of 2012 the Dutch government concluded a 'Green Deal' to improve the sustainability of the concrete supply chain with the organisation MVO Netwerk Beton, made up of 21 companies and 6 trade associations involved in the chain. The aim is to achieve a 100% sustainable concrete chain in 2050, with initial tangible steps being taken in the short term. In the context of this Green Deal CE Delft was asked to analyse the environmental footprint of concrete use by the Dutch construction industry, including an analysis of a number of improvement options. In 2010 14 million m{sup 3} of concrete was used in Dutch construction and around 550 kt of reinforcement steel. From cradle to grave this concrete use had a climate impact of 3.5 Mt CO2 (1.7% of Dutch national emissions). The analysis also encompassed the carbon emissions of energy consumption during the use phase of homes and offices in 2010. Restricting ourselves to the energy used for space heating in homes built in 2010, under the current EPC standard (0.8) the climate impact of concrete use in homes is estimated to be approximately the same as that of heating a home for five years. Over a lifespan of 50 years, then, it takes roughly ten times as much energy to heat a home built in 2010 as it does to produce the reinforced concrete used to build it. The following improvement options are discussed: (1) use of concrete grade CEM III rather than CEM I; (2) various options to reduce the environmental footprint of cement production (biomass use, carbon capture and storage, etc.); (3) use of Concrete Core Activation in homes and offices to save on space heating energy consumption. While conducting the analysis a number of issues were noted that can lead to improvements in this analysis and in LCA assessments by other researchers: (a) There is scope for improving familiarity with and general availability of environmental data on various concrete and cement grades, specifically for the Dutch situation. For

  13. Environmental impact of concrete use in the Dutch construction industry. Status quo and assessment of improvement options; Milieu-impact van betongebruik in de Nederlandse bouw. Status quo en toetsing van verbeteropties

    Energy Technology Data Exchange (ETDEWEB)

    Bijleveld, M.; Bergsma, G.; Van Lieshout, M.

    2013-04-15

    At the end of 2012 the Dutch government concluded a 'Green Deal' to improve the sustainability of the concrete supply chain with the organisation MVO Netwerk Beton, made up of 21 companies and 6 trade associations involved in the chain. The aim is to achieve a 100% sustainable concrete chain in 2050, with initial tangible steps being taken in the short term. In the context of this Green Deal CE Delft was asked to analyse the environmental footprint of concrete use by the Dutch construction industry, including an analysis of a number of improvement options. In 2010 14 million m{sup 3} of concrete was used in Dutch construction and around 550 kt of reinforcement steel. From cradle to grave this concrete use had a climate impact of 3.5 Mt CO2 (1.7% of Dutch national emissions). The analysis also encompassed the carbon emissions of energy consumption during the use phase of homes and offices in 2010. Restricting ourselves to the energy used for space heating in homes built in 2010, under the current EPC standard (0.8) the climate impact of concrete use in homes is estimated to be approximately the same as that of heating a home for five years. Over a lifespan of 50 years, then, it takes roughly ten times as much energy to heat a home built in 2010 as it does to produce the reinforced concrete used to build it. The following improvement options are discussed: (1) use of concrete grade CEM III rather than CEM I; (2) various options to reduce the environmental footprint of cement production (biomass use, carbon capture and storage, etc.); (3) use of Concrete Core Activation in homes and offices to save on space heating energy consumption. While conducting the analysis a number of issues were noted that can lead to improvements in this analysis and in LCA assessments by other researchers: (a) There is scope for improving familiarity with and general availability of environmental data on various concrete and cement grades, specifically for the Dutch situation. For

  14. Quick concrete

    OpenAIRE

    Olaya Beracasa, Santiago Eduardo; Flórez Gutiérrez, Richard Daniel

    2016-01-01

    QUICK CONCRETE es un emprendimiento el cual se planteó como una empresa prestadora de servicios en el sector de la construcción en la ciudad de Ibagué, Colombia. Con ayuda de empresas ya reconocidas a nivel regional como lo son: la distribuidora de materiales y ferretería La Española, A&C y la ladrillera Ladrillos Roma. Se espera impactar en el mercado con un método diferente y un precio competitivo de servicio. El mayor impulso de la construcción puede estar asociado a una mayor demanda de v...

  15. Bamboo Reinforced Concrete Truss Bridge for Rural Infrastructure

    OpenAIRE

    D. Nuralinah; S. M. Dewi

    2014-01-01

    Bamboo is one of a potential renewable construction material in the village. Bamboo is known to have a high mechanical strength in direction of the fibers. The weakness of bamboo in lateral direction of the fiber could be solved by constructing a composite structure with the concrete. The appropriate construction with hold the loads in axial direction is a truss structure. In a bamboo concrete truss structure, the bars are composed from the concrete column with a bamboo reinforcem...

  16. comparative analysis of the compressive strength of concrete with ...

    African Journals Online (AJOL)

    2013-03-01

    Mar 1, 2013 ... in compression than in tension, for structures required to carry only ... properties determine the quality of concrete [1]. Concrete is one of the .... strength concrete made with crushed brick as coarse aggregate and ... aggregates that have been produced from demolition and construction waste. According to ...

  17. Aspects Concerning the Use of Recycled Concrete Aggregates

    Science.gov (United States)

    Robu, I.; Mazilu, C.; Deju, R.

    2016-11-01

    Natural aggregates (gravel and crushed) are essential non-renewable resources which are used for infrastructure works and civil engineering. Using recycled concrete aggregates (RCA) is a matter of high priority in the construction industry worldwide. This paper presents a study on the use of recycled aggregates, from a concrete of specified class, to acquire new cement concrete with different percentages of recycled aggregates.

  18. Color landscape plan of the concrete Consideration on the harmony of concrete and landscape; Konkurito no shikisai keikan keikaku. Keikan to konkurito no chowa wo kangaeru

    Energy Technology Data Exchange (ETDEWEB)

    Akiyama, Hiroshi [Landscape Planning and Design with Concrete and Color, Tokyo (Japan)

    1999-03-10

    In Ministry of Construction, they positively promote the natural river make, and they have announced the basic design with the aim of river which does not use the concrete and river in which the concrete is not seen. It is the design control in using the concrete to be necessary for this. They introduced color landscape plan of the pile block of the concrete as a case in aiming at the harmony of concrete and landscape of being more concrete. They introduced concrete product which could express the local color characteristics of colors of the concrete which it does not suit for the landscape, usage of the concrete, concrete of the warm color, colors of concrete product of France, examples of the Disneyland, colors concrete lied, landscapes and cost, etc. (NEDO)

  19. Spectral algorithm for non-destructive damage localisation: Application to an ancient masonry arch model

    Science.gov (United States)

    Masciotta, Maria-Giovanna; Ramos, Luís F.; Lourenço, Paulo B.; Vasta, Marcello

    2017-02-01

    Structural monitoring and vibration-based damage identification methods are fundamental tools for condition assessment and early-stage damage identification, especially when dealing with the conservation of historical constructions and the maintenance of strategic civil structures. However, although the substantial advances in the field, several issues must still be addressed to broaden the application range of such tools and to assert their reliability. This study deals with the experimental validation of a novel method for non-destructive damage identification purposes. This method is based on the use of spectral output signals and has been recently validated by the authors through a numerical simulation. After a brief insight into the basic principles of the proposed approach, the spectral-based technique is applied to identify the experimental damage induced on a masonry arch through statically increasing loading. Once the direct and cross spectral density functions of the nodal response processes are estimated, the system's output power spectrum matrix is built and decomposed in eigenvalues and eigenvectors. The present study points out how the extracted spectral eigenparameters contribute to the damage analysis allowing to detect the occurrence of damage and to locate the target points where the cracks appear during the experimental tests. The sensitivity of the spectral formulation to the level of noise in the modal data is investigated and discussed. As a final evaluation criterion, the results from the spectrum-driven method are compared with the ones obtained from existing non-model based damage identification methods.

  20. A completely transparent, adhesively bonded soda-lime glass block masonry system

    Directory of Open Access Journals (Sweden)

    F. Oikonomopoulou

    2015-01-01

    Full Text Available A pioneering, all transparent, self-supporting glass block facade is presented in this paper. Previously realized examples utilize embedded metal components in order to obtain the desired structural performance despite the fact that these elements greatly affect the facade’s overall transparency level. Undeniably, the oxymoron ‘transparency and strength’ remains the prime concern in such applications. In this paper, a new, innovative structural system for glass block facades is described, which demonstrably meets both criteria. The structure is exclusively constructed by monolithic glass blocks, bonded with a colourless, UV-curing adhesive, obtaining thus a maximum transparency. In addition, the desired structural performance is achieved solely through the masonry system, without any opaque substructure. Differing from previous realized projects, solid soda-lime glass blocks are used rather than borosilicate ones. This article provides an overview of the integrated architectural and structural design and discusses the choice of materials. The structural verification of the system is demonstrated. The results show that the adhesively bonded glass block structure has the required self-structural behaviour, but only if strict tolerances are met in the geometry of the glass blocks.