Download or read book Bond Behavior of Reinforcing Steel in Ultra high Performance Concrete written by and published by . This book was released on 2014 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: This document is a technical summary of the Federal Highway Administration (FHWA) report "Bond Behavior of Reinforcing Steel in Ultra-High Performance Concrete" (FHWA-HRT-14-090). Ultra-high performance concrete (UHPC) has garnered interest from the highway infrastructure community for its greatly enhanced mechanical and durability properties. The objective of this research is to extensively evaluate the factors that affect bond strength between deformed reinforcing bar and UHPC, and to facilitate the development of design guidelines for using field-cast UHPC in innovative connection details. The results of the research effort and the design recommendations for reinforcing bar embedded in UHPC are provided in this TechBrief.

Download or read book Bond behavior of reinforcing steel in ultra high performance concrete written by Benjamin A. Graybeal and published by . This book was released on 2014 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bond of Reinforcement in Concrete written by fib Fédération internationale du béton and published by fib Fédération internationale du béton. This book was released on 2000-01-01 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: "In 1993, the CEB Commission 2 Material and Behavior Modelling established the Task Group 2.5 Bond Models. It's terms of reference were ... to write a state-of-art report concerning bond of reinforcement in concrete and later recommend how the knowledge could be applied in practice (Model Code like text proposal)... {This work} covers the first part ... the state-of-art report."--Pref.

Download or read book Bond Behavior of High Performance Reinforcing Bars for Concrete Structures written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Bond between the concrete and the reinforcing steel is a major factor affecting the performance of reinforced concrete structures. Advances in material science led to the production of High Performance Steel that has enhanced corrosion resistance and higher strength compared to conventional Grade 60 steel. Such material can lead to more economical design reducing the material requirements for a particular project and expanding its life span. The objective of this research is to study the bond behavior of High Performance reinforcing bars for concrete structures and to evaluate the effect of different parameters believed to affect the bond characteristics. Twenty-two large scale reinforced concrete splice beams were constructed using No. 8 and No. 11 reinforcing bars, having different cross-sections with varying concrete compressive strengths and development lengths. The beams were tested using four point bending setup to provide a constant moment region over the splice zone. Test results indicate that stresses up 90 ksi can be achieved in the No. 8 bars and up to 70 ksi in the No. 11 bars without confinement; however, it is recommended to use transverse reinforcement to confine the High Performance bars in order to ensure ductility. These stresses can be evaluated at failure using a simple proposed equation. Test results were used to extend the current ACI Committee 408 equations to better predict the stresses in the High Performance Steel.

Download or read book fib Model Code for Concrete Structures 2010 written by fib - federation internationale du beton and published by John Wiley & Sons. This book was released on 2013-12-04 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: The International Federation for Structural Concrete (fib) is a pre-normative organization. 'Pre-normative' implies pioneering work in codification. This work has now been realized with the fib Model Code 2010. The objectives of the fib Model Code 2010 are to serve as a basis for future codes for concrete structures, and present new developments with regard to concrete structures, structural materials and new ideas in order to achieve optimum behaviour. The fib Model Code 2010 is now the most comprehensive code on concrete structures, including their complete life cycle: conceptual design, dimensioning, construction, conservation and dismantlement. It is expected to become an important document for both national and international code committees, practitioners and researchers. The fib Model Code 2010 was produced during the last ten years through an exceptional effort by Joost Walraven (Convener; Delft University of Technology, The Netherlands), Agnieszka Bigaj-van Vliet (Technical Secretary; TNO Built Environment and Geosciences, The Netherlands) as well as experts out of 44 countries from five continents.

Download or read book Bond Behaviour of Steel Reinforcing Bars Embedded in Ultra High Performance Steel Fiber Reinforced Concrete written by Elisabeth Rita Saikali and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultra-High-Performance Steel Fiber Reinforced Concrete (UHP-SFRC) is an emerging concrete considered as an optimal, durable material that can substitute conventional concrete owing to its distinct fresh and hardened properties. Thus, it is essential to understand the mechanism of stress transfer between this concrete and conventional reinforcement that permits the composite action of both materials. A four-point bending test program (FPBT) was arranged and conducted on 19 beams designed for the bond development to occur in the constant moment region along a short embedment length in order to achieve a uniform distribution of bond stresses, enabling measurement of bond strength through reverse engineering of beam strength and deformation. Additional material testing was conducted on prisms under 4-point loading in order to extract the mechanical properties for all material mixes considered. The bond-specimens failed either by pullout or by cone formation with minimal deterioration of the concrete cover, illustrating the high confinement provided by the novel concrete surrounding the bar in tension. The bond strength was determined to be directly proportional to the tensile strength capacity of the design mix, where for the strongest material the bond strength was approximately 30 MPa. Moreover, the test results indicated a very ductile flexural beam response accompanied by significant mid-span deflection reaching 27 mm and substantial bar-slip values attaining 19 mm. Different UHP-SFRC mixes, concrete covers, and embedment lengths were considered. A numerical model was developed to simulate the FPBT using a nonlinear finite element analysis platform, VecTor2, with the ability to model this novel concrete. This high bond strength provided by the concrete cover enables a significant reduction in the design development length as compared to what is used today for conventional concrete.

Download or read book Bond Behavior of High Performance Reinforcing Bars for Concrete Structures written by Amr Ihab-Ahmed Hosny and published by . This book was released on 2007 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: Reinforced Concrete, High Strength Steel, High Performance Steel, Bond.

Download or read book Ultra High Performance Concrete and High Performance Construction Materials written by Ekkehard Fehling and published by kassel university press GmbH. This book was released on 2016-03-01 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bond Strength of Spliced High Strength Steel Reinforcing Bars in Ultra High Performance Concrete UHPC Beams written by and published by . This book was released on 2021 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Guide for the Design and Construction of Concrete Reinforced with Fiber Reinforced Polymer Bars written by ACI Committee 440 and published by . This book was released on 2003 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ultra High Performance Concrete and High Performance Construction Materials written by Bernhard Middendorf and published by BoD – Books on Demand. This book was released on 2020-01-01 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: With HiPerMat 5 on March 11-13, 2020 the 5th International Symposium on Ultra-High Performance Concrete and High Performance Construction Materials documents the actual state of development of application in the fields of: Material Science and Development, Composite Concrete Materials, Strength and Deformation behaviour of UHPC, Durability and Sustainability of UHPC, Design and Construction with UHPC, Structural Modelling and Optimisation, Lightweight Concrete Structures, High-Precision Manufacturing for Pre-Fabrication, Nanotechnology for Construction Materials, Innovative Applications, Smart Construction Materials, This volume contains the short versions (two pages) of all contributions that have been accepted for publication at HiPerMat 5.

Download or read book High Performance Concretes written by Paul Zia and published by . This book was released on 1991 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: This state-of-the-art report summarizes the results of an extensive search and review of available literature on the mechanical properties of concrete, with particular reference to high performance concrete for highway applications. Included in the review and discussion are the behavior of plastic concrete as well as the strength and deformation characteristics of hardened concrete. Both short-term and long-term effects are considered. Based on the review of the available information, research needs are identified. It is concluded that much research is needed to develop data on the strength and durability properties of concrete which develops high strength, particularly very early strength.

Download or read book Interfacial Transition Zone in Concrete written by J.C. Maso and published by CRC Press. This book was released on 2004-03-01 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important new state-of-the-art report prepared by RILEM Technical Committee 108 ICC. It has been written by a team of leading international experts from the UK, USA, Canada, Israel, Germany, Denmark, South Africa, Italy and France. Research studies over recent years in the field of cement science have focused on the behaviour of the interfaces between the components of cement-based materials. The techniques used in other areas of materials science are being applied to the complex materials found in cements and concretes, and this book provides a significant survey of the present state of the art.

Download or read book High performance Hybrid fibre Concrete written by Ivan Marković and published by IOS Press. This book was released on 2006 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: "In the research project presented in this PhD-thesis, an innovative type of fibre concrete is developed, with improved both the tensile strength and the ductility: the Hybrid-Fibre Concrete (HFC). The expression "Hybrid" refers to the "hybridisation" of fibres: short and long steel fibres were combined together in one concrete mixture. This is opposite to conventional steel fibre concretes, which contain only one type of fibre. The basic goal of combining short and long fibres is from one side to improve the tensile strength by the action of short fibres, and from the other side to improve the ductility by the action of long fibres." "In this research project, all important aspects needed for the development and application of Hybrid-Fibre Concrete have been considered. In total 15 mixtures, with different types and amounts of steel fibres were developed and tested in the fresh state (workability) as well as in the hardened state (uniaxial tensile tests, flexural tests, pullout tests of single fibres and compressive tests). A new analytical model for bridging of cracks by fibres was developed and successfully implemented for tensile softening response of HFC. At the end, the utilisation of HFC in the engineering practice was discussed, including a case-study on light prestressed long-span beams made of HFC."--BOOK JACKET.

Download or read book Advances on bond in concrete written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 2022-12-01 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structural behavior of reinforced concrete elements strongly depends on the interaction between the reinforcing bars and the surrounding concrete, which is generally referred as “bond in concrete”. In service conditions, the reinforcement-to-concrete bond governs deformability through the tension stiffening of concrete surrounding the bar as well the crack development and crack width. At Ultimate Limit State, bond governs anchorage and lap splices behavior as well as structural ductility. When plain (smooth) bars were used, the steel-to-concrete bond was mainly associated with “chemical adhesion/friction” that is related to the surface roughness of the rebar. As steel strengths increased the need to enhance interaction between steel and the surrounding concrete was recognized, and square twisted rebars, indented rebars or, later on, ribbed rebars came into the market, the latter being the type of deformed bar most commonly adopted since the 1960/70s. When ribbed rebars became widely used, several research studies started worldwide for better understanding the interaction between ribs and the surrounding concrete. Researchers evidenced the development of micro-cracks (due to the wedge action of the ribs) towards the external face of the structural element. If confinement is provided by the concrete cover, by transverse reinforcement or by an external transverse pressure, the full-anchorage capacity is guaranteed and a pull-out failure occurs, with crushing of concrete between the ribs. On the contrary, with lesser confining action, a splitting failure of bond occurs; the latter may provoke a brittle failure of the lap splice or, in some cases, of anchorages. However, after many years of research studies on bond-related topics, there are still several open issues. In fact, new materials entered into the market, as concrete with recycled aggregates or fibre reinforced concrete; the latter, having a kind of distributed reinforcement into the matrix (the fibres), provides a better confinement to the wedge action of the ribs. In addition, concrete and steel strength continuously increased over the years, causing changes in the bond behavior due to differences in mechanical properties of materials but also to the different concrete composition at the interface with the steel rebar causing a different bond behavior. Moreover, the lower water/cement ratio of these high-strength concrete makes the bleeding phenomena less evident, changing the concrete porosity in the upper layers of the structural element and thus making the current casting position parameters no-longer reliable. Finally, concrete with recycled aggregates are becoming more important in a market that is looking forward to a circular economy. As such, all the experimental results and database that allowed the calibration of bond rules now present in building codes for conventional concrete, may be not be representative of these new types of materials nowadays adopted in practice. Furthermore, after more than 50 years of service life, structural elements may not satisfy the current safety requirements for several reasons, including material degradation (with particular reference to steel corrosion) or increased loads, by also considering the seismic actions that were non considered by building codes at the time of the original design. The structural assessment of existing structures requires proper conceptual models and new approaches for evaluating the reliability of existing structures by also considering the remaining expected service life. In addition, specific rules for older materials, as plain smooth bars, should be revised for a better assessment of old structures. Last, but not least, interventions in existing structures may require new technologies now available such as post-installed rebars. While many advances have been achieved, there remain areas where a better understanding of bond and its mechanisms are required, and where further work is required to incorporate this understanding into safe and economic rules to guide construction and maintenance of existing infrastructures. These aspects were widely discussed within the technical community, particularly in the fib Task Group 2.5 and in the ACI 408 Committee dealing with bond and anchorage issues. Furthermore, special opportunities for discussing bond developments were represented by the International Conferences on ‘Bond in Concrete’ held each decade since 1982 as well as by joint workshops organized by fib TG2.5 and ACI 408. Within this technical collaboration, this Bulletin was conceived, and, thus, it collects selected papers presented at the joint fib-ACI Convention Session on Bond in Concrete held in Detroit (USA) in 2017. The bulletin is based on four main Sections concerning: - General aspects of bond - Anchorages and laps of bars and prestressing tendons - Bond under severe conditions - Degradation of bond for corrosion - Bond in new types of concrete The main aim of the Bulletin is to shed some new lights on the advances in understanding and application of bond related issues achieved over the last few years, and identify the challenges and priorities to be addressed in the next years. Another important aspect of the bulletin is to provide practical information from research findings.

Download or read book Bond in Concrete written by Peter Bartos and published by . This book was released on 1982 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ultra High Performance Concrete and High Performance Building Materials for Sustainable Construction written by Ekkehard Fehling and published by BoD – Books on Demand. This book was released on 2024-01-01 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sustainable construction, with the overarching goal of reducing the environmental footprint of everything we build is becoming increasingly important and urgent in the light of the climate change the world is facing. The use of innovative and sustainable building materials, especially concrete as the worldwide most commonly used building material, offers a great opportunity to significantly reduce climate-relevant emissions in the construction sector. Due to their performance and reliable durability, the use of innovative high-performance concretes will help to reduce the need for new constructions and to sustainably repair existing infrastructure. In new buildings in particular, the use of high-performance materials can help to save energy and natural resources, which reduces climate-relevant emissions and thus global warming. With the current HiPerMat 6, we are responding to the growing understanding of the impact of our construction activities on the environment by placing greater emphasis on sustainability issues.