Download or read book Structural Performance of High Strength Reinforced Concrete Beams Built with Synthetic Fibers written by Roukaya Bastami and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the results of a research program examining the effects of macro-synthetic fibers on the shear and flexural behaviour of high-strength concrete (HSC) beams subjected to static and blast loads. As part of the study, a series of seventeen fiber-reinforced HSC beams are built and tested under either quasi-static four-point bending or simulated blast loads using a shock-tube. The investigated test parameters include the effects of: macro-synthetic fibers, fiber hybridization, combined use of fibers and stirrups and longitudinal steel ratio and type. The results show that under slowly applied loads, the provision of synthetic fibers improves the shear capacity of the beams by allowing for the development of yield stresses in the longitudinal reinforcement, while the combined use of synthetic fibers and stirrups is found to improve flexural ductility and cracking behaviour. The results also show that the provision of synthetic fibers delays shear failure in beams tested under blast pressures, with improved control of blast-induced displacements and increased damage tolerance in beams designed with combined fibers and stirrups. The study also shows that the use of hybrid fibers was capable of effectively replacing transverse reinforcement under both loading types, allowing for ductile flexural failure. Moreover, the use of synthetic fibers was effective in better controlling crushing and spalling in beams designed with Grade 690 MPa high-strength reinforcement. Furthermore, the results demonstrate that synthetic fibers can possibly be used to relax the stringent detailing required by modern blast codes by increasing the transverse reinforcement hoop spacing without compromising performance. As part of the analytical study, the load-deflection responses (resistance functions) of the beams are predicted using sectional (moment-curvature) analysis, as well as more advanced 2D finite element modelling. Dynamic resistance functions developed using both approaches, and incorporating material strain-rate effects, are then used to conduct non-linear single-degree-of-freedom (SDOF) analyses of the blast-tested beams. In general, the results show that both methods resulted in reasonably accurate predictions of the static and dynamic experimental results.

Download or read book Structural Behavior of Rubberized Concrete Containing Synthetic Fibers written by Basem Hassan Abdelbaset Abdelaleem and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This research program aims to investigate the combining effect of crumb rubber (CR) and synthetic/metal fibers (SFs/MFs) in the development of concrete suitable for structural applications subjected to monotonic and cyclic loading. The research also aims to overcome the challenge of optimizing the strength and stability of self-consolidating concrete (SCC) containing CR and SFs/MFs. Five comprehensive experimental studies were conducted on both small-scale and large-scale concrete samples to meet the research objectives. The first study aimed to develop and optimize a number of successful self-consolidating rubberized concrete (SCRC) and synthetic fiber SCRC (SFSCRC) mixtures with a maximized percentage of CR and minimized reduction in strength. The variables in this study included various supplementary cementing materials (SCMs) specifically metakaolin (MK), silica fume (SLF), fly ash (FA), and ground granulated blast-furnace slag (GGBS), different binder contents (500, 550, and 600 kg/m3), varying percentages of CR (0% to 30%), different types of SFs specifically micro-synthetic fibers (MISFs), and macro-synthetic fibers (MASFs), different lengths of SFs (19mm, 27mm, 38mm, 50mm, and 54mm), and different SFs volume fractions (0%, 0.2%, and 1%). The second and third studies evaluated the flexural and shear behavior of large-scale reinforced concrete beams made with SCRC, vibrated rubberized concrete (VRC), SFSCRC, and synthetic fiber VRC (SFVRC). The fourth study investigated the structural performance of rubberized beam-column joints reinforced with SFs/MFs under reverse cyclic loading. This study consisted of three stages: the first stage contained a total of six SCRC mixtures selected to cast six beam-column joints with varied percentages of CR (0-25%). The second stage included eight rubberized concrete mixtures with different coarse aggregate sizes and different MFs lengths and volumes selected to pour eight beam-column joints to be tested under cyclic loading. The third stage contained seven rubberized concrete beam-column joints reinforced with different types, lengths, and volumes of SFs to be tested under cyclic loading. The fifth study evaluated the cyclic behavior of engineering cementitious composite (ECC) beam-column joints made with different percentages of CR, different SCMs, and different sand types. In this study a total of eight beam-column joints were cast and tested under reverse cyclic loading. The main results drawn from the first study indicated that the addition of SFs reduced the fresh properties, which limited the maximum percentage of CR that could be used in SCRC mixtures to 20%, compared to a 30% maximum percentage of CR used in developing successful SCRC mixtures without SFs. However, using SFs in SCRC mixtures increased the impact resistance and appeared to alleviate the reduction in splitting tensile strength (STS) and flexural strength (FS) that resulted from adding CR. The main results of the flexural testing conducted in study 2 indicated that using MISFs slightly enhanced the deformability, flexural stiffness, ductility, energy absorption, first cracking moment, and bending moment capacity, while this enhancement significantly increased when MASFs were used. Combining high percentage of MASFs (1%) with high percentage of CR (30%) compensated for the reduction in the bending moment capacity that resulted from using high percentage of CR, and helped to develop semi-lightweight concrete beams. The inclusion of CR in study 3 negatively affected the ultimate shear load, post-diagonal cracking resistance, and first cracking moment of the tested beams while it improved the deformation capacity, self-weight, and cracking pattern. Combining CR with MISFs or MASFs, further improved the deformation capacity, self-weight, and narrowed the crack widths of the tested beams. The results of this study also indicated that the use of a relatively higher percentage of fibers (1% compared to 0.2%) in VRC beams significantly compensated for the reduction in shear strength resulting from a high CR percentage (30%). The results of the fourth study revealed that the optimum percentage of CR to be used in beam-column joint mixtures is 15%. Although using this percentage slightly reduced the load carrying capacity, it greatly enhanced the ductility, brittleness index, deformability, and energy dissipation. The results also revealed that using MISFs slightly improved the structural performance of beam-column joints, while using MASFs had a significant effect on enhancing the load carrying capacity, ductility, stiffness, and energy dissipation of tested joints. The main results of the fifth study reported that increasing the percentage of CR up to 15% significantly increased the deformability, cracking behavior, ductility, and energy dissipation of ECC joints, while the initial stiffness, first crack load, and ultimate load were decreased.

Download or read book PRO 6 3rd International RILEM Workshop on High Performance Fiber Reinforced Cement Composites HPFRCC 3 written by Hans Wolfgang Reinhardt and published by RILEM Publications. This book was released on 1999 with total page 726 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Response of Ultra High Performance Fiber Reinforced Concrete Beams Under Flexure and Shear written by Roya Solhmirzaei and published by . This book was released on 2021 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultra high performance concrete (UHPC) is an advanced cementitious material made with low water to binder ratio and high fineness admixtures, and possesses a unique combination of superior strength, durability, corrosion resistance, and impact resistance. However, increased strength of UHPC results in a brittle behavior. To overcome this brittle behavior of UHPC and improve post cracking response of UHPC, steel fibers are often added to UHPC and this concrete type is designated as Ultra High Performance Fiber Reinforced Concrete (UHPFRC). Being a relatively new construction material, there are limited guidelines and specifications in standards and codes for the design of structural members fabricated using UHPFRC. To develop a deeper understanding on the behavior of UHPFRC flexural members, seven beams made of UHPFRC are tested under different loading conditions. The test variables include level of longitudinal reinforcement, type of loading (shear and flexure), and presence of shear reinforcement. Further, a finite element based numerical model for tracing structural behavior of UHPFRC beams is developed in ABAQUS. The developed model can account for the nonlinear material response of UHPFRC and steel reinforcement in both tension and compression, as well as bond between concrete and reinforcing steel, and can trace the detailed response of the beams in the entire range of loading. This model is validated by comparing predicted response parameters including load-deflection, load-strain, and crack propagation against experimental data obtained from tests on UHPFRC beams with different material characteristics and under different loading configurations. The validated model is applied to conduct a set of parametric studies to quantify the effect of different parameters on structural response of UHPFRC beams, including the contribution of stirrups and concrete to shear capacity of beams, to explore feasibility of removing the need for shear reinforcement in UHPFRC beams. Results from experiments and numerical model reveal that UHPFRC beams exhibit distinct cracking pattern characterized by the propagation of multiple micro cracks followed by widening of a single crack leading to failure. Also, UHPFRC beams exhibit high flexural and shear capacity, as well as ductility due to high compressive and tensile strength of UHPFRC and fiber bridging developing at the crack surfaces that leads to strain hardening in UHPFRC after cracking. Thus, absence of shear reinforcement in UHPFRC beams does not result in brittle failure, even under dominant shear loading. Data from the conducted experiments as well as those reported in literature is utilized to develop a machine learning (ML) framework for predicting structural response of UHPFRC beams. On this basis, a comprehensive database on reported tests on UHPFRC beams with different geometric, fiber properties, loading and material characteristics is collected. This database is then analyzed utilizing different ML algorithms, including support vector machine, artificial neural networks, k-nearest neighbor, support vector machine regression, and genetic programing, to develop a data-driven computational framework for predicting failure mode and flexural and shear capacity of UHPFRC beams. Predictions obtained from the proposed framework are compared against the values obtained from design equations in codes, and also results from full-scale tests to demonstrate the reliability of the proposed approach. The results clearly indicate that the proposed ML framework can effectively predict failure mode and flexural and shear capacity of UHPFRC beams with varying reinforcement detailing and configurations. The research presented in this dissertation contributes to the development of preliminary guidance on evaluating capacity of UHPFRC beams under different configurations.

Download or read book Causes Mechanism and Control of Cracking in Concrete written by ACI Committee 224--Cracking and published by . This book was released on 1968 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fibre Reinforced Concrete Improvements and Innovations written by Pedro Serna and published by Springer Nature. This book was released on 2020-11-05 with total page 1180 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume highlights the latest advances, innovations, and applications in the field of fibre reinforced concrete (FRC) and discusses a diverse range of topics concerning FRC: rheology and early-age properties, mechanical properties, codes and standards, long-term properties, durability, analytical and numerical models, quality control, structural and Industrial applications, smart FRC’s, nanotechnologies related to FRC, textile reinforced concrete, structural design and UHPFRC. The contributions present improved traditional and new ideas that will open novel research directions and foster multidisciplinary collaboration between different specialists. Although the symposium was postponed, the book gathers peer-reviewed papers selected in 2020 for the RILEM-fib International Symposium on Fibre Reinforced Concrete (BEFIB).

Download or read book Fibre Reinforced Concrete From Design to Structural Applications written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 2020-08-01 with total page 555 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first international FRC workshop supported by RILEM and ACI was held in Bergamo (Italy) in 2004. At that time, a lack of specific building codes and standards was identified as the main inhibitor to the application of this technology in engineering practice. The workshop aim was placed on the identification of applications, guidelines, and research needs in order for this advanced technology to be transferred to professional practice. The second international FRC workshop, held in Montreal (Canada) in 2014, was the first ACI-fib joint technical event. Many of the objectives identified in 2004 had been achieved by various groups of researchers who shared a common interest in extending the application of FRC materials into the realm of structural engineering and design. The aim of the workshop was to provide the State-of-the-Art on the recent progress that had been made in term of specifications and actual applications for buildings, underground structures, and bridge projects worldwide. The rapid development of codes, the introduction of new materials and the growing interest of the construction industry suggested presenting this forum at closer intervals. In this context, the third international FRC workshop was held in Desenzano (Italy), four years after Montreal. In this first ACI-fib-RILEM joint technical event, the maturity gained through the recent technological developments and large-scale applications were used to show the acceptability of the concrete design using various fibre compositions. The growing interests of civil infrastructure owners in ultra-high-performance fibre-reinforced concrete (UHPFRC) and synthetic fibres in structural applications bring new challenges in terms of concrete technology and design recommendations. In such a short period of time, we have witnessed the proliferation of the use of fibres as structural reinforcement in various applications such as industrial floors, elevated slabs, precast tunnel lining sections, foundations, as well as bridge decks. We are now moving towards addressing many durability-based design requirements by the use of fibres, as well as the general serviceability-based design. However, the possibility of having a residual tensile strength after cracking of the concrete matrix requires a new conceptual approach for a proper design of FRC structural elements. With such a perspective in mind, the aim of FRC2018 workshop was to provide the State-of-the-Art on the recent progress in terms of specifications development, actual applications, and to expose users and researchers to the challenges in the design and construction of a wide variety of structural applications. Considering that at the time of the first workshop, in 2004, no structural codes were available on FRC, we have to recognize the enormous work done by researchers all over the world, who have presented at many FRC events, and convinced code bodies to include FRC among the reliable alternatives for structural applications. This will allow engineers to increasingly utilize FRC with confidence for designing safe and durable structures. Many presentations also clearly showed that FRC is a promising material for efficient rehabilitation of existing infrastructure in a broad spectrum of repair applications. These cases range from sustained gravity loads to harsh environmental conditions and seismic applications, which are some of the broadest ranges of applications in Civil Engineering. The workshop was attended by researchers, designers, owner and government representatives as well as participants from the construction and fibre industries. The presence of people with different expertise provided a unique opportunity to share knowledge and promote collaborative efforts. These interactions are essential for the common goal of making better and sustainable constructions in the near future. The workshop was attended by about 150 participants coming from 30 countries. Researchers from all the continents participated in the workshop, including 24 Ph.D. students, who brought their enthusiasm in FRC structural applications. For this reason, the workshop Co-chairs sincerely thank all the enterprises that sponsored this event. They also extend their appreciation for the support provided by the industry over the last 30 years which allowed research centers to study FRC materials and their properties, and develop applications to making its use more routine and accepted throughout the world. Their important contribution has been essential for moving the knowledge base forward. Finally, we appreciate the enormous support received from all three sponsoring organizations of ACI, fib and Rilem and look forward to paving the path for future collaborations in various areas of common interest so that the developmental work and implementation of new specifications and design procedures can be expedited internationally.

Download or read book Performance of Fiber reinforced Self consolidating Concrete for Repair of Bridge Sub structures and Fiber reinforced Super workable Concrete for Infrastructure Construction written by Kamal H. Khayat and published by . This book was released on 2017 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proposed research investigates the combined use of self-consolidating concrete (SCC) and fibers reinforcements to develop a novel repair material, fiber-reinforced self-consolidating concrete (FR-SCC) that can be used for the rehabilitation and strengthening of existing structures. Furthermore, the feasibility of using super workable concrete (SWC) reinforced with different types of fibers for new structural cast-in-place applications is investigated. The use of SCC matrix can greatly enhance the workability of fibrous mixtures along with incorporation of greater volume of fibers. SWC is a new type of flowable concrete with lower workability than SCC. Containing lower binder content can be more cost effective than SCC. SWC requires some mechanical consolidation energy to ensure proper filling of the formwork. Eight types of fibers, including a propylene synthetic fiber, five steel fibers and a hybrid steel and polypropylene synthetic fiber were investigated. Fibers were incorporated at a volume of 0.5% in FR-SCC and at 0.5% and 0.75% in FR-SWC. Two types of expansive agents (EA), Type G and Type K, were added to both concrete types to reduce shrinkage and enhance resistance to restrained shrinkage cracking. The optimized mixtures exhibited high workability, mechanical properties, and freeze/thaw durability. The incorporation of fibers with 4% Type-G EA in FR-SCC increased the 56-day flexural strength by up to 32%, and flexural toughness up to 23 times. The incorporation of 0.5% of the 1.18 in. (30-mm) hooked end steel fibers (ST1) in FR-SCC made with 4% Type-G EA increased the elapsed time to cracking determined from restrained shrinkage ring test from 16 to 20 days compared to FR-SCC made with 0.5% ST1 fibers without EA. The use of ST1 steel fibers and 4% Type-G EA decreased the 1-year drying shrinkage by 48% compared to the reference SCC mixture without any fibers and expansive agent. In case of FR-SWC, the decrease in shrinkage was 37% compared to SWC. In addition, 20 monolithic full-scale beams were cast using different types of concrete, including conventional vibrated concrete (CVC), fiber-reinforced conventional vibrated concrete (FR-CVC), SCC, FR-SCC, SWC and FR-SWC. Twelve reinforced concrete beams were cast using CVC to fill two thirds of the beam height. They were then filled with five different types of FR-SCC and SCC to simulate beam repair in the tension zone. Findings indicated that macro fibers can be used with FR-SCC designated for repair with fiber length ≤ 2 in. (50 mm) up to 0.5% fiber volume. Macro fibers can be used with FR-SWC designated for construction with fiber length ≤ 2.6 in. (65 mm) up to 0.75% fiber volume. Fibers had great impact on structural performance of the full-scale monolithic beams. The incorporation of 0.5% of the 1.18 in. (30-mm) hooked end steel fibers combined with 0.5 in. (13-mm) straight steel fibers at ratio 4 to1 (STST) with 4% Type-G EA increased toughness of FR-SWC beams by 95% compared to SWC beams and by 86% in case of 0.75% 5D fibers. Repair using FR-SCC increased the flexural capacity of the beam by 6% and the toughness by 110% in case of using 0.5% ST1 fibers with 4% Type-G EA.

Download or read book Designing and Building with UHPFRC written by Jacques Resplendino and published by John Wiley & Sons. This book was released on 2013-01-29 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the proceedings of the international workshop “Designing and Building with Ultra-High Performance Fibre-Reinforced Concrete (UHPFRC): State of the Art and Development”, organized by AFGC, the French Association for Civil Engineering and French branch of fib, in Marseille (France), November 17-18, 2009. This workshop was focused on the experience of a lot of recent UHPFRC realizations. Through more than 50 papers, this book details the experience of many countries in UHPFRC construction and design, including projects from Japan, Germany, Australia, Austria, USA, Denmark, the Netherlands, Canada... and France. The projects are categorized as novel architectural solutions, new frontiers for bridges, new equipments and structural components, and extending the service life of structures. The last part presents major research results, durability and sustainability aspects, and the updated AFGC Recommendations on UHPFRC.

Download or read book Advanced Concretes and Their Structural Applications Volume II written by Zhigang Zhang and published by Frontiers Media SA. This book was released on 2023-07-10 with total page 235 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structural Performance of Concrete Beams with Micro reinforcement Strengthened with GFRP Laminates Under Monotonic Loading written by L. K. Rex and published by . This book was released on 2020 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: The behavior of structural elements under different loading conditions decides the performance of the built structures. Fiber-reinforced concrete and fiber-reinforced polymers (FRPs) have received increasing attention in recent years for many structural applications. Steel fibers, when added into concrete as micro-reinforcement, impart a bridging effect, resulting in enhanced mechanical properties. FRPs are most commonly composed of glass, aramid, or carbon fibers in a polymeric matrix and can be tailor-made to provide a large variety of material properties to suit the prerequisites of the engineer. This article presents an experimental investigation of steel fiber reinforced concrete beams externally strengthened with glass fiber reinforced polymer (GFRP) laminates to study their static flexural behavior and failure modes. The experimental program consisted of six concrete beams strengthened with GFRP laminates, and one concrete beam was left unstrengthened to serve as the control beam. The beams were designed for under-reinforced conditions and cast with different fiber volume fractions ( V f ) and GFRP laminate thickness ( t f ). The beams were tested under monotonic loading until failure. The experimental results showed that the strengthened beams exhibit significantly improved performance compared with the control beams in terms of strength, deformation, ductility, and crack resistance under monotonic loads.

Download or read book Nonconventional Concrete Technologies written by Committee on Nonconventional Concrete Technologies for Renewal of the Highway Infrastructure and published by National Academies Press. This book was released on 1997-04-08 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonconventional Concrete Technologies: Renewal of the Highway Infrastructure identifies research and development opportunities in innovative, nonconventional materials and processes that have the potential to accelerate the construction process, improve the durability of highway pavement and bridges, and enhance the serviceability and longevity of new construction under adverse conditions.

Download or read book Proceedings of 17th Symposium on Earthquake Engineering Vol 2 written by Manish Shrikhande and published by Springer Nature. This book was released on 2023-07-19 with total page 823 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents select proceedings of the 17th Symposium on Earthquake Engineering organized by the Department of Earthquake Engineering, Indian Institute of Technology Roorkee. The topics covered in the proceedings include engineering seismology and seismotectonics, earthquake hazard assessment, seismic microzonation and urban planning, dynamic properties of soils and ground response, ground improvement techniques for seismic hazards, computational soil dynamics, dynamic soil–structure interaction, codal provisions on earthquake-resistant design, seismic evaluation and retrofitting of structures, earthquake disaster mitigation and management, and many more. This book also discusses relevant issues related to earthquakes, such as human response and socioeconomic matters, post-earthquake rehabilitation, earthquake engineering education, public awareness, participation and enforcement of building safety laws, and earthquake prediction and early warning system. This book is a valuable reference for researchers and professionals working in the area of earthquake engineering.

Download or read book Geopolymer Concrete Structures with Steel and FRP Reinforcements written by Mohamed Elchalakani and published by Elsevier. This book was released on 2023-02-15 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geopolymer Concrete Structures with Steel and FRP Reinforcements: Analysis and Design focuses on structural behavior, including the aspects of compression, bending strength and combined action of GPC members, with the book's content based on published studies over the last two decades. Geopolymer concrete (GPC) structural members reinforced with FRP reinforcement have some advantages in resisting forces compared to conventional concrete or steel tubular members. Among the most important are the high strength and bending stiffness, fire and impact performance and favorable, construction ability and durability. To this end, there are no significant applications of these new structural elements worldwide, partly due to the lack of the understanding of their behavior and insufficient design provisions in different design manuals. This book, therefore, seeks to highlight their characteristics and future potential. Provides comprehensive, up-to-date advances on Geopolymer Concrete (GPC) reinforced with steel and FRP bars and stirrups construction with a summary of over 100 papers published in the last decade Compares the behavior and failure modes between Geopolymer Concrete (GPC) structures and Ordinary Portland Concrete (OPC) structures Explains important concepts such as bond, confinement, fracture of stirrups and buckling of FRP bars Includes an in-depth analysis of ultimate strength of GPC and OPC, considering governing failure modes Presents design examples following international standards, including North America ACI 440.1R-15, Canadian CAN/CSA S806, and Australian such as AS 3600

Download or read book Mechanical Properties of Ultra High Strength Fiber Reinforced Concrete written by Hafeez Mohammed and published by . This book was released on 2015 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: The usage of Ultra High Strength Fiber Reinforced Concrete (UHSFRC) with higher compressive strength (15,000-29,000 psi) in construction industry has been increasing worldwide. UHSFRC is also known as reactive powder concrete (RPC) which exhibits excellent durability and mechanical properties. This is one of the latest and emerging topics in the concrete technology. Structural elements cast with UHPC can carry larger loads and exhibit energy absorption capacity with smaller sections.The high compressive strength, higher tensile strength along with almost negligible water and chloride permeability therefore better durability of this new concrete material makes it UHSFRC. The basic principle in UHSFRC is to make the cement matrix as dense as possible, by reducing the micro cracks and capillary pores in the concrete and also to make a dense transition zone between cement matrix and aggregates. These special properties of concrete can be achieved by eliminating the coarse aggregates and replacing them with quartz sand of maximum size of 600 microns.The possibility of achieving high strength, durability, and ductility concrete encourages engineers to use this innovative material in many applications such as nuclear waste containment structures, high rise structures, long span bridges, walkways and in many more applications.ivConcrete (UHSFRC) using materials that are available locally are always economical since the patented products are very expensive and the materials such as silica sand and quartz powder are not readily available. The research also includes use of recognized mineral admixtures, natural river sand, steel fibers, and superplasticizers (Sika Viscocrete 2100 - 3% by weight of cement, Melflux 4930 - 1% by weight of cementitious material) without using any coarser aggregates, and an optimum dosage of silica fume was 15 % by weight of the cement.The structural integrity and durability of concrete used in shear keys is vital for the performance of bridges constructed using precast concrete components. The use of UHPC in the construction of shear keys can be a good solution for achieving long lasting bridge systems. The evaluation of UHPC shear key was conducted by connecting the precast concrete girders together via shear key. The test specimen was a simply supported beam with the shear key connection at mid span.The fresh and hardened mechanical properties of the UHSFRC were studied such as workability of the mix, compression test on cubes, split tensile test on cylinders, flexural tensile test for both reinforced and unreinforced concrete beams, rebar pull-out tests, impact test on panels and testing for shear keys.Two different curing practices were used in this work: Moist Curing (MC) and Heat Curing (HC). Two different types of cements used were ASTM Type I and Type III cements. Type I cement is commonly used in all the construction works whereas Type III cement is used in special applications where early high strengths are required. Both the cements are used for the comparative study, keeping all the proportions constant.vCompressive strength of 21,500 psi was achieved with concrete made of type III cement using moist curing practice. Split tensile strength of 2,300 psi and flexural strength of 3,300 psi were gained using Type III cement and moist curing practice. Highest compressive strength of 28,150 psi is achieved using heat curing practice. It was found that heat curing practice may be artificially inflating the compressive strength. The split tensile strength, and flexural strength results of heat-cured specimens have lower strength compared to moist cured specimens. The moment capacity of the fiber reinforced concrete is twice than the conventional concrete, due to the denser microstructure, absence of coarse aggregates, and cement silica reaction. Potential application of UHSFRC in shear keys of adjacent box beam girder bridges was demonstrated on small joint test specimens with sand blasted surface. It is concluded that the use of the mix design developed in this study for UHSFRC is feasible for such box beam bridges.

Download or read book Composites for Construction written by Lawrence C. Bank and published by John Wiley & Sons. This book was released on 2006-07-21 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first textbook on the design of FRP for structural engineering applications Composites for Construction is a one-of-a-kind guide to understanding fiber-reinforced polymers (FRP) and designing and retrofitting structures with FRP. Written and organized like traditional textbooks on steel, concrete, and wood design, it demystifies FRP composites and demonstrates how both new and retrofit construction projects can especially benefit from these materials, such as offshore and waterfront structures, bridges, parking garages, cooling towers, and industrial buildings. The code-based design guidelines featured in this book allow for demonstrated applications to immediately be implemented in the real world. Covered codes and design guidelines include ACI 440, ASCE Structural Plastics Design Manual, EUROCOMP Design Code, AASHTO Specifications, and manufacturer-published design guides. Procedures are provided to the structural designer on how to use this combination of code-like documents to design with FRP profiles. In four convenient sections, Composites for Construction covers: * An introduction to FRP applications, products and properties, and to the methods of obtaining the characteristic properties of FRP materials for use in structural design * The design of concrete structural members reinforced with FRP reinforcing bars * Design of FRP strengthening systems such as strips, sheets, and fabrics for upgrading the strength and ductility of reinforced concrete structural members * The design of trusses and frames made entirely of FRP structural profiles produced by the pultrusion process

Download or read book Expanding Boundaries Systems Thinking in the Built Environment written by Guillaume Habert and published by vdf Hochschulverlag AG. This book was released on 2016-08-15 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt: Consuming over 40% of total primary energy, the built environment is in the centre of worldwide strategies and measures towards a more sustainable future. To provide resilient solutions, a simple optimisation of individual technologies will not be sufficient. In contrast, whole system thinking reveals and exploits connections between parts. Each system interacts with others on different scales (materials, components, buildings, cities) and domains (ecology, economy and social). Whole-system designers optimize the performance of such systems by understanding interconnections and identifying synergies. The more complete the design integration, the better the result. In this book, the reader will find the proceedings of the 2016 Sustainable Built Environment (SBE) Regional Conference in Zurich. Papers have been written by academics and practitioners from all continents to bring forth the latest understanding on systems thinking in the built environment.