Download or read book Structural Behaviour of Self Consolidating Steel Fiber Reinforced Concrete Beams written by Michael I. Cohen and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: When subjected to a combination of moment and shear force, a reinforced concrete (RC) beam with either little or no transverse reinforcement can fail in shear before reaching its full flexural strength. This type of failure is sudden in nature and usually disastrous because it does not give sufficient warning prior to collapse. To prevent this type of shear failure, reinforced concrete beams are traditionally reinforced with stirrups. However, the use of stirrups is not always cost effective since it increases labor costs, and can make casting concrete difficult in situations where closely-spaced stirrups are required. The use of steel fiber reinforced concrete (SFRC) could be considered as a potential alternative to the use of traditional shear reinforcement. Concrete is very weak and brittle in tension, SFRC transforms this behaviour and improves the diagonal tension capacity of concrete and thus can result in significant enhancements in shear capacity. However, one of the drawbacks associated with SFRC is that the addition of fibers to a regular concrete mix can cause problems in workability. The use of self-consolidating concrete (SCC) is an innovative solution to this problem and can result in improved workability when fibers are added to the mix. The thesis presents the experimental results from tests on twelve slender self-consolidating fiber reinforced concrete (SCFRC) beams tested under four-point loading. The results demonstrate the combined use of SCC and steel fibers can improve the shear resistance of reinforced concrete beams, enhance crack control and can promote flexural ductility. Despite extensive research, there is a lack of accurate and reliable design guidelines for the use of SFRC in beams. This study presents a rational model which can accurately predict the shear resistance of steel fiber reinforced concrete beams. The thesis also proposes a safe and reliable equation which can be used for the shear design of SFRC beams.

Download or read book Behaviour of Self Consolidating Steel Fiber Reinforced Concrete Beams Under Reversed Cyclic Loading written by Nima Aghniaey and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Steel Fiber Reinforced Concrete written by Harvinder Singh and published by Springer. This book was released on 2016-10-26 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses design aspects of steel fiber-reinforced concrete (SFRC) members, including the behavior of the SFRC and its modeling. It also examines the effect of various parameters governing the response of SFRC members in detail. Unlike other publications available in the form of guidelines, which mainly describe design methods based on experimental results, it describes the basic concepts and principles of designing structural members using SFRC as a structural material, predominantly subjected to flexure and shear. Although applications to special structures, such as bridges, retaining walls, tanks and silos are not specifically covered, the fundamental design concepts remain the same and can easily be extended to these elements. It introduces the principles and related theories for predicting the role of steel fibers in reinforcing concrete members concisely and logically, and presents various material models to predict the response of SFRC members in detail. These are then gradually extended to develop an analytical flexural model for the analysis and design of SFRC members. The lack of such a discussion is a major hindrance to the adoption of SFRC as a structural material in routine design practice. This book helps users appraise the role of fiber as reinforcement in concrete members used alone and/or along with conventional rebars. Applications to singly and doubly reinforced beams and slabs are illustrated with examples, using both SFRC and conventional reinforced concrete as a structural material. The influence of the addition of steel fibers on various mechanical properties of the SFRC members is discussed in detail, which is invaluable in helping designers and engineers create optimum designs. Lastly, it describes the generally accepted methods for specifying the steel fibers at the site along with the SFRC mixing methods, storage and transport and explains in detail methods to validate the adopted design. This book is useful to practicing engineers, researchers, and students.

Download or read book Structural Behaviour of Steel Fibre Reinforced Concrete Members written by Hassan Aoude and published by . This book was released on 2007 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Self Consolidating Concrete written by Joseph Daczko and published by CRC Press. This book was released on 2012-03-06 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A very interesting and useful book for all the different practitioners in the concrete industry. Each necessary step is thoroughly dealt with and explained in a nice and pedagogic way." Peter Billberg, Swedish Cement and Concrete Research Institute (CBI)"Quite comprehensive and with a narrative style at the practitioner level." Lloyd Keller, Direc

Download or read book Shear Behavior of Steel fiber Reinforced Ultra High strength Self compacted Concrete Beams written by Omar Jumah Zaal Rawashdeh and published by . This book was released on 2015 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultra-high-strength concrete is a new class of concrete that has been the result of the progress in concrete material science and development. This new type of concrete is characterized with very high compressive strength; about 100 MPa. Ultra-high strength concrete shows very brittle failure behavior compared to normal-strength concrete. Steel fibers will significantly reduce the workability of ultra-high strength concrete. The development and use of self-compacting concrete has provided a solution to the workability issue. The combination of technology and knowledge to produce Ultra-High strength fiber reinforced self-compacting concrete was proved to be feasible. Few studies investigated the effect of incorporating steel fibers on the shear behavior of ultra-high-strength reinforced concrete beams. The research consists of a test series and analytical investigation. The present research investigated the shear behavior of reinforced beams made of normal-strength-concrete fiber-reinforced self-compacting concrete (28 MPa), high-strength concrete fiber-reinforced self-compacting concrete (60 MPa) and ultra-high-strength fiber-reinforced self-compacting concrete (100 MPa). The test parameters included two different shear span-to-depth ratios of 2.22 (deep beam action) and 3.33 (slender beam action), and three different steel fiber volume fractions of 0.4%, 0.8%, and 1.2%. The test results showed that the shear strength gain ranged from 20% to 129% for the beams having a concrete grade of 28 MPa, 26% to 63% for the beams having a concrete grade of 60 MPa, and 8.6% to 94% for the beams with a concrete grade of 100 MPa. For the deep beams, the shear strength gain tended to decrease by increasing the concrete grade. For the slender beams with steel fiber volume fractions of 0.4% and 0.8%, varying the concrete grade had no obvious effect on the shear strength gain. For the viii slender beams with the higher steel fiber volume fraction of 1.2%, the shear strength gain tended to decrease with an increase in the concrete grade. In the analytical investigation, the accuracy and validity of published analytical models have been demonstrated. Predictions of analytical models by Ashour et al. (1992) and Narayanan et al. (1987) were in good agreement with the experimental results.

Download or read book Fiber Reinforcement in Prestressed Concrete Beams written by Hemant B. Dhonde and published by . This book was released on 2005 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Short Term and Long Term Behaviour of Reinforced Self Compacting Concrete Structures written by Farhad Aslani and published by Trans Tech Publications Ltd. This book was released on 2014-06-24 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume is indexed by Thomson Reuters BCI (WoS). Self-Compacting Concrete (SCC) refers to a 'highly flow-able,non-segregating concrete that can be spread into place, fill the formwork,and encapsulate the reinforcement without the aid of any mechanicalconsolidation. SCC is regarded as one of the most promising developments inconcrete technology due to significant advantages over Conventional Concrete(CC). In this study cracking caused by external loads in reinforced SCC andFRSCC slabs is examined experimentally and analytically. The mechanismsassociated with the flexural cracking due to the combined effects ofconstant sustained service loads and shrinkage are observed. One of theprimary objectives of this study is to develop analytical models thataccurately predict the hardened mechanical properties of SCC and FRSCC.Subsequently, these models have been successfully applied to simulatetime-dependent cracking of SCC and FRSCC one-way slabs.

Download or read book Structural Behaviour of Conventionally Reinforced Concrete Beams with Steel Fibres written by Sa'ad A. Al-Ta'an and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Self Compacting Concrete Materials Properties and Applications written by Rafat Siddique and published by Woodhead Publishing. This book was released on 2019-11-19 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: Self-Compacting Concrete: Materials, Properties and Applications presents the latest research on various aspects of self-compacting concrete, including test methods, rheology, strength and durability properties, SCC properties at elevated temperature, SC manufacturing with the use of SCMs, recycled aggregates and industrial by-products. Written by an international group of contributors who are closely associated with the development of self-compacting concrete, the book explores the main differences between SCC and normal concrete in terms of raw materials, fresh properties and hardened properties. Other topics discussed include the structure and practical applications of fiber reinforced SCC. Researchers and experienced engineers will find this reference to be a systematic source to SCC with its accounting of the latest breakthroughs in the field and discussions of SCC constructability, structural integrity, improved flows into complex forms, and superior strength and durability. Offers a systematic and comprehensive source of information on the latest developments in SCC technology Includes mix design procedures, tests standards, rheology, strength and durability properties Explores the properties and practical applications of SCC

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 Dynamic Properties and Application of Steel Fiber Reinforced Self consolidating Concrete to Segmental Bridge Columns in Moderate to high Seismic Regions written by Nasi Zhang and published by . This book was released on 2014 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, the application of steel fiber reinforced self-consolidating concrete (SFRSCC) to precast unbonded post-tensioned segmental bridge columns in moderate-to-high seismic regions is evaluated numerically and experimentally. Drop weight impact tests are first conducted on plain concrete and steel fiber reinforced concrete (SFRC). The standard drop test recommended by the American Concrete Institute (ACI) is first conducted and a modification to this standard ACI, which involves visual inspection of first cracking and ultimate failure, is then developed. The Kolmogorov-Smirnov (K-S) test along with fitted normal and lognormal distributions are used to examine the distribution of the number of blows required to cause first cracking and ultimate failure of the concrete. The minimum sample size required to calculate the impact strength of SFRC is determined using equations available in the literature. This sample size is used in the subsequent impact study on SFRSCC specimens. The static and dynamic properties of ten groups of SFRSCC, including one group of self-consolidating concrete (SCC) without steel fibers, are studied and compared. Dramix℗ʼ ZP305, RC-65/35-BN, and RC-80/30-BP steel fiber (glued and hooked end) at a volume of 0. 25%, 0. 5% and 1% are considered in the study. The static properties are calculated using compression tests, split-tension tests and flexural beam tests. The dynamic properties are determined using the modified ACI impact test. A dynamic load sensor is installed underneath the base plate of the impact test machine to measure the relative reaction force history. The recorded reaction forces are used to develop an automated impact test method, which can circumvent visual inspections. Two large-scale (1:3. 37), precast, unbonded and post-tensioned segmental columns, one constructed with SCC and one constructed with SFRSCC (with 0. 5% of ZP305 steel fiber by volume), are tested under cyclic loading. These segmental columns incorporate shear keys at the joints. The backbone force-displacement relationships of the segmental columns are calculated from a pushover model available in the literature. The hysteretic behavior of the segmental columns under cyclic loading is also simulated by a numerical model developed on the OpenSEES platform. A single span, large-scale (1:3. 37) bridge model incorporating SFRSCC segmental columns (with 0. 5% of ZP305 steel fiber by volume) is tested on a shake table. Two types of cap beam-to-superstructure connections are considered for the bridge model: a connection using non-seismic rubber bearing and a fixed connection. The bridge model is tested for far field and near field ground motions along various directions and with increasing peak ground accelerations (PGAs). The evolution of the cumulative damage to the bridge model after each seismic test is evaluated through a system identification involving white noise excitation. A flag-shaped hysteretic model is proposed and validated through the cyclic test results obtained in this research and those available in the literature. The proposed flag-shaped model is used to predict the seismic response of the bridge model. Adding steel fibers to concrete significantly improves its impact strength and ductility. The SFRSCC segmental columns suffered less damage than the SCC columns for the same level of drift. The large-scale bridge model incorporating SFRSCC segmental columns sustained high intensity far field and near field ground motions with limited damage. The proposed flag-shaped hysteretic model can be used to simulate the cyclic behavior of segmental columns, and to provide reasonable estimates of their seismic response under strong ground motions.

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 Flexural Behavior of Steel Fiber Reinforced Prestressed Concrete Beams and Double Punch Test for Fiber Reinforced Concrete written by Netra Bahadur Karki and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Steel fibers have widely been used in the past to reinforce brittle materials in many nonstructural applications such as pavement, tunneling lining, etc. On the basis of numerous previous studies, ACI 318-11 [2011] has recently accepted steel fiber as a minimum shear reinforcement replacement with minimum 0.75% volume fraction for both reinforced concrete and prestressed concrete members. However, not much previous research has talked about the flexural behavior of fiber reinforced concrete (FRC). As per ACI 318-11 for tension-controlled sections, the net tensile strains in the outermost layer of steel, et, should be greater than or equal to 0.005 and for the moment redistribution in continuous beam the section should sufficiently ductile (et [greater or equal to] 0.0075). For this, the sections should have small longitudinal reinforcement ratio which ultimately leads to an inefficient beam section with a large cross-sectional area. In contrast, the use of smaller concrete cross sections can lead to a diminished ductile flexural behavior as well as premature shear failure. In this context, the use of steel fiber reinforced concrete could be a potential solution since fiber can increase both the concrete shear strength and it's usable compressive strains. However limited previous researches on the flexural behavior on SFRC beams are available and most of them are of small scales and concentrated only basically for shear behavior. To the best of our knowledge, the large-scale prestressed fiber reinforced concrete beam specimens have yet to be studied for flexure behavior. In this project, six large scale prestressed concrete beams with or without steel fiber along with some material test were tested. Our experimental investigations indicated that even with inclusion of small percentage volume of fraction of steel fiber (Vf =0.75%) could not only increase the ductility and shear strength of the SFRPC beam but also change the failure pattern by increasing usable strain in concrete and steel. A modification on the limit for c/dt ratio and [phi] factor for design of flexural member given in current ACI could be proposed which could imply the smaller sections with higher longitudinal reinforcement ratio and less shear reinforcement. could be used. Any standard material test results have to ensure that FRC has, at least, been batched properly and it can give indications of probable performance when used in structures. In the current material testing method suggested by ACI, the third point bending test (ASTM C1609) has an inherent problem in that the coefficients of variations for post cracking strength and residual strength are generally very high on the order of 20%. The direct tensile test can be a more appropriate material. However, it is currently not recommended as standard method in the U.S. Because of it's difficultly in gripping arrangement which will lead to cracking of the specimen at the grips. Both the test methods also require close loop servo controlled machine. The round panel test method (ASTM C1550) requires large size specimen and heavy steel supports prevents performing test in small laboratories. Split cylinder test (ASTM C496), do not necessarily reflect the true properties of the material as the specimen is forced to fail in the line of the application of the load and the test method is also not recommended by ACI for SFRC. In order to improve the material assessment procedure, the double Punch Test (DPT) introduced by Chen in 1970 [Chen, 1970] was extensively evaluated to develop a simple, quick and reliable testing method for SFRC. Various tests were carried out in order to evaluate peak and residual strength, stiffness, strain hardening and softening, toughness and other post crack properties. Our test results indicated that the DPT method could be immersed as reliable, easier and economical material test method. It could be used to distinguish the peak strength, residual strength, toughness stiffness and crack resistance, of different SFRC mixtures with less scatter results compared to other material test methods.

Download or read book Restrained Shrinkage Behavior of Crimped Steel Fiber Reinforced Self consolidating Concrete written by Giuseppe Liberti and published by . This book was released on 2017 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Flexural Shear and Mechanical Behaviour of Self consolidating rubberized Concrete With without Steel Fibres written by Mohamed Karam Hussein Ismail and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This research program focuses on investigating the applicability of using crumb rubber (CR) as a replacement for fine aggregate in developing a novel eco-friendly concrete type suitable for structural applications, especially when self-consolidating concrete (SCC) is used. Four extensive experimental studies have been carried out on both small- and large-scale concrete specimens to accomplish the research objective. The first and second studies aimed to optimize a number of successful self-consolidating rubberized concrete (SCRC) and steel fibre SCRC (SFSCRC) mixtures with maximized percentages of CR and minimized reduction in the stability and strength. The first parametric study included 27 SCRC mixtures developed with different binder contents (500-550 kg/m3), supplementary cementing materials (SCMs) (metakaolin (MK), fly ash (FA), and ground granulated blast-furnace slag (GGBS)), coarse aggregate sizes (10-20 mm), and entrained air admixture. The second parametric study included 19 SFSCRC mixtures developed with different binder content (550-600 kg/m3), steel fibre (SF) volume fractions (0.35% and 0.5%), and lengths of SFs (35 and 60 mm). In this study (study 2), another three vibrated rubberized concrete (VRC) and four steel fibre VRC (SFVRC) mixtures were developed for comparison. In both study 1 and 2, the fresh and mechanical properties of the developed mixtures were evaluated using small-scale specimens. The fresh properties included flowability, passing ability, high-range water-reducer admixture (HRWRA) demand, coarse aggregate segregation, and CR distribution. On the other hand, the evaluation of mechanical properties in both study 1 and 2 included compressive strength, splitting tensile strength (STS), flexural strength (FS), modulus of elasticity, impact resistance, ultrasonic pulse velocity, and acoustic emission measurements. The third and fourth studies evaluated the structural performance (flexural and shear) of large-scale reinforced concrete beams made with SCRC, VRC, SFSCRC, and SFVRC. In these studies, a total of 36 optimized mixtures from study 1 and 2 were selected to cast 36 large-scale reinforced concrete beams to be tested in flexure and shear (24 beams in flexure and 12 beams in shear). The performance of some design codes and empirical equations in predicting the first cracking moment, flexural, and shear capacity of the tested beams was also evaluated in study 3 and 4. The results showed that using CR in SCRC helped to develop mixtures with improved impact resistance, acoustic absorption capacity, and lower self-weight, but their stability, fresh, and mechanical properties were decreased. However, using higher binder content, different SCMs, and entrained air in SCRC improved their fresh properties and allowed high percentages of CR to be used, successfully. Moreover, MK was found to be the most effective SCMs that could obviously improve the stability and strength of SCRC. Although using SFs in SCRC mixtures negatively affected the fresh properties of the mixtures, they proved to have a significant enhancement on the mixtures' strengths, especially STS, FS, and impact resistance. Since the challenge to optimize mixtures with high flowability and passing ability was not a factor in developing vibrated mixtures, it was possible to develop SFVRC mixtures with higher percentage of CR and SFs. This high combination of CR and SFs provides a new concrete composite with further improvement in ductility, toughness, impact resistance, and with further reduction in self-weight. The results of the flexural testing conducted in study 3 indicated that increasing the CR appeared to narrow crack widths and improve deformability of SCRC and VRC beams at given load. The safe use of CR in structural applications was found to be 15%. Further increase in the CR content showed a significant reduction in the first cracking moment and ultimate flexural capacity of the tested beams, while the ductility and toughness did not show a confirmed effect for the higher percentages of CR. On the other hand, in SFVRC, the addition of 1% SFs (35 and 60 mm) helped to extend the possible safe content of CR to 35%, achieving successfully semi-lightweight concrete beams with a sufficient capacity, ductility, and toughness for multiple structural applications. In shear testing conducted in study 4, using CR in SCRC and VRC beams showed a reduction in their shear capacity, post-diagonal cracking resistance, and energy absorption. These reductions could be alleviated by inclusion of SFs. The composite effect of CR and SFs also helped to narrow the developed cracks and change the failure mode from a brittle shear failure to a ductile flexural failure, particularly for SFs volume of 1%. The comparisons between the predictions and the experimental results (obtained from study 3 and 4) indicated that most of the proposed equations can satisfactorily estimate the flexural and shear capacity, but the first cracking moment was overestimated.

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).