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Behavior Of High Performance Steel As Shear Reinforcement For Concrete Beams
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Book Synopsis Behavior of High Performance Steel as Shear Reinforcement for Concrete Beams by : Matthew Scott Sumpter
Download or read book Behavior of High Performance Steel as Shear Reinforcement for Concrete Beams written by Matthew Scott Sumpter and published by . This book was released on 2007 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: reinforced concrete beams, shear, high performance steel, MMFX, high strength, crack width.
Book Synopsis Behavior of High Performance Steel as Shear Reinforcement for Concrete Beams by :
Download or read book Behavior of High Performance Steel as Shear Reinforcement for Concrete Beams written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this research is to study the feasibility of using high performance steel as shear reinforcement for concrete beams. High performance steel is characterized by enhanced corrosion resistance and higher strength in comparison to conventional Grade 60 steel reinforcement. Advantages of using higher strength steel include the ability to design for longer span lengths and/or reducing the amount of material needed for design. This could greatly reduce the overall costs of construction for future structures. Nine reinforced concrete beams were constructed using No. 9 longitudinal bars and No. 3 bars for the stirrups. The main variables considered in the study are the stirrup spacing and the type of reinforcing steel material. Testing was performed using a single concentrated load positioned closer to one end of the beam, which allowed for two tests per beam. Research findings indicate that using MMFX stirrups increases the overall shear strength and enhances serviceability by distributing cracks and reducing crack width. Pairing high performance longitudinal and transverse reinforcement shows an optimum design in terms of strength gain and reduction in crack width. Enhanced serviceability behavior can be attributed to the better bond characteristics of MMFX steel in comparison to conventional Grade 60 steel. Test results suggest that combining high performance steel with high strength concrete could lead to a better utilization of the materials. Analysis shows that the ACI 318-05, CSA, and AASHTO LRFD design codes can conservatively be used for the design of high performance steel up to a yield strength of 80 ksi. Detailed analysis using the Modified Compression Field Theory can be used to accurately predict the behavior of the beams.
Book Synopsis Shear Behavior of Concrete Beams Reinforced with High Performance Steel Shear Reinforcement by :
Download or read book Shear Behavior of Concrete Beams Reinforced with High Performance Steel Shear Reinforcement written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The current shear design provisions of the ACI 318 specifications limit the yield strength in transverse reinforcement to 60 ksi. Advancement in technology has led to the fabrication of High Performance steel. Use of HP steel in reinforced concrete could lead to cost savings by reducing the amount of steel required due to the inherited high strength and increase of the service life of structural members due to its enhanced corrosion resistance. This research is undertaken to examine the use of high performance steel as a feasible reinforcement material for reinforced concrete structures. Commercially available steel, Micro-Composite Multi-Structural Formable (MMFX), conforming to ASTM A 1035, was selected for this study. MMFX steel has minimum yield strength of 100 ksi. This experimental program comprised eighteen tests using nine large-scale reinforced concrete beams subjected to static loading up to failure. The key parameters considered in experimental program were the steel type and the amount of shear reinforcement. This research investigated crack width, modes of failure, deflection, stirrup strain, ultimate load carrying capacity and the behavior of the MMFX steel as transverse reinforcement for concrete beams. Results from the experimental program show that by utilizing the higher yield strength and consequently reducing the reinforcement ratio of MMFX steel, the beams can achieve almost the same load-carrying capacity as the beams reinforced with conventional Grade 60 steel. Also, beams reinforced with MMFX showed similar deflections at service load as the beams reinforced with Grade 60 steel. Therefore, reduction in the reinforcement ratio of MMFX steel, did not affect the serviceability of these beams. Analysis shows that the ACI 318, CSA, and AASHTO LRFD design codes can closely predict the ultimate shear strength for beams reinforced with high performance steel having yield strength up to 100 ksi. The beams were also analyzed using a well-established Mo.
Book Synopsis Shear Behavior of Concrete Beams Reinforced with High Performance Steel Shear Reinforcement by : Aruna Munikrishna
Download or read book Shear Behavior of Concrete Beams Reinforced with High Performance Steel Shear Reinforcement written by Aruna Munikrishna and published by . This book was released on 2008 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: MMFX, Shear.
Author :fib - federation internationale du beton Publisher :John Wiley & Sons ISBN 13 :3433030618 Total Pages :434 pages Book Rating :4.4/5 (33 download)
Book Synopsis fib Model Code for Concrete Structures 2010 by : fib - federation internationale du beton
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.
Book Synopsis Advances in Civil Engineering and Building Materials by : Shuenn-Yih Chang
Download or read book Advances in Civil Engineering and Building Materials written by Shuenn-Yih Chang and published by CRC Press. This book was released on 2012-10-31 with total page 974 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Civil Engineering and Building Materials presents the state-of-the-art development in: - Structural Engineering - Road & Bridge Engineering- Geotechnical Engineering- Architecture & Urban Planning- Transportation Engineering- Hydraulic Engineering - Engineering Management- Computational Mechanics- Construction Technology- Buildi
Book Synopsis Steel Fiber Reinforced Concrete by : Harvinder Singh
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.
Book Synopsis Studies on Shear Strength of High Performance Concrete Beams by : P. Y. L. Kong
Download or read book Studies on Shear Strength of High Performance Concrete Beams written by P. Y. L. Kong and published by . This book was released on 1997 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Shear Behavior of Steel Fiber Reinforced Prestressed Concrete Beams Without Shear Reinforcement by : Jae-Sung Cho
Download or read book Shear Behavior of Steel Fiber Reinforced Prestressed Concrete Beams Without Shear Reinforcement written by Jae-Sung Cho and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The ACI 318-08 building code allows to use the steel fiber reinforcement as alternative shear reinforcement with satisfying certain criteria when a beam is required minimum shear reinforcement. However, this provision applies to a nonprestressed and prestressed concrete beam such that it could be conservative since the shear strength of prestressed concrete beam is generally enhanced due to the prestressing force. This is due partially to the fact that the provision has been accepted based on researches, mostly conducted in nonprestressed concrete beam. Most of experiments conducted for prestressed concrete beam in small scale tests, with a height of specimens were less than 10 in. A larger scale of experiment is required due to concerns of size effect. In addition, in order to evaluate the qualification of a Steel Fiber Reinforced Concrete (SFRC) mixture used for structural applications, such as increasing shear resistance, a material evaluation method is essential. Currently ASTM or ACI Committee 544 (Fiber-Reinforced Concrete) does not recommend any standardized test method for evaluating shear performance of a particular SFRC material. This study addresses the research gaps described above by testing large-scale Steel Fiber Reinforced Prestressed Concrete (SFRPC) beams as well as developing a simple laboratory test techniques. A total 13 simply-supported beams for large-scale test with a shear span to effective depth ratio of 3.0 and a height of 24 in. were subjected to monotonically-increased, concentrated load. The test parameters were mainly included compressive strength, volume fraction of steel fibers, compressive reinforcement ratio. The results of large-scale test showed that the use of hooked steel fibers in a volume fraction greater than or equal to 0.50% volume fraction of steel fibers (67 lb per cubic yard), which is less than requirement by ACI 318-08 (0.75%, 100 lb per cubic yard), led to substantial enhancement of shear behaviors including the first cracking, the ultimate, and ductility. High compressive strength of SFRC, greater than 9000 psi, which is higher than ACI 318-08 requirement (less than 6000 psi) could be used as well. However, there was no significant effect from compressive reinforcement ratio. A simply shear test method for SFRC was proposed in this study. The test apparatus is almost exactly the same as the conventional ASTM bending test with only minor modification, in addition, it could simulate a pure shear stress by adjusting loading and support positions. By introducing a proper reinforcement for bending stress, it was possible to evaluate shear performance of SFRC with clear and uncomplicated shear stress field in the critical section.
Download or read book EASEC16 written by Chien Ming Wang and published by Springer Nature. This book was released on 2020-12-22 with total page 2093 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents articles from The 16th East Asian-Pacific Conference on Structural Engineering and Construction, 2019, held in Brisbane, Australia. It provides a forum for professional engineers, academics, researchers and contractors to present recent research and developments in structural engineering and construction.
Book Synopsis Response of Ultra High Performance Fiber Reinforced Concrete Beams Under Flexure and Shear by : Roya Solhmirzaei
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.
Book Synopsis Flexural Behavior of Steel Fiber Reinforced Prestressed Concrete Beams and Double Punch Test for Fiber Reinforced Concrete by : Netra Bahadur Karki
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.
Book Synopsis Design of Concrete Structures Using High-strength Steel Reinforcement by : Bahram M. Shahrooz
Download or read book Design of Concrete Structures Using High-strength Steel Reinforcement written by Bahram M. Shahrooz and published by Transportation Research Board. This book was released on 2011 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB's National Cooperative Highway Research Program (NCHRP) Report 679: Design of Concrete Structures Using High-Strength Steel Reinforcement evaluates the existing American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) Bridge Design Specifications relevant to the use of high-strength reinforcing steel and other grades of reinforcing steel having no discernible yield plateau. The report also includes recommended language to the AASHTO LRFD Bridge Design Specifications that will permit the use of high-strength reinforcing steel with specified yield strengths not greater than 100 ksi. The Appendixes to NCHRP Report 679 were published online.
Book Synopsis Guide for the Design and Construction of Concrete Reinforced with Fiber-Reinforced Polymer Bars by : ACI Committee 440
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:
Book Synopsis Ultra-High Performance Concrete UHPC by : Ekkehard Fehling
Download or read book Ultra-High Performance Concrete UHPC written by Ekkehard Fehling and published by John Wiley & Sons. This book was released on 2015-04-20 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selected chapters from the German concrete yearbook are now being published in the new English "Beton-Kalender Series" for the benefit of an international audience. Since it was founded in 1906, the Ernst & Sohn "Beton-Kalender" has been supporting developments in reinforced and prestressed concrete. The aim was to publish a yearbook to reflect progress in "ferro-concrete" structures until - as the book's first editor, Fritz von Emperger (1862-1942), expressed it - the "tempestuous development" in this form of construction came to an end. However, the "Beton-Kalender" quickly became the chosen work of reference for civil and structural engineers, and apart from the years 1945-1950 has been published annually ever since. Ultra high performance concrete (UHPC) is a milestone in concrete technology and application. It permits the construction of both more slender and more durable concrete structures with a prolonged service life and thus improved sustainability. This book is a comprehensive overview of UHPC - from the principles behind its production and its mechanical properties to design and detailing aspects. The focus is on the material behaviour of steel fibre-reinforced UHPC. Numerical modelling and detailing of the connections with reinforced concrete elements are featured as well. Numerous examples worldwide - bridges, columns, facades and roofs - are the basis for additional explanations about the benefits of UHPC and how it helps to realise several architectural requirements. The authors are extensively involved in the testing, design, construction and monitoring of UHPC structures. What they provide here is therefore a unique synopsis of the state of the art with a view to practical applications.
Book Synopsis Shear Behavior of Steel -fiber Reinforced Ultra- High-strength Self -compacted Concrete Beams by : Omar Jumah Zaal Rawashdeh
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.
Book Synopsis Behavior of UHPC Structural Members subjected to Pure Torsion by : Mohammed Ismail
Download or read book Behavior of UHPC Structural Members subjected to Pure Torsion written by Mohammed Ismail and published by kassel university press GmbH. This book was released on 2015-01-01 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultra High Performance Concrete (UHPC) is characterized by a very high compressive strength which may reach more than 200 MPa. The behavior of this material under tension and compression actions has been established to be very brittle in nature. Discontinuous fibers (normally steel fibers) are usually added to the UHPC mix to introduce ductility. In order to investigate the beneficial effects of using fiber reinforced UHPC in structural members subjected to torsion, a series of experimental tests on 17 UHPC beams subjected to pure torsion were carried out. The test beams consisted of plain UHPC beams, UHPC beams reinforced with steel fibers only, UHPC reinforced with steel fibers and different combinations of traditional longitudinal and transverse reinforcement. The plain UHPC beams showed very brittle behavior, whereas the UHPC beams with steel fibers only showed a post cracking ductile behavior. The addition of little steel fiber volume (e.g. 0.5 %) to the plain UHPC beams enhanced the ductility. The enhancement at the ultimate capacity amounts to about 20 %. Meanwhile, the steel fibers with 0.9 % by volume showed much enhanced ductility and a maximum enhancement of the torsional carrying capacity up to 32 %. The addition of moderate steel fiber volume (e.g. 0.9 %) to one type of traditional reinforcement (either longitudinal or transverse) accomplished an effective post cracking torsional carrying mechanism. The steel fibers shows a tendency to replace the missing type of traditional reinforcement, however this should be confirmed by more tests and by using higher steel fiber volumes. A series of experimental tests on fiber reinforced UHPC prisms to investigate the post cracking shear strength and stiffness of the used UHPC mix (e.g. M3Q) was conducted. The results of these tests revealed that this fine grained UHPC mix has a weak post cracking shear behavior. The results of these tests were used later in the Finite Element (F.E) model. An analytical model based on the well known thin-walled tube analogy was developed in order to estimate the torsional carrying capacity of beams under pure torsion having different combinations of steel fibers and traditional reinforcement. The comparison between the test and model results showed very good agreement for all cases. A finite element model based on calibrated small scale tests was developed using ATENA F.E. package to predict the full load-deformation behavior of the test beams. The predictions of the model show very good agreement with the test results.
