Download or read book Shear Behavior of Large scale Concrete Beams Strengthened with Fibre Reinforced Polymer FRP Sheets written by David Alan Schnerch and published by . This book was released on 2001 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Shear Behavior of Large scale Concrete Beams Strengthened with Fibre Reinforced Polymer FRP Sheets written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Behavior of Full scale RC T beams Strengthened in Shear with Externally Bonded FRP Sheets written by Antonio Brancaccio and published by . This book was released on 2008 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Shear deficiencies in many bridges may be considered even more critical than flexural deficiencies since shear failures occur without advance warning and are more catastrophic. Deficiencies in shear can be due to insufficient shear reinforcement, use of outdated design codes, a reduction in the steel area due to corrosion, or an increase in the service load due to change of occupancy for the structure. In recent years, many research studies have investigated the shear behavior of reinforced concrete (RC) beams strengthened with fiber-reinforced polymer (FRP) composites, however, most of them were conducted on small-scale specimens. Thus, analytical models and design equations developed from those studies may not predict the actual behavior of full-scale RC beams strengthened with FRPs. A comprehensive review and analysis of previous experimental studies and analytical models available in the literature, conducted as part of an ongoing NCHRP project, was updated in this study in order to identify the main parameters affecting the shear behavior of beams strengthened with FRP. An experimental study was then carried out using three full-scale RC T-beams in order to understand the behavior of full-scale bridge beams strengthened with FRP and to evaluate the effectiveness of anchorage systems for wet lay-up FRP applications. The main parameters investigated during the present study were the transverse steel reinforcement ratio and the effect of mechanical anchorage systems. Efficiency of existing analytical models and design equations in predicting the shear contribution of the FRP to the total shear resistance was also investigated based on the experimental results of this study. The experimental results indicated that an increase in shear strength is obtained when FRP is used. Further increase in the shear capacity can be reached by using a proper mechanical anchorage system. As confirmed from previous studies, an interaction between transverse steel reinforcement and FRP strengthening was also observed. Furthermore, the strain distribution on the FRP over the test region was found to be nonlinear, however for design purposes an average strain can be assumed to calculate the shear carried by the FRP sheets"--Abstract, leaf iii.

Download or read book Behaviour of Shear critical Reinforced Concrete Beams Strengthened with Fiber Reinforced Cementitious Mortar written by Rizwan Azam and published by . This book was released on 2016 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extensive research has been conducted on strengthening of shear-critical reinforced concrete (RC) beams, particularly using fiber reinforced polymer (FRP) strengthening systems. This previous research has helped to better understand the behaviour of shear strengthening systems and has improved the performance of existing shear strengthening systems. However, there is still a potential to further improve upon the performance of existing shear strengthening systems. A cement-based composite system is an innovative strengthening system that has similar benefits (such as light weight, ease of installation and non-corroding) to FRP systems, but overcomes some of the draw backs (such as poor compatibility with concrete substrate, lack of vapour permeability and fire resistance) of using epoxy as bonding agent in FRP systems. A cement-based composite replaces the epoxy with cementitious mortar and the fiber sheets with fabric or grids. The current study presents the results of an experimental study conducted to investigate the effectiveness of cement-based composite systems in comparison to an existing epoxy-based system (carbon fiber reinforced polymer, CFRP) to strengthen shear-critical RC beams. Two types of cement-based systems were investigated in this study: carbon fiber reinforced polymer (CFRP) grid embedded in mortar (CGM) and carbon fabric reinforced cementitious mortar (CFRCM). The experimental study consisted of two phases. Phase I focused on flexural testing of seven medium-scale shear-critical reinforced concrete (RC) beams. The objective of this phase was to evaluate the potential of FRCM shear strengthening. The test variables included the type of FRCM (carbon FRCM or CFRCM and glass FRCM or GFRCM) and the strengthening scheme (side bonded vs. U-wrapped). Phase II was designed based on results of Phase I study, and it consisted of flexural testing of twenty (20) large-scale shear-critical RC beams strengthened with cement-based systems. The objective of this phase was to evaluate the effectiveness of the two types of cement-based strengthening systems in comparison to the existing epoxy-based FRP system. The test variables included: the shear span to depth ratio (slender and deep beams), amount of internal transverse steel reinforcement and type of strengthening system (CFRCM, CGM and CFRP). The results showed that the cement-based systems (CFRP grid in mortar and CFRCM) performed better compared to the epoxy-based system (CFRP sheet) in terms of the increase in shear capacity relative to the ultimate strength of the strengthening systems. The results also showed that the bond of cement-based system with the concrete substrate was sufficient that u-wrapping may not be required; the studied side-bonded systems did not exhibit signs of premature debonding. This is in contrast to most FRP fabric strengthening systems were u-wrapping is required for adequate bond. In addition, cement-based systems exhibited a better ability to control diagonal (shear) crack widths compared to the epoxy-based system tested, providing a greater reduction in diagonal crack width despite the relative lower ultimate strength and stiffness of the cement-based systems. Shear strengthening resulted in reduced shear strength contribution from stirrups. The strengthened beams with stirrups exhibited steeper shear cracks compared to control unstrengthened beams with stirrups. Similarly, the presence of stirrups reduces the shear strength contribution from strengthening. Again, the addition of stirrups results in steeper shear cracks which intersect fewer fibers tows in the strengthening system which results in a reduced shear strength contribution from strengthening layer. Lastly, the existing models to predict the ultimate load of strengthened shear-critical RC beams were evaluated and modifications to these methods were proposed.

Download or read book Reinforced Concrete Deep Beams written by F K Kong and published by CRC Press. This book was released on 1991-05-01 with total page 305 pages. Available in PDF, EPUB and Kindle. Book excerpt: The contents of this book have been chosen with the following main aims: to review the present coverage of the major design codes and the CIRIA guide, and to explain the fundamental behaviour of deep beams; to provide information on design topics which are inadequately covered by the current codes and design manuals; and to give authoritative revie

Download or read book Design of FRP Systems for Strengthening Concrete Girders in Shear written by Abdeldjelil Belarbi and published by Transportation Research Board. This book was released on 2011 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB's National Cooperative Highway Research Program (NCHRP) Report 678: Design of FRP Systems for Strengthening Concrete Girders in Shear offers suggested design guidelines for concrete girders strengthened in shear using externally bonded Fiber-Reinforced Polymer (FRP) systems. The guidelines address the strengthening schemes and application of the FRP systems and their contribution to shear capacity of reinforced and prestressed concrete girders. The guidelines are supplemented by design examples to illustrate their use for concrete beams strengthened with different FRP systems. Appendix A of NCHRP Report 678, which contains the research agency's final report, provides further elaboration on the work performed in this project. Appendix A: Research Description and Findings, is only available online.

Download or read book Handbook of Materials Selection written by Myer Kutz and published by John Wiley & Sons. This book was released on 2002-07-22 with total page 1524 pages. Available in PDF, EPUB and Kindle. Book excerpt: Erstmals in einem Band werden Werkstoffe hier (in zwei getrennten Systemen) sowohl nach ihrer technischen Anwendung als auch nach ihren Eigenschaften geordnet. - Benutzer können deshalb zunächst nach der Gruppe von Materialen suchen, die für eine spezielle Anwendung geeignet sind, und anschließend Details über jedes einzelne Material finden - Suchkriterien sind Eigenschaften wie Wärmeleitfähigkeit, optisches Reflexionsvermögen, Elastizität usw. und Anwendungsgebiete wie Bauwesen, Biomedizin, Fahrzeugbau, Luftfahrttechnik, Elektrotechnik usw. - berücksichtigt werden sowohl herkömmliche Werkstoffe (Eisen- und Nichteisenmetalle, Kunststoffe, Klebstoffe) als auch Kompositwerkstoffe und synthetische Materialen wie Laminate, Fasern und Keramiken

Download or read book Shear Strengthening of Reinforced Concrete Beams Using Fiber Reinforced Polymer Wraps written by and published by . This book was released on 1998 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies have shown that fiber-reinforced polymer (FRP) wraps can improve the capacity of rectangular beam sections. This technology has potential application to highway bridges that may have less shear capacity than flexural capacity or require added load capacity to handle current traffic demands. Compared with steel repair materials FRP offers several benefits, such as corrosion resistance and field-workability. Several studies have investigated the use of externally bonded FRP sheets to improve strength and stiffness of reinforced concrete (R/C) beams, but most have addressed flexural strength, not shear. The objective of the current study was to test the effectiveness of FRP wraps in repairing full-scale prestressed high-strength concrete joists fabricated with insufficient shear reinforcement. Four prestressed high-strength concrete tee-beams (joists) with integral web openings were tested. Two of the joists were repaired or upgraded with FRP wraps to improve shear performance and two were used as control specimens. Performance criteria were specified, and standard structural engineering practice for shear design was employed to determine wrap thickness. The results of the tests indicate that significant increases in the shear strength of R/C beams with insufficient shear capacity can be achieved by proper application of FRP wraps.

Download or read book Shear Behavior of Reinforced Concrete T beams Strengthened with Carbon Fiber Reinforced Polymer CFRP Sheets and CFRP Anchors written by Yun Gon Kim and published by . This book was released on 2011 with total page 810 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this research is the evaluation of shear behavior of full-scale reinforced concrete T-beams strengthened with carbon fiber reinforced polymer (CFRP) sheets and CFRP anchors. Although the CRFP material has high tensile strength, premature failure due to debonding CFRP sheets prevents utilizing that strength. The use of CFRP anchors prevents this failure, so the CFRP sheets are able to reach ultimate strain. The current shear design is based on plasticity, which assumes that all steel (ductile material) stirrups, across the critical section yield at ultimate. However the strain in the CFRP (brittle material), is essential to estimate the shear contribution of CFRP. To evaluate the validity of CFRP strengthening for shear, 24 tests were conducted with several parameters including shear-span-to-depth ratio, depth of beams, different transverse reinforcement ratios, and the layout of CFRP strips. In addition, a simple shear behavior model was developed to explain the differences between ductile and brittle material. From test observation, the use of CFRP anchors resulted in U-wrap application to perform like continuous wrapping which implies that a CFRP strip reached rupture strain because the anchors prevented debonding failure. However, all FRP strips did not rupture simultaneously because the strain distribution across a critical crack was not uniform. The average strain across the critical crack was about 0.005. Therefore a conservative value of effective strain (0.004) was selected for design purposes. In addition, when a beam is strengthened with CFRP, interactions between the contributions of the CFRP, steel or concrete must be taken into account. Factors ka, ks, and kf were introduced in the proposed shear design equations. Factor ka reflects the change in the material contributions as the shear span to depth ratio (a/d ratio) changes in deep beams. Factors ks and kf account for the change in steel or CFRP shear contribution due to the change in the critical crack angle as well as the interactions between the steel and FRP transverse reinforcement. As the amount of either steel or FRP material increase, the efficiency of the other material decreases.

Download or read book ACI 440 2R 17 Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures written by ACI Committee 440 and published by . This book was released on 2017-04-27 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Behavior of Shear Deficient Rc Beams Strengthened with Frp written by Bhattacharyya Shriman and published by LAP Lambert Academic Publishing. This book was released on 2015-05-21 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: The phenomenon of shear failure in reinforced concrete members is complex. For shear strengthening of reinforced concrete T-beam, fibre-reinforced plastic (FRP) may be provided in the form of bonded external FRP sheets or strips as web reinforcement. The use of FRP as external web reinforcement for strengthening of beams in shear introduces two additional failure modes: FRP rupture and FRP debonding. These generate additional levels of complexity to the failure behaviour of such beams. In the present study, the characteristics of shear deficient reinforced concrete T-beam retrofitted with FRP composites are explored. The effectiveness of strengthening of beams using FRP is found to depend on several factors like properties of laminate and interface, amount of stirrups, nature of the interface between different constituents of the beam strengthened with FRP, the FRP configuration, the amount of laminate used, the provision of fillets and anchors at the web-flange junction, shear span to depth ratio, size effect, concrete strength and the nature of the bond between the external and internal reinforcements and concrete.

Download or read book FRP written by J. G. Teng and published by John Wiley & Sons. This book was released on 2002 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fibre-reinforced polymer (FRP) composites are used to strengthen reinforced concrete (RC) structures. A large amount of research now exists on this. This book brings together all existing research into one volume.

Download or read book Rapid Strengthening of Concrete Beams with Powder actuated Fastening Systems and Fiber Reinforced Polymer FRP Composite Materials written by David T. Borowicz and published by . This book was released on 2002 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Strengthening Design of Reinforced Concrete with FRP written by Hayder A. Rasheed and published by CRC Press. This book was released on 2014-12-16 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: Strengthening Design of Reinforced Concrete with FRP establishes the art and science of strengthening design of reinforced concrete with fiber-reinforced polymer (FRP) beyond the abstract nature of the design guidelines from Canada (ISIS Canada 2001), Europe (FIB Task Group 9.3 2001), and the United States (ACI 440.2R-08). Evolved from thorough cla

Download or read book Shear Strengthening of Reinforced Concrete Beams with Bi directional Carbon Fiber Reinforced Polymer CFRP Strips and CFRP Anchors written by Nawaf Khaled Alotaibi and published by . This book was released on 2014 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of externally bounded Carbon Fiber Reinforced Polymer (CFRP) for strengthening existing RC structures has shown promising results. Although CFRP materials have high tensile strength, the ability to utilize that strength is limited by debonding of the CFRP laminates from the concrete surface. In order to prevent or delay debonding, CFRP anchors were used to provide an alternative means of transferring forces from CFRP strips to the concrete. Previous tests on prestressed I-girders strengthened with uni-directional and bi-directional CFRP strips showed that bi-directional CFRP application resulted in significant shear strength gain in comparison to a uni-directional application. The objective of this thesis is to evaluate the behavior of reinforced concrete beams strengthened in shear with bi-directional CFRP strips and CFRP anchors so that the findings from the previous work can be understood and implemented. Four 24 in. deep T-beams were fabricated at the Phil M. Ferguson Structural Engineering Laboratory at The University of Texas at Austin. Eight tests were conducted on these specimens to examine the effect of the bi-directional layout of CFRP on the shear strength. Specimens with 14-in. web width were selected as a part of the experimental program to allow for direct comparison with test results from the previous project. Additional beams with a web width of 8 in. were included to evaluate thinner webs similar to those in the I-girders. Test results indicate a significant increase in shear strength due to the bi-directional application of CFRP strips with CFRP anchors installed on beams with a shear span-to-depth ratio (a/d) of 3. Substantial shear strength gain up to 62% was achieved in beams with 14-in. webs. and up to 43% for beams with 8-in. webs. However, negligible shear strength gain was observed in beams with a/d of 1.5 (deep beams). Experimental test results demonstrate an interaction between the contribution of concrete, transverse steel and CFRP to the shear resistance of a reinforced concrete beam. The findings of this research contribute to a better understanding of the shear behavior of reinforced concrete members strengthened with externally bonded CFRP applied bi-directionally. Experimental results from this research project provide data needed in the field of CFRP shear strengthening since limited data are available on large-scale tests.

Download or read book Behaviour of Shear Critical Reinforced Concrete Beams Retrofitted with Externally Applied Fibre Reinforced Polymers written by Michael Anthony Colalillo and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scale Effects on Reinforced Concrete Beams Strengthened for Shear with Discrete Externally Bonded Carbon Fiber reinforced Polymer U wraps written by Matthew Ryan Dawson and published by . This book was released on 2008 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current ACI design provisions for shear in reinforced concrete (RC) beams strengthened with externally bonded carbon fiber-reinforced polymer (CFRP) U-wraps may not adequately account for the effect of scale. This paper describes tests of 6 geometrically scaled beams to identify possible scale effects of such beams. Results indicated that effective depth (d), shear span-to-depth ratio (a/d), flexural-tension steel reinforcement ratio (pf), transverse steel reinforcement ratio (pv), FRP reinforcement ratio (pf), FRP strip width (wf) and U-wrap orientation may affect the shear capacity of scaled specimens. In addition, local strain variations in surface bonded CFRP are investigated and recommendations on how to quantify CFRP strain are provided.