Download or read book Finite Element Evaluation of the Effects of Lateral Anchorage Strips on the Behavior of CFRP strengthened RC Beams written by José Javier Pérez Corrales and published by . This book was released on 2005 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: The accuracy of the model has been validated comparing the results obtained from the six beam tests to the ones determined using the FE approach. Good agreement between the two has been found.

Download or read book Behavior of Carbon Fiber Reinforced Polymer CFRP Anchors Strengthening Reinforced Concrete Structures written by Wei Sun and published by . This book was released on 2014 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon Fiber Reinforcement Polymer (CFRP) materials are widely used to strengthen reinforced concrete structures because they are light weight, have high strength, and are relatively easy to install. In strengthening applications, CFRP strips are typically attached to the concrete surface using epoxy resin with fibers oriented in the direction needing additional tensile strength. However, if CFRP strips rely exclusively on bond strength with concrete, only 40% to 50% of the CFRP tensile strength can be developed before debonding occurs. In order to fully develop the tensile strength of CFRP strips, some form of anchorage is needed. CFRP anchors can be applied with relative ease and have recently been shown to provide effective anchorage of CFRP strips to concrete members. In many cases, however, current anchorage details may resulting in fracture or failure of CFRP anchors prior to developing the full strength of CFRP strips. Many design parameters, the effects of which are not well understood, can affect the behavior and strength of CFRP anchors. Moreover, previous studies have demonstrated that the quality of installation can influence anchor strength substantially. The objectives of the study presented are to: 1) provide engineers with design guidelines for CFRP anchors, and 2) deliver a reliable test for controlling the quality of installation and materials of CFRP anchorage systems. In all, 39 tests on 6"×6"×24" rectangular concrete beams were conducted to study the influence of five parameters on CFRP anchor strength and effectiveness: 1) the width of the CFRP strip being developed, 2) the material ratio of CFRP anchor to CFRP strip, 3) the concrete strength, 4) the length/angle of anchor fan, and 5) the bond between CFRP strip and concrete (bonded/unbonded). The same tests also served to develop the test methodology for quality control of the CFRP anchorage system. Based on experimental results, guidelines for designing CFRP anchors are proposed. A test specimen and methodology are also proposed for qualifying CFRP materials and anchorage-system installations. A Finite Element (FE) formulation was selected to provide a computational tool that is suited for simulating the behavior of CFRP strips and CFRP anchors. The ability of the selected FE formulation to reproduce the effects on behavior of varying the anchor-material ratio, concrete strength, length of anchor fan, and bond conditions was investigated. Six FE simulations were built by adjusting simulation parameters and comparing results with six experimental tests. Comparisons between experimental and numerical results indicate that the proposed FE formulation and parameter selections reproduced load-deflection and local strain behaviors with high fidelity.

Download or read book Influence of Anchorage on the Behavior of CFRP RC Beams in Flexure written by Samir Dawood and published by LAP Lambert Academic Publishing. This book was released on 2012-01 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structural elements such as beams, slabs and columns may require strengthening during their service life period. The need for strengthening may arise due to one or a combination of several factors including construction or design defects, increased load carrying demands, change in use of structure, seismic upgrade, or meeting new code requirements. Studies have shown that Fiber Reinforced Polymer (FRP) composites, in the form of sheets, have emerged as a viable, cost-effective alternative to steel plates or other techniques in strengthening RC members. The principal advantages of FRP sheets over steel plates include high strength-to-weight ratio, corrosion resistance and flexibility in its use. Another significant advantage of this repair technique is that overall repair cost in terms of labor, material and equipment is low and can offset the high material cost. However, the long-term durability and performance of FRP sheet strengthened RC members is a concern in civil engineering community. This work study involves experimental and theoretical investigations of the behavior of flexural debonding carbon fiber reinforced polymer (CFRP) laminates with steel anchorages.

Download or read book Behavior of Reinforced Concrete Beams Strengthened Using CFRP Sheets with Superior Anchorage Devices written by Mohammed Ameen Zaki and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of carbon fiber reinforced polymer (CFRP) anchors can improve the performance of reinforced concrete (RC) beams strengthened in flexure with CFRP sheets. This improvement results from delaying or controlling the debonding of FRP sheets at failure. In this research, six full-scale T beams and six full-scale rectangular beams are prepared and tested as two separate series. All the specimens are strengthened identically using three layers of unidirectional CFRP sheets and one layer of bidirectional CFRP sheet. The first strengthened beam in each series is anchored with side GFRP bars inserted longitudinally to both sides of the beam. The second strengthened beam in each series is anchored with GFRP patches applied to both sides of the beam. CFRP spike anchors are utilized for the other beams in the two series. The third beam in each series is secured with CFRP spike anchors of 16 mm diameter at 140 mm spacing along the shear span. The fourth strengthened beam in each series is anchored with CFRP spike anchors of 19 mm diameter at 203 mm spacing along the shear span. Four CFRP anchors are applied to each shear span of the fifth beam in each series with 16 mm- diameter (spaced at 406 mm) to secure the flexural CFRP sheets. An end CFRP anchorage technique is considered for the last beam in each series, which includes installing one CFRP spike anchor placed at 76 mm from the free edge of CFRP sheets. The beams were tested under four-point bending until failure and the results for each series are evaluated. In addition, the outcome is compared with other anchorage techniques that have been examined by some researchers utilizing the same beam geometry and properties. The experimental testing and nonlinear analysis showed improvement in the flexural performance of anchored beams compared with those strengthened beams without anchorage. By attaining debonding or rupture failure modes for the T beams and concrete crushing failure mode for the rectangular specimens, the ultimate sectional force capacity is achieved. Accordingly, the results prove that the anchors offer an effective solution against premature debonding failure.

Download or read book Metals Abstracts written by and published by . This book was released on 1998 with total page 1042 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Simulation of Behavior of Composite Grid Reinforced Concrete Beams Using Explicit Finite Element Methods written by Federico A. Tavárez and published by . This book was released on 2001 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Element Analysis of RC Deep Beams with Openings Strengthened by Carbon Fiber Reinforced Polymer CFRP written by Chun Mun Seow and published by . This book was released on 2015 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Strengthening of Reinforced Concrete Structures written by L C Hollaway and published by Elsevier. This book was released on 1999-03-05 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: The in situ rehabilitation or upgrading of reinforced concrete members using bonded steel plates is an effective, convenient and economic method of improving structural performance. However, disadvantages inherent in the use of steel have stimulated research into the possibility of using fibre reinforced polymer (FRP) materials in its place, providing a non-corrosive, more versatile strengthening system.This book presents a detailed study of the flexural strengthening of reinforced and prestressed concrete members using fibre reinforces polymer composite plates. It is based to a large extent on material developed or provided by the consortium which studied the technology of plate bonding to upgrade structural units using carbon fibre / polymer composite materials. The research and trial tests were undertaken as part of the ROBUST project, one of several ventures in the UK Government's DTI-LINK Structural Composites Programme.The book has been designed for practising structural and civil engineers seeking to understand the principles and design technology of plate bonding, and for final year undergraduate and postgraduate engineers studying the principles of highway and bridge engineering and structural engineering. - Detailed study of the flexural strengthening of reinforced and prestressed concrete members using fibre reinforced polymer composites - Contains in-depth case histories

Download or read book Nonlinear Finite Element Analysis of RC T Beam Strengthened in the Negative Moment Region with NSM CFRP Rods and CFRP Sheets Subjected to Monotonic and Low Rate Reverse Cyclic Loading written by and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nonlinear Behavior of Reinforced Concrete Beams by the Finite Element Method written by Alexander Jean Lassker and published by . This book was released on 1972 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design Considerations Based on Size Effects of Anchored Carbon Fiber Reinforced Polymer CFRP Systems written by Douglas Karl Pudleiner and published by . This book was released on 2016 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to their high strength, limited architectural impact, and speed of installation, externally applied carbon fiber reinforced polymer (CFRP) materials are gaining use in infrastructure rehabilitation. To be effective, CFRP materials must be adequately anchored to develop their full capacity. Many anchorage materials and systems have been proposed for CFRP strips and laminates. CFRP spike anchors can develop the full tensile strength of CFRP strips and offer several advantages over other anchorage methods. Namely, they are easy to install, flexible, which allows them to overcome geometric complications, and resilient to environmental and corrosive factors. However, only a limited number of studies have been conducted on CFRP strips anchored using CFRP anchors. These studies identified clear size effects that influence the strength of CFRP anchors and strips. However, past research was conducted on relatively small anchor and strip systems that are on the low end of practical sizes for infrastructure retrofit and repair applications. The objectives of this study were to investigate size effects in anchored CFRP systems and provide design guidelines for CFRP anchors. Twelve tests were conducted on concrete beams reinforced in flexure with anchored CFRP strips up to 10-in. wide. The primary parameters investigated were: width of CFRP strip, number of layers of fabric in CFRP strips, number of anchors per strip width, ratio of anchor to strip cross-sections, anchor fan overlap length, and chamfer radius of the anchor hole. The full distribution of strains at the surface of the anchored CFRP strips was monitored using an optical measurement system. These measurements helped evaluate the effectiveness of various anchor details in distributing strains across strips. The experimental program confirmed the size effects uncovered in previous studies. CFRP anchors were able to fracture CFRP strips at stresses above the expected and design stresses provided by the manufacturer. However, the larger the CFRP strip area developed per anchor, the lower the stress at fracture of that strip. In addition, the anchor-hole chamfer radius was found to influence both anchor strength and the strain distribution in CFRP strips. Guidelines for designing and detailing CFRP anchors are given based on experimental results.

Download or read book Evaluation of the Use of Anchorage Systems for Strengthening Concrete Members Reinforced by Fiber reinforced polymer FRP Laminate written by Mai Abd Alrhman alrhman Aljaberi and published by . This book was released on 2021 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: An anchorage system is the most effective method for preventing or delaying the debonding of fiber-reinforced polymer laminates; however, despite extensive studies, the related design information is still unclear and limits its use. The goal of this research, therefore, is to investigate the parameters that affect the debonding strain of CFRP beams secured with different types of anchors.For this purpose, 34 small-scale beams were tested under four-point loading. Two (2) of them were control beams (no FRP, no anchors), 8 were strengthened with FRP at their tension sides, and the remaining 24 were secured with different types of anchor systems (U-wrap, mechanical, or fan). The parameters examined included the compressive strength of the concrete and the number of longitudinal FRPs. It was concluded that these parameters have a considerable effect on the strength of the beams, as well as on the maximum strain of the FRP. The experimental results were compared to the ACI equation and the previous studies to investigate the efficiency of different types of anchors.

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 Flexural and Long term Behavior of CFRP strengthened Reinforced Concrete Beams written by Mohamed Morsy Abd El-Ghaffar Salem and published by . This book was released on 2012 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Finite Element Analysis of Shear Strength of Reinforced Concrete Beams written by J. Houde and published by . This book was released on 1974 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Temperature on the Adhesive Bonding in Steel Beams Reinforced with CFRP Composites written by Ghayth Hassein Abed and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of carbon fibre reinforced polymer (CFRP) composites in strengthening and repairing steel beams and girders in existing structural bridges has become wide spread in recent years. Though the previous studies had showed significant improvement in the load carrying capacity and the fatigue life of the strengthened structures, they did not take into consideration the effects of extreme summer temperature on the behaviour of the reinforced structure because they were carried out at room temperature. The change of temperature affects the mechanical properties of the adhesive epoxy. Moreover, thermal stresses are induced in the adhesive bond due to the significant difference in the coefficients of thermal expansion between CFRP and steel materials. The main aspects investigated in this thesis are the changes in the adhesive mechanical properties due to the change in the temperature and the impact of these changes on the failure mechanism, the failure load, the fatigue life and the stresses distributions of steel beams strengthened with CFRP plates. In order to achieve the aims of the research, the following procedures are carried out: First, tensile tests on adhesive specimens were carried out at different temperatures to investigate adhesive properties temperature dependency. Second, static tests were conducted on both double-lap shear and three-point bending specimens at temperatures ranging between 20 to 60°C to examine the influence of temperature on the failure mechanism and the failure load. Third, an analytical model was developed to calculate the interfacial stresses in the reinforced beam by approximating the adhesive nonlinear behaviour at elevated temperatures with the elastic perfectly-plastic representation. Fourth, finite element analysis was conducted to validate the analytical results assuming bilinear elastic-plastic adhesive behaviour. Finally, fatigue tests were carried out on both double-lap shear and three-point bending specimens at different load and temperature ranges to identify their fatigue life temperature dependency. Adhesive materials showed significant reduction in the strength and the stiffness coupled with nonlinear behaviour as the temperature reaches the adhesive glass transition temperature (Tg). Thus, the failure load and fatigue life of the strengthened structures were reduced significantly at Tg with a change in the failure mechanism. Both the analytical and finite element results were capable of defining the length of the plastic zone occurring at the plate end due to the high shear stress concentration. The length of the plastic zone depends on several parameters, including the elastic modulus and the thickness of the CFRP plate, the applied load and the temperature. The study of these parameters shows that it is possible to avoid CFRP plate debonding at extreme temperature by using thinner and longer CFRP plates with high modulus instead ultra-high modulus.