Download or read book Behavior of Carbon Fiber Reinforced Polymer Prestressed Box beams Under Shear Load written by Sunup Sam Mathew and published by . This book was released on 2004 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bond Behavior of Carbon Fiber Composite Cables CFCC in Fatigue Flexure and Shear written by Kerolos A. Abdo and published by . This book was released on 2017 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bond between spliced Carbon Fiber Composite Cables (CFCC) and concrete is a critical design parameter that controls the performance of reinforced concrete members at service and ultimate limit states. Bond of spliced bars is dependent on transfer of tensile stress from the spliced reinforcement to the surrounding concrete which is in turn counts on various parameters such as: strand diameter, splice length, and surface configuration. The current design codes for steel reinforcement (ACI 318-14; CSA A23.3-94) are not applicable to FRPs due to the substantial differences in their mechanical properties. However, ACI 440 Committee has developed an equation to estimate the average bond strength for FRP bars from GFRP database that rendered conservative and inconvenient for the CFCC reinforcement. Therefore, more research is required to examine and quantify the average bond strength of the spliced CFCC reinforcement. Three types of bond tests were considered in this investigation; bond fatigue, flexure bond, and shear bond. To determine the CFCC upper value of bond strength, a pullout test was conducted on 29 small-scale specimens according to ACI 440.3R. These specimens consisted of concrete cubes reinforced with a single 0.6 in. (15.2 mm) CFCC strand embedded vertically along the central axis inside concrete. The high values of bond strength exhibited in static pullout tests did not reflect that in structural members where cover splitting or slippage of the strands could govern ultimate failure. For that purpose, and to study the bond strength of CFCC reinforcement, two different test configurations were examined in flexure and shear. In the flexure bond study, ten beams reinforced with two different sizes of CFCC strands of 0.5 in. (12.5 mm) and 0.6 in. (15.2 mm) that were tested under four point loading flexural test setup to failure. The beams were divided into two series, each series consisted of five beam specimens, one beam reinforced with continuous CFCC strands and four beams reinforced with spliced CFCC strands in the constant moment region with splice lengths of 1 ft (305 mm), 2 ft (610 mm), 3 ft (914 mm), and 4 ft. (1219 mm). The shear bond study for CFCC stirrups involved the construction and testing of four prestressed box-beams under shear loading test setup to failure. Further, to assess the performance of CFCC stirrups against that of steel, CFCC stirrups were provided from one beam end and steel stirrups were provided from the other beam end. The shear loading system of the box-beams included loading CFCC reinforced beam ends to failure followed by testing the steel stirrup beam ends under identical shear load configuration.

Download or read book Behavior of Partially Debonded Carbon Fiber Reinforced Polymer Prestressed Beams written by Julia E. Marshall and published by . This book was released on 2001 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Behavior of Concrete Beams with Corroded Reinforcement Retrofitted with Carbon Fiber Reinforced Polymer written by and published by . This book was released on 2016 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Severe premature deterioration has been reported in a large number of reinforced concrete (RC) structures in corrosive environments. This research project focused on the behavior of beams that contained corroded steel and were retrofitted with CFRP. The experimental program included testing five simply supported rectangular cross section concrete beams. The first specimen was a control beam with voids representing deteriorated steel. The second specimen was a plain concrete beam without voids. The third beam was another control specimen with flexural and shear reinforcement intact, representing the "original" beam before steel corrosion. The two remaining deteriorated beams were strengthened by externally bonding one and two layers of CFRP in the longitudinal and transverse directions. Beams were tested under third-point loading. Load carrying capacity, deflection, and ductility of the beams were measured.

Download or read book Concrete Beams Prestressed Using Carbon Fiber Reinforced Polymer written by H. Celik Ozyildirim and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Corrosion of reinforcement in reinforced concrete leads to damage in both the concrete and the reinforcement that requires costly repairs and inconvenience to the traveling public. When concrete is reinforced with steel prestressing strands that are under sustained tensile stress, corrosion is more critical than in non-prestressed concrete with non-prestressed steel reinforcement. Corrosion-free carbon fiber reinforced polymer reinforcement may be used instead of prestressing steel and reinforcing bars to mitigate the corrosion problem in prestressed concrete elements such as beams. The Virginia Department of Transportation (VDOT) placed beams with carbon fiber reinforced polymer reinforcement in a two-span bridge in Halifax County, Virginia. The bridge has two 84-ft spans, continuous for live load, and each span has four 45-in-deep prestressed bulb-T beams. The first two beams were cast using a traditional concrete mixture with conventional slump. The remaining six beams were cast with self-consolidating concrete to facilitate the placement operation. The deck was cast with conventional concrete and corrosion-resistant reinforcing bars. Concrete for both the beams and the deck was tested at the fresh and hardened states. The structure was inspected visually immediately after construction and 8 months and 3.5 years later. The beams were performing well with no deficiencies. The deck was also performing well except that the continuity diaphragm over the pier had several longitudinal cracks. The continuity diaphragm concrete was placed, in accordance with normal VDOT practice, after the deck concrete had been placed on both sides of the pier. Cracks at the deck level in the continuity diaphragms are generally attributed to restrained shrinkage when the diaphragm concrete is placed after the deck concrete. The study recommends that VDOT's Structure and Bridge Division use beams with self-consolidating concrete and carbon fiber reinforced polymer reinforcement as an option in severe environments since the fabrication and constructability challenges described herein were successfully overcome.

Download or read book Fundamental Behavior of Steel Concrete Composite Beams Strengthened with High Modulus Carbon Fiber Reinforced Polymer CFRP Materials written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: There is a growing need for a cost-effective, durable repair system that can be used for the repair and strengthening of steel bridges. Recently, high modulus carbon fiber reinforced polymers (CFRP) have been developed with a modulus of elasticity approximately two times greater than that of steel. Externally bonded high modulus CFRP materials have successfully been used to increase the elastic stiffness and ultimate capacity of steel-concrete composite beams However, since the technology is relatively new, the detailed behavior of steel bridge members strengthened with high modulus CFRP is not yet well understood. The current research investigates three aspects of the behavior of steel-concrete composite beams in detail. An experimental program was conducted to investigate the behavior of steel-concrete composite beams strengthened with high modulus CFRP materials. In the first phase of the study the behavior under overloading conditions was investigated. In the second phase of the research, the fatigue durability of the system was examined. In the third phase, the possible presence of shear-lag between the steel beam and the CFRP materials was investigated in detail. An analytical model was developed which can be used to determine the ultimate capacity and elastic stiffness increase for steel beams strengthened with high modulus CFRP materials. Additionally, a set of criteria are proposed which can be used to determine the allowable increase in the live load level for steel beams strengthened with high modulus CFRP materials.

Download or read book Behavior of Carbon Fiber Composite Tendon Prestressed Concrete Planks Under Static and Fatigue Loading written by Lei Zhao and published by . This book was released on 1994 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Long term and Fatigue Behaviour of Carbon Fibre Reinforced Polymer Prestressed Concrete Beams written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Shear Behavior of Prestressed Concrete Box beams Reinforced with CFRP Stirrups written by Omkar D. Karekar and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book FRP Composites in Civil Engineering CICE 2004 written by R. Seracino and published by CRC Press. This book was released on 2004-12-15 with total page 1005 pages. Available in PDF, EPUB and Kindle. Book excerpt: The range of fibre-reinforced polymer (FRP) applications in new construction, and in the retrofitting of existing civil engineering infrastructure, is continuing to grow worldwide. Furthermore, this progress is being matched by advancing research into all aspects of analysis and design. The Second International Conference on FRP Composites in

Download or read book Building Code Requirements for Structural Concrete ACI 318M 08 and Commentary written by American Concrete Institute and published by . This book was released on 2008 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pretensioned Box Beams written by Alejandro Raul Avendaño Valderrama and published by . This book was released on 2011 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pretensioned concrete box beams have been used in highway bridges for more than half a century. Due to their geometry, they have often been used as a viable alternative to the classic I-shaped girders. Box beams are highly effective in cases where speed of construction is a priority. However, the detailing and design of box beams are more complicated than that of I-shaped girders. The flow of forces at the beam's end blocks must be understood in order to detail reinforcement adequately. The following were the objectives of this research study: (i) quantify the demands placed on box beam end blocks upon prestress transfer, (ii) characterize the demands placed on box beam end blocks upon the application of superimposed loads, (iii) evaluate the effects of alternative void geometries at skewed ends of box beams on curing temperatures, (iv) based on the knowledge gained in (i), (ii) and (iii), improve the box beam end blocks, (v) test the improved end block under worst case scenario demands at prestress transfer and under extreme loading conditions, and (vi) validate currently used shear strength design methodologies in their application to pretensioned box beams. In order to achieve these objectives, an experimental program was conducted. The experimental program included the load testing of ten 4B28 and five 5B40 box beams, for a total of twenty nine load tests. The influence of several factors that distinguish box beam behavior from the better-understood I-shaped girder behavior was studied. Additionally, the experimental program included the fabrication, instrumentation and early-age behavior study of five 5B40 box beams. The first three beams were used to vii assess the behavior of box beams fabricated with the current TxDOT standard details (from December 2006). The fourth beam incorporated modifications to the standard reinforcement details based on the observations made through the study of the first three 5B40 box beams. The last specimen corresponded to a new box beam cross section (5XB40) optimized to be used in a spread-box beams configuration.

Download or read book FRP Composites for Reinforced and Prestressed Concrete Structures written by Perumalsamy Balaguru and published by CRC Press. This book was released on 2008-11-05 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: High strength fibre composites (FRPs) have been used with civil structures since the 1980s, mostly in the repair, strengthening and retrofitting of concrete structures. This has attracted considerable research, and the industry has expanded exponentially in the last decade. Design guidelines have been developed by professional organizations in a nu

Download or read book Shear Strengthening of RC Deep Beams with Large Openings Using Carbon Fiber Reinforced Polymers CFRP written by Foo Sheng Tong and published by . This book was released on 2015 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research deals with the experimental study of the behaviour of reinforced concrete deep beams with or without large rectangular openings as well as openings strengthened using externally bonded Carbon Fiber Reinforced Polymer (CFRP) composites in shear. The structural behaviour, including the load deflection, cracking patterns, failure mode, and effectiveness of the CFRP wraps were investigated. A total of four (4) specimens of beams with compressive strength of 35 MPa were tested to induce shear failure under 4 points loading test, which included one solid deep beam acted as a control beam (CB), one of which was tested without strengthening (US-BRO), and the remaining beams were strengthened with CFRP wraps in varying configurations around the opening (S-BRO-1, S-BRO-2). The beam had a cross section of 120 mm in width and 600 mm in depth as well as a length of 2400 mm. All the test specimens had a same geometry, main reinforcement arrangements and openings location. All the preparatory works of specimen materials were conducted in Laboratory FKASA. The examined parameter was the effect of configurations of the CFRP wraps used for the shear strengthening. The inclusion of un-strengthened large rectangular openings in the shear zone of a reinforced concrete deep beam leads to a reduction of ultimate beam strength by approximately 70%. The application of CFRP wraps with the presented strengthening configurations restricted the propagation of the diagonal crack and effectively increases ultimate load-carrying capacity as well as the ductility of the beam. The strength re-gains by U-shaped strengthening configuration around the openings was approximately 36% as compared to the beam with un-strengthened openings. However, the deep beam with U-shaped CFRP with horizontal fiber strengthened at the top and bottom chords of the openings were not capable to restore the control beam's original structural strength remarkably. The beam only managed to re-gain about 41% of the control beam's capacity.

Download or read book Fundamental Behavior of Steel concrete Composite Beams Strengthened with High Modulus Carbon Fiber Reinforced Polymer CFRP Materials written by Mina Magdy Riad Dawood and published by . This book was released on 2005 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: High Modulus CFRP, Steel-Concrete Composite Beams, Overloading, Fatigue, Shear-lag, Moment-Curvature Analysis.

Download or read book The Shear Behavior of Concrete Beams Reinforced with Continuous Carbon Fiber Fabric written by Kristina Marie Hanes and published by . This book was released on 1992 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Carbon Fiber Reinforced Polymer Grids for Shear and End Zone Reinforcement in Bridge Beams written by John Ward and published by . This book was released on 2018 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: Corrosion of reinforcing steel reduces life spans of bridges throughout the United States; therefore, using non-corroding carbon fiber reinforced polymer (CFRP) reinforcement is seen as a way to increase service life. The use of CFRP as the flexural reinforcement in bridge girders has been extensively studied. However, CFRP transverse reinforcement has not been investigated as rigorously, and many of those studies have focused on carbon fiber composite cable (CFCC) stirrups. The use of C-Grid or NEFMAC grid as options for transverse reinforcing has not been previously investigated. This testing program first determined the mechanical properties of C-Grid and NEFMAC grid and their respective development lengths. Five 18-ft long, 19-in deep beams were fabricated to test the C-Grid and NEFMAC, as well as conventional steel and CFCC stirrups. The beams were loaded with a single point load closer to one end of the beam to create a larger shear load for a given moment. Overall beam displacement was measured, and beams were fitted with rosettes and instrumentation to capture initiation of shear cracking. Test results were compared to theoretical shear capacities calculated using four different methods. The design method which provided the best prediction of shear strength was the AASHTO modified compression field theory, using equations for beta and theta. The manufacturer’s guaranteed tensile strength should be used for design, as long as that strength is the average strength, as determined by at least five tests, reduced by three standard deviations. Shear cracks were controlled to a similar width as in beams with steel stirrups when at least two layers of grid were in place. An additional study was undertaken to determine if CFRP grids, either alone or in combination with traditional steel stirrups, could be used to control cracking in the end zones of pretensioned I-beams. Unfortunately, it was determined that, due to its low modulus, the amount of CFRP grid required to control cracking in the end zones was not economically feasible. Nevertheless, this study concluded that C-Grid and NEFMAC grid are both viable shear reinforcement options outside of the end regions. This report presents the initial recommendations for design.