Journal articles: 'Prestressed concrete beams Prestressed concrete beams Flexure'

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Li, Feng Ge, and Rong Li. "Theoretical Analysis of Natural Vibration Frequency for Unbonded Prestressed Concrete Beams." Advanced Materials Research 594-597 (November 2012): 882–85. http://dx.doi.org/10.4028/www.scientific.net/amr.594-597.882.

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This papers deals with the study of the influence of prestress force on the natural frequencies for unbonded prestressed concrete beams. A total of 5 unbounded prestressed concrete simply support beams were constructed and tested. The test results show that the prestress force has little effect on the nature frequencies of unbonded prestressed concrete beams. A model of variable stiffness is proposed to calculate the natural frequencies of prestressed concrete beams with unbonded tendons, which assumed that the flexural rigidity of the beam is changing when beams vibrating. The calculate results show that the calculation results by the proposed model agree well with experimental ones.

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Wang, Bo, and Guang Xin Men. "Study of Flexural Property of Prestressed Carbonfiber-Reinforced Plastics (CFRP) Reinforced Concrete Beams." Applied Mechanics and Materials 351-352 (August 2013): 1503–8. http://dx.doi.org/10.4028/www.scientific.net/amm.351-352.1503.

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To study the effect of prestress level on beam for its flexural property, through comparing of the stress property of non-reinforced beam, non-prestressed fiber beam, and prestressed fiber beam. The experimental results show that non-prestressed fiber makes little difference in improving beams flexural property, while prestressed fiber has improved beams cracking load, yield load, bending rigidity greatly.

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Liang, Jiong Feng, Jian Bao Wang, and Jian Ping Li. "Experimental Research on Bending Performance of Concrete Beams Reinforced with CFRP-PCPs Composite Rebars." Applied Mechanics and Materials 438-439 (October 2013): 804–6. http://dx.doi.org/10.4028/www.scientific.net/amm.438-439.804.

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The flexural behavior of concrete beams reinforced with CFRP-PCPs composite rebars was studied. Experimental results showed that the deflection of beams reinforced with highly prestressed prisms is at service loads coMParable to deflection of steel reinforced beam. Flexural cracks of CFRP-PCPs composite rebars reinforced beams are hairline before prism cracking, and widened after the prism cracking. When the concrete beam was reinforced with the prestressed concrete prisms, the crack width decreased as the prestress in the prism increased.

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Badawy, Amr H., Ahmed Hassan, Hala El-Kady, and L. M. Abd-El Hafez. "The Behavior of Reinforced and Pre-Stressed Concrete Beams under Elevated Temperature." International Journal of Engineering Research in Africa 47 (March 2020): 15–30. http://dx.doi.org/10.4028/www.scientific.net/jera.47.15.

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The behavior of unbounded post tension and reinforced concrete beams under elevated temperature was presented. The experimental work was consisted of two major phases. In the first phase, the objective was studying the mechanical performance of prestressed beam, prestressed beam with steel addition and reinforced concrete beams respectively were studied. In the second phase, the residual mechanical performance of prestressed beam, prestressed beam with steel addition and reinforced concrete beams under elevated 400oC, for 120 minutes durations. The failure mechanisms, ultimate load capacity, and deflection at critical sections were monitored. The numerical prediction of the flexural behavior of the tested specimens is presented in this paper. This includes a comparison between the numerical and experimental test results according to ANSYS models. The results indicate that the prestressed beam with steel addition and reinforced concrete beams had higher resistance to beams under elevated 400oC than that of prestressed concrete beam in terms of ultimate capacity. It is also shown that the reinforced concrete beams have higher resistance to beams under elevated temperature than that of prestressed beam, prestressed beam with steel addition.

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Kim, Yail J., Mark F. Green, and R. Gordon Wight. "Flexural behaviour of reinforced or prestressed concrete beams including strengthening with prestressed carbon fibre reinforced polymer sheets: application of a fracture mechanics approach." Canadian Journal of Civil Engineering 34, no. 5 (May 1, 2007): 664–77. http://dx.doi.org/10.1139/l06-161.

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This paper describes the application of a fracture mechanics model (Hillerborg 1990) to concrete structures, including strengthening with prestressed carbon fibre reinforced polymer (CFRP) sheets. One benefit of the proposed fracture mechanics model, consisting of a unique combined stress–strain response of concrete, is that it includes the size effect of reinforced concrete beams; however, its application and validation have not been fully investigated. The proposed model is reviewed and further developed to cover prestressed concrete beams including a beam strengthened with a prestressed CFRP sheet. To evaluate the model, various approaches such as finite element analysis, a strength-based model, a conventional design method, and experimental results are compared with the fracture mechanics model. The size-dependent parameter (ε1) significantly affects the predicted behaviour of reinforced or prestressed concrete beams, depending on the contribution of reinforcement. Based on the current assessment, ε1 = 0.005 is recommended as an upper limit for normal strength concrete.Key words: carbon fibre reinforced polymer sheet, flexure, fracture mechanics, prestressed concrete beam, reinforced concrete beam, strengthening, size effect.

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Deng, Lang Ni, Peng Zhang, and Hua Chen. "Flexural Behaviour of RC Beams Strengthened with Prestressed CFRP Plates：Comparisons of Bonded and Unbonded Method." Key Engineering Materials 480-481 (June 2011): 283–87. http://dx.doi.org/10.4028/www.scientific.net/kem.480-481.283.

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In this study, a total of 5 CFRP-strengthened reinforced concrete beams were tested in flexure based on the independent development prestressing anchorage system. The various variables included bonding or no bonding of the CFRP and the amount of prestressing. The experiments consisted of one control beam, two prestressed CFRP-unbonded beams, and two prestressed CFRP-bonded beams, all the beams were subjected to four-point bending tests. The ultimate load, deformation, and CFRP strain were examined. The aim of this investigation was to study the flexural performance of reinforced concrete members strengthened using CFRP plates, employing different CFRP bonding and prestressing methods. The failure mode of the prestressed CFRP-plated beams was not debonding, but concrete crushing or FRP rupture. For the reinforced concrete members strengthened with externally bonded prestressed CFRP plates, after the debonding of the CFRP plates that occurred in the bonded cases, the behaviour of the bonded CFRP-plated beams changed to that of the unbonded CFRP-plated beams due to the effect of the anchorage system. The ductility indices of the beams in an unbonded system were less than that of those in a bonded system.

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Cai, Jiang Yong, Zhi Feng Tu, Su Min Gong, and Li Zhuang. "Evaluation of Flexural Performance for Prestressed Concrete Beams with FRP Tendons." Advanced Materials Research 383-390 (November 2011): 3128–33. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.3128.

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Prestressed concrete beams with vertically distributed FRP tendons possess some flexural performance obviously different from prestressed concrete beams with steel tendons. This paper provides a complete theoretical approach to analyze and evaluate the flexural behavior of prestressed concrete beams with FRP tendons. Calculation and analysis results show that a prestressed concrete beam with FRP tendons designed at balanced ratio reaches the maximum of its deformability. The increase of prestressing ratio and number of reinforcement layer will increase, respectively, its moment capacity but simultaneously decrease its deformability.

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Yu, Jian Jun, and Lian Guang Wang. "Nonlinear Analysis of Prestressed Cold-Formed U-Shaped Steel and Concrete Composite Beams." Advanced Materials Research 594-597 (November 2012): 749–52. http://dx.doi.org/10.4028/www.scientific.net/amr.594-597.749.

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Cold-formed U-shaped steel and concrete composite beam is a kind of composite beam which the steel and the concrete are integrated by welding connections on the cold-formed U-shaped steel and then pouring concrete on the steel. Now, many experts and scholars have carried out many experimental research and theoretical analysis about it. But, prestressed Cold-formed U-shaped steel and concrete composite beams have not been studied. Based on the structure , the nonlinear analysis mode of prestressed cold-formed U-shaped steel and concrete composite beams is proposed, the calculating program is researched. The calculating results show that the bearing capacity of composite beam increases with the increments of thickness of steel plate and concrete strength, and the thickness of steel plate has a larger effect than the width of the flange plate of concrete, applying prestress can enhance the bearing capacity and flexural rigidity of the composite beam.

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Shen, Jie, Ismail Yurtdas, Cheikhna Diagana, and Alex Li. "Influence of Compressive Strength of Self-Compacting Concrete on Shear Behavior of Prestressed RC Beams." Applied Mechanics and Materials 147 (December 2011): 14–18. http://dx.doi.org/10.4028/www.scientific.net/amm.147.14.

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The shear behavior of prestressed self-compacting concrete (SCC) beams has been investigated in this study. The effect of compressive strength of SCC on the shear strength has been taken into account in test program. Based on the experimental data, the failure mechanism of the prestressed SCC beams was discussed and the shear transfer mechanism of the RC beam after the flexure-shear cracking was also analyzed.

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Yang, Jun, Tong Guo, and Aiqun Li. "Experimental investigation on long-term behavior of prestressed concrete beams under coupled effect of sustained load and corrosion." Advances in Structural Engineering 23, no. 12 (May 11, 2020): 2587–96. http://dx.doi.org/10.1177/1369433220919067.

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Prestressed concrete beams are widely used in construction, while they may be attacked by the corrosion medium during the service. Past research works show that coupled effect of high stress and corrosion can significantly deteriorate the performance of prestressed concrete structures. This article presents an experimental investigation on long-term behavior of prestressed concrete beams under the coupled effect of sustained load and corrosion. During the accelerated corrosion process, six prestressed concrete beams were subjected to different levels of sustained loads, and time-dependent prestress loss and concrete stains were recorded and analyzed. It is observed that the local corrosion (i.e. pitting corrosion) of the steel strands was significantly affected by the sustained load level, and the coupled effect led to more serious damage on the beams than individual sustained load or corrosion. Bending loads were finally applied to investigate the influence of corrosion on flexural capacities of these beams. It was found that the flexural capacities and failure mode of the beams were significantly influenced by corrosion. Meanwhile, the corrosion has more significant effect on tension strength of strands rather than bond strength.

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Chen, Hua, Kan Kang, and Lang Ni Deng. "Construction Technology Research of RC Beams Strengthened with Prestressed CFRP Plates." Advanced Materials Research 268-270 (July 2011): 659–63. http://dx.doi.org/10.4028/www.scientific.net/amr.268-270.659.

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The method of applying prestress to CFRP plates can make full use of the characteristics of high-strength, enhance the force properties, prevent peeling damage and reduce the strain lag. Construction technology of prestressed CFRP plates strengthening reinforcement concrete beams was introduce in this paper, and bending test of 6 reinforcement concrete beams strengthened with prestressed CFRP plates were carried out based on the self-developed prestressed CFRP plates supporting anchorages. The test results indicate that the flexural capacity and crack resistance capacity can be increased compared with non-prestressed CFRP plates, and the construction technology can be adopted in practical projects.

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Bonopera, Marco, Kuo-Chun Chang, Chun-Chung Chen, Yu-Chi Sung, and Nerio Tullini. "Feasibility Study of Prestress Force Prediction for Concrete Beams Using Second-Order Deflections." International Journal of Structural Stability and Dynamics 18, no. 10 (October 2018): 1850124. http://dx.doi.org/10.1142/s0219455418501249.

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The safety and sustainability of prestressed concrete bridges can be improved with accurate prestress loss prediction. Considerable loss of the prestress force may imply damages hidden in the bridge. In this study, a prestress force identification method was implemented for concrete beams. Based on the Euler–Bernoulli beam theory, the procedure estimates the prestress force by using one or a set of static displacements measured along the member axis. The implementation of this procedure requires information regarding the flexural rigidity of the beam. The deflected shape of a post-tensioned concrete beam, subjected to an additional vertical load, was measured in a short term in several laboratory experiments. The accuracy of the deflection measurements provided favorable prestress force estimates. In particular, the “compression-softening” theory was validated for uncracked post-tensioned concrete beams.

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Du, Xiu Li, Zuo Hu Wang, and Jing Bo Liu. "Flexural Capacity of Concrete Beams Prestressed with Carbon Fiber Reinforced Polymer (CFRP) Tendons." Advanced Materials Research 168-170 (December 2010): 1353–62. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.1353.

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Fiber reinforced polymer (FRP), particularly those incorporating carbon fiber (CFRP), has high strength, high stiffness-to-weight ratio and high resistance to corrosion, which shows potential for use as prestressing tendons in corrosive environment. However, concrete beams prestressed with FRP tendons have showed brittle flexural failure due to the elastic rupture of FRP tendons. In order to improve the ductility, a combination of bonded and/or unbonded prestressing tendons was used. Nine prestressed concrete beams were tested up to failure to study the effect of bonded and unbonded FRP tendons on their flexural capacity. Three factors were taken into consideration; the bonding condition of CFRP tendons, the location of CFRP tendons and the prestressing ratio. Also an analytical investigation was carried out to extend some flexural capacity calculation equations to this beam type. The results of the experimental showed that under the same condition, the carrying capacity of concrete beam prestressed with bonded FRP tendons was 20% higher than that of internal unbonded prestressed beam, and was 40% higher than that of external unbonded prestressed beam without deviators. By combination of bonded and unbonded FRP tendons, the ductility of prestressed concrete beams can be improved.

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El-Hacha, Raafat, Mark F. Green, and R. Gordon Wight. "Flexural behaviour of concrete beams strengthened with prestressed carbon fibre reinforced polymer sheets subjected to sustained loading and low temperature." Canadian Journal of Civil Engineering 31, no. 2 (February 1, 2004): 239–52. http://dx.doi.org/10.1139/l03-091.

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This paper presents results of an experimental investigation that examined concrete beams post-tensioned with bonded carbon fibre reinforced polymer (CFRP) sheets and then exposed to either room (+22 °C) or low (-28 °C) temperatures. The primary objective of this investigation was to assess the flexural behaviour of the strengthened beams after sustained loadings at both room and low temperatures. The strengthened beams showed significant increases in flexural stiffness and ultimate capacity as compared with the control-unstrengthened beams. Failure of the strengthened beams was by tensile rupture of the prestressed CFRP sheets. Test results showed that the long-term and low temperature effects did not adversely affect the strength of the beams. Long-term loading and low temperature exposure caused prestress losses in the CFRP sheets. The loaddeflection behaviour of the long-term beams was predicted accurately by an analytical model. These results suggest that bonded prestressed CFRP sheets could be used to increase the strength of damaged prestressed concrete girders under extreme environmental conditions.Key words: strengthening, anchorage, low temperature, long-term, prestress losses, sustained load, carbon fibre reinforced polymer sheet.

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Jeon, Chi-Ho, and Chang-Su Shim. "Flexural Behavior of Post-Tensioned Concrete Beams with Multiple Internal Corroded Strands." Applied Sciences 10, no. 22 (November 11, 2020): 7994. http://dx.doi.org/10.3390/app10227994.

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The corrosion of prestressing steel in prestressed concrete bridges is a critical safety issue. To evaluate the strength of a prestressed concrete beam with corroded strands, it is necessary to know the mechanical properties of the corroded strands in terms of their tensile strength and ductility. In this study, material models were suggested using tensile tests of corroded strands which had been taken from existing bridges. Five prestressed concrete beams with multiple internal corroded strands of different corrosion levels and locations were fabricated and tested using the three-point bending test. The beams with corroded strands near the support did not show meaningful flexural behavior changes, while the beams with corrosion in the mid-span showed significant strength reduction. In order to suggest the appropriate evaluation of the flexural strength of a prestressed concrete beam with corroded strands, material models of the corroded strands were divided into two model categories: a bi-linear material model and a brittle material model. Strength evaluations of the corroded prestressed concrete beams according to fps approximation and strain-compatibility using OpenSEES were conducted. Results suggested the use of the strain compatibility method only when the section loss was greater than 5%.

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Yang, Jian, and Zhi Fang. "Behavior of Prestressed Ultra High Performance Concrete Beams." Key Engineering Materials 400-402 (October 2008): 385–90. http://dx.doi.org/10.4028/www.scientific.net/kem.400-402.385.

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An experimental program was formulated to investigate the characteristics of complete stress-strain curve of UHPC in uniaxial compression and flexural behaviors of prestressed UHPC beams. The particular focus was the influence of the partial prestress ratio and jacking stress on the flexural response of UHPC beams. The tests of beams demonstrated that the UHPC beams have an excellent behavior in load carrying capacity, crack distribution and deformability; their ultimate deflection can reach 1/34～1/42 of the span. Based on this investigation, theoretical correlations for the prediction structure response of UHPC beams are proposed.

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Ding, Ya Hong, and Yan Jie Ma. "Reseach on Flexural Behavior of Reinforced Concrete Beams Strengthened with Prestressed Near Surface Mounted CFRP Tendons." Advanced Materials Research 163-167 (December 2010): 3537–44. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.3537.

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The effectiveness of strengthening reinforced concrete (RC) beams with prestressed near- surface mounted (NSM) carbon fiber reinforced polymer (CFRP) rods has been investigated. The RC beams are tested under monotonic loading. The stressing process, failure capacity, flexural capaticy, displacement ductility and deformation are systematically studied. The text results show that the new strengthening technique with prestressed NSM CFRP rods can enhance the first-crack load, steel-yielding load of beams compared to the control beam. It is worth noting that the prestress can limit the crack width all the way up to failure, reduce the midpoint deflection, and improve the service performance of the strengthened beams. The strengthening method offers an alternative way to existing strengthening method. The results provide a reference for engineering application.

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Meng, Gang, Li Hua Zhang, and Jin Qing Jia. "Numerical Analysis on Flexural Capacity of Prestressed Steel Reinforced Ultra-High Strength Concrete Beams." Key Engineering Materials 531-532 (December 2012): 429–34. http://dx.doi.org/10.4028/www.scientific.net/kem.531-532.429.

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As a new type of composite structural system, the prestressed steel reinforced ultra-high strength concrete (PSRUHC) beam was applicable to large-span structures and those structures which must bearing heavy loading. But by now there is no mature calculation method for the beam with a good accuracy. So the experiment on eight post-tensioned bonded prestressed steel reinforced ultra-high strength concrete beams had been carried out to investigate the flexural performance of PSRUHC beams. Based on the test results, the flexural capacity of PSRUHC beams were analysed by the large general-purpose finite element program ANSYS. Compared the simulation results of cracking load, ultimate load, yielding load and load-displacement curve with the test results, it is proved that the numerical method is effective for analyzing flexural capacity of prestressed steel reinforced ultra-high strength concrete beams, which provides theoretical foundation for practical application of PSRUHC beam.

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Yang, Jian, Zhi Fang, and Gong Lian Dai. "Flexural Behavior of Prestressed UHPC Beams." Advanced Materials Research 243-249 (May 2011): 1145–55. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.1145.

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Ultra High Performance Concrete (UHPC), which has very special properties that are remarkably different to the properties of normal and high performance concrete, is being increasingly used for the construction of structure. In this paper, an experimental program was formulated to investigate the characteristics of complete stress-strain curve of UHPC in uniaxial compression and flexural behaviors of prestressed UHPC beams. The particular focus was the influence of the partial prestress ratio and jacking stress on the flexural response of UHPC beams. The results show that UHPC is of good deformability, and a general form of the serpentine curve is proposed to represent the complete stress-strain relationship of UHPC in compression. The tests of beams demonstrated that the UHPC beams have an excellent behavior in load carrying capacity, crack distribution and deformability, their ultimate deflection can reach 1/34～1/70 of the span. Based on this investigation, theoretical correlations for the prediction structure response of UHPC beam are proposed.

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Zhang, Guanhua, Jiawei Wang, Jinliang Liu, Yanmin Jia, and Jigang Han. "Analysis of loss in flexural stiffness of in-service prestressed hollow plate beam." International Journal of Structural Integrity 10, no. 4 (August 12, 2019): 534–47. http://dx.doi.org/10.1108/ijsi-09-2018-0055.

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Purpose During service, cracks are caused in prestressed concrete beams owing to overload or other non-load factors. These cracks significantly affect the safety of bridge structures. The purpose of this paper is to carry out a non-linear iterative calculation for a section of a prestressed concrete beam and obtain the change in stiffness after the section cracks. Design/methodology/approach The existing stress of prestressed reinforcement was measured by performing a boring stress release test on two pieces of an in-service 16 m prestressed concrete hollow plate. Considering the non-linear effects of materials, the calculation model of the loss in the flexural stiffness of the prestressed concrete beam was established based on the existing prestress. The accuracy of the non-linear calculation method and the results obtained for the section were verified by conducting a bending destruction test on two pieces of the 16 m prestressed concrete hollow plate in the same batch and by utilising the measured strain and displacement data on the concrete at the top edge of the midspan section under all load levels. Findings The flexural stiffness of the section decreases rapidly at first and then gradually, and structural rigidity is sensitive to the initial cracking of the beam. The method for calculating the loss in the flexural stiffness of the section established with the existing stress of prestressed reinforcement as a parameter is accurate and feasible. It realizes the possibility of assessing the loss in the rigidity of a prestressed concrete structure by adopting the existing stress of prestressed reinforcement as a parameter. Originality/value A method for quickly determining the loss in the stiffness of structures using existing prestress is established. By employing this method, engineers can rapidly determine whether a bridge is dangerous or not without performing a loading test. Thus, this method not only ensures the safety of human life, but also reduces the cost of testing.

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Li, Hong Fang, Chang Gong, and Zhi Fang. "Behaviors of Concrete Beam Prestressed with External CFRP Tendons." Key Engineering Materials 400-402 (October 2008): 559–66. http://dx.doi.org/10.4028/www.scientific.net/kem.400-402.559.

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The purpose of present paper is to study the flexural behaviors of concrete T-beams prestressed with external carbon fiber reinforced polymer(CFRP) tendons. Tests were carried out on 5 beams under four-point load, of which four beams were reinforced with hybrid both external CFRP tendons and internal steel rebars and another one only reinforced with internal steel rebars. Such parameters as the different initial loading states at external CFRP tendon jacking and different jacking stress in tendon were considered in experiment. A program was developed to predict the behaviors of those beams prestressed with externally prestressed tendons and the parametric study was conducted using the program. The predicted results from the program were in good agreement with the test results. Such parameters as jacking stress, elastic modulus of external tendons, configuration of deviators and ratio of span to effective depth of beam were chosen as primary analytical factors for the study on the flexural behaviors of beams prestressed with external tendons. The initial loading state on the beam before tendon jacking has no significant influence on the ultimate loading capacity and deflection.

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Li, Qian Qian, Li Xin Liu, and Sheng Dong He. "Experimental Study on Fatigue Behavior of Prestressed Concrete Beams with Manufactured Sand." Key Engineering Materials 517 (June 2012): 595–600. http://dx.doi.org/10.4028/www.scientific.net/kem.517.595.

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This paper presents the test results of 2 prestressed concrete beams with manufactured sand under cyclic loading, the concrete is made of manufactured sand to replace natural sand with different replacement rates of 50% and 100%. The stress of re-bars and prestressed strands and the strain of manufactured sand concrete are discussed, the rigidity and cracking of the prestressed beams under cyclic loading are analyzed, and the flexural behavior of the beams after 2.5 million times cyclic loading are also discussed and analyzed. The results show that the fatigue behavior of the prestressed concrete beams with manufactured sand to replace the natural sand under cyclic loading is satisfied, the flexural bearing capacity of the prestressed beams after 2.5 million times cyclic loading is still sufficient. The results also show that the crack width and the mid-span deflection of the prestressed beams are in the allowable range at the serviceability limit state. This may be regarded as a reference for the applications of manufactured sand in the prestressed concrete structure .

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Xu, Ping, Min Xia Zhang, Ya Hong Ding, and Xing Guo Wang. "Experimental Research on Flexural Behavior of Load-Bearing Characteristics on Reinfoeced Concrete Beams Strengthened with near Surface Mounted Prestressed CFRP Tendons." Applied Mechanics and Materials 94-96 (September 2011): 1415–19. http://dx.doi.org/10.4028/www.scientific.net/amm.94-96.1415.

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In order to improve flexural behavior of concrete beams, the 7mm-diameter carbon fiber reinforced plastic (CFRP) tendons applied different levels of prestress were put in to 20×20mm grooves opened in the concrete surface of the tensile region in the concrete beams.Grooves were filled with building structural adhesive, when it solidified bending test of strengthened beams would carry out. Flexural behavior of nine RC beams strengthened with prestressed near surface mounted CFRP tendons applied different levels of prestress and one unstrengthened RC beam were studied. In these tests, bending stiffness and load-bearing characteristics of test specimens were studied. Experimental results show that the high-strength performance of CFRP have been made full use; the stiffness of strengthened beams risen notably, the maximal crack load increased by 303.17%, the maximal ultimate load increased by 237.92%.

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Yao, Guo Wen, Yan Li Wei, and Shi Ya Li. "Experimental Research on the Flexural Performance of the Strengthened Concrete Beams with Prestressed CFRP." Advanced Materials Research 255-260 (May 2011): 105–8. http://dx.doi.org/10.4028/www.scientific.net/amr.255-260.105.

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Three-bending experiments were performed on RC beams strengthened with prestressed CFRP under static and cycle loading. Prestressed CFRP obviously increases the load-carrying capacity and fatigue life of strengthened RC beam. And it greatly increases the flexural stiffness of strengthened beam. The failure modes of the beams go through concrete cracking, CFRP debonding from concrete and beam fractured. The vertical flexibility history at midspan is decomposed into three stages. And then fatigue damage is defined by flexural stiffness and its evolvement shows three stages of nucleation, growth and mutation.

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Bryan, Paul E., and Mark F. Green. "Low temperature behaviour of CFRP prestressed concrete beams." Canadian Journal of Civil Engineering 23, no. 2 (April 1, 1996): 464–70. http://dx.doi.org/10.1139/l96-050.

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The corrosion of steel prestressing tendons exposed to deicing salts is increasingly becoming a significant problem in Canada. New fibre reinforced plastic (FRP) materials with high strength-to-weight ratios and noncorrosive characteristics are strong alternatives to solve this problem. Carbon fibre reinforced plastic (CFRP) is one of the most promising among available FRPs. Nevertheless, for CFRP rods to gain acceptance in Canada and other cold regions, their behaviour at low temperatures must be investigated. This paper describes an investigation of the feasibility of using CFRP LEADLINE rods to prestress concrete beams. The results of an experimental program on the short-term behaviour of CFRP prestressed concrete beams at low temperature (−27 °C) are discussed. A simple analytical model is used to predict the flexural response of CFRP beams at low temperature. The experimental results agree well with the analytical predictions. The behaviour of the CFRP tendons is shown to be unaffected by short-term exposure to this low temperature. Key words: carbon fibre, fibre reinforced plastic (FRP), advanced composite materials, prestressed concrete, low temperature, cold regions.

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Atutis, Mantas. "CALCULATING THE CARRYING CAPACITY OF FLEXURAL PRESTRESSED CONCRETE BEAMS WITH NON-METALLIC REINFORCEMENT." Mokslas - Lietuvos ateitis 2, no. 6 (December 31, 2010): 5–13. http://dx.doi.org/10.3846/mla.2010.104.

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The article reviews moment resistance design methods of prestressed concrete beams with fibre-reinforced polymer (FRP) reinforcement. FRP tendons exhibit linear elastic response to rupture without yielding and thus failure is expected to be brittle. The structural behaviour of beams prestressed with FRP tendons is different from beams with traditional steel reinforcement. Depending on the reinforcement ratio, the flexural behaviour of the beam can be divided into several groups. The numerical results show that depending on the nature of the element failure, moment resistance calculation results are different by using reviewed methods. It was found, that the use of non-metallic reinforcement in prestressed concrete structures is effective: moment capacity is about 5% higher than that of the beams with conventional steel reinforcement.

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Zhou, An. "Flexural Stiffness of Steel-Prestressed Concrete Composite Beam." Key Engineering Materials 400-402 (October 2008): 843–48. http://dx.doi.org/10.4028/www.scientific.net/kem.400-402.843.

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For continuous composite beams that in normal working stage, due to concrete cracks at negative moment region are restricted by transverse tendon reinforcements at the slab, it would be reasonable to consider concrete contribution to the bending capacity of such composite beams. Based on this, a variable stiffness method is proposed in this paper to calculate the composite beam deflection. Before concrete slab cracks, the flexural stiffness (the maximum value) is calculated according to the reduced transformed beam section, with the consideration of concrete contribution; After concrete cracks, this stiffness value will be decreased as per the increase of the concrete crack, and at final stage, when concrete contribution to the flexural stiffness reach zero, the stiffness value reach it’s minimum value. The loads capacity at such maximum and minimum stiffness values could be considered as the beam capacity before concrete cracking as per current code, and the elastic moment capacity after concrete cracking respectively, while the stiffness between these maximum and minimum values could be determined by linear interpolation. The bending stiffness derived from this method has a higher precision than the method presented in current China specification in which the concrete contribution is totally neglected. Especially, this procedure would be more useful for those prestressed concrete composite beams, as they have higher crack- resistance capability.

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Oh, Jae Yuel, Deuck Hang Lee, Sang Hum Cho, Hyun Kang, Hae-Chang Cho, and Kang Su Kim. "Flexural Behavior of Prestressed Steel-Concrete Composite Members with Discontinuous Webs." Advances in Materials Science and Engineering 2015 (2015): 1–13. http://dx.doi.org/10.1155/2015/278293.

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The corrugated webbed prestressed (CWPS) composite member was developed to improve the efficiency of the prestress introduced into the steel beam, and experimental studies were performed to examine its structural behavior. Additionally, a unified analysis model that can estimate the nonlinear flexural behavior of the composite member and the accordion effect of the corrugated webbed steel beams at the prestressing stage was proposed. As a consecutive experimental series, in this study, the discontinuous-webbed prestressed (DWPS) composite member was developed, and this innovative composite member can reduce the amount of steel materials used, compared with the former CWPS composite member. Flexural tests were carried out to investigate their structural performances, and their behaviors were analyzed in detail by a nonlinear finite element analysis.

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Liu, Wei, and Zhen Fu Chen. "Experimental Study on Bearing Properties of Self-Compacting Prestressed Concrete Beams." Advanced Materials Research 163-167 (December 2010): 918–27. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.918.

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Five different types of self-compacting unbonded prestressed concrete beams are designed to study the bearing properties of self-compacting prestressed concrete flexural members. And experimental studies are conducted on their cracking loads, flexural strengths, ductility of members and failure forms. The testing results provide references for design and establishing related codes of self-compacting prestressed concrete structures.

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Wang, Xiao Dong, Wen Zhong Zheng, and Ying Wang. "Research on Stress Increase of Unbonded Tendons at Ultimate in Prestressed Concrete Continuous Beams." Applied Mechanics and Materials 166-169 (May 2012): 1554–57. http://dx.doi.org/10.4028/www.scientific.net/amm.166-169.1554.

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Rational evaluation for stress increase of unbonded tendon at ultimate is the basis to exactly compute flexural load bearing capacity of unbonded prestressed concrete beams. Moment-curvature nonlinear analysis method is adopted to compile programs for calculating stress increase at ultimate in unbonded prestressed continuous beams. The precision of the method is proved by comparing results of 16 experimental two-span unbonded prestressed continuous beams to the prediction value of stress increase at ultimate. Based on the simulation analysis, law of the influence of some basic factors to stress increase at ultimate in unbonded tendons in continuous beams is obtained, such as non-prestressed reinforcement index, prestressed reinforcement index, ratio of span to depth and loading type. Then formulas for calculating stress increase at ultimate in unbonded tendons in prestressed concrete continuous beams were established.

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Zhang, Chun Sheng, Hui Min Hao, Mei Xiang Zhang, and Ya Hong Ding. "Experimental Study of RC Beams Strengthened with Prestressed near Surface Mounted Helical Rib Steel Wire." Applied Mechanics and Materials 204-208 (October 2012): 1189–93. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.1189.

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A new reinforcement technique with prestressed helical rib steel wires is presented, and one control beam, three strengthened beams under monotonous loads are tested. The flexural capacity, load-deflection relation, cracks and deformation of reinforced concrete beams are systematically studied under the same initial prestress level and amount of reinforcement, different groove size. The test results indicate that the strengthening technique could significantly improve the first-crack load, steel-yielding load, ultimate load of the beams, and improves the service performance of the strengthened beams. The high performance of the helical rib steel wires is allowed for a better utilization. The results provide a reference for engineering applications.

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Hussein, Herish A., and Zia Razzaq. "Strengthening Prestressed Concrete Bridge Girders and Building Beams with Carbon Fiber Reinforced Polymer Sheets." European Journal of Engineering and Technology Research 6, no. 1 (January 10, 2021): 55–57. http://dx.doi.org/10.24018/ejers.2021.6.1.2323.

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The effect of Carbon Fiber Reinforced Polymer (CFRP) retrofitting and concrete type on the flexural strength of prestressed concrete I-section girders used in bridges and beams in buildings is investigated. Non-linear moment-curvature relationships are predicted using an iterative algorithm for both non-retrofitted and CFRP-retrofitted prestressed concrete girder and beam cross-sections with various concrete types. Two different CFRP-retrofitting schemes are analyzed for comparing their effectiveness. It is found that although non-retrofitted beam section exhibits greater ductility, the use of CFRP retrofitting in both tension and compression regions simultaneously results in a significant increase in flexural strength. It is also found that the higher the ultimate concrete strength, the higher is the influence of CFRP-retrofitting on increasing flexural strength.

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El-Hacha, Raafat, and Khaled Soudki. "Prestressed near-surface mounted fibre reinforced polymer reinforcement for concrete structures — a review." Canadian Journal of Civil Engineering 40, no. 11 (November 2013): 1127–39. http://dx.doi.org/10.1139/cjce-2013-0063.

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The specialized application of prestressing the near-surface mounted (NSM) fibre reinforced polymer (FRP) reinforcement for strengthening reinforced concrete (RC) structures combines the benefits of the FRP reinforcement with the advantages associated with external prestressing. By applying a prestress to the NSM FRP the material is used more efficiently since a greater portion of its tensile capacity is employed. This paper presents a comprehensive review on the performance of RC members strengthened using prestressed NSM FRP reinforcement. Several techniques and anchorage systems developed to prestress the NSM FRP are presented. The static flexural and fatigue performance of RC beams strengthened using prestressed NSM FRP in comparison to non-prestressed NSM is presented. Research on the long-term performance under freeze–thaw exposures and sustained loading is also presented.

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Guo, Yong Chang, and J. H. Xie. "Interface Properties of Cracked RC Beams Strengthened with Prestressed Hybrid FRP - Part I: Crack Height." Advanced Materials Research 163-167 (December 2010): 3673–76. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.3673.

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This study is the first part of investigation into the interfacial mechanics performances of cracked reinforced concrete (RC) beam strengthened with prestressed hybrid fiber reinforced polymer (HFRP). Finite element (FE) analysis models were established for such beams with different concrete crack height in this paper. The analysis results indicate that the existing of the flexural cracks obviously affect the stress distribution in the interface between concrete and HFRP, and a sudden change of the stress would arise at the cracks. For cracked RC beams strengthened with prestressed HFRP, both the shearing stress and normal stress of the adhesive layer and fiber sheet are much larger than those without cracks, and the growth rate increases with the crack height.

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Diep, Bui Khac, and Lam Huu Quang. "Calculation of loading-induced tendon slip in beams prestressed with external tendons. Part I: Experiment." Vietnam Journal of Mechanics 28, no. 3 (October 1, 2006): 165–75. http://dx.doi.org/10.15625/0866-7136/28/3/5576.

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This study consists of two parts, in which both experimental and numerical studies on externally prestressed concrete beams were investigated. In Part I, three identical beams of T-shaped section prestressed with external tendons have been tested to failure to investigate the effects of geometry of the applied load on flexural behavior of externally prestressed concrete beams. The tendon slip at deviators was also monitored in order to examine the evolution of stress in the external tendons. Test results were presented with emphasis on the effects of geometry of applied load and tendon slip at deviators.

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Atutis, Mantas, and Juozas Valivonis. "REINFORCEMENT CHARACTERISTICS OF PRESTRESSED CONCRETE BEAMS WITH FIBER-REINFORCED POLYMER (FRP) TENDONS." Engineering Structures and Technologies 2, no. 2 (June 30, 2010): 71–78. http://dx.doi.org/10.3846/skt.2010.10.

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The basic advantages of fiber-reinforced polymer (FRP) reinforcement are reviewed. FRP tendons exhibit linear elastic response to rupture without yielding and thus failure is expected to be brittle. Structural beahaviour of beams prestressed with FRP tendons is different from that of beams with traditional steel reinforcement. Strength design approach for prestressed beams with FRP tendons is based on the concept of brittle ratio, reinforcement ratio at which concrete fails in compression at the same time as FRP tendon ruptures. Depending on reinforcement ratio, the flexural behaviour of the beam can be devided into several groups. If reinfrocement ratio is equal to brittle ratio, beams fail by rupture of tendons and crushing of concrete simultaneously. Beams with reinforcement ratio, less than brittle ratio, are under-reinforced and will fail by rupture of tendons. When reinforcement ratio is greater than brittle ratio, concrete fails in compresion prior to rupture of tendons. Brittle ratio was calculated by different expressions proposed in scietific literature, and particular results were given. It has been shown, that brittle ratio is influenced by the mechanical properties of FRP and concrete.

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LUCCIONI, B. M., J. C. REIMUNDIN, and R. F. DANESI. "PRESTRESSED CONCRETE I-BEAMS UNDER COMINED MIXED TORSION, FLEXURE AND SHEAR." Proceedings of the Institution of Civil Engineers 91, no. 3 (September 1991): 577–92. http://dx.doi.org/10.1680/iicep.1991.15631.

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Pan, Li Yun, Song Chen, Shun Bo Zhao, and Chang Yong Li. "Experimental Study of Cyclic Loading Behaviors of Impaired Reinforced Concrete Beams Strengthening with Prestressed CFRP Sheets." Applied Mechanics and Materials 201-202 (October 2012): 483–86. http://dx.doi.org/10.4028/www.scientific.net/amm.201-202.483.

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The experimental study was carried out on the cyclic loading behaviors of impaired reinforced concrete beams strengthening with prestressed CFRP sheets. Eight beams in four groups with or without strengthening with prestressed CFRP sheets were tested, in which one or two layers of prestressed CFRP sheet were bonded on the bottom surface of the beams. Based on the analyses of test results, the flexural stiffness and ultimate resistance under cyclic load were effectively enhanced for the strengthened beams with the increasing layers of CFRP sheet, but the ductility of their mid-span deflection was reduced.

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Wang, Jiawei, Yanmin Jia, Guanhua Zhang, Jigang Han, and Jinliang Liu. "Experimental study on prestressed concrete hollow slabs in service strengthened with prestressed CFRP plates." International Journal of Structural Integrity 9, no. 5 (October 1, 2018): 587–602. http://dx.doi.org/10.1108/ijsi-08-2017-0049.

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Purpose Most existing studies are confined to model beam tests, which cannot reflect the actual strengthening effects provided by prestressed carbon-fiber-reinforced polymer (CFRP) plates to existing bridges. Hence, the actual capacity for strengthening existing bridges with prestressed CFRP plates is becoming an important concern for researchers. The paper aims to discuss these issues. Design/methodology/approach Static load tests of in-service prestressed concrete hollow slabs before and after strengthening are conducted. Based on the results of the tests, the failure characteristics, failure mechanism and bending performance of the slabs are compared and analyzed. Nonlinear finite element method is also used to calculate the flexural strength of the strengthened beams prestressed with CFRP plates. Findings Test results show that prestressed CFRP plate strengthening technology changes the failure mode of hollow slabs, delays the development of deflection and cracks, raises cracking and ultimate load-carrying capacity and remarkably improves mechanical behavior of the slab. In addition, the nonlinear finite element analyses are in good agreement with the test results. Originality/value Strengthening with prestressed CFRP plates has greater advantages compared to traditional CFRP plate strengthening technology and improves active material utilization. The presented finite element method can be applied in the flexural response calculations of strengthened beams prestressed with CFRP plates. The research results provide technical basis for maintenance and reinforcement design of existing bridges.

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Adjrad, Arezki, Youcef Bouafia, Mohand Said Kachi, and Hélène Dumontet. "Modeling of Externally Prestressed Beams until Fracture in Non Linear Elasticity." Applied Mechanics and Materials 749 (April 2015): 379–85. http://dx.doi.org/10.4028/www.scientific.net/amm.749.379.

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In this paper, we present an analytical model to analyze reinforced and prestressed concrete beams loaded in combined bending, axial load and shear, in the frame of non linear elasticity. In this model, the equilibrium of the beam is expressed by solving a system of equations, governing beams equilibrium, based on the stiffness matrix of the beam, which connects the load vector to the node displacements vector of the beam. It is built from the stiffness matrix of the section which takes into account a variation of the shearing modulus (depending on the shear variation) instead of assuming a constant shearing modulus as in linear elasticity. For the internal tendons, the stiffness matrix is completed by the terms due to the prestress effect in flexural equilibrium and by the balancing of one part of the shear by the transverse component of the force in the inclined cables.

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Wang, Zhong Qiang, and Zhi Wu Yu. "The Experimental Research and Theoretical Analysis of Unbonded Prestressed Concrete Flat Beams at High Temperature." Advanced Materials Research 250-253 (May 2011): 2242–52. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.2242.

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The experiments of 26 unbonded prestressed concrete flat beams under fire with elevating the temperature according to the ISO time-temperature standard curve were accomplished in the large structures electrical heating furnace that was manufactured independently. The macroscopical phenomena of water penetration, the lube flowing, the spalling of concrete and the corlor change of aspect were observed. The laws of behaviors such as temperature distribution on section,the deformation characteristic and stress varieties of prestressed tendons were investigated through the tests. The experiments indicated that temperature distribution was not uniform, the dynamic continuous deformation and the complicated varieties of prestressed stress occurred at high temperature. Based on the increment temperature-stress coupling constitutive models and chief deformation compatibility of the unboded prestressed tendons, the nonlinear finite element calculation formula took the unknown nodes displacements and the tensile forces in the unbonded tendons as unsolved column matrix simultaneously. The Increment format of nonlinear finite element method and calculation model for whole process analysis of unbonded prestressed concrete flexural members at high temperature were presented. The solution of nonlinear equilibrium equations for unboded prestressed concrete flexural members at high tempure was proposed, and a FORTRAN program named NAUPCLF was developed also and the results were in good agreement. The conclusions can supply the way and basis for further fire-resistant design and analysis of prestressed concrete structures.

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Wang, Petrů, Ai, and Ou. "Parametric Study of Flexural Strengthening of Concrete Beams with Prestressed Hybrid Reinforced Polymer." Materials 12, no. 22 (November 18, 2019): 3790. http://dx.doi.org/10.3390/ma12223790.

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The strengthening method of using hybrid fiber reinforced polymer is an effective way to increase the strengthening efficiency and lower the cost. This paper focuses on simulating the flexural behavior of reinforced concrete beam strengthened by prestressed C/GFRP (Carbon-Glass hybrid Fiber Reinforced Polymer) with different hybrid ratios and prestress levels. An elastoplastic damage constitution is used to simulate the mechanical behavior of concrete. A cohesive zone model under mixed mode is adopted to describe the debonding behavior of the FRP-concrete and concrete-steel interface. The results show good agreement with the experiment in the load-deflection curve, load-stress curve of steel, and HFRP. Furthermore, the failure mode of concrete and FRP debonding obtained from numerical simulation is the same as the test. Considering the improvement of the bending capacity, stiffness, and ductility of the strengthened beam in this paper, the best hybrid ratio of carbon to glass fiber is 1:1, and the suitable prestress level is between 30 and 50% of its ultimate strength.

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Wang, Kun, and Huihui Luo. "Test on Hysteretic Behaviour of Prestressed Composite Joints with Concrete-Encased CFST Columns." Advances in Civil Engineering 2019 (August 14, 2019): 1–13. http://dx.doi.org/10.1155/2019/4523045.

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Four composite joint specimens consisted of concrete-encased steel beams and concrete-encased concrete-filled steel tube (CFST) columns were tested under lateral cyclic loading, in which three specimens were prestressed and the other was not. In the tests, crack distributions and failure modes of the joint specimens were acquired, and the energy dissipation, rigidity degeneration, ductility, and residential deformation were investigated. Meanwhile, the strain variation of longitudinal rebars and I-steel flanges at beam ends as well as steel tubes in panel zones were analysed. The experimental results showed that a type of mixed mode consisting of shear failure in the panel zone and flexural failure at beam ends was found for three prestressed joint specimens, whilst only flexural failure at beam ends was observed for the non-prestressed one, and all joint specimens showed good hysteretic behaviour. In addition, as can be seen from the skeleton curves, the lateral peak loads of prestressed joint specimens could be enhanced to some extent by increasing the prestressing level, and the axial compression ratio had little effect on lateral loads; meanwhile, the ductility and energy dissipation for prestressed joint specimens also could be reduced by increasing the prestressing level and axial compression ratio.

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Rashid, Muhammad U., Liaqat A. Qureshi, and Muhammad F. Tahir. "Investigating Flexural Behaviour of Prestressed Concrete Girders Cast by Fibre-Reinforced Concrete." Advances in Civil Engineering 2019 (April 1, 2019): 1–11. http://dx.doi.org/10.1155/2019/1459314.

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The main objective of this research was to investigate the effect of adding polypropylene and steel fibres on flexural behaviour of prestressed concrete girders. Although the construction industry is frequently using prestressed concrete to increase the load-carrying capacity of structures, it can be further enhanced by using fibres. In this paper, experimental work was carried out to encourage the construction industry in utilizing fibres in prestressed concrete members to improve the mechanical properties of these members. As past investigations on fibre-reinforced prestressed beams were limited, the present work was done on small-scale fibre-reinforced I-shaped prestressed concrete girders. Six small-scale prestressed concrete girders were cast comprising a control girder, a hybrid girder, two girders with varying percentages of steel fibres, and two girders with varying percentages of polypropylene fibres. These girders were tested by centre point loading up to failure. It was concluded that, by the addition of small volume fraction of fibres, not only the ductility but also the tensile strength and flexural strength of FRC girders could be improved. It also altered the failure pattern positively by enhancing large strains in concrete and steel. Steel fibre-reinforced concrete showed higher energy absorption and deflection at ultimate loads in comparison to other specimens.

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Batchelor, B. deV, and Jayanth Srinivasan. "Calculation of stress in prestressing steel at ultimate conditions." Canadian Journal of Civil Engineering 16, no. 4 (August 1, 1989): 576–82. http://dx.doi.org/10.1139/l89-088.

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This paper reviews different methods available for the calculation of stress in prestressing steel at ultimate, ƒps, and the methods are evaluated using a nonlinear analysis computer program. The development of a nonlinear model for the analysis of partially prestressed concrete flexural members is described. The model takes the material nonlinearities into account by the use of appropriate stress–strain relationships for steel and concrete. A parametric study of partially prestressed beams was conducted to study the effect of various parameters on stress in prestressing steel at ultimate conditions. Two types of sections, rectangular and T sections, were studied. The prediction equation, recommended in the Canadian Code Can3-A23.3-M84, for calculating the stress in prestressing steel at ultimate is found to be very conservative for all the cases studied, which covered all possible ranges of partial prestressing ratio. The present restriction in the Canadian Code, for the use of their prediction equation only when the ratio of the neutral axis depth, Cu, to the depth of the centroid of prestressing steel, dps, is less than or equal to 0.3, is found to be too restrictive. An alternative equation for ƒps, suggested by Loov, is found to be more suitable than the present equation in the Canadian Code; however, a more practical upper limit for cu/dps ratio is suggested in the paper. It is shown that the proposed equation can be used conservatively over the complete range of partially prestressed concrete. Key words: analysis, concrete (prestress), flexure, partial prestressing, prestressing, strain, stress, steel.

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Vorel, Jan, Mahendra Gattu, and Zdeněk P. Bažant. "Size Effect in Flexure of Prestressed Concrete Beams Failing by Compression Softening." Journal of Structural Engineering 140, no. 10 (October 2014): 04014068. http://dx.doi.org/10.1061/(asce)st.1943-541x.0000983.

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Lou, Tiejiong, Muyu Liu, Sergio M. R. Lopes, and Adelino V. Lopes. "Effect of bond on flexure of concrete beams prestressed with FRP tendons." Composite Structures 173 (August 2017): 168–76. http://dx.doi.org/10.1016/j.compstruct.2017.04.021.

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Casadei, Paolo, Antonio Nanni, Tarek Alkhrdaji, and Jay Thomas. "Performance of Double-T Prestressed Concrete Beams Strengthened with Steel Reinforcement Polymer." Advances in Structural Engineering 8, no. 4 (August 2005): 427–42. http://dx.doi.org/10.1260/136943305774353124.

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In the fall of 2002, a two-storey parking garage in Bloomington, Indiana, built with precast prestrestressed concrete (PC) double-T beams, was decommissioned due to a need for increased parking-space. This led to the opportunity of investigating the flexural performance of the PC double-T beams, upgraded in the positive moment region with steel reinforced polymer (SRP) composite materials, representing the first case study where this material has been applied in the field. SRP makes use of high-strength steel cords embedded in an epoxy resin. This paper reports on the test results to failure of three beams: a control specimen, a beam strengthened with one ply of SRP and a third beam strengthened with two plies of SRP anchored at both ends with SRP U-wraps. Results showed that SRP can significantly improve both flexural capacity and enhance pseudo-ductility. Preliminary analytical work shows that the same approach used for externally bonded fiber reinforced polymer (FRP) can be satisfactorly used for SRP.

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Zhou, Rui, Mei Zhen Zhang, and Zhou Hong Zong. "Experimental Study on Flexural Behavior of Damaged RC Beams Strengthened with Prestressed CFRP Plate." Advanced Materials Research 250-253 (May 2011): 2263–70. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.2263.

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Strengthening using prestressed CFRP plate is a new developed technology in recent years, which can significantly improve the flexural behavior of reinforced concrete (RC) beams. In this paper, an experimental study including four RC beams stengthened with CFRP plates using self-developed anchorage system was carried out. The nonlinear finite element models of the strengthened beams were constructed to simulate the influence of flexural behavior on RC beams strengthened with CFRP plates under different damage degrees. The experimental results indicated that initial damage degrees have greatly influence on the crack distribution and ductility, deflection and the ultimate flexural strength of the strengthened beams, as well as steel reinforcement strain and CFRP plate strain. Meanwhile, the finite element model can predict accurately performances of strengthened RC beams before CFRP debonding. In addition, the numerical analysis indicated that the sustained loading while strengthening RC beam using prestressed CFRP plates would induce adverse effect, so the live loading should be removed before starting the strengthening works.

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Zamblauskaitė, Renata, Gintaris Kaklauskas, Darius Bačinskas, and Morten Bo Christiansen. "SHORT-TERM DEFORMATIONAL ANALYSIS OF PRESTRESSED CONCRETE BEAMS USING FLEXURAL CONSTITUTIVE MODEL." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 9, no. 4 (December 31, 2003): 280–83. http://dx.doi.org/10.3846/13923730.2003.10531340.

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In this paper, an attempt has been made to extend application of the recently proposed Flexural constitutive model to short-term deformational analysis of flexural prestressed concrete members. The relationship of tensile concrete is based on smeared crack approach and accumulates cracking and the tension stiffening effects. The Flexural constitutive model was applied in a simple engineering technique based on principles of strength of materials and the layered approach. To assess accuracy of the technique, deflections have been calculated for experimental prestressed concrete beams reported in the literature. Comparison has been earned out with the predictions of the well-known design code methods of different countries.

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Journal articles on the topic 'Prestressed concrete beams Prestressed concrete beams Flexure'

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