The repair of reinforced concrete(RC)beams with carbon fiber reinforced polymers(CFRP)is experimentally investigated in this study.The four T-section reinforced reactive powder concrete beams with many locations of ci...The repair of reinforced concrete(RC)beams with carbon fiber reinforced polymers(CFRP)is experimentally investigated in this study.The four T-section reinforced reactive powder concrete beams with many locations of circular opening were repaired by CFRP and investigated under pure torsion.The repairing beams were tested to obtain the effect of the amount of CFRP laminate on beams cracking and ultimate torque behavior,angle of twist and failure modes.The results obtained from the adopted repairing technique showed a significant effect of external high strength CFRP laminates on effectively restore of section solid of 85%of crack torsional strength effectively restored.In addition,the results show that effectively restoring of section opening by 82%-80%of crack torsional strength,and the adopted repairing technique gives a good strength to the beams.展开更多
An experimental study was conducted to investigate the behavior of composite concrete beams damaged and cracked under pure torsion, and then repaired by external strengthening. This was achieved using high strength Ca...An experimental study was conducted to investigate the behavior of composite concrete beams damaged and cracked under pure torsion, and then repaired by external strengthening. This was achieved using high strength Carbon Fiber Reinforced Polymer (CFRP) laminates bonded with epoxy four composite modify reactive powder concrete (MRPC) I-beams. Different types of section (Solid & with opening) were tested to obtain the effect of amount of CFRP laminate on beams ultimate torque behavior, angle of twist and failure modes. The results obtained showed that a significant effect of external high strength CFRP laminates on effectively restore of section solid, the range of 89.8% to 91.2% of ultimate torsional strength effectively restored as well as effectively restoring of section opening by 83.48% - 86.67% of ultimate torsional strength. The repaired beams give high efficiency in ultimate torsional strength, and indicate that the adopted technique gives a good torsional strength.展开更多
Damage caused due to low-velocity impacts in composites leads to substantial deterioration in their residual strength and eventually provokes structural failure.This work presents an experimental investigation on the ...Damage caused due to low-velocity impacts in composites leads to substantial deterioration in their residual strength and eventually provokes structural failure.This work presents an experimental investigation on the effects of different patch and parent laminate stacking sequences on the enhancement of impact strength of Carbon Fiber Reinforced Polymers(CFRP)composites by utilising the adhesively bonded external patch repair technique.Damage evolution study is also performed with the aid of Acoustic Emission(AE).Two different quasi-isotropic configurations were selected for the parent laminate,viz.,[45°/45°/0°/0°]s and[45°/0°/45°/0°]s.Quasi Static Indentation(QSI)test was performed on both the pristine laminates,and damage areas were detected by using the C-scan inspection technique.Damaged laminates were repaired by using a single-sided patch of two different configurations,viz.,[45°/45°/45°/45°]and[45°/0°/0°/45°],and employing a circular plug to fill the damaged hole.Four different combinations of repaired laminates with two configurations of each parent and patch laminate were produced,which were further subjected to the QSI test.The results reveal the effectiveness of the repair method,as all the repaired laminates show higher impact resistance compared to the respective pristine laminates.Patches of[45°/0°/0°/45°]configuration when repaired by taking[45°/45°/0°/0°]s and[45°/0°/45°/0°]s as parents exhibited 68%and 73%higher peak loads,respectively,than the respective pristine laminates.Furthermore,parent and patch of configuration[45°/0°/45°/0°]s and[45°/0°/0°/45°],respectively,attain the highest peak load,whereas[45°/45°/0°/0°]s and[45°/45°/45°/45°]combinations possess the most gradual decrease in the load.展开更多
采用非线性有限元法对中拱和中垂工况条件下碳纤维增强聚合物(Carbon Fiber Reinforced Polymer,CFRP)修复的浮式生产储卸油装置(Floating Production Storage and Offloading,FPSO)点蚀船体梁极限强度进行仿真分析。对比FPSO的完整船...采用非线性有限元法对中拱和中垂工况条件下碳纤维增强聚合物(Carbon Fiber Reinforced Polymer,CFRP)修复的浮式生产储卸油装置(Floating Production Storage and Offloading,FPSO)点蚀船体梁极限强度进行仿真分析。对比FPSO的完整船体梁、点蚀船体梁和CFRP修复的点蚀船体梁的中拱极限弯矩和中垂极限弯矩,分析CFRP对FPSO点蚀船体梁的修复效果,并分析胶层失效规律。结果表明,CFRP可为船舶的高效修复提供一种新的方式。展开更多
In this study, three rapid repair techniques are proposed to retrofit circular bridge piers that are severely damaged by the flexural failure mode in major earthquakes. The quasi-static tests on three 1：2.5 scaled ci...In this study, three rapid repair techniques are proposed to retrofit circular bridge piers that are severely damaged by the flexural failure mode in major earthquakes. The quasi-static tests on three 1：2.5 scaled circular pier specimens are conducted to evaluate the efficiency of the proposed repair techniques. For the purpose of rapid repair, the repair procedure for all the specimens is conducted within four days, and the behavior of the repaired specimens is evaluated and compared with the original ones. A finite element model is developed to predict the cyclic behavior of the repaired specimens and the numerical results are compared with the test data. It is found that all the repaired specimens exhibit similar or larger lateral strength and deformation capacity than the original ones. The initial lateral stiffness of all the repaired specimens is lower than that of the original ones, while they show a higher lateral stiffness at the later stage of the test. No noticeable difference is observed for the energy dissipation capacity between the original and repaired pier specimens. It is suggested that the repair technique using the early-strength concrete jacket confined by carbon fiber reinforced polymer （CFRP） sheets can be an optimal method for the rapid repair of severely earthquake-damaged circular bridge piers with flexural failure mode.展开更多
文摘The repair of reinforced concrete(RC)beams with carbon fiber reinforced polymers(CFRP)is experimentally investigated in this study.The four T-section reinforced reactive powder concrete beams with many locations of circular opening were repaired by CFRP and investigated under pure torsion.The repairing beams were tested to obtain the effect of the amount of CFRP laminate on beams cracking and ultimate torque behavior,angle of twist and failure modes.The results obtained from the adopted repairing technique showed a significant effect of external high strength CFRP laminates on effectively restore of section solid of 85%of crack torsional strength effectively restored.In addition,the results show that effectively restoring of section opening by 82%-80%of crack torsional strength,and the adopted repairing technique gives a good strength to the beams.
文摘An experimental study was conducted to investigate the behavior of composite concrete beams damaged and cracked under pure torsion, and then repaired by external strengthening. This was achieved using high strength Carbon Fiber Reinforced Polymer (CFRP) laminates bonded with epoxy four composite modify reactive powder concrete (MRPC) I-beams. Different types of section (Solid & with opening) were tested to obtain the effect of amount of CFRP laminate on beams ultimate torque behavior, angle of twist and failure modes. The results obtained showed that a significant effect of external high strength CFRP laminates on effectively restore of section solid, the range of 89.8% to 91.2% of ultimate torsional strength effectively restored as well as effectively restoring of section opening by 83.48% - 86.67% of ultimate torsional strength. The repaired beams give high efficiency in ultimate torsional strength, and indicate that the adopted technique gives a good torsional strength.
基金the financial support by the Council of Scientific&Industrial Research(CSIR)-Research Scheme,India(22/0809/2019-EMR-II)。
文摘Damage caused due to low-velocity impacts in composites leads to substantial deterioration in their residual strength and eventually provokes structural failure.This work presents an experimental investigation on the effects of different patch and parent laminate stacking sequences on the enhancement of impact strength of Carbon Fiber Reinforced Polymers(CFRP)composites by utilising the adhesively bonded external patch repair technique.Damage evolution study is also performed with the aid of Acoustic Emission(AE).Two different quasi-isotropic configurations were selected for the parent laminate,viz.,[45°/45°/0°/0°]s and[45°/0°/45°/0°]s.Quasi Static Indentation(QSI)test was performed on both the pristine laminates,and damage areas were detected by using the C-scan inspection technique.Damaged laminates were repaired by using a single-sided patch of two different configurations,viz.,[45°/45°/45°/45°]and[45°/0°/0°/45°],and employing a circular plug to fill the damaged hole.Four different combinations of repaired laminates with two configurations of each parent and patch laminate were produced,which were further subjected to the QSI test.The results reveal the effectiveness of the repair method,as all the repaired laminates show higher impact resistance compared to the respective pristine laminates.Patches of[45°/0°/0°/45°]configuration when repaired by taking[45°/45°/0°/0°]s and[45°/0°/45°/0°]s as parents exhibited 68%and 73%higher peak loads,respectively,than the respective pristine laminates.Furthermore,parent and patch of configuration[45°/0°/45°/0°]s and[45°/0°/0°/45°],respectively,attain the highest peak load,whereas[45°/45°/0°/0°]s and[45°/45°/45°/45°]combinations possess the most gradual decrease in the load.
文摘采用非线性有限元法对中拱和中垂工况条件下碳纤维增强聚合物(Carbon Fiber Reinforced Polymer,CFRP)修复的浮式生产储卸油装置(Floating Production Storage and Offloading,FPSO)点蚀船体梁极限强度进行仿真分析。对比FPSO的完整船体梁、点蚀船体梁和CFRP修复的点蚀船体梁的中拱极限弯矩和中垂极限弯矩,分析CFRP对FPSO点蚀船体梁的修复效果,并分析胶层失效规律。结果表明,CFRP可为船舶的高效修复提供一种新的方式。
基金National Natural Science Foundation of China under Grant No.51678150Science for Earthquake Resilience under Grant No.XH17064Australian Research Council Discovery Early Career Researcher Award(DECRA)
文摘In this study, three rapid repair techniques are proposed to retrofit circular bridge piers that are severely damaged by the flexural failure mode in major earthquakes. The quasi-static tests on three 1：2.5 scaled circular pier specimens are conducted to evaluate the efficiency of the proposed repair techniques. For the purpose of rapid repair, the repair procedure for all the specimens is conducted within four days, and the behavior of the repaired specimens is evaluated and compared with the original ones. A finite element model is developed to predict the cyclic behavior of the repaired specimens and the numerical results are compared with the test data. It is found that all the repaired specimens exhibit similar or larger lateral strength and deformation capacity than the original ones. The initial lateral stiffness of all the repaired specimens is lower than that of the original ones, while they show a higher lateral stiffness at the later stage of the test. No noticeable difference is observed for the energy dissipation capacity between the original and repaired pier specimens. It is suggested that the repair technique using the early-strength concrete jacket confined by carbon fiber reinforced polymer （CFRP） sheets can be an optimal method for the rapid repair of severely earthquake-damaged circular bridge piers with flexural failure mode.
