Study On Flexural Behavior Of Reinforced Concrete Beams Strengthened With High Performance CFRP Plates

Various types of bridge diseases often occur in the bridge structure under the coupling effect of harsh environment and different types of load.It will cause the performance degradation of bridge structure which is urgent to strengthen the structure.Carbon Fiber Reinforced Polymer(CFRP)is a material with high tensile performance and good durability.It is often applied to the reinforcement of bridge structure to improve the bearing capacity and other aspects.The CFRP plates strengthened Reinforced Concrete(RC)slab beams with additional anchoring measure were investigated in this paper.The influence of additional anchorage position on the flexural mechanical properties of test beams after high temperature effect of asphalt paving construction action was studied.The main contents are as follows:(1)The bridge reinforcement project of CFRP plate strengthened box girder roof was taken as the background.The mechanical characteristics of the box girder structure was analyzed.The specimens of CFRP plate strengthened concrete slab beam were designed according to the equivalence principle of mechanical performance.The specimens were subjected to the high temperature action of asphalt paving construction.Then,the three-point flexural performance tests were carried out on the specimens.(2)For the typical debonding failure of CFRP plate in the CFRP plate strengthened concrete structure,an improved additional anchoring measure was proposed to delay the occurrence of debonding failure.Experimental investigations were performed on the CFRP strengthened specimens with different anchoring positions.The influence of anchorage position was studied by the flexural test carrying out on the CFRP plate strengthened concrete beam.(3)Based on the test results,the flexural performance of CFRP plate strengthened concrete beams were analyzed form the aspects of load-deflection relationship,CFRP plate strain distribution,beam crack distribution,and CFRP-concrete interfacial shear stress.The flexural behavior of CFRP strengthened concrete beam was analyzed,and the influence of different additional anchoring positions on its flexural performance was analyzed.(4)A finite element model of the CFRP plate strengthened concrete beam was established according to the structural parameters of the test beams.By introducing reasonable material constitutive models and setting appropriate interfacial boundary conditions,the mechanical behavior of CFRP plate-concrete interface after high-temperature asphalt paving construction was simulated.The numerical analysis results were also compared with the test results to analyze the flexural performance of CFRP plate reinforced beams with different additional anchoring positions after the high temperature of asphalt,and the reliability of the finite element model was verified.