Theoretical Analysis And Numerical Simulation On Shear Performance Of BFRP Reinforced RAC Deep Beams

The traditional reinforced concrete structure under erosion environment often occurred durability and applicability problems caused by steel corrosion,and the Fiber-Reinforced Polymer(FRP)bar has good corrosion resistance,can effectively supplement the insufficient part of the Reinforced concrete structures;On the other hand,with the economic and social development,the construction and demolition of concrete buildings not only consumes a lot of natural resources but also causes huge environmental pollution,and the application of the recycled aggregate concrete(RAC)technology is an effective solution.Combining the BFRP bar and RAC,this study explores the shear behavior of BFRP reinforced RAC deep beams with and without stirrups,and the applicability of the nonlinear finite element model analysis is studied by ABAQUS numerical simulation.The main research work is peformed as follows:(1)The shear mechanism,influence factors of shear strength and shear model of FRP reinforced concrete beam were discussed.(2)According to the shear tests of BFRP reinforced RAC beams with and without stirrups.The failure modes and cracking patterns were observed;the influence of shear span ratio,reinforcement ratio,and concrete compressive strength on the cracking load,ultimate bearing capacity and deflection of the beams were also analyzed.At the same time,the difference with steel reinforced concrete beams is analyzed.(3)Based on the shear model and data of FRP reinforced concrete beams,the shear strength of FRP reinforced concrete beam with and without stirrups was calculated,and compared with the test results.The shear calculation involves the American standard ACI 440.1R,China standard GB 50608-2010,Canada standard CSA 608-12,simplified modified conpression field theory.According to the calculation results,the comparison and analysis of different models are carried out.(4)The finite element model is established on the basis of the existing experiments,and the accuracy and applicability of the selected model are verified by comparing the difference between the simulation results and the experimental results.The results show that under the load,the crack of BFRP reinforced RAC beams develops rapidly and the crack width is larger,and the ultimate bearing capacity of beams increased with the decrease of shear span ratio and the increase of reinforcement ratio,But the increase of reinforcement ratio has no obvious effect on the ultimate bearing capacity of BFRP reinforced RAC beams,The effect of the compressive strength of recycled concrete is minimal.The Canada standard CSA 608-12 predicted well the shear capacity for members with and without stirrups.The nonlinear model based on ABAQUS can be used to simulate the whole stressing process of the test beam well,but the ideal simplified model still has some deviation in predicting the ultimate bearing capacity and deformation of the beam.