Numerical simulation and influence factor analysis on mechanical performance of reinforced recycled coarse aggregate concrete beams

In order to study the mechanical performance of the reinforced recycled coarse aggregate concrete beams, extensive analysis of numerical simulation was conducted based on the test results. Firstly, the feasibility of the numerical simulation was proved by comparing the simulation results and test ones of mechanical behavior of six reinforced recycled coarse aggregate concrete beams. On this basis, 27 computational models were built to conduct systematical finite element analysis and to explore the calculating method of ultimate bending strength and shear strength. The variable parameters of the models were: coarse aggregate replacement ratio, shear span ratio, stirrup ratio, longitudinal reinforcement ratio and calculation length of the beam. As conclusion, the numerical simulation results agree well with the test ones. The ultimate bearing capacity decreases remarkably with the increase of the shear span ratio whereas slightly with the replacement ratio. In some certain range, stirrup ratio and reinforcing bar ratio would be the influence factors influencing the bearing capacity. The capacity increases sharply when the section area increases. Considering the influence of aggregate ratio, the bending and shear strength formulas of concrete beams based on the code were amended and might be adopted in the structural designing in practical engineering.