Study on Mechanical Properties and Mesoscopic Numerical Simulation of Recycled Concrete

Abstract

To obtain the mechanical properties of recycled concrete (RC) under different replacement rates (RRs) of recycled coarse aggregate (RCA), a quasi-static uniaxial compression test, a uniaxial splitting tension test and a uniaxial dynamic compression test of RC with replacement rates (RRs) of 0%, 20%, 40%, 60%, 80% and 100% were carried out. ABAQUS was used to investigate the cracking and failure of RC. The results showed that, when the RR was less than 60%, the uniaxial compressive and tensile strengths of RC decreased with the increase in RR, but slightly increased when RR was greater than 80%. Under impact load, the dynamic compressive strength of RC increased linearly with the increase in the strain rate, showing an obvious strain rate effect. With the increase in RR, the strain rate sensitivity of RC gradually decreased. The concrete damage plastic (CDP) model can describe the mechanical behavior of RC well. The damage and failure of RC occurred first at the old interface transition zone (ITZ) and old mortar. As the strain rate increases, the damage and failure rate of the specimens is intensified. Research on the mechanical properties of RC can provide a basis for the application and promotion of RC technology.