Failure Criteria and Mechanical Properties of Recycled Concrete with Different Replacement Ratios of Coarse Aggregates under Multiaxial Compression

Abstract

In this paper, experiments of recycled aggregate concrete under multiaxial compression with five different replacement ratios (0%, 25%, 50%, 75%, and 100%) of coarse aggregates were implemented by using the true triaxial apparatus and the failure modes were compared under different conditions. According to the obtained stress-strain curves, the peak stresses and peak strains were extracted and analyzed to study the mechanical properties of recycled aggregate concrete under multiaxial compression. Meanwhile, the failure modes are described. The results show that the increasing coefficients of peak stresses of recycled aggregate concrete under biaxial compression are higher than those of ordinary concrete, with the highest pertaining to the replacement ratio of 75%. Nevertheless, the increasing coefficients of peak stresses of recycled aggregate concrete under triaxial compression are lower than those of ordinary concrete. As for peak strains analysis, those under uniaxial compression exceed those under biaxial compression, which are lower than those under triaxial compression. The peak strains of ordinary concrete are higher than those of recycled aggregate concrete, with that of 100% replacement ratios being the lowest. Based on the experimental data and the failure characteristics, the failure criteria of recycled aggregate concrete with different replacement ratios under multiaxial compression are proposed, which is of great significance to the research and application of secondary utilization of concrete waste as well as building environmental protection.