Mechanical Performance of RAC under True-Triaxial Compression after High Temperatures

Abstract

In recent years, the mechanical behavior of recycled aggregate concrete (RAC) under different condition has attracted great attention from researchers. As RAC can make full use of the concrete waste generated by the demolition of buildings, it can promote the development of green and sustainable construction technology. The true-triaxial compression tests of RAC with different replacement rates (0%, 50%, 100%) after high temperatures (200°C, 400°C) were carried out for the first time. Through the study, the triaxial compressive strength, deformation and stress-strain curve of RAC under different stress ratios are obtained. The improved failure criterion of concrete is established. It is found that the true-triaxial compressive strength and peak strain under high temperature are greater than those under uniaxial compressive strength and room temperature. The main failure modes of RAC specimens under true-triaxial test are sheet splitting and shear failure. The research results obtained in this work are the first to study the true-triaxial compression behavior of RAC after exposure to high temperatures.