Mechanical properties of recycled aggregate concrete containing brick particles

Abstract

To investigate the mechanical properties of recycled aggregate concrete containing brick particles (RACB), compressive strength tests were conducted on RACBs with different water/cement ratios and recycled fine aggregate substitution rates. The changes in compressive strength, elastic modulus and peak strain of RACB were analysed as a function of the proportion of substituted recycled fine aggregate, and a stress–strain equation was established. A damage model was established using ultrasonic non-destructive testing technology to reveal the damage mechanism of RACB. Results show that the basic mechanical properties of RACB are best when the replacement proportion of recycled fine aggregate (r) is 30%. The model parameter a of the stress–strain curve equation is consistent with the change of elastic modulus with r. The model parameter b has a quadratic function relationship with r, reflecting the brittleness of RACB. The initial damage of RACB is relatively large, and cracks penetrate the recycled coarse aggregate, leading to specimen failure.