Mechanical properties of recycled aggregate concrete under multiaxial compression

The mechanical properties of recycled aggregate concrete under multiaxial compression were tested by servo-controlled setup (TAWZ-5000/3000). Properties of strength and stress-strain relation were obtained, and the influence factors of stress ratio and recycled coarse aggregate replacement ratio were analyzed. The results show that the strength of recycled aggregate concrete under multiaxial compression is higher than that of under uniaxial state, the stress ratio and recycled coarse aggregate replacement ratio have obvious effect on strength, and the shape of stress-strain curve is also varied with different levels of the two factors. Failure criterion can reflect the strength relation for recycled concrete under multiaxial stress state. Kupfer's failure criterion is selected to describe strength properties under biaxial stress state, and the failure envelope reflects the energy absorption of different mix series. Based on octahedral stress theory, the tensile and compressive meridians have been proposed to analyze the strength characteristics under triaxial compression, and the theoretical values are well coherent with the test data.