Strength and deformation of recycled aggregate concrete under triaxial compression

Experiment was carried out to better understand the behaviors of recycled aggregate concrete under triaxial compressive stresses. The test was performed on 100mm×100mm×100mm cubic specimens with five replacement ratios of recycled coarse aggregate (RCA) at four kinds of stress ratios, using a servo-controlled static-dynamic triaxial machine (TAWZ-5000/3000). The failure modes, ultimate strength and deformation under triaxial compression were observed, and the effect of RCA replacement ratio and stress ratio on these characteristics was analyzed. The results show that the triaxial compressive strength of the specimens is much higher than the corresponding uniaxial strength, and the strength and deformation depend on both RCA replacement ratio and stress ratio. Moreover, the factors affecting triaxial strength were quantitatively analyzed by variance calculation. Based on the triaxial strength, the relationship between normalized octahedral normal stress σoct/fc and octahedral shear stress τoct/fc with RCA replacement ratio and stress ratio was discussed.