The mechanical performance of steel slag concrete (SSC) under biaxial compression is investigated by a servo-controlled static-dynamic true triaxial machine (TAWZ-5000/3000). Three replacement ratios of steel slags and four kinds of stress ratio (0.25:1, 0.5:1, 0.75:1, and 1:1) are examined in this study. According to the test results, the influences of replacement ratio and stress ratio on the strength, deformation properties, stress-strain curves, and failure mode of SSC are analyzed. The results show that the failure mode of SSC under biaxial compression is plate-splitting crack. Both the strength and deformation of SSC are larger than the corresponding values of the uniaxial compression. Under the same stress ratio, the value of principal stress σ 3 f increases first and then decreases with the increase in the replacement ratio. Under the same replacement ratio, σ 3 f increases first and then decreases as the stress ratio increases, and the maximum of σ 3 f is obtained at the stress ratio of α = 0.5:1. Based on the analysis and test data, the strength failure criterion of SSC under biaxial compression stresses is proposed.
Keywords: biaxial compression; replacement ratio; steel slag concrete; strength failure criterion; stress ratio.