A MODEL FOR PREDICTING THE MOMENT-CURVATURE BEHAVIOR OF STEEL TUBE CONFINED REINFORCED SELF-STRESSING STEEL SLAG CONCRETE COLUMNS UNDER CYCLIC LOADING

This paper evaluates the moment-curvature response of steel tube confined reinforced self-stressing steel slag concrete (STCRSSSC) columns by conducting cyclic loading tests on ten STCRSSSC columns and four steel tube confined reinforced steel slag concrete (STCRSSC) columns. Four parameters are considered: axial compression ratio, shear-span ratio, diameter-thickness ratio, and expansion rate of steel slag concrete (SSC). The results show that the specimens exhibit a bending failure mode. As the expansion rate of SSC or shear-span ratio increase, the area of the moment-curvature hysteretic loops expands, but the slope of the skeleton curve remains basically unchanged. The slope of the skeleton curve rises as the diameter-thickness ratio or axial compression ratio increase. With the reduction of the axial compression ratio or diameter-thickness ratio, the area of the hysteretic loops increases. Based on the experimental results, the characteristic points of the response are identified, and a simplified model is proposed to predict the skeleton curves. Lastly, a hysteresis rule of the specimens is suggested based on the Clough trilinear degeneration model, and a predicting model of the response of the specimens is established.