The uniaxial compressive stress-strain relations of steel slag fine aggregate concrete under steam curing

The purpose of this paper is to investigate the uniaxial compressive stress-strain behavior of steel slag fine aggregate concrete (SSC), which composed of steel slag fine aggregate (SSA), natural fine aggregate, and natural coarse aggregate under steam curing conditions. The uniaxial compressive behavior of SSC with various volume replacement rate of SSA and various water-cement ratio was studied under steam curing conditions. The results indicated that the peak stress of SSC initially increased and then decreased with increasing volume replacement rate of SSA. SSA and steam curing well improved the deformation performance of concrete, and SSA effectively enhanced the elastic modulus of concrete. Then, the test stress-strain data of SSC were compared with existing stress-strain models of concrete. The comparison results exhibited that the existing models cannot be well predicted the stress-strain relationship of SSC under steam curing conditions. Based on the test results, this study developed the uniaxial compressive stress-strain constitutive model for SSC under steam curing conditions by modifying the shape parameters for the existing concrete constitutive model, considering both SSA volume replacement rate and water-cement ratio. The discussion of verification results showed that maximum R2 is 0.99, and the study model can commendably predict the stress-strain relationship of SSC under steam curing. Meanwhile, the damage model of SSC under steam curing was established based on test results and the constitutive model.