Axial Compression Performance of Structural Ceramsite Concrete Reinforced with Steel Fiber

This study investigates the influence of steel fiber content (0%, 0.3%, 0.6%, 0.9%) on the axial compressive performance of ceramsite concrete. Four types of ceramsite concrete specimens were prepared and the cube compressive strength of each type of ceramsite concrete was tested. Four sets of uniaxial compression tests on prismatic specimens of ceramsite concrete were conducted. The failure process and characteristics of the specimens were analyzed, and the uniaxial compressive performance of each group of specimens was systematically studied. Additionally, the stress-strain curves equations were proposed. The research indicates that, after the addition of steel fibers, the strength and ductility of ceramsite concrete are significantly enhanced. The compressive strength of cubic specimens can increase by up to 42.6%, axial compressive strength can increase by up to 25.6%, and residual stress can increase by more than 300%. Ceramsite concrete with a steel fiber volume fraction of 0.9% demonstrates clear advantages. Its energy dissipation coefficient has increased by 17%, ductility coefficient has improved by 33%, toughness coefficient has enhanced by 68%, and stiffness degradation has noticeably become more gradual. The stress-strain curve model proposed in this study aligns well with the experimental results, accurately describing the stress-deformation characteristics of steel fiber ceramsite concrete under uniaxial compression. It demonstrates good applicability. The research findings of this study can provide a theoretical foundation for the structural analysis and design of such concrete, which is of significant importance for the utilization of ceramsite concrete as both a structural material and as a component in prefabricated lightweight wall panels.