Failure analysis and damage characterization of steel fiber reinforced manufactured sand concrete column under axial compression

Manufactured sand (MS) is a beneficial and sustainable supplement to natural sand (NS). This study investigated the mechanical properties of manufactured sand concrete (MSC) columns under axial compression. The effects of test parameters including MS replacement rate, reinforcement ratio, slenderness ratio, and steel fiber content on the failure modes, concrete strain, stiffness, and flexibility, etc., were analyzed and demonstrated. The results showed that the MS replacement rate and reinforcement rate presented less effect on the concrete strain, whereas decreasing the slenderness ratio of the specimens and increasing the steel fiber contents significantly increased the strain of the concrete. The 100% MS replacement rate exhibited little effect on the strain of concrete and the stiffness of members, while the bearing capacity was increased to 9.3% compared with the 0% MS replacement rate. Incorporating steel fibers significantly improved MSC's mechanical properties and increased the members' strength and flexibility. In addition, the constitutive model of MSC was established, and the model's accuracy was verified based on finite element analysis, which exhibited favorable accuracy with an error of less than 5%.