Experimental Study and Analysis on Axial Compression Performance of High-Strength Recycled Concrete-Filled Steel Tube Column in Corrosive Environments

摘要

To explore the axial compression performance of high-strength recycled concrete-filled steel tube (RCFST) column in corrosive environments, ten high-strength RCFST columns with different wall thicknesses of steel tube and corrosion degrees and two ordinary concrete-filled steel tube (CFST) columns were designed. Subsequently, an axial compression test was carried out on these specimens to obtain the load–displacement curve, skeleton curve, and rigidity degeneration curve. The stress process, failure morphology, characteristic load, and characteristic displacement were analyzed. According to the research findings, the steel tube at the end of each specimen bulges. With increasing load, buckling occurs in the middle region, and the core concrete is crushed. The higher the corrosion degree of a specimen, the more obvious the buckling on its surface. The corrosion of a steel tube significantly affects the initial stiffness of high-strength RCFST column, which results in a significant decline in its bearing capacity and stiffness. An increase in the wall thickness of steel tubes can enhance the bearing capacity of a specimen. The ultimate balance theory was used to derive the calculation formula for the bearing capacity of each specimen, and the effects of different lateral pressure coefficients on the results were compared and analyzed. Reasonable values were obtained by comparing with the experimental results. The software ABAQUS was used to establish a finite element numerical analysis model, and the damage deformation and load–displacement curves of each specimen were obtained. The analysis and comparison of the results obtained by the model and the obtained results verify the accuracy of the finite element analysis model.