Experimental and theoretical analysis of copper tailings‐laden geopolymer concrete‐steel tubular columns under axial compression

Abstract In this study, the mechanical performance of copper tailings‐laden geopolymer concrete‐steel tubular columns under axial compression was investigated to improve the utilization of copper tailings and promote the application of geopolymer concrete in construction engineering. The effects of design parameters, such as concrete strength, section size (i.e., the outer diameter of the column), and steel‐tube thickness, were analyzed in detail. The test results illustrated that the effect of section size on the axial compression performance of the tubular columns was the most significant. After reaching the peak load, all specimens exhibited varying degrees of strength degradation. With the yielding of the steel tubes, bulging initiated at the ends, which gradually shifted toward the middle, ultimately showing a barrel‐shaped failure. The compressive force efficiency, defined as the ratio of average compressive force to ultimate compressive force, ranged from 0.71 to 0.78. The ductility coefficient varied between 13.37 and 31.48, with an average of 19.85, indicating excellent load‐bearing capacity and deformation performance of the specimens. Additionally, the axial compressive load capacity of the tubular columns was predicted based on mainstream codes. The results showed that the Eurocode yielded the best agreement with the experimental results, with the ratio of the predicted to experimental values ranging from 0.899 to 1.185 (average of 1.045). Finally, an established finite element analysis model was applied and the results were compared with the experimental ones. The ratio of the peak experimental load to the simulation results for the specimens ranged from 0.92 to 1.16, thus validating the finite element simulation.