Experimental Study of Rubber-Concrete-Filled CST Composite Column Under Axial Compression

摘要

Abstract Rubber concrete has been proposed to address the environmental challenges caused by waste tires and the shortage of natural aggregates worldwide; however, its strength and elastic modulus reduction hinder its wide application in structure members. This study proposes filling corrugated steel tubes with rubber concrete (RuCFCST) and using the non-uniform confinement provided by corrugated steel tubes (CSTs) to compensate for the loss in strength and elastic modulus of rubber concrete. We conducted monotonic axial compression tests on 12 tubular specimens to evaluate the effects of the steel tube type, loading mode, diameter-to-thickness ratio, and rubber concrete strength on the axial shortening behavior and strength. The test results confirmed the effectiveness of CST confinement in strengthening the axial behavior of rubber concrete and CST had a higher confinement efficiency than plain straight steel tubes. The strength and ductility indices of the specimens increased by 10 and 30, respectively; however, the strength of the concrete core decreased by 38.4 owing to the incorporation of rubber particles. These results suggest that such columns can be used in infrastructure, such as in seismic bridge piers, mine roadway supports, and underground structural columns, where load-bearing capacity and ductility are required. The current specifications lack consistency in predicting the axial strength of RuCFCST columns and the results of our proposed modified formulas were in good agreement with the experimental data, and the formulas predicted the axial strength of piers well.