Research on mechanical properties and bearing capacity calculation models of concrete-filled circular aluminum alloy tubular stub columns under axial compression

Abstract:

This study aims to clarify the working mechanism of concrete-filled circular aluminum alloy tubular columns andverify/improve the reliability of the bearing capacity calculation models. The available experimental tests for concrete-filled circular aluminum alloy tubular stub columns under axial compression were collected and analyzed in this paper, with the experimental database established. The mechanical properties of the concrete-filled circular aluminum alloy tubular stub columns under axial compression were further investigated, and the applicability of the existing five typical bearing capacity calculation models was evaluated. A new calculation model with higher accuracy for predicting the compressive bearing capacity of concrete-filled circular aluminum alloy tubular stub columns was proposed. The investigated results indicate that some of the test variables of the existing studies may be beyond the scope of “steel-concrete composite structures”, which should be analyzed individually. The boundary confinement factor of concrete-filled circular aluminum alloy tubular columns is higher than that of conventional concrete-filled circular steel tubular columns under the same condition which can be taken as 1.75, approximately. The five typical existing calculation models can be used to provide an approximate prediction of the compressive bearing capacity of concrete-filled circular aluminum alloy tubular stub columns. However, there are still 5.6% to 32.4% of the collected specimens with predicted deviations exceeding 20%, which are mainly concentrated in the range of lower confinement factors (ξ<1.0). The proportion of the collected test specimens with deviations beyond 20% in the compressive bearing capacity predicted by the proposed calculation model in this paper is less than 3%.