Axial compression performance of coral concrete-filled aluminum alloy tube (CCFAT) circular short columns

The use of aluminum alloy-reinforced coral concrete columns is an effective measure for enhancing the bearing capacity of coral concrete columns. To understand the axial compression performance of aluminum alloy circular tube-reinforced coral concrete short columns, this paper first designed nine short columns for axial compression testing with the parameters of aluminum contents (alpha, i.e., 0.085, 0.148, and 0.216) and coral concrete strength (C20, C30, and C40). The failure pattern, bearing capacity, and load-deformation relationship was obtained, and the effects of the coral concrete strength (fc), aluminum content (alpha), and hoop coefficient (xi) on the bearing capacity, stiffness, and ductility of the combined columns were analyzed. The finite element method was used to analyze the parameter extension. Eight models were subsequently tested for their applicability to determining the bearing capacity of CCFAT circular short columns via experiments and finite element analyzes. The results showed that the failure patterns of the CCFAT short columns were similar, the load-deformation relationships included three stages, and the combination of aluminum alloy round tubes and coral concrete exhibited good performance. The ultimate bearing capacity and axial compressive stiffness increased with increasing coral concrete strength and aluminum content, respectively. The strength index showed approximately quadratic growth with the hoop coefficient, and the stiffness index was positively correlated with the hoop coefficient. Its ultimate strain increased with increasing aluminum content and decreased with increasing coral concrete strength. The yield strain did not show any significant changes in characteristics. The ductility index exhibited a strong positive correlation with the hoop coefficient. The finite element validation results were preferable, the accuracy of the computations was high, the hoop coefficient was more important than the coral concrete strength for enhancing the ultimate bearing capacity, and the Mir or STL model can be used to calculate the bearing capacity of CCFAT short columns.