Abstract:In order to study the mechanical properties of the recycled aggregate concrete and its steel tube columns made from earthquake waste, twenty steel tube columns filled with recycled aggregate concrete, which comprising of ten double skin circular and ten double skin square sections columns, were prepared. The main experimental parameters included the replacement ratio of recycled coarse aggregates, i.e. 0%, 25%, 50%, 75% and 100%, and the cross sections of steel tube columns, i.e. circular or square sections. The results show that the structural performance of steel tube columns filled with recycled aggregate concrete is similar to that filled with normal concrete. The load deformation curves and the strains response were compared. The results also show that the load carrying capacity becomes weaker as the replacement ratio of recycled coarse aggregates is higher. The compressive load versus displacement of the steel tube columns were calculated according to the stress strain relationship of the steel tubes and the recycled aggregate concrete. It is found that the calculated results are in good agreement with the experimental ones. Finally, the load carrying capacity of the columns was also calculated by the relative design rules. The results show that the theoretical calculations correlate reasonably well with the experimental data.