Abstract:
In order to investigate the aseismic performance of recycled concrete filled circular steel-tube (RCFCST) columns, ten specimens were designed for a low cyclic reverse loading test. The four parameters such as recycled coarse aggregate replacement percentage, slender ratio, axial compression ratio and steel tube thickness were considered in the test. The failure process and modes of specimens were observed, and the hysteretic curves also obtained. Based on the test data, the effects of these parameters on the aseismic performance indexes such as displacement ductility, strength, stiffness and energy dissipation coefficients of specimens were discussed. The study results indicates that:the failure modes of RCFSST columns are similar to that of normal concrete filled circular steel-tube columns, and all of specimen's failure modes were local steel tube buckled and concrete crushed at the bottom of columns. The hysteretic curves are plump, whose shapes change from the early fusiformis to later arches. The aseismic performance index of a RCFSST column can meet the Chinese aseismic code requirements; and it can be used in the building of an anti-earthquake zone. With the decrease of slender ratio, only the energy dissipation coefficient is decreased, and the others aseismic performance indexes are increased. In this experimental vary range, the variation range of axial compression ratios is not sensitive to the aseismic performance of specimens, only the stiffness has a little decreased with the axial compression ratio's decreasing. With the steel tube thickness's increasing, the strength, elastic stiffness and energy dissipation coefficients of specimens are obvious improved.