STUDY OF MECHANICAL BEHAVIOR OF RECYCLED AGGREGATE CONCRETE FILLED CIRCULAR STEEL TUBE COLUMNS UNDER ECCENTRIC LOADING AFTER HIGH TEMPERATURE

To study the mechanical behavior of recycled aggregate concrete-filled circular steel tube ( ＲACFCST) columns under eccentric loading after high temperatures，by changing parameters including replacement ratio and high temperature， 9 ＲACFCST columns with different recycled coarse aggregate after different high temperatures were designed and tested under monotonic static loading． The failure modes of specimens were observed，and then the loading-deformation and loading-strain curves of the entire loading process were obtained． The influence of the two varying parameters on the mechanical behavior of ＲACFSCT eccentric compression columns， for instance，bearing capacity，stiffness degradation， displacement ductility，and energy dissipation was analyzed． The results showed that the failure process and failure modes of ＲACFCST columns after high temperature were similar to normal specimens． It was found that ＲACFCST columns had high bearing capacity and better deformation performance．With the increase of temperature，ultimate bearing capacity and initial stiffness of RACFCST columns significantly reduced，while the influence of aggregate replacement ratio on the mechanical behaviors，such as bearing capacity，stiffness etc was not obvious．