TEST OF RECYCLED AGGREGATE CONCRETE FILLED SQUARE STEEL TUBE COLUMN SUBJECTED TO ECCENTRIC COMPRESSION AFTER HIGH TEMPERATURE

In order to investigate mechanical performance of recycled aggregate concrete filled square steel tube column after high temperature subject to eccentric compression，eccentric compression static monotonic loading test were carried out to nine specimens． Two main influence factors including replacement rate of recycled coarse aggregate and highest temperature of the specimens experienced were considered． It was observed the whole experiment process and the failure modes of the specimens，and got some important information such as ultimate bearing capacity，loaddeformation curves and cross section strain distribution． It was analyzed the influence of the changing parameters on the four main mechanical properties including ultimate bearing capacity，compressive stiffness，ductility and energy dissipation capacity． The destructive process was made up of three stages，the elastic stage，yield stage，and destruction stage． The results showed that the highest temperature had great impact on mechanical properties of specimens: with increase of temperature，the ultimate bearing capacity and the compressive stiffness of specimens decreased obviously; while the replacement rate of recycled coarse aggregate had little influence on the mechanical properties of specimens．