STUDY ON ECCENTRIC COMPRESSION BEHAVIORS OF RECYCLED AGGREGATE CONCRETE FILLED STEEL TUBULAR LONG COLUMNS

Eccentric compression static monotonic loading test was carried out on 10 recycled aggregate concrete(RAC) filled cycled steel tubular long columns and 10 RAC filled square steel tubular long columns. The changing parameters including replacement rate of recycled coarse aggregate, slenderness ratio and eccentricity were considered. The whole force process and failure modes were observed, while important curves about load-deformation and load-strain were drawn, while strain distribution along cross section height was made. The influence of the changing parameters on the ultimate bearing capacity was analyzed, while the ultimate bearing capacity of two section types was calculated by 8 related procedures. It is shown that force process is made up of elastic stage, yield stage and destruction stage, while failure modes are mainly destruction of elastic-plastic instability. It is suggested that the ultimate bearing capacity of RAC filled cycled steel tubular long columns under eccentric compression can be designed using DL/T 5085-1999 and DBJ13-51-2003, while RAC filled square steel tubular can be designed using CECS159:2004 and DBJ13-51-2003.