PUSH-OUT TESTS ON CIRCULAR CONCRETE-FILLED DOUBLE-SKIN STEEL TUBULAR COLUMNS
Wei Li * and Bing Chen
Department of Civil Engineering, Tsinghua University, Beijing, PR China
This paper experimentally studies the bond-slip behavior of steel tubes to sandwich concrete interfaces of circular concrete-filled double skin steel tubes (CFDST). A series of push-out tests were conducted on CFDST specimens. The parameters included the diameter to thickness ratio of both outer and inner steel tubes, the hollow ratio of the cross section, the roughness of steel surface, the shrinkage of sandwich concrete and the cross-sectional dimensions. The load-slip curves and the strain of steel tubes were recorded in the tests. The influences of parameters were analyzed. It was found that the bond strength of the outer tube to concrete interface of CFDST was comparable to that of concrete-filled steel tube, and the bond strength of the inner tube to concrete interface was generally higher than that of the outer tube to concrete interface.
CFDST column; Push-out test; Bond behaviour; Steel tubes to concrete interfaces; Bond stress-slip relation.