Experimental study on CFNRST members under combined compression and bending

Abstract The concrete filled narrow rectangular steel tube (CFNRST) member is being increasingly used in the apartment buildings in China. Experimental study is conducted on the behavior of CFNRST members subjected to combined compression and uniaxial bending about the weak axis. Eleven specimens were fabricated considering the variation of key parameters including the slenderness, the width/height ratio of cross-section and eccentricity of compression. Comparisons are made between the predictions of representative solutions of design codes and the test results to examine their capacity for predicting the ultimate load of CFNRST members. New solutions with modifications on two existing solutions are proposed for the ultimate load of CFNRST members subjected to combined compression and uniaxial bending. Good agreements are achieved between the predictions of the proposed solutions and test results.