MECHANICAL PROPERTIES OF HGMFSST COLUMNS UNDER AXIAL COMPRESSION-EXPERIMENT AND ANALYSIS

High-strength grouting material (HGM) has the characteristics of early strength, high strength, high self-flow, and micro-expansion, but research on composite columns formed by steel tube and HGM is relatively scarce. Therefore, in this paper, the mechanical properties of HGM-filled square steel-tube columns (HGMFSST columns) under axial compression were experimentally studied. The main parameters included tube thickness (t) and HGM strength (fck). The test results showed that members with t = 4 mm failed due to local buckling, and members with thicker steel tube thickness failed mainly due to overall buckling. The measured and predicted ultimate bearing capacity values of the HGMFSST columns based on the existing standards of GB 50936-2014, CECS 159: 2004, AISC/ANSI 360-16, EC4, and AS/NZS 2327: 2017 were compared. The ultimate bearing capacity derived with CECS 159: 2004 was the closest to the measured values and had minimum discreteness.