本文分别进行了4根管径为219 mm和4根管径为273 mm、壁厚为8 mm的钢管混凝土轴心抗压试验，其核心混凝土膨胀剂参量分别为0%、5%、7%、9%。并通过有限元对核心混凝土膨胀剂参量分别为0%、5%、7%、9%，管径为219、273、350、400，壁厚为8的钢管混凝土进行分析。结果显示，膨胀剂参量为5%、7%时，钢管混凝土的承载力分别提高53.0%、44.5%；膨胀剂参量为9%时，钢管混凝土承载力反而有所降低。因此膨胀参量应控制在5%~7%较为合理。
In this paper, the axial compression test of concrete filled steel tube with 4 pipe diameters of 219 mm and 4 pipe diameters of 273 mm and wall thickness of 8 mm was conducted respectively, which the core concrete expansion agent parameters are 0%, 5%, 7% and 9% respectively. And the finite element model was used to analyze the core concrete expansion agent parameters of 0%, 5%, 7%, 9%, and pipe diameters of 219, 273, 350, 400 and wall thickness of 8. The results show that when the expansion agent parameters are 5% and 7%, the bearing capacity of the concrete-filled steel tube is increased by 53.0% and 44.5%, respectively. When the expansion agent parameter is 9%, the bearing capacity of the concrete-filled steel tube is reduced. Therefore, the reasonable expansion parameters should be controlled at 5% to 7%.
