花纹方钢管与混凝土间粘结强度的推出试验研究

Push-out test study on the bond strength between square checkered steel tube and concrete

从提高钢管与混凝土自然粘结强度的角度,采用内置花纹的钢管进行9个方钢管混凝土的推出试验。考虑混凝土强度、花纹凸起高度2个因素的影响,得出钢管的荷载-滑移曲线、钢管应变沿纵向分布及特征粘结强度的大小。综合考虑这2个影响因素,统计回归出特征粘结强度的计算公式。试验结果表明,将花纹钢管引入钢管混凝土中,可显著提高钢管与混凝土界面上的极限粘结强度,同时极限粘结强度随花纹凸起高度的增大而增大;特征粘结强度的回归公式能够很好地拟合试验结果。

From the perspective of improving the natural bond strength between steel tube and concrete,the push-out tests of nine specimens about concrete filled square checkered steel tube were carried out. Considering the influences of two factors including concrete strength and the checkered pattern height,the load-slip curve,strain of the steel tube along the longitudinal position and the characteristic bond strength were obtained. Synthetically considering the two factors,a set of calculative formulas of three characteristic bond strengths were presented by regression analysis. The experimental results show that the introduction of checkered steel tube in concrete filled steel tube can significantly improve the interface ultimate bond strength between the steel tube and concrete,meanwhile the ultimate bond strength increases with the height of checkered pattern increasing; the regression formulas of characteristic bond strength agrees well with the test results.