高温后圆钢管高强混凝土界面黏结性能试验研究

为揭示历经高温作用后圆钢管与高强混凝土界面间的黏结滑移性能，设计17个试件进行推出试验，试验考虑了高强混凝土强度等级、历经最高温度和界面黏结长度3个变化参数，通过试验，观察了试件的破坏过程及形态，得到试件加载端及自由端的荷载-滑移曲线，基于试验实测数据深入分析各变化参数对黏结强度、界面耗能及损伤的影响规律，提出了高温后圆钢管高强混凝土界面黏结强度的计算式以及黏结滑移本构方程。结果表明：随历经温度的升高，圆钢管与高强混凝土界面黏结强度呈现先增大后减小的变化规律；随着历经温度的升高，黏结强度随混凝土强度等级的提高而增大的影响程度逐渐减弱；界面黏结损伤随历经温度的升高有所推迟；界面黏结耗能能力随历经温度与混凝土强度等级的提高而下降。

INTERFACE BOND BEHAVIOR BETWEEN CIRCLE STEEL TUBE AND HIGH STRENGTH CONCRETE AFTER HIGH TEMPERATURES

In order to reveal the interface bond behavior between a circle steel tube and high strength concrete (HCST) after high temperatures, a total of 17 circle steel tubes filled high strength concrete specimens were designed for a push-out test after high temperatures, by considering three parameters such as high strength concrete grade, max high temperature and of bond length. The load-slip curves, bond strain distribution and parameters of feature points were obtained. After that, the computational formulas for residual bond strength were gained by regression. The influence of change factors on the slip behavior of HCST specimens was analyzed, and the bond slip constitutive formula was put forward. The results show that:the bond strength decreases with the increase of temperature, the effect of bond strength increases with the strengthen of concrete subsided after temperature; the bond damage process was postponed with the increase of temperature; the energy dissipation capacity of the bonding interface increased with the rise of concrete strength grade and temperature.