腐蚀与荷载耦合作用下钢-混凝土组合梁长期变形研究

为探究腐蚀与荷载耦合作用下钢 混凝土组合梁长期变形规律，对钢-混凝土组合梁进行腐蚀与荷载耦合作用225d的长期性能试验，考虑不同加载龄期、栓钉锈蚀率对钢-混凝土组合梁界面相对滑移和长期挠度的影响。研究结果表明：在腐蚀与荷载耦合作用下，栓钉锈蚀率越高，组合梁的界面相对滑移及长期挠度也越大；长期挠度增长与混凝土徐变发展规律类似，与混凝土加载龄期7d的组合梁相比，混凝土加载龄期28d的组合梁长期挠度较小；基于龄期调整的有效模量法和应力重分布原理，考虑组合梁由混凝土收缩徐变和栓钉锈蚀引起的附加挠度，提出栓钉锈蚀条件下组合梁的长期挠度计算公式；组合梁长期挠度理论计算值与实测值吻合较好，可为工程实际运用提供参考。

Long-term deformation of steel-concrete composite beams subjected to coupling effect of corrosion and loading

To study the long-term deformation rule of steel-concrete composite beams under the coupling effects of corrosion and loading, taking corrosion rate of studs and loading age as variables, a long-term performance experiment over 225 days was carried out on steel-concrete composite beams. The result shows that, under the coupled effect of corrosion and load, both long-term relative slip of interface and deflection increases with the corrosion rate of studs. The increased rule of long-term deflection law is similar to that for creep of concrete. The long-term deflection of composite beams with a loading period of 28 days is smaller than that of 7 days. Based on the age-adjusted effective modulus method and the principle of stress redistribution, considering the additional deflection caused by the shrinkage and creep of concrete and the corrosion of studs, a long-term deflection calculating formula for corrosion of studs is proposed for steel-concrete composite beams. The theoretical value of long-term deflection of the composite beam has good agreement with the measured value, which indicates that the formula can provide reference for the practical application of engineering.