氯氧镁水泥钢筋混凝土通电锈蚀的断裂性能分析

为了得到氯氧镁水泥钢筋混凝土开裂时的临界锈胀力,基于断裂力学研究了氯氧镁水泥钢筋混凝土在通电锈蚀试验下的断裂性能.根据Glinka-Shen权函数法,利用已知参考荷载下的裂纹尖端应力强度因子,得到孔边单裂纹方形板的权函数;然后推导出孔边单裂纹方形板的裂纹尖端应力强度因子计算公式;最后,由混凝土断裂准则给出通电锈蚀下混凝土开裂时临界锈胀力的计算公式及变化规律.结果表明:随着裂纹长度的增加,裂纹尖端应力强度因子增加,临界锈胀力减小;随着钢筋直径的增加,裂纹尖端应力强度因子减小.

Fracture Behavior Analysis of Magnesium Oxychloride Cement ReinforcedConcrete under Electric Corrosion

In order to obtain the critical rust expansion force of magnesium oxychloride cement reinforced concrete during cracking, the fracture behavior of magnesium oxychloride cement reinforced concrete under electric corrosion was studied based on fracture mechanics. According to Glinka Shen weight function method, the weight function of square plate with single crack at hole edge was obtained by using the known stress intensity factor at crack tip under reference load. Then the formula of stress intensity factor at crack tip of square plate with single crack at hole edge was deduced. Finally, according to the fracture criterion of concrete, the formulas for calculating the critical rust expansion force of concrete cracking under electric corrosion and its variation law were given. The results show that with the increase of interfacial crack length, the stress intensity factor at crack tip increases while the critical rust expansion force decreases. The stress intensity factor at crack tip decreases with the increase of the diameter of reinforcing bar.