震后混凝土缺陷加固修复构件性能实验分析

Experimental Analysis of the Performance of Reinforcement and Repair Members on Concrete Defects after Earthquake

摘要:

为避免震后建筑工程加固不合理导致再次受损，并为加固修复工程提供合理化建议，促进震后救灾工作顺利开展，提出震后建筑工程混凝土缺陷加固修复方法的研究。首先，对混凝土梁试件和混凝土柱试件进行设置，研究基于碳纤维布或外包钢套加固方法对混凝土梁和混凝土柱试件展开循环荷载试验；其次，通过混凝土梁试件滞回曲线、骨架曲线、延性及耗能情况，分析不同加固修复方法的混凝土梁试件抗震性能；最后，通过混凝土柱试件延性及耗能、刚度退化和承载力退化情况，分析采用不同加固方法修复的混凝土柱试件抗震性能。试验结果显示：高配筋率可提升混凝土梁试件滞回特性，外包钢套加固混凝土梁试件滞回饱满程度较高、耗能较少，碳纤维布加固梁试件可将加载位移由10 mm延缓至30 mm，提升延性；碳纤维布加固可提升混凝土柱延性，外包钢套加固重度缺陷混凝土柱可以良好抑制其刚度和承载力退化。试验结果验证了碳纤维加固可提升震后建筑工程混凝土结构延性，外包钢套加固可抑制混凝土结构刚度、承载力退化。

Abstract:

To prevent re-damage caused by the inadequate reinforcement of post-earthquake construction projects, provide reasonable suggestions for reinforcement and repair projects, and promote the smooth performance of post-earthquake disaster relief work, in this paper, we present our research on the reinforcement and repair methods used to address concrete defects in post-earthquake construction projects. First, we arranged concrete beam and concrete column specimens for testing and conducted cyclic load tests of these specimens using two types of reinforcement methods:carbon-fiber-reinforced polymer (CFRP) and enveloped steel. Then, based on the hysteretic curves, skeleton curves, ductility, and energy dissipation of the concrete beam specimens, we analyzed their seismic performances after they had undergone different reinforcement and repair methods. Lastly, based on the ductility, energy dissipation, stiffness degradation, and load-bearing degradation of the concrete column specimens, we analyzed their seismic performances after they had undergone different repair and reinforcement methods. The test results show that a high reinforcement ratio can improve the hysteretic characteristics of concrete beams, concrete beams strengthened with enveloped steel exhibit high hysteretic saturation and little energy consumption, and beams strengthened with CFRP can restrict loading displacement from 10 mm to 30 mm. Strengthening the CFRP can improve the ductility of concrete columns, and strengthening enveloped steel can restrain the degradation of stiffness and bearing capacity of these columns. The test results verify that CFRP reinforcement can improve the ductility of concrete structures in post-earthquake construction projects, and enveloped steel reinforcement can restrain the degradation of stiffness and bearing capacity of concrete structures.