利用iTECS检测桥梁混凝土结构的内部缺陷

Detection of internal defects of concrete based on iTECS

通过iTECS(Integrity Test Equipment for Concrete Structures)检测三小营南桥T梁混凝土厚度,利用最大熵频谱分析和傅里叶频谱分析结果误差很小,最大熵谱分析更精确.通过多次试验,得出根据测试厚度判断混凝土结构内部离析、不密实与空洞的不同方法:当测试的厚度明显小于实际厚度时表明该混凝土构件内部存在孔洞;当测试的厚度远大于实际厚度时表明该混凝土构件内部存在不密实、离析等缺陷.通过对室内大厚度混凝土结构的厚度探测,发现当混凝土结构内部缺陷深度超过一定范围时,利用iTECS只能测试混凝土结构内部缺陷的位置,而不能精确的探测出缺陷的深度.同时对正对空洞处及空洞边缘处测试到的明显不同厚度进行了探究.

It was found that iTECS based on impact-echo method can accurately detect the thickness of concrete structure with two frequency spectrum analysis methods which are MEM and FFT. Through many experiments, the different ways to judge the internal segregation, not dense and voids of con- crete construction were obtained base on the measuring thickness. Results was detected based on the iTECS. It was showed that there were voids in the concrete if the thickness of the test was significantly less than the actual thickness of the concrete structures, there was segregation and not dense in the concrete if the thickness of the test is much larger than the actual thickness of the concrete structures. Through laboratory experiments, it was found that if the depth of internal defect in the concrete exceeds a certain range, the iTECS can only test the general location, but cannot accurately detect the depth of internal defects. This paper also analyzed the reason of the obvious difference in thickness between the voids and the edge.