冲击回波法检测混凝土结构厚度与缺陷的试验研究

Experimental Study on Detecting Thickness and Defects of Concrete Structure by Impact-Echo Method

为了验证冲击回波法检测混凝土结构厚度及内部缺陷的有效性与适用性,根据实际工程中混凝土结构常见的质量缺陷特征,设计制作了一系列含有不同类型和性质缺陷以及无缺陷的混凝土模型试件,并应用冲击回波法对这些模型试件进行检测试验,据此深入研究了冲击回波方法所激发的低频应力波在混凝土介质中传播的基本特性及影响因素,并对冲击回波法检测混凝土厚度和内部缺陷的检测识别方法以及检测适用范围进行了系统的研究。试验结果表明:对于只具备单一检测面的混凝土结构检测,冲击回波法是目前最为有效的无损检测方法,在其适用范围内能够得到较好的检测结果,但是,目前该方法在测试能力上尚存在一定的局限性。

To verify the effectiveness and applicability of Impact-Echo method in detecting the thickness and internal defects of concrete structures,in this study we design defect-free concrete specimens and concrete specimens containing different types and properties of defects in line with common defects of concrete structure in practical engineering,and apply Impact-Echo method to testing these model specimens. The basic characteristics and influence factors of low frequency stress wave excited by the impact echo method are studied,and the detection techniques and application range of impact echo method are analyzed systematically. Research results show that the impact echo method is currently the most effective non-destructive testing method for concrete structures with only a single detection surface. Within its scope of application,satisfactory detection results can be achieved,yet still with some limitations in the test capability.