探地雷达应用于混凝土缺陷探测的试验研究

Experimental Study on Application of Ground Penetrating Radar to Detect Concrete Defects

探地雷达具有高精度、快速、无损、经济的特点,在水利、建筑等工程的混凝土质量检测中得到一定的应用,但都只是辅助手段,无法推广。通过制作存在干碎石层、漏振等质量缺陷及埋设钢筋、PVC管的混凝土模型,应用探地雷达对这些模型进行了探测试验。结果表明:采用探地雷达可以较为明显地判断出混凝土中存在的漏振、干碎石层缺陷,漏振区在雷达图像上表现为错层,干碎石层在雷达图像上呈现出高亮反应;单层钢筋的探测效果比较明显,在雷达图像上呈现出三层高亮反应,但其直径分辨比较困难;双层平行钢筋和十字交叉钢筋在雷达图像上可以分辨,但较为困难;双层十字交叉钢筋在雷达图像上分辨不出来;探地雷达检测上层钢筋、下层PVC管的图像效果比较明显。

Ground penetrating radar with the features of high-precision,rapid detection,non-destructive testing and less cost has been used to detect quality of concrete structures in such fields as hydraulic engineering and architectural engineering,however,it was not widely applied,only used as an auxiliary means.In the paper the testing process and result of ground penetrating radar made on concrete models prepared with quality defects such as dry gravel layer and non-vibrated section or embedded with steel bars or PVC pips was introduced.The test result indicates that ground penetrating radar can detect non-vibrated section and dry gravel layer in concrete model.The non-vibrated section is reflected as split layer in the radar image and dry gravel layer is reflected as high light section in the radar image.The single layer steel bars can be detected clearly and reflected as three layers high light reaction,however,the diameter can not be determined precisely.Double layer parallel bars and cross bars can be identified in the radar image,but quite difficult.Double cross bars can not be identified in radar image.Ground penetrating radar can clearly indicate upper layer of steel bars and lower layer of PVC pipes in the image.