Application of Ground Penetrating Radar Technique in Defect Detection for External Wall Thermal Insulation System of Inorganic Thermal Insulation Mortar

In view of the widespread potential dangers such as cracking, hollowing and falling off in the external wall thermal insulation system of inorganic thermal insulation mortar, the basic principle of ground penetrating radar (GPR) technique for nondestructive testing of the external wall thermal insulation system is analyzed, and the technique is applied to the defect identification of the external wall thermal insulation system of inorganic thermal insulation mortar. Based on the GPR scanning profile images, the preset defects in the specimen of the external wall thermal insulation system of inorganic thermal insulation mortar are detected. Meanwhile, the applicability of the GPR detection technique to detect the defects with different locations and sizes in the specimen is discussed. Subsequently, the GPR scanning profile images are compared with the results of the acoustic signal, endoscopic imaging, local chiseling damage method and pull-out test in the field detection of the external wall thermal insulation system of inorganic thermal insulation mortar, and the sensitivity of the GPR detection technique to identify different defects is investigated. The research results show that the defects in the external wall thermal insulation system of inorganic thermal insulation mortar can be successfully detected based on the GPR detection technique.