Rebar Detection Using Gpr: an Emerging Non Destructive Qc Approach

Civil infrastructure especially the rigid pavements have been increasingly covering a huge part of the infrastructure around us with the demand of rapid urbanization. The quality and condition assessment of it after its construction is an important issue with the engineers. The need for defect diagnosis and verification of their various design parameters is vital and important for quality control and decision making steps because of various economic, quality and safety reasons. In India, the pavement evaluation is done solely by conventional destructive methods involving a lengthy procedure of core drilling, sampling and laboratory testing which, due to the same reason, is time consuming, costly and traffic disturbing in nature. An innovative non-destructive high resolution subsurface imaging technique (ground penetrating radar ‘GPR’) has been used to monitor the RCC (reinforced cement concrete) pavements parameters at IIT Roorkee, India, to overcome the existing difficulties. It has substantially reduced manpower requirement, time, money and traffic disturbances. In this paper a successful attempt has been made nondestructively using 1000 MHz antenna based GPR to verify the presence and array size of rebars used in RCC roads along with its depth, concrete thickness and the masking effects of rebars on deep features.