Wideband Subsurface Radar for Bridge Structural Health Monitoring and Nondestructive Evaluation

The nondestructive evaluation (NDE) inspection for building and bridge structures has attracted a lot of attentions for the fundamental research and the sensor system development. In this paper, development of a distant subsurface imaging radar is reported. Theoretical background of subsurface radar imaging is first provided. Experimental laboratory measurements using radar signals in the frequency range of 1-18 GHz were conducted. From the theoretical analysis and the initial experimental results on a laboratory reinforced concrete specimens, it is proved that the proposed subsurface imaging radar system can detect the location of steel reinforcement inside a concrete cylinder and identify the material property of panel specimens. Range-dependent attenuation of radar signals is experimentally studied using different materials. Findings are reported in the summary.