ESTIMATION OF REBAR DIAMETER IN CONCRETE STRUCTURAL ELEMENTS USING GROUND PENETRATING RADAR

The objective of the present study is to locate the rebar and estimate the rebar diameter in reinforced concrete (RC) structures non-destructively, using Ground Penetration Radar (GPR). Laboratory studies have been carried out on specially cast concrete block specimens with known rebar diameter.Radargrams have been collected using GPR with 1.6 GHz antenna. The collected radargrams have been converted into ASCII files that contain the amplitude values of the reflected signals at every interface. The key function of the process is converting the analog signals into digital signals. The digital signal is represented by numerically encoded values corresponding to the amplitude of the electromagnetic waves reflected from the concrete-steel interface. Based on the available procedures, a methodology is proposed to get the relation between the power reflectivity and length of the scan. Based on the available procedures and limited laboratory studies, it is found that the estimated rebar diameter is in close agreement with the actuals.