Modeling for apparent resistivity estimation along direction of electrode array above rebar in electrical resistivity measurement

This paper proposes a method for estimating the resistivity of concrete surrounding a specific reinforcing bar using an electrical resistivity method above the steel bar. The previously proposed resistivity estimation model (REM) can estimate apparent resistivity and considers various factors such as concrete resistivity, steel resistivity, steel bar radius, concrete cover depth, and electrode interval. However, it is only applicable in the electrode array direction parallel to the steel bar. The proposed improved REM (I-REM) extends the analysis area to estimate the apparent resistivity depending on the measurement angle between an electrode array and the embedded steel bar. To verify the efficacy of the I-REM, the apparent resistivity of different experimental specimens were measured for various measurement angles and compared with the theoretical apparent resistivities estimated using the I-REM. Both sets of values were found to be in good agreement.