Concrete Resistivity Measurements for Chloride-Induced Accelerated Corrosion Monitoring of Reinforced Concrete Slabs

Corrosion of steel embedded in concrete and succeeding concrete cracking is a major reason for damage to reinforced concrete (RC) structures. The quality of concrete surrounding reinforcing steel bars plays a very important role in controlling the corrosive environment in concrete. The degradation of concrete quality due to the penetration of chloride ions through the microstructure of concrete highly depends on the electrical resistivity of concrete. Therefore, electrical resistivity measurements on the concrete are gaining importance in structural health monitoring surveys. Concrete electrical resistivity measurements are affected by various parameters such as concrete cover, geometrical confinement, ambient conditions, presence of rebar, spacing of rebars, rebar diameter, probe configuration, and spacing of probes. This paper aims to study the effect of various electrode probe configurations on concrete resistivity measurements during the monitoring of accelerated corrosion in RC slabs. An experimental investigation is carried out to monitor the chloride-induced accelerated corrosion in RC slabs using concrete resistivity as well as half-cell potential techniques. The result showed that the electrode probe configuration has a significant effect on concrete resistivity measurements. Besides this effect, the investigation has confirmed that the concrete resistivity technique can be effectively used for monitoring the chloride-induced accelerated corrosion process in RC slabs.