Chloride-induced corrosion is one of the primary causes of the degradation of reinforced steel in concrete structures. Currently, the rapid chloride permeability test (RCPT) is the most specified method to determine the concrete’s resistivity to chloride ingress, thus a determining factor in assessing the durability of concrete. While it is widely specified, it is also one of the most criticized test methods in research. There have been significant research efforts to correlate surface resistivity measurements to RCPT values. This study expands on the knowledge of resistivity measurements, correlating experimental data from bulk and surface resistivity measurements to the formation factor. The formation factor is the bulk resistivity of the concrete normalized by the pore solution resistivity. This method overcomes the criticism of the RCPT method, including mitigating the Joule effect and incorporating the pore solution composition. This study also compares porosity and sorptivity results to formation factor measurements. The results show a strong correlation between surface resistivity measurements and the formation factor suggesting that the formation factor is a viable replacement for the RCPT method as a performance-based specification.
As a result of the ingress of chloride ions, corrosion of reinforcing steel may cause premature deterioration and ultimately structural failure resulting in a shortened service-life of the structure. The apparent diffusion coefficient is a vita parameter in service-life modelling and can be measured through ASTM C1556. This study compares the values measured according to ASTM C1556 to the predicted apparent diffusion coefficient utilizing the experimentally obtained measurements of the formation factor, porosity, and binding isotherms.