Current codes and standards use a prescriptive-based approach for the durability design of concrete, whereby requirements for compres- sive strength, cement content and water/cement ratio are prescribed based on the exposure class and life span of the structure. Additionally, for reinforcement corrosion, codes and standards also specify maximum flexural crack widths. Of late however there has been a shift from prescriptive-based durability design approach to that of performance–based approach. The latter approach requires the durability control- ling parameter(s) to be identified along with corresponding test(s) and an appropriate service life prediction model to determine the service life of the structure. This article describes the use of electrical resistivity of concrete as a durability performance parameter, as well as the additional information that the resistivity provides, such as the setting period, the mechanical strength and the degree of curing. A brief method on how to design a concrete mix for a target resistivity is also provided.
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