Factors affecting the electrical resistivity of concrete

Field experience indicates that the traditional design methods are not effective for obtaining durable structures and performance-based methods are attaining more interest. For the production of new concrete structures in severe environments, requirements to chloride diffusivity are increasingly being used as a performance-based specification for concrete durability. As a basis for the concrete quality control during concrete construction, however, the testing of chloride diffusivity is both time-consuming and elaborate. Therefore, the relationship between chloride diffusivity and electrical resistivity should first be established. Then the chloride diffusivity can indirectly be controlled by routine-based measurements of the electrical resistivity during concrete construction. Electrical resistivity is a non-destructive testing method, which allows rapid inspection of concrete structures. Several factors affect such measurements. To provide more information about some of those factors that may affect the results and establish some simple procedures for a routine-based quality control of the electrical resistivity during concrete construction, an experimental program was carried out. The test program included different environmental conditions such as temperature and humidity as well as different concrete mixtures and factors such as binder type, and aggregate content were investigated.