Electrical Resistivity Measurements for Quality Control During Concrete Construction

In severe environments, new concrete structure production increasingly uses chloride diffusivity requirements as a concrete durability performance-based specification. Chloride diffusivity testing is both elaborate and time-consuming, however, as a concrete quality control basis during concrete construction. Using the Nernst-Einstein equation as a basis, the given concrete's electrical resistivity and chloride diffusivity relationship should therefore first be established. Then routine-based electrical resistivity measurement during concrete construction can indirectly control chloride diffusivity. There are several test methods for concrete electrical resistivity measurement. Such measurements may also be affected by several factors. An experimental program was carried out in order to provide more information about some of those factors, since, in regard to electrical resistivity during concrete construction, they may affect results and allow simple routine-based quality control procedures to be established. Primarily based on four-electrode (Wenner) electrical resistivity testing, the test program included different test specimen geometry and probe spacing. Some two-electrode measurements were also performed for comparison. Test results are primarily presented as relative resistivities that two different test methods obtained in order to describe various factor effects that resistivity may be affected by. That, for given testing conditions, Wenner-method obtained electrical resistivity differs from two-electrode method obtained resistivity is shown in the results. The authors conclude that, however, for a given concrete specimen type with given temperature and moisture conditions, a suitable and reliable test method for performance-based electrical resistivity quality control, and hence, concrete durability, during concrete construction appears to be the Wenner method.