Concrete Hydration Based on Electrical Resistivity Measurement

The hydration process of concrete has been studied §using a non-contact electrical resistivity §measurement. Cement hydration stages have been §classified and the hydration mechanism has been §interpreted based on the analysis of resistivity §development curve and the investigations of §microstructure. The proposed concrete conduction §model shows that the degree of hydration dominates §concrete resistivity. It also proposes some §practical applications of the resistivity §measurement in the activity evaluation of mineral §admixtures, the selection of a superplasticizer and §the determination of concrete setting time. A §criterion has been proposed for selecting a suitable §superplasticizer. The more suitable superplasticizer §is the one which gives the mixture a higher Kr and a §higher Kt at the saturation dosage. The quantitative §relationship between the setting time of concrete §measured with the traditional penetration resistance §method and the time at which the electrical §resistivity critical points occurred has been §developed. The electrical resistivty measurement can §be used as an alternative method to determine the §setting times of concrete.