Application of electrical resistivity for estimating compressive strength of FRC at early-ages

The addition of fibers improves the ductility and compressive strength of concrete. Utilizing fiber in concrete, on the other hand, alter the electrical conductivity of concrete and that is especially important when concrete is being used in applications that electrical resistivity of concrete has been taken into account in the design process. Electrical resistivity of concrete can be measured using nondestructive testing techniques. Electrical resistivity has been proven to be in relationship with compressive strength of cementitious materials. The link between surface electrical resistivity (ER) and compressive strength (CS) of FRC at early ages has been investigated in the current study. Twenty-one distinct FRC mixtures have been cast using various fiber types, w/c ratios and fiber volume fractions. Test results have shown a strong relationship between electrical resistivity and mechanical properties of fiber reinforced concrete. A novel empirical equation has been proposed to estimate the compressive strength of early-age fiber reinforced concrete. The adequacy of this equation was determined by comparing actual and projected compressive strength values for FRC using a coefficient of variation. The early-age compressive strength of FRC was found to be reliable when the proposed equations were utilized.