Electrical Resistivity Measurement to Study Alkali-Silica-Reaction Cracking in Mortar

Alkali-silica-reaction (ASR) cracking in concrete is one of the primary concerns in the structural integrity assessment of concrete infrastructures. Therefore, characterizing the susceptibility of concrete to ASR and ways to address this issue is crucial in the design of concrete structures. In this paper, electrical resistivity measurement was used to study ASR in mortar containing reactive aggregate and correlated with the mortars' expansion. Mechanical strength tests and microscopic examination were carried out to obtain an understanding of the effect of ASR on the mortar strength and microstructure. Control mortar and mortar with glass powder as a supplementary cementitious material were prepared and used for comparison. The results indicated that ASR cracking in the microstructure of the control mortar significantly affected electrical resistivity and resulted in a degradation of the mechanical strength of mortars. It was shown that glass powder modified mortar was resistant to ASR expansion and alkali binding was a primary mechanism mitigating ASR in the glass modified mortar.