Effect of polycarboxylate superplasticizer on contribution of interfacial transition zone to electrical conductivity of Portland cement mortars

摘要

The effect of a polycarboxylate high-range water-reducing admixture on the electrical conductivity and interfacial transition zone (ITZ) characteristics of portland cement mortars was evaluated using AC impedance spectroscopy, mercury intrusion porosimetry, and two electrical conductance models: the interfacial excess conductance and Bruggeman's asymmetrical effective medium theories. Mechanical tests were also performed. Mortar specimens used had sand-cement ratios (s/c) of 0.5, 1.0, and 1.5, aqueous high-range water-reducing admixture dosages 0, 0.3, and 0.75% (by mass of cement) and a water-cement ratio (w/c) of 0.35. The results showed that the presence of the polycarboxylate high