A new method of enhancing cement-aggregate interfaces II. Mechanical properties and sulphate attack resistances of mortars

Effects of interfacial microstructures on mechanical properties and sulphate attack resistances of mortars were investigated based on a new method of enhancing cement-aggregate interfaces. The experimental results indicate that both mechanical properties and sulphate attack resistances of mortars can be substantially increased by using aggregates having hydraulic surface layers. The cause lies in that very dense interfacial zones form during the process of hydration in mortars containing these aggregates. As a comparison, the same properties of mortars containing inert aggregates were studied, and the results show that much lesser mechanical strengths and sulphate attack resistances were obtained just because much looser transition zones than the bulk pastes occur in these mortars.