Compressive Strength and Electrical Resistivity Development of Cement Mortars Containing Silica Fume and Fly Ash

Abstract

The main aim of this research was to study the development of engineering properties and electrical resistivity of ternary blended cement mortars containing Portland cement, silica fume, and fly ash. Test results showed that the replacement of Portland cement with silica fume and fly ash resulted in a small increase in setting times, as compared to the control mortar (OPC). In general, compressive strength of cement mortar containing cement and silica fume (10SF) was the highest at all tested ages. The use of 10% silica fume combined with various amounts of fly ash led to a systematic decrease in compressive strength at 24 hours, as compared to the mixes without fly ash. However, after the age of 24 hours, compressive strengths of all fly ash containing mortars were higher than that of the control sample. For the electrical resistivity test, it was found that the rate of strength gain was linearly correlated with the rate of electrical resistivity increase during the first three days.