Compressive strength and sulfate resistance of limestone and/or silica fume mortars

In this study, compressive strength and sulfate resistance of mortars containing silica fume and/or limestone in different replacement levels were examined. For this purpose, limestone was used as 5%, 20%, 35% and silica fume was used as 5%, 10%, 15% by weight of cement. Sixteen different blended cements were prepared containing limestone and/or silica fume in different ratios. Mortar mixtures were prepared using these 16 cements. Flow values and 2, 7, 28, 90, 180 day-compressive strengths of the mortar mixtures were determined. In addition, sulfate resistances of mortars were separately determined in sodium and magnesium sulfate solutions. Consequently, it was seen that negative effect of silica fume on workability of mortars and limestone on compressive strength of mortars can be compensated by using limestone and silica fume together. Simultaneous use of limestone and silica fume was showed to increase sulfate resistance of mortars.

► The negative effect of silica fume on workability can be compensated by use of limestone and silica fume together.
► The negative effect of limestone on compressive strength can be compensated by use limestone and silica fume together.
► Simultaneous using of limestone and silica fume was significantly increased sulfate resistance of mortars.
► Sulfate expansions of all mortar mixtures in magnesium sulfate solution were higher than in sodium sulfate solutions.