Effect of limestone fines as a partial replacement of cement on the chemical, autogenous, drying shrinkage and expansion of mortars

The use of limestone with its different applications in paste, mortar, and concrete has become a common practice, not only for the urge to control the environmental impact and conserving the virgin materials but also to improve their performance in different environment. This study focused on the effect of incorporating different percentage levels of limestone fines (LF) on the shrinkage and expansion development of mortar specimens for a total period of 28 days. To observe this effect, a total of 5 mortar mixes were employed with five substitution rate of cement with LF ranging from 0 to 20%. The ratios of water to binder and sand to binder remain constant at 0.45 and 2 respectively. Testing consisted of three types of length change; chemical, drying and autogenous shrinkage as well as expansion. It was observed that adding up to 10% LF enhanced the chemical and autogenous shrinkage of mortars. Likewise, incorporating up to 10% LF increased the expansion in mortar specimens. However, drying shrinkage of mortars increased as LF content went up. Overall, the results indicate that there is strong correlation between the chemical shrinkage and the other length change parameters and expansion.