Effects of ultra fines in quarry dust on properties of mortar

Abstract

The Quarry dust (QD) is being extensively used as fine aggregates for both mortar and concrete applications as an alternative to river sand. Because of the limited availability of river sand it is necessary to search for alternatives and QD has been identified as one of the best preferred options. QD in this article is referred to quarry dust without changing its original composition. The differences in chemical and physical properties of river sand and OD are significant enough to behave differently in their applications. The primary reason which causes the difference is the physical property. One of the noticeable physical difference is that the possession ultra fines (UF) in different quantities. UF in this context is re ferred as particles less than 75pm. Effects of UF on properties of mortar such as workability, compressive strength, tensile strength and sorptivity were evaluated. Mix proportion of 1:3 cement : fine aggregate was selected with fixed w c ratio of 0. 7. QD with different UF contents (i.e. 5%, 10%. 15 <5:25%) and river sand were considered in study. Results showed that complete removal of UF gave high compressive strength, increased workability', increased sorptivity and lower shrinkage than QD.