Influence of pre-soaked recycled fine aggregate on the properties of masonry mortar

•The use of pre-soaked recycled fine aggregate (RFA) slightly reduced the consistency of masonry mortars.•Pre-soaking increased the compressive strength of masonry mortar.•Only mortars with pre-soaked RFA matched the compressive strength of the control mortar.•Using RFA without increasing total water content gave greater compressive strength than natural aggregate mortars.

The main aim of this study has been to determine the influence of pre-soaked recycled fine aggregate (RFA) on the properties of masonry mortar. A control mortar and six mortar series were prepared in which 25%, 50%, 75% and 100% natural aggregate (NA) was replaced with pre-soaked or non-pre-soaked RFA. Total water content of the recycled mortars was equal to or greater than that of the control mortar. The results show that pre-soaking slightly reduced the consistency of the mortar while improving bulk density (in both the fresh and hardened state) and air content, particularly with total NA substitution; compressive and flexural strength were increased with all RFA ratios. Therefore, the pre-soaking method of masonry mortar manufacture can help reduce the absorption capacity of these aggregates and improving recycling.