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.