Effects of water to cement ratio, recycled fine aggregate and air entraining/plasticizer admixture on masonry mortar properties

•The effects of w/c ratio, RFA and admixture on masonry mortar properties are analysed.•Masonry mortars manufactured with up to 100% of RFA are technically feasible.•The w/c ratio was the major determinant for consistency, dry bulk density, and mechanical strength.•The RFA was the most determining factor for fresh bulk density.•The AEPA was the major determinant for air content and capillary water absorption coefficient. The main aim of this study has been to determine the influence of total water to cement ratio, recycled fine aggregate from construction and demolition waste, and air entraining/plasticizer admixture on the properties of masonry mortar. Two mortar series were prepared using varying percentages of dry or pre-soaked recycled fine aggregate to replace natural fine aggregate, and four different dosages of air entraining/plasticizer admixture. Data were analysed using three-way and one-way ANOVA, in order to determine the effect of the factors and to compare the means of the mortars manufactured. The results showed the technical feasibility of masonry mortars manufactured with up to 100% of recycled fine aggregate. In addition, total water to cement ratio was the most determining factor for consistency, dry bulk density, and compressive and flexural strength; the recycled fine aggregate for bulk density; and the air entraining/plasticizer admixture for air content and capillary water absorption coefficient.