Development of mix design methodology for the masonry mortar with crushed sand and fly ash

The objective of this study is to design a comprehensive method for mix design of masonry mortar utilizing crushed sand (M-sand) as a sustainable replacement to natural sand by weight batching. The research analyses the performance of mortar at w/c ratios of 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1.0 at target flow values of 100% and 150%, except 0.3 for 150% flow. Two mix variations were designed: one composed of 100% Ordinary Portland Cements (OPC) and the other with a 30% replacement of OPC with fly ash as a supplementary cementitious material (SCM). Workability was flow tested following relevant standard codes, and mechanical performance was assessed by a compressive strength test. Correlations between compressive strength and water-cement ratio are established using the results. It helps in optimizing masonry mortar mix proportions with M-sand and fly ash, with a minimum masonry mortar proportion to achieve sustainable construction while maintaining specification requirements appropriate for workability and strength.