Mitigating strength loss in mortar due to application delay: quantified impact of additional water and cement

Abstract This study examines how application (i.e., “casting” another widely used term) delays affect the compressive and shear strengths of mortar in masonry constructions. It also explores the impact of adding supplementary materials like water and cement to the mortar. Mortar mixes were prepared using sand with a fineness modulus (FM) of 1.7 for plaster and 1.9 for brick binder, subjected to casting delays ranging from 0 to 4 h. Three physical conditions were utilized as follows: the 1st case—WAAW (without adding additional water); the 2nd case—AAW (adding additional water), maintaining initial mortar flow; and the 3rd case—AAWC (adding additional water and cement), maintaining initial mortar flow and initial mortar strength. In the 1st case, the fall of strength was greater than in the 2nd case. In the 3rd case, the amounts of additional cement and water were quantified to restore the initial strength of the mortar. This quantification can help avoid material loss in construction sites.