🕑 Reading time: 1 minuteCompressive strength of mortar is determined by using 2 inch or 50mm cubes as per ASTM C109 / C109M - Standard Test Method for Compressive Strength of Hydraulic Cement Mortars. Mortar is a combination of cement, sand mixed with water. It is used for masonry works such as brick masonry and stone masonry and for plastering walls, columns etc. Common mix ratio of mortar used in masonry works are 1:3, 1:4 and 1:6 of cement to sand ratio. For important masonry structures such as brick walls, 1:3 ratio is used.