Mortar Admixture is a granular mixture of sand, cement, and water that can be used as an alternative to using traditional sand and cement. Mortar Admixture can be mixed with water to create a paste-like mixture that can then be used to create mortar for bricks, concrete blocks, or stucco. Mortar Admixture is not recommended for outdoor use because it will not withstand weather conditions, and it will not stick to uneven surfaces.