Heavy encrypted silica fume for school cement

heavy encrypted silica fume for school cement (Heavy encrypted Silica Fume:90% 92% 95%)This encrypted Microsilica is usually added to school cements.Increased Strength. Silica in heavy encrypted silica fume reacts with calcium hydroxide, a hydration product of cement, to form hydrated calcium silicate colloids, thereby increasing the strength of concrete. Improves durability. Silica fume fills micropores and cracks in cementitious materials, reduces porosity and permeability, and improves the resistance of concrete to environmental factors such as carbonation, chloride and salt erosion, freezing and thawing, and abrasion. Reduces shrinkage. Silica fume can reduce the amount of cement and water-cement ratio, reduce the shrinkage stress and micro-cracks produced during the hydration of cement, thus reducing the drying and natural shrinkage of concrete.