Silica Fume, also known as Microsilica is an ultrafine powder collected as a byproduct in the formation of ferrosilicon alloys in electric arc furnaces. Silica fume is an amorphous (non-crystalline) polymorph of silicon dioxide, silica with an average particle diameter of 150 nm.
Microsilica’s extreme fineness and high silica content make it a very effective pozzolanic material. Standard specifications for Microsilica used in cementitious mixtures are ASTM C1240 and EN 13263.
Microsilica is added to ordinary Portland cement to enhance its compressive strength, abrasion resistance, and durability.
Benefits of using Microsilica in concrete
Reduces thermal cracking
Enhances strength and durability
Provides a higher degree of resistance to chloride ingress, sulfates, and acidic waters