Silica fume is a highly reactive material that is used in relatively small amounts to enhance the properties of concrete. It is a by-product of producing certain metals in electric furnaces.

One of the most beneficial uses for silica fume is in concrete. Because of its chemical and physical properties, it is a very reactive pozzolan. Concrete containing silica fume can have very high strength and can be very durable. Silica fume for use in concrete is available in wet or dry forms. It is usually added during concrete production at a concrete plant.