Silica fume

Abstract

Silica fume concretes have been used since the mid-1970s, in many areas of the world. Such uses have included high strength, high chemical resistance—especially high chloride and sulfate resistance—abrasion and erosion resistance. With the increased focus on sustainability, silica fume—being a by-product—is used to great effect in reducing the Portland cement content of a mix, and allowing the use of higher cement replacement levels of other SCMs such as blastfurnace slag and fly ash. This can reduce both the energy used and the carbon footprint. The higher performance of the silica fume concrete, in terms of strength, can allow for reductions in structural element size, thus reducing the concrete volume needed, saving natural resources. The increased durability can provide greatly extended lifetimes compared to normal Portland concretes, thus also reducing the need for repairs and replacement. Numerous examples are available from the past 40 years of use, and reference should be made to the relevant manufacturers and associations web-sites, for more information.