Supplementary Cementing Materials
By using materials that “do more with less”, valuable resources are conserved. For example, by increasing the use of fly ash (an industrial byproduct) in place of cement, material is re-used while the carbon dioxide emissions from cement manufacturing are reduced. Supplementary cementing materials (SCMs) contribute to the properties of hardened concrete through hydraulic or pozzolanic activity.
Typical examples of SCMs are fly ashes, slag cement (ground, granulated blast-furnace slag), and silica fume. These can be used individually with portland or blended cement, or in different combinations. SCMs are often added to concrete to make concrete mixtures more economical, reduce permeability, increase strength, or influence other concrete properties.