Supplementary cementitious materials (SCM) are formed as a by-product of other manufacturing processes. Fly ash, silica fumes, and slag cement are the most commonly used products. SCMs are added to concrete mixtures and other building products to enhance properties of the base material. The current trend is to use various SCMs according to their inherent chemical properties and to the eventual purpose of the resulting concrete.

The global SCM market was valued at more than $79.2 billion in 2015 and is estimated to be more than $103.2 billion by 2020, increasing at a compound annual growth rate (CAGR) of 5.4% from 2015 through 2020 (Table 1). Increasing infrastructure expenditure on a global scale is expected to drive demand for concrete mixtures that include SCM. In addition, changing practices within the construction industry are expected to impact demand. For instance, use of brick has been replaced by concrete mixtures to a large extent.