A review on alkali-activated slag cements incorporated with supplementary materials

Supplementary cementitious materials are commonly used in portland cement concrete, which have both environmental and technical benefits. Various supplementary materials have been used in alkali-activated cements and can effectively improve some of their properties. This article reviewed the characteristics, classification, and potential actions of these supplementary materials used in alkali-activated slag cements (AASCs). A new approach was proposed to classify the supplementary materials for AASCs into three groups: (1) chemically active, (2) physically active, and (3) physically active and reactive. Chemically active supplementary materials consist of amorphous structures which form hydration products with cementitious properties and modify the composition of the binder gel. Physically active supplementary materials consist of crystalline and (or) chemically inert structures, which do not modify the composition of the binder gel, but affect the physical structure of the mixed binder. Physically active and reactive supplementary materials have both above the properties.