The Water Absorption of Alternative Supplementary Cementitious Materials and its Impact on the Rheological Properties of Fresh Paste

Supplementary cementitious materials (SCMs) are used to reduce the global warming potential (GWP) of concrete as cement replacements. ASTM 311 has historically been used to determine the water demand of SCMs; however, recent work has shown that the specific gravity, particle shape, and water absorption of the SCM can all impact the water demand. Alternative SCMS can have variable composition, specific gravity, reactivity, surface area, and water absorption. This study evaluates the rheology and setting time of alternative SCMs after accounting for their specific gravity and internal porosity. The yield stress development and water absorption of the natural pozzolans (NPs) are discussed with respect to water demand and structure development.