Alternative supplementary cementitious materials for sustainable concrete structures: a review on characterization and properties

Abstract

Currently, one of the main priorities for a government is to realize sustainable development. Strategies are required to protect the global environment, enhance employee health and safety, reduce emissions, and use fuels and raw materials responsibly across all sectors of the economy. Blended Portland cements containing supplementary cementitious materials (SCMs), usually industrial by-products, are excellent examples of industrial ecology. In particular, they offer a solution for reducing environmental impacts from several industries. In fact, with every ton of cement produced, nearly a ton of CO2 is emitted. The use of SCMs as a cement substitution reduces these CO2 emissions, saves non-renewable material sources, minimizes waste, and enhances the properties of the concrete. High-quality SCMs are becoming increasingly restricted. With the growing demands for cement, new sources of SCMs, often called alternative SCMs (ASCMs), will need to be used. However, this brings another challenge, as ASCMs are often comprised of local materials, with smaller volumes and more variable compositions. Accordingly, efficient and rapid methods are necessary for evaluating their performance and reactivity in concrete materials. Moreover, there is a need to characterize the chemical, physical, and mineralogical properties of the ASCMs. This paper presents the requirements for materials to qualify as SCMs, an example of a rapid screening test for assessing the performance of ASCMs, and an inventory of materials with favorable properties.