Assessment of Industrial Large-Volume Wastes with High Potential to Be Used as Emerging Alkali-Activated Precursors: A Review

Abstract

Alkali-activated binders (AABs) have been recognized as a viable alter-native to ordinary Portland cement (OPC) due to their mechanical performance and excellent resistance to chemical attacks. In addition, the possibility of manufacturing various waste and by-products has made them a more environmentally friendly solu-tion than OPC. However, the high global cement demand that is currently required still cannot be replaced with the alkali-activated precursors assessed in the literature to date. Therefore, it is necessary to study and evaluate new cementing raw mate-rials that can be formulated based on alkaline activation technology. In this sense, various large-volume industrial waste such as Construction and Demolition Waste (CDW), Electric Arc Furnace Slags (EAFS), and some natural stone waste (NSW), among others, have emerged in the last decades as unconventional precursors for alkali-activated binders due to their high contents of silica, alumina, and calcium oxide. This study aims to update the state of the art of AABs formulated using these novel precursors, mainly focusing on the influence of the chemical composition, the alkaline activator solutions used, and the curing temperature conditions in their final mechanical performance.