Unlock the full potential of ordinary Portland cement with hydration control additive enabling low-carbon building material

Abstract

Abstract Ordinary Portland cement (OPC) is the core ingredient of many construction materials. In 2022, 4.1 billion tons were used worldwide, contributing to approximately 8% of anthropogenic CO2 emissions (~3 Gt/year). There are alternatives to OPC such as aluminate cement and geopolymers, but due to the cost and availability of raw materials, their application is limited2. Thus, the use of OPC-based construction materials is expected to remain significant. Nevertheless, the complete strength-generating capacity of OPC remains unrealized due to the restricted conversion of aluminates to ettringite, caused by conventional hydration kinetics. In this study, we employ a hydration control additive that selectively modifies the hydration kinetics, thereby facilitating enhanced dissolution of aluminates in OPC, which promotes the formation of ettringite at a specific desired time. The increased ettringite content improves packing of the cement, resulting in ~50% higher specific strength thus enables cement reduction. The increased efficiency of strength development of OPC reduces the carbon footprint by at least ~30%. The use of this additive can be combined with methods such as reducing the amount of water and/or using supplementary cementitious materials (SCMs) to prepare building materials with significantly fewer CO2 emissions than those from conventional OPC.