A review: Alkali-activated cement and concrete production technologies available in the industry

A growing interest in alternative cements has emerged with the sole purpose of reducing the environmental footprint associated with cement production. One of the promising alternatives is to use non-carbonate materials such as alkali-activated materials. They have demonstrated to have a similar performance as traditional Portland cement and have the potential to significantly reduce CO2 emissions. This paper reviews the main relevant technologies that are already available in the construction industry and explains how to consider them for alkali-activated cement and concrete production. This includes aluminosilicate pre-treatment methods (drying, grinding, and calcining) to increase the precursor's reactivity and degree of amorphization, alkali activation by two-part or one-part mix, as well as, mixing and casting fresh alkali-activated concrete ensuring low porosity and adequate strength development. This review also presents an overview of the alkali-activated cements market, providing examples of commercialized products, estimating related CO2 and costs, as well as future considerations for standardization and commercialization. Most of the commercialized alkali-activated materials are two-part mixes despite their limitations for in-situ applications. CO2 emissions can be reduced by more than 68% when compared to Portland cements. However, they have been estimated to be 2 to 3 times more expensive and the cost is primarily dependent on the aluminosilicate and alkali activators source.

Automated summary

There is a growing interest in alternative cements to reduce the environmental impact of cement production. One promising option is alkali-activated materials, which have similar performance to traditional cement and can significantly reduce CO2 emissions. This paper reviews relevant technologies for alkali-activated cement production and discusses considerations for mixing and casting concrete. It also provides an overview of the market, including commercialized products, CO2 emissions, costs, and future considerations. Alkali-activated materials can reduce CO2 emissions by over 68% compared to Portland cement but are estimated to be 2 to 3 times more expensive.