• Jensen, Peter Arendt
• Damø, Anne Juul
• Pol Segura, Isabel
• Ranjbar, Navid
• Jensen, Lars Skaarup
• Canut, Mariana

Abstract

<p>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.</p>

Topics

• impedance spectroscopy
• grinding
• strength
• cement
• casting
• activation
• porosity
• drying