Carbonate binders: Historic developments and perspectives

This paper reviews the historic developments and provides some perspectives of carbonate binders. Various carbonatable materials have been used to produce carbonate binders using different carbonation techniques. The carbonate binders are mainly composed of calcium/magnesium carbonate and silica/alumina gels. Three crystalline polymorphs, namely calcite, aragonite and vaterite can be formed. The properties of carbonate binders are strongly affected by the crystalline polymorphs and also the polymerization degree of amorphous silica gel. During the past 4 years, physical, chemical and biological methods have been proposed to control the polymorphous of calcium carbonate. Some industrial demonstration and applications have already been successfully implemented. The production and application of carbonate binders can use up to several hundred million tons of CO2. However, there is an urgent need to increase the carbonation degree and to regulate the composition and structure of carbonate binders so to achieve better performance of carbonated construction products.