Enforced carbonation of cementitious materials

Abstract

CO2 mineralization of cement materials utilizes reaction of calcium or magnesium with carbonate ions forming insoluble carbonates. Recent research has demonstrated that this process is applicable in several favorable ways at different stages of the concrete life cycle. This review focusses on the application of carbonation technologies to valorize the industrial material streams related to cement: recycled concrete paste, steel slags and fly ashes. These technologies enable CO2 sequestration and production of a new type of pozzolan. Different approaches and technologies for carbonation are discussed along with the associated reaction mechanisms for the relevant phase assemblages. Reactivity and applications of the carbonated materials as pozzolanic additives are also addressed. Enforced carbonation of the industrial materials can be conducted at ambient temperature and pressure, achieving high degrees of CO2 sequestration. The usage of the carbonated materials as supplementary cementitious materials makes an important contribution to the circularity in building industry.