Controlling the hydration and carbonation in lime-based materials: Advantage of slow carbonation in CO2 curable construction materials

In this study, the role of natural additives (sodium chloride or sugar) in aerial lime mortar was elucidated. It was found that both the hydration and carbonation were accelerated by sodium chloride but retarded by sugar. Especially, sugar prevented the rapid clogging of pores around the mortar surface, which caused the even formation of calcium carbonate crystals throughout the volume of mortar. Therefore, the strength development was significantly accelerated. The slow carbonation and resulting rapid strength development can be practically implementable since it does not rely on long term atmospheric carbonation or use of high concentration of CO2 gas. (C) 2020 Elsevier Ltd. All rights reserved.