Lime plaster Lime plaster Lime plaster is a type of plaster composed of sand, water, and lime, usually non-hydraulic hydrated lime (also known as slaked lime, high calcium lime or air lime). Ancient lime plaster often contained horse hair for reinforcement and pozzolan additives to reduce the working time. Traditional non-hydraulic hydrated lime only sets through carbonatation when the plaster is kept moist and access of CO from the air is possible. It will not set when submersed in water. When a very thick layer or several layers are applied, the lime can remain soft for weeks. The curing time of lime
Alite in the area of Tournai (Belgium), the Tournaisian limestones are particularly rich in amorphous silica and exploited as building stone and for making lime mortar since very ancient ages. It is unknown if the cathedral builders of this area were aware of the hydraulic properties of their lime mortar or intentionally developed its use after their fortuitous finding. See the article on belite. Alite Alite is an impure form of tricalcium silicate, CaSiO, sometimes formulated as 3CaO·SiO (CS in cement chemist notation, CCN) with typically 3-4% of substituent oxides. It is the major, and characteristic, mineral phase in Portland cement.