Building materials
Historical buildings, comfortable homes and modern skyscrapers would all be impossible without lime. Lime proves its value hundreds of times every day in the building materials industry. Concrete reinforcement or steel structures would not exist without lime. Lime is essential for the production of steel, 50 % of which is used in construction. Lime confers stability to such white wall-building materials as sand-lime bricks and autoclaved aerated concrete, is used as an aggregate in concrete, cements the stones together in mortar and spruces up our façades when used as render. Lime is the link element in the construction industry and is synonymous with ecological construction.
Sand-lime brick
Lime proves its value in the building materials industry every single day.
Made entirely of natural sand, lime and water, the raw sand-lime brick compound matures in reactors before it is compressed under vapour pressure to form sand-lime bricks.
During the process of pressure-hardening in autoclaves, the large proportion of available calcium oxide in lime ensures that optimum calcium silicate hydrate crystals are formed to give the brick its high mechanical strength, density and stability.
Aerated autoclave concrete
Outstanding thermal insulation combined with low weight are the special properties of autoclaved aerated concrete. Quicklime is mixed with cement, sand, water and aluminium powder to provide a slurry which rises and sets to form honeycomb structured blocks that have excellent thermal and sound insulation properties.
Its porous structure is due to the formation of gas in the cast raw compound. Through its specific and precise reactivity, this lime controls the complex expansion and maturing process before the bricks are solidified by hardening in steam.
Mortar
Mortar is essential in the construction industry: without it we would have nothing to hold the bricks together that form our houses, offices and other buildings.
Current cement-lime mixes provide the most efficient mix in regards to possessing both good ‘soft’ properties as well as controlled strength. The benefits of using lime and lime-cement mortars are many: their water retention properties are very high, making them particularly suitable for use with absorptive units. Incorporating lime in mortar improves adhesion and reduces rain penetration and can often increase the resistance of mortar to attack by sulphate.
Mortars containing lime absorb carbon dioxide from the atmosphere which dissolves within any water present in the mortar, and reacts with the lime to produce carbonate crystals.
Links: Publications on lime and mortar