subject: Effect Of Limestone In Building Field [print this page] Generally most limestone is chiefly composed of calcium carbonate, the organic remains of shells and coral.Dolomitic limestones are chemically magnesium carbonate. The fossils and other sedimentary structures which limestone contains provides a key as to the environment in which limestones where formed.Limestone was formed from materials that were deposted as soft sediments laid down as layers in beds under water. Over millions of years these sediments were buried, mineralized, compressed and became cemented together into a rock.Those limestones with a porosity of less than 5% and will take a full polish are called hard limestone.Limestone used outside must be protected from water and frost damage. If the porosity of the stone is to high, water may collect in the stone, freeze, and then swell. This may cause the stone to flake, crack or to split.Limestone is also used to make lime cement. This process involves burning the limestone in kilms to produce the lime cement. And this lime cement when mixed with sand and water would be used to cement the building stones or fired clay bricks together to form walls and other parts of the castle. This process of making and using lime cement will be discused in detail later.
There are three general classifications of slate: mica, clay and igneous. For our discussion we will deal with the mice form. This is because this slate is what slate roofs are made from. Mica is a generic term for any group of minerals that crystallizes in thin easily separated layers. In slate, the mineral is primarily silcon dioxide in the form of crystalline quartz.
