Basalt and limestone Which rocks are not suitable for building materials? Why?
Basalt is a good raw material for the production of "cast stone." "Cast stone" is a material that is developed by melt casting, crystallization, and annealing. It is harder and wear resistant than alloy steel and is resistant to corrosion than lead and rubber. In a kind of advanced technology of cast steel, it plays the role of "lubricant", can be a long casting life. At the same time, basalt can also be drawn into glass fiber, than the general glass cloth anti-alkali strong, high temperature performance.
Multi-stomatal basalt (pumice), because it is more stomatal, and quite hard, so it will be mixed with concrete, can reduce the weight of concrete, but still very strong, while noise, heat insulation and other characteristics, is high-rise building Light concrete is a good aggregate. Pumice is still a good grinding material, can be used to mill metal, grinding stone; in the industry can do filters, dryers, catalysts and so on.
Basalts are mostly black, dark brown or dark green, and because of their dense texture, the proportion of granite, limestone, sandstone and shale is heavy, but some basalts are much more , Even in the water can float up.Therefore, this kind of porous body light basalt, called "pumice".
According to the structure, can be divided into stomatal basalt, almond-shaped basalt, etc .; according to the chemical composition and mineral composition, can be divided into high-alumina basalt, basalt, basalt, Alkaline basalt and pull basalt.
Basaltic bulk density of 2.3.3g / cm3, dense compressive strength is very large, up to 300MPa, sometimes higher, the existence of vitreous and stomatal strength is reduced. Basalt durability is very high, joint and more, and brittle, And thus difficult to take large pieces of stone, due to stomatal and almond structure common, although the basaltic surface is widely distributed, but can be made no small stone.
Basalt is the main component of silica, aluminum oxide, iron oxide, calcium oxide, magnesium oxide (and a small amount of potassium oxide, sodium oxide), which contains the largest silica, accounting for about 45 percent to About fifty
Did not hear what is not suitable for building materials, two are commonly used in building materials.
The mineral composition of the basalt is mainly composed of basic feldspar and pyroxene. The secondary minerals are olivine, amphibole and biotite. The rocks are dark, usually black, sometimes grayish green and dark purple, etc. Stomatal structure and almond structure are common.
