Granite is a type of tectonite that is formed by a volcanic eruption lava that rises to the surface of the earth's crust in a molten state under considerable pressure. The magma does not spurt out of the ground, but slowly forms a tectonic rock under the ground. Acidic igneous rock, belonging to magmatic rock (igneous rock). Granite is mainly composed of quartz, feldspar and mica.
Granite is a unique material, and the physical characteristics of these are mainly as follows：
First, porosity / permeability: the physical permeability of granite is almost negligible, between 0.2% - 4%；
Second, thermal stability: Granite has high strength and heat stability, it will not change due to changes in external temperature, granite due to its high density and will not change due to changes in temperature and air composition.
Third, granite is highly resistant to corrosion and is therefore widely used in chemical storage products.
Fourth, the hardness of granite is high, its Mohs hardness is about 6, and its density is between 2.63g/cm3 and 2.75g/cm3. Its compressive strength is 100-300MPa, and fine-grained granite can be as high as 300MPa or more. The bending strength is generally 10 to 30 MPa.
Fifth, the granite structure is dense, the compressive strength is high, the water absorption rate is low, the surface hardness is large, the chemical stability is good, the durability is strong, but the fire resistance is poor.
The use of granite depends on the size of the grain: fine grain can be polished or carved, as a decorative sheet or artwork; medium-grained is often used to build piers, bridges, dams, seaports, feet, foundations, pavements Etc.; coarse grain rolling into gravel, is an excellent aggregate of concrete. Because granite is acid-resistant, it is also used as an acid-resistant lining and container in chemical and metallurgical production.