Fire resistance
All kinds of stones are different, and some stones undergo chemical decomposition under the action of high temperature.
(1) Gypsum: decomposes when the temperature is higher than 107 ℃.
(2) Limestone and marble: decomposed when the temperature is higher than 910 ℃.
(3) Granite: cracks due to uneven heating of constituent minerals at 600 ℃
Expansion and contraction
It is also hot expansion and cold contraction. However, if it is cooled after being heated, its shrinkage cannot return to its original volume, and it will retain part of it to become permanent expansion; The American arsenal has tested from 0 ℃ to 100 ℃ and then to 0 ℃.
Frost resistance
At minus 20 ℃, freezing occurs, and the water expansion in the pores is 1/10 larger than the original volume. If the rock cannot resist the force caused by this expansion, it will be damaged. Generally, if the water absorption is less than 0.5%, its anti-freezing performance will not be considered.
Durability
Stone has good durability, and the structure built with stone has permanent possibility. Ancient people have long recognized this, so many important buildings and memorial structures are built with stone
compressive strength
The compressive strength of stone materials will vary due to the mineral composition, crystal size, uniformity of cementitious materials, loading area, angle of loading and cleavage, and other factors. If other conditions are the same, usually the dense material with fine crystalline particles bonded together has high strength. There is no difference in compressive strength of dense volcanic rocks after drying and saturated with water (water absorption is very low). If they are porous and water-resistant cemented rocks, their dry and wet strength will be significantly different.
There are two kinds of stone materials for building decoration: natural stone and artificial stone, mainly natural stone. It is an advanced decorative material, mainly used in projects with high decoration requirements.
