Concrete refers to the artificial stone made of cement as the main cementing material, water, sand, stone, chemical additives and mineral admixtures when necessary, mixed in a proper proportion, and then uniformly stirred, compacted and maintained. Concrete is mainly divided into two stages and states: the plastic state before setting and hardening, that is, fresh concrete or concrete mixture;

The hard state after hardening, that is, hardened concrete or concrete. The strength grade of concrete is divided by the standard value of cubic compressive strength. The strength grades of ordinary concrete in China are 14: C 15, C20, C25, C30, C35, C40, C45, C50, C55, C60, C65, C70, C75 and C80.

Extended data

Important indicators of concrete:

⑴ Impermeability: Impermeability refers to the ability of concrete to resist the infiltration of pressure water (or oil).

⑵ Frost resistance: The frost resistance of concrete refers to the ability of concrete to maintain its strength and appearance integrity under repeated freeze-thaw cycles in the use environment.

⑶ Corrosion resistance: The erosion of concrete by environmental media is mainly the erosion of cement stone, which usually includes soft water erosion, acid, alkali and salt erosion.

Baidu encyclopedia-ordinary concrete