What are the advantages and disadvantages of ordinary concrete?

The main disadvantages: self-heavy, stupid; very low tensile strength, brittle; easy to crack when the construction is not when; not easy to cut, cut, planing, chopping; cast-in-place after the slow hardening, long construction period and so on. The particle shape and surface characteristics of coarse aggregate will also affect its bonding with cement and the fluidity of concrete mix. Crushed stone has angular, rough surface, and cement bond is better, while pebbles are round, smooth surface, and cement bond is worse, in the case of the same amount of cement and water, crushed stone mixed with poorer fluidity of concrete, but higher strength, while pebbles mixed with better fluidity of concrete, but lower strength. If the fluidity of the same requirements, the use of pebbles can be less water, the result is not necessarily lower strength.