Crushed sand (Manufactured sand) contains stone ash which has two effects on the working performance of concrete. On the one hand, the increase of stone ash content will lead to the increase of water demand of concrete because stone ash will adsorb certain water and additives; On the other hand, the manufactured sand with poor grading is easy to cause concrete segregation and bleeding. Appropriate stone powder can increase the consistency of concrete and improve the workability of concrete. In addition, the manufactured sand has a multi-prismatic structure and has a larger specific surface area. These properties are conducive to improve the strength and volume stability of concrete. Properly increasing the particles of 0.15-0.3mm and 0.3-0.6mm in manufactured sand is more conducive to improve the workability of manufactured sand concrete.

Finally, natural river sand, as a non renewable energy, will eventually be exhausted if it is used endlessly. The selection of manufactured sand not only delays the process of resource depletion, but also protects the environment. It has to be recognized that manufactured sand, as a substitute for natural sand, is the general trend of social development.