Generally, the higher the water content of concrete, the better its fluidity and workability. But when concrete has enough moisture, the strength of concrete after solidification is inversely proportional to the moisture content. Therefore, if the concrete is to have high strength, the water content of the concrete cannot be too much, and the workability at this time will become poor.
The plasticizer can reduce the water content of the concrete without affecting the workability of the concrete (therefore it is called a water reducing agent). ), it also improves the strength of concrete. This method is often used to increase the strength when producing high-strength concrete or fiber reinforced concrete.
Plasticizers are usually polar or partly polar in structure, and are liquids or low-melting solids with high boiling point, hard to volatilize and good miscibility with polymers.
The plasticizer is distributed between the macromolecular chains, which can reduce the intermolecular force, reduce the viscosity of the polymer and increase the flexibility. Plasticizers are divided into two categories: primary plasticizers and secondary plasticizers. The main plasticizers are compatible with resins, have low permeability and low volatility, and can improve plasticization efficiency.
Different types of plasticizers have different effects on the performance of products. In actual production, one plasticizer is rarely used alone, and several plasticizers are often mixed with complementary performances to achieve a good plasticizing effect.