The mechanism of action of water reducing agents mainly includes the following aspects:
1. Dispersion effect: The surfactant in the water reducing agent can form a layer of dispersant film on the surface of cement particles, increasing the electrostatic repulsion force between cement particles, thereby reducing particle aggregation and sedimentation, and improving the fluidity and pumpability of concrete.
2. Adsorption: The chemical components in the water reducing agent can interact physically or chemically with the surface of cement particles, causing them to carry a certain charge, thereby improving the dispersibility and fluidity of concrete.
3. Water reducing effect: The organic macromolecular compounds in the water reducing agent can disperse the water in the whole concrete system through adsorption, reduce the adsorbed water on the surface of cement particles, thus reducing the Water–cement ratio of concrete and improving the strength and durability of concrete.
4. Hardening regulation effect: The chemical components in the water reducing agent can react with the hydration products of cement, regulating the hardening process of cement, delaying the setting and hardening time of cement, thereby improving the delayed setting performance of concrete, facilitating construction operation and control.
In summary, water reducing agents alter the physical and chemical properties of concrete through mechanisms such as dispersion, adsorption, water reducing, and hardening regulation, improving its fluidity, pumpability, crack resistance, and strength, achieving the goal of reducing cement consumption, improving concrete quality, and construction efficiency.