Water reducing agent, also known as plasticizer

Water reducing agent, also known as plasticizer, is the most widely used concrete admixture at present. Most of the water reducers are surfactants, which are mainly used for surface activity in concrete. Surfactant molecules are composed of hydrophobic groups and hydrophilic groups. The hydrophobic groups are generally various organic compound hydrocarbons. Class, hydrophilic groups are salts that can dissociate various ions.

In addition, the water reducing agent also has the function of wetting the cement particles and lubricating, so as long as a small amount of water is used, the concrete can be easily mixed evenly, so that the workability of the freshly mixed concrete is improved, or Under the condition of keeping the workability unchanged, the water-cement ratio of concrete is significantly reduced, and it plays the role of water reduction and enhancement.

The head of the superplasticizer molecule is hydrophilic, and the long tail is hydrophobic, and the number of water molecules in fresh concrete is obviously more than that of the superplasticizer molecule. In this case, we can compare the water reducing agent molecules to the fish in the water. Its swimming acts as agitation, so that the water molecules can play their role more fully; moreover, when a large number of water molecules undergo hydration , the superplasticizer molecules will naturally precipitate from the aqueous solution, and the cement particles are the ideal nucleation centers, so the superplasticizer molecules will gradually attach to the cement particles to form a solvated water film; in addition, due to its hydrophilic The role of the group makes it not completely insoluble in water like oil, which will affect the pH of fresh concrete to a certain extent.