Water reducing agent refers to an admixture that can keep the workability of concrete unchanged, while significantly reducing its mixing water consumption. Since the water reducing agent is added to the mixing house, the workability can be significantly improved if the unit water consumption is not changed, so the water reducing agent is also called a plasticizer.
1. The mechanism of action of water reducing agent. After the cement is mixed with water, the cement particles will attract each other and form many flocs in the water. In the flocculent structure, a lot of mixing water is wrapped, so that the water cannot play the role of increasing the fluidity of the slurry.
When the water-reducing agent is added, the water-reducing agent can dismantle these flocculent structures and liberate the free water in the package, thereby improving the fluidity of the mixture. At this time, if the workability of the original concrete still needs to be kept unchanged, the mixing water can be significantly reduced to reduce water, so it is called a water reducer.
If the strength is kept constant, the amount of cement can be reduced while reducing water to achieve the purpose of saving cement.
2. The technical and economic effects of using water reducing agents have the following technical and economic effects
(1) While maintaining the workability and not reducing the amount of cement, the amount of mixing water can be reduced by 5-25% or more. As the water-cement ratio is reduced by reducing the amount of mixing water, the strength can be increased by 15-20%, especially the early strength increase is more significant.
(2) While keeping the original mix ratio unchanged, the slump of the mixture can be greatly increased (can be increased by 100~200mm), which is convenient for construction and can meet the requirements of pumping concrete construction.
(3) 10~20% cement can be saved if the strength and workability are maintained.
(4) As the amount of mixing water is reduced, bleeding and segregation of the mixture can be improved, which can improve the frost resistance and impermeability of concrete. Therefore, the durability of concrete will be improved.