The principle and application of polycarboxylic acid superplasticizer in concrete

2020-04-17 16:14:38

High-efficiency superplasticizer has a robust dispersing effect on cement, which can significantly improve the fluidity of cement mixture and the slump of concrete, and at the same time greatly reduce the water consumption and significantly improve the workability of concrete. However, some high-efficiency water-reducing agents will accelerate the slump loss of cement. High-efficiency water-reducing agent does not change the setting time of concrete. When the amount is significant (overdose incorporation), it has a slight retarding effect, but it does not delay the early strength growth of hardened concrete.
It can significantly reduce water consumption and significantly increase the strength of concrete at all ages. When the concentration is kept constant, cement can be saved by 10% or more.

The chloride ion content is minimal, and it does not cause corrosion to the steel bars. Can enhance the impermeability, freeze-thaw resistance and corrosion resistance of concrete, and improve the durability of concrete


The superplasticizer currently on the market are mainly poly-fusidic acid water-reducing agents, which play a significant role in foaming cement or concrete slurries
1. Lubrication: The hydrophilicity of polycarboxylic acid superplasticizer is very strong, so the adsorption film of polycarboxylic acid superplasticizer on the surface of cement particles can form a stable solvated water film with water molecules. The water film has an excellent lubricating effect, which can effectively reduce the sliding resistance between cement particles, thereby further improving the fluidity of concrete.
2. Dispersion: After the cement is mixed with water, due to the molecular gravity of the cement particles, the cement slurry forms a flocculation structure, so that 10% to 30% of the mixing water is wrapped in the cement particles and cannot participate in free flow and lubrication Effect, thereby affecting the fluidity of the concrete mixture. When the polycarboxylic acid superplasticizer is added, the polycarboxylic acid superplasticizer molecules can be adsorbed on the surface of the cement particles, so that the surface of the cement particles has the same charge (usually negative charge), which forms an electrostatic repulsion effect, The cement particles are dispersed with each other, the flocculation structure is destroyed, and part of the wrapped water is released to participate in the flow, thereby effectively increasing the fluidity of the concrete mixture.
3. Water reducing effect. When commercial concrete is mixed with high-efficiency water-reducing agent, the water-cement ratio can be significantly reduced while maintaining fluidity. The water-reducing rate of the high-performance concrete plasticizer can reach 10% to 25%, while the water-reducing price of common concrete plasticizer is 5% to 15%. The reason for the plasticizer admixture effect is mainly due to the adsorption and dispersion of the water-reducing agent by commercial concrete.
4. Plasticization. After being mixed with superplasticizer, commercial concrete can increase the fluidity while keeping the water-cement ratio unchanged. The general water-reducing agent can increase the slump of newly mixed commercial concrete by more than 10cm while keeping the amount of cement constant. High-performance water-reducing agents can prepare commercial concrete with a drop of 25cm.
At present, high-efficiency water reducer is suitable for industrial fields
1 Ideal for precast and cast-in-place reinforced concrete in various industrial and civil buildings, water conservancy, transportation, port, municipal, and other projects.
2 Suitable for high-strength, ultra-high-strength, and medium-strength concrete, as well as concrete that requires new strength, moderate frost resistance, and high fluidity.
3 Precast concrete components suitable for the steam curing process.
4 Suitable for making water-reducing and enhancing components of various compound additives.

5 Lightweight foam concrete such as foamed cement backfill, lightweight concrete panels, CLC block CLC bricks etc.

Cie-China.org is the leading foam concrete additives provider providing concrete foaming agent, superplasticizer,foam concrete strength enhancer for lightweight concrete, CLC blocks. If you are looking for foaming agentplease feel free to contact us.



<< Prev Next >>