1.The mechanism of action of powder polycarboxylate Superplasticizer
Polycarboxylate superplasticizer achieves dispersion through the electrostatic repulsion of the molecular main chain and the steric hindrance effect of the side chains. Its molecular structure is composed of a main chain containing carboxylic acid groups and polyether side chains. By adsorbing on the surface of cement particles, it forms a three-dimensional barrier and effectively inhibits particle agglomeration. Compared with liquid products, powder polycarboxylate superplasticizer is prepared through spray drying or physical adsorption processes and has the following characteristics:
(1) Dispersion stability: The powder form can prevent the molecular chain degradation problem of liquid products caused by long-term storage.
(2) Slow-release performance: Some powder products achieve the slow release of water-reducing components through coating technology, thereby extending the slump retention time.
(3) Wide adaptability: It has better adaptability to highly adsorptive aggregates (such as machine-made sand) or concrete systems in high-temperature environments.
For concrete systems, we have launched a series of concrete powder polycarboxylate superplasticizer products, which can meet the demands of high water reduction rate, extended slump retention time and wide adaptability of concrete.
Polycarboxylate superplasticizer, as the third-generation high-performance superplasticizer, has become one of the core materials in modern concrete technology due to its strong designability of molecular structure, high water reduction rate and excellent environmental protection performance. In recent years, powder polycarboxylate superplasticizer has demonstrated significant advantages in the concrete field due to its convenient transportation, high storage stability and ability to adapt to special engineering requirements.
2. The application advantages of powder polycarboxylate superplasticizer
(1) High water reduction rate and low dosage: The solid content of powder polycarboxylate superplasticizer is usually ≥95%, and the dosage is only 0.1% to 0.3% of the mass of the cementitious material, which can achieve a water reduction rate of 25% to 40%, significantly improving the compactness and strength of concrete.
(2) Construction performance optimization
Slump retention: By adjusting the length of the side chain and the proportion of functional groups, a slump retention time of 2 to 6 hours can be customized to meet the requirements of long-distance pumping.
Viscosity adjustment: Applicable to self-compacting concrete (SCC), reducing viscosity without segregation.
(3) Environmental protection and economy
Low transportation cost: The powder form reduces the transportation volume by approximately 70% compared to the liquid product, lowering carbon emissions. Alkali-free chlorine addition: Avoids the risk of alkali-aggregate reaction introduced by traditional water reducers and enhances the durability of concrete.
