Polycarboxylate Superplasticizer in Construction
Polycarboxylic acid high-efficiency water reducer is a high-performance admixture widely used in concrete engineering. The following is an introduction from the aspects of its basic information, performance characteristics, mechanism of action, and application:
Basic information
Main ingredients: Polycarboxylic acid high-efficiency water reducer is usually prepared by chemical synthesis with polycarboxylic acid as the main ingredient. Its molecular structure contains active groups such as carboxyl and sulfonic acid groups, as well as long-chain structures such as polyoxyethylene.
Appearance and form: Generally a colorless to light yellow transparent liquid, and some products are also made into powder.
Performance characteristics
High water reduction rate: The water reduction rate of polycarboxylic acid high-efficiency water reducer can usually reach 25% - 40%, or even higher. Compared with traditional water reducers, it can achieve better water reduction effect at a lower dosage, effectively reduce the water-cement ratio of concrete, and improve the strength and durability of concrete.
Good slump retention: It can significantly delay the loss of concrete slump, so that the concrete can maintain good working performance for a long time, and meet the construction requirements of concrete during transportation and pouring.
Significant strengthening effect: Since it can effectively reduce the water-cement ratio, the early and late strength of concrete can be significantly improved while ensuring the working performance of concrete. Generally speaking, the early strength of concrete using polycarboxylic acid high-efficiency water reducer can be increased by 50%-100%, and the late strength can also be increased by 20%-50%.
Low shrinkage: Compared with other types of water reducers, polycarboxylic acid high-efficiency water reducer can effectively reduce the shrinkage of concrete, reduce the risk of concrete cracking, and improve the stability and durability of concrete structure.
Good environmental performance: Polycarboxylic acid high-efficiency water reducer usually does not contain harmful substances such as formaldehyde, is environmentally friendly, and meets the environmental protection requirements of modern construction projects.
Mechanism of action
Electrostatic repulsion: After the polycarboxylic acid molecules are adsorbed on the surface of cement particles, the surface of cement particles carries the same charge. Through the electrostatic repulsion, the cement particles are dispersed from each other, thereby releasing the water wrapped by the cement particles to achieve the effect of water reduction.
Steric hindrance: The long chain structure in the polycarboxylic acid molecule forms a three-dimensional steric hindrance layer on the surface of cement particles, preventing the cement particles from approaching and aggregating with each other, further enhancing the dispersion effect of cement particles, and making the concrete have good fluidity and stability.
Retarding effect: Certain groups in polycarboxylic acid high-efficiency water reducer can react chemically with the mineral components in cement, delaying the hydration process of cement, thereby playing a retarding role and helping to maintain the working performance of concrete.
Application areas
High-performance concrete: In projects with high requirements for concrete performance such as high-rise buildings, large-span bridges, and hydraulic structures, polycarboxylic acid high-efficiency water reducer is one of the key admixtures for preparing high-performance concrete, which can meet the requirements of these projects for high strength, high durability, and high workability of concrete.
Self-compacting concrete: Self-compacting concrete requires good fluidity, filling and anti-segregation properties. The high water reduction rate and good slump retention of polycarboxylic acid high-efficiency water reducer enable it to meet the performance requirements of self-compacting concrete well, and is widely used in projects such as basements and tunnels.
Precast concrete components: In the production of precast concrete components, the use of polycarboxylic acid high-efficiency water reducer can improve the molding quality and production efficiency of concrete, ensure the dimensional accuracy and appearance quality of components, and is widely used in the production of precast beams, precast panels, precast columns and other components.
Commercial concrete: Commercial concrete needs to maintain good working performance during transportation and pouring. Polycarboxylic acid high-efficiency water reducer can effectively control the slump loss of concrete, so that commercial concrete can meet the construction requirements under different construction environments and conditions. It is an indispensable admixture in the production of commercial concrete.
- Brand
- XYDCHEM
- Model
- 1
- Country of origin
- China