some problems in the application of polycarboxylate superplasticizerii
Compatibility of polycarboxylate superplasticizer with other admixtures.
Beijing Dongke United Technologies Co.,Ltd.
If you need to know What is the use of superplasticizer in concrete, the first you need to know what is superplasticizer? Polycarboxylate superplasticizer is a high-performance water-reducing agent and a cement dispersant in the application of cement concrete. Widely used in highways, bridges, dams, tunnels, high-rise buildings and other projects.
For the synthesis of polycarboxylate superplasticizers, the design of molecular structure is crucial, including the main chain groups in the molecule, the density of side chains and the length of side chains. The synthesis methods mainly include in-situ polymerization grafting method, first polymerization and then functionalization method and monomer direct copolymerization method.
Dosage range: Under normal circumstances, when converted to 20% solid content, the dosage is 0.5 to 1.5% of the weight of the cementitious material, and the recommended dosage is 1.0%.
Performance characteristics
The slump loss over time is small, the slump loss rate of ready-mixed concrete is less than 5% in 1h and less than 10% in 2h;
The reinforcement effect is remarkable, the 3d compressive strength of concrete is increased by 50-110%, the 28d compressive strength is increased by 40-80%, and the 90d compressive strength is increased by 30-60%;
The concrete has excellent workability, no segregation and bleeding, and the appearance and color of the concrete are uniform. When used to prepare high-grade concrete, the concrete has good cohesion and is easy to mix;
The air content is moderate, it has no adverse effect on the elastic modulus of concrete, and the frost resistance durability is good;
It can reduce the early hydration heat of cement, which is beneficial to mass concrete and summer construction;
It can reduce the early hydration heat of cement, which is beneficial to mass concrete and summer construction;
Low shrinkage, which can significantly reduce the shrinkage of concrete, and its freeze-thaw resistance and carbonation resistance are significantly better than those of ordinary concrete; it can significantly improve the volume stability and long-term durability of concrete;
The alkali content is extremely low, the alkali content is less than or equal to 0.2%, which can effectively prevent the occurrence of alkali-aggregate reaction
The product has good stability, no stratification or precipitation occurs in long-term storage, and no crystal precipitation occurs at low temperature;
The product is green and environmentally friendly, does not contain formaldehyde, and is an environment-friendly product;
Good economic benefits, the comprehensive construction cost of the project is lower than that of other types of products, and 15-25% of cement can be saved under the same strength conditions.
Good economic benefits, the comprehensive construction cost of the project is lower than that of other types of products, and 15-25% of cement can be saved under the same strength conditions.
Compatibility of polycarboxylate superplasticizer with other admixtures.
Polycarboxylic acid high-efficiency water reducing agent is characterized by low dosage and high water reducing rate.
Polycarboxylic acid water reducing agent with high efficient water reducing performance is often used in construction concrete.
Polycarboxylate superplasticizer is a new generation of water-reducing agent based on modified polycarboxylic acid.
Polycarboxylate (PCE) superplasticizers are known as high range water-reducing admixtures in concretes, such as ready-mix concretes, self-compacting concretes (SCC), ultra-high strength concretes (UHPC) and at the same time give an extended slump retention.
The polycarboxylic acid-based high-performance water-reducing agent, has truly designed an effective molecular structure based on the mechanism of dispersed cement. It has a super-dispersed type and can prevent concrete slump loss.