Polycarboxylate Ether Superplasticizer Properties

The chemical composition of polycarboxylate ether powder determines its good properties. The water-reducing performance of a polycarboxylic acid water-reducing agent is related to the type of polymerized monomer selected and the composition of each blockchain. This polymer electrolyte prepared by free radical solution polymerization has a very small amount (0.1%- Under the condition of 0.2%), a larger dispersion effect can be produced, and it has excellent retardation, early strength, or protection. The ethoxy chain on the side chain of the polymer is sometimes also called the linked chain. This structural feature not only affects the water reducing agent but also plays an important role in inhibiting slump loss.

The polycarboxylic acid water reducer has a small amount of adsorption on the surface of cement particles, but because it has many branches, it can produce a co-steric hindrance effect, so when the dosage is very low, a better hindrance effect can be achieved. The presence of branch chains is in the form of tooth-shaped adsorption, making it difficult for the initial cement hydration product to cover the adsorption layer of water-reducing agent molecules. Therefore, the effective time of the water-reducing agent on the surface of cement particles has a low parameter and maintains a slump. The characteristics of good performance and good adaptability to cement are the first choices for the preparation of low-water ratio, high-strength, high-lasting concrete.

High water reduction and high plasticity retention

PCE powder is the first choice for non-vibration self-compacting high-performance concrete and high-strength high-performance concrete. The design parameters of the concrete mix ratio have changed greatly, and the performance has been significantly improved. Under the condition of maintaining the workability and high fluidity of the concrete, the water-cement ratio of the concrete can be minimized. In the case of the same water-cement ratio water-reducing agent content, compared with the naphthalene-based high-performance water-reducing agent, the polycarboxylic acid-based water-reducing agent has better dispersibility to cement and can be more Significantly improve the fluidity of cement paste. Between the effective dosage of the polycarboxylic acid-based high-performance water-reducing agent, the fluidity of the cement slurry after 1 hour is greater than 250mm, and the fluidity loss within 1 hour is about 10%, and the plasticity retention is excellent.

The problem of excessive content of PCE

Since polycarboxylate ether superplasticizer has the characteristics of high water-reducing rate and low dosage, when formulating polycarboxylic-based high-performance water-reducing agent concrete, it should be calculated strictly according to the minimum dosage and water consumption after trial mixing, And require the measurement equipment and measurement accuracy to be accurate and sensitive. Otherwise, when the polycarboxylic acid-based high-performance water-reducing agent is excessively mixed, undesirable phenomena such as segregation, bleeding, or excessive air content will occur. When the polycarboxylate high-performance water-reducing agent is mixed in a certain amount, the fluidity of the cement paste shows a downward trend, indicating that the water-reducing effect has a limit value. When the limit value is exceeded, the fluidity of the cement decreases, and the water-reducing effect becomes worse.

Cement adaptability issues

Because the variety and quality of cement in my country are generally complex and changeable, especially when encountering cement with extremely poor adaptability; when the mud content of sand and stone exceeds the standard, the polycarboxylate water-reducing agent concrete will still have poor fluidity and poor mixing. The phenomenon of large slump loss, so when using polycarboxylic acid water reducing agent, it is necessary to ensure that the adaptability of cement is good, and strictly control the mud content of sand and stone.

Kingsun is a professional concrete admixtures manufacturer and supplier.