Features of Polycarboxylate Superplasticizer

The water reduction effect is highly dependent on the concrete raw materials and mix ratio. Kingsun Polycarboxylate superplasticizers have been proven to have better water-reducing effects at lower dosages, and their water-reducing rate is much greater than other types of water-reducing agents. But it must be noted that, compared with other water-reducing agents, the water-reducing effect of polycarboxylic acid-based water-reducing agents is more affected by test conditions.

First of all, the water-reducing effect of polycarboxylic acid-based water-reducing agents has a great influence on the amount of cement in concrete. After testing the same water reducing agent with the same dosage, when the benchmark concrete cement dosage is 330kg/m3, 350kg/m3, 380kg/m3, and 420kg/m3, the measured "water reduction rate" is 18 %, 22%, 28%, and 35%. The particle gradation and sand ratio of the aggregate in the concrete have a great influence on the plasticizing effect of the polycarboxylic acid-based water-reducing agent. Compared with other superplasticizers such as the naphthalene series, the plasticizing effect of polycarboxylic acid series superplasticizers is greatly affected by the sludge content of the fine aggregate.

In addition, the polycarboxylic acid-based water-reducing agent, like other water-reducing agents, its water-reducing rate also depends on the mixing process. If manual mixing is used, the measured water reduction rate is often 2-4% lower than mechanical mixing. If admixtures are added to the concrete, the water reduction rate of course also depends on the type and amount of admixtures. For concrete with a large number of admixtures, the water-reducing effect of polycarboxylic acid-based water-reducing agents is better than that of naphthalene-based water-reducing agents. You may visit this website: https://www.kingsunconcreteadmixtures.com/ to get more details about other water reducers.

The water-reducing effect of the polycarboxylic acid-based water-reducing agent is greatly dependent on its dosage. Generally, as the dosage of the water-reducing agent increases, the water-reducing rate increases. But there are often exceptions, that is, after reaching a certain dosage, even as the dosage increases, the water reducing effect "decreases". This is not to say that the water-reducing effect of the increase in the amount has decreased, but because the concrete has serious bleeding at this time, the concrete mixture is hardened, and the fluidity is difficult to reflect by the slump method.

The performance of PCE-prepared concrete mixture is very sensitive to water consumption. The indicators that reflect the performance of concrete mixtures usually include fluidity, cohesion, and water retention. The concrete prepared with polycarboxylic acid-based water-reducing agents does not always fully meet the requirements for use. The properties of concrete mixtures prepared with most polycarboxylic acid water-reducing agents are very sensitive to water consumption. Sometimes the water consumption only increases (1-3) kg/m3, and the concrete mixture bleeds seriously. The use of this mixture cannot guarantee the uniformity of pouring, and it is easy to cause unacceptable defects such as pitting, sanding, and holes on the surface of the structure, and the strength and durability of the structure are also reduced. 

Due to the lack of strict control over the moisture content of the aggregate in the commercial concrete mixing plant, it is easy to cause excessive water addition in the production, leading to bleeding and segregation of the concrete mixture.