What are the factors that affect the polycarboxylate superplasticizer.

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New Earth Group


What are the factors that affect the polycarboxylate superplasticizer.

    Polycarboxylate superplasticizerThere is a big gap between the entry inspection data and the actual production. Under the condition of the same pumping agent dosage, the water consumption required for the production of concrete is about 20kg more than that for the entry inspection. And the collapse of the concrete mixture is also significantly accelerated. The main reason is that the volume of production is large, the temperature of the cementitious material in the powder bin is high (above 80 ℃ in summer), the temperature of the material is high, the pumping agent will be adsorbed, resulting in a reduced water reduction effect; also because the temperature of the concrete is high, the collapse of the mixture will be significantly accelerated. Therefore, when the polycarboxylic acid pumping agent is inspected, the water consumption can be controlled at 150~155kg/m3, and the slump of the concrete can reach 210mm or more.
Not the same batch of pumping agent, due to the different water reduction effect of raw materials, resulting in water reduction rate (in the same dosage) increased or decreased. In actual production, if other raw materials have not changed significantly, the water consumption has not changed, the production of concrete mixture becomes dry: this shows that the water reduction rate of pumping agent becomes smaller, should immediately increase the dosage of pumping agent. If the concrete mixture produced becomes thinner, this means that the water reduction rate of the pumping agent becomes larger, and the dosage of the pumping agent should be reduced immediately. The specific amount of increase or decrease shall be determined according to the difference between the slump of concrete mixture and the slump required to be taken out of the machine, and the content can be increased or decreased by 0.1 per 20mm of slump difference.
The setting time of concrete pumping agent changes with the change of atmospheric temperature. The setting time of admixture mixed with concrete is a formula designed according to the recent average atmospheric temperature. When the atmospheric temperature changes suddenly, if the dosage of pumping agent is not adjusted in time, the retarding accident of concrete may occur. Especially in late autumn and early spring, there are often strong winds and cooling weather. When it is known from the forecast that there is a strong wind to cool down, the concrete production mix ratio should be adjusted 12h in advance, that is, the concrete mix ratio should be increased by one grade, the pumping agent dosage of 1/4 (on the basis of the original dosage) should be reduced, and the water consumption of 15~20kg should be increased. This prevents the concrete from retarding.

Key words:

Polycarboxylate superplasticizer