A kind of surface tension adjustment shrinkage-reducing type polycarboxylate water reducing agent and preparation method thereof

Abstract

The present invention provides a preparation method of a surface tension adjustment reduction type polycarboxylate superplasticizer. The method is simple and high in cost performance, wherein raw materials are easily available and low in cost. The invention also provides a surface tension adjustment reduction type polycarboxylate superplasticizer prepared by the above method. The surface tension adjustment reduction type polycarboxylate superplasticizer can significantly reduce the surface tension of the aqueous solution. The result of the reduction test on the concrete shows that, the surface tension adjustment reduction type polycarboxylate superplasticizer is good in reduction effect. Compared with a conventional ether type polycarboxylate superplasticizer produced by the company of the invention, the shrinkage ratio of the concrete is reduced by 71%. When the polycarboxylate superplasticizer is applied to the concrete, the workability and the strength of the concrete are not affected at all. Therefore, the cost performance is high.

Description

technical field [0001] The invention relates to a shrinkage-reducing water reducer, in particular to a surface tension-adjusting shrinkage-reducing polycarboxylate water reducer and a preparation method thereof. Background technique [0002] The emergence, development and wide application of concrete admixtures have endowed concrete with new vitality. Water reducing agents mixed into fresh concrete can destroy the flocculation structure of cement particles and play a role in dispersing cement particles and cement hydration particles. Thereby releasing the free water in the flocculation structure and increasing the fluidity of the concrete mixture. Polycarboxylic acid (PCEs) superplasticizers are anionic surfactants, which are mixed into cement paste, adsorbed on the surface of cement particles with cations, and dissociate into organic anion groups with hydrophilic and lipophilic effects. [0003] The molecular skeleton of PCEs superplasticizer consists of a main chain and m...

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Problems solved by technology

However, the use of expansive agent requires concrete to be cured with water in the early stage, and the conditions are harsh, and there are serious problems such as cement adaptability and delayed ettringite formation. In addition, it is difficult to adjust its addition amount. If the amount is too small , the effect cannot be achieved. If the dosage is too large, the excess part may expand the crack due to expansion, so the use of expansion agent has certain uncertainty on the final result.

[0007] The other is to add fiber, but the addition of fiber can only improve the crack resistance of concrete, and cannot reduce the shrinkage of concrete. At the same time, the price of fiber is high, and there is a problem of compatibility with concrete.

It also greatly limits its promotion

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