Concrete anti-sensitive polycarboxylate superplasticizer and preparation method thereof

Abstract

The invention provides a concrete anti-sensitive polycarboxylate superplasticizer and a preparation method thereof. The concrete anti-sensitive polycarboxylate superplasticizer is prepared from the following materials: deionized water, block modified unsaturated polyoxyethylene ether, isopentenol polyoxyethylene ether, unsaturated carboxylic acid, an ester functional monomer, a sulfonic acid functional monomer, a chain transfer agent, an oxidizing agent, an emulsifying agent and a reducing agent. According to the invention, the molecular side chains of a plurality of polyethers including the block unsaturated polyoxyethylene ether and the isopentenol polyoxyethylene ether are combined, so that the characteristics of different side chain molecules can be fully exerted, the sensitivity is low, the mixing amount range is large, the cement workability is good, and the use cost is low; emulsion polymerization is adopted, so that the reaction efficiency of ester functional monomers is effectively improved, and the performance of the superplasticizer is improved; and the superplasticizer is green and environment-friendly, the production process is simple, and the product does not containchloride ions and heavy metal components and has no corrosion harm to concrete reinforcing steel bars.

Description

technical field [0001] The invention relates to the technical field of building admixtures, in particular to a concrete anti-sensitive polycarboxylate water reducer and a preparation method thereof. Background technique [0002] Polycarboxylate superplasticizer, as a new type of high-performance superplasticizer, has outstanding advantages such as high water-reducing rate, good performance of concrete, and no pollution to the environment. It has gradually replaced the commonly used naphthalene-based superplasticizer. The rate has reached more than 80%. Compared with naphthalene-based water-reducers, polycarboxylate water-reducers have a higher water-reducing rate, up to 40%, which can significantly reduce the amount of water in concrete and improve the strength. However, high water reduction will greatly increase the sensitivity of concrete to water. In addition, the application of materials with poor water retention such as slag cement and machine-made sand makes many conc...

AI Technical Summary

Problems solved by technology

However, high water reduction will greatly increase the sensitivity of concrete to water. In addition, the application of materials with poor water retention such as slag cement and machine-made sand makes many concretes prone to bleeding, segregation, bottom scratching, and hardening during construction.

Seriously affected the construction quality and construction progress

[0003] Faced with this situation, some manufacturers will solve the problem by adjusting the aggregate ratio of concrete, but the materials in the construction market are deteriorating day by day, and the quality of materials is unstable, which greatly increases the production cost

On the other hand, some manufacturers reduce the sensitivity to water and materials and improve the workability of concrete by compounding an appropriate amount of water-retaining viscosity-adjusting agent and workability regulator in the water-reducing agent, but the cost of such products is too high. High, incompatible with polycarboxylate superplasticizer, has the disadvantages of precipitation and delamination, and will also increase the viscosity of concrete and affect fluidity; And the polycarboxylate superplasticizer with excellent water reducing effect and slump retention effect is of great significance

[0004] The publication number is CN105217992A, which discloses an efficient solution to improve the segregation and bleeding of concrete due to overmixing. The method is to dissolve a certain proportion of polyethylene glycol solutions with different molecular weights in the water reducer, and improve the state of the concrete mixture. , the advantage of this method is that it is easy to use and has good compatibility. The disadvantage is that polyethylene glycol has a large air-entraining property, which easily leads to an increase in the air content of concrete and reduces the strength of concrete; the publication number is CN109021180A, which discloses a low-sensitivity shrinkage-reducing poly Carboxylic acid water reducer and its preparation method, which can effectively reduce the sensitivity of the water reducer to mud content by inserting a rigid benzene ring structure into the polycarboxylic acid molecular chain to make it well dispersed and adaptable

However, the process of this invention is relatively harsh, and the raw materials need to be reacted under high temperature and nitrogen protection conditions, and the process is complicated and the cost is high

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