Mud resisting and slump retaining type polycarboxylic acids water reducer and preparation method thereof

Abstract

The invention discloses a mud resisting and slump retaining type polycarboxylic acids water reducer and a preparation method thereof. The mud resisting and slump retaining type polycarboxylic acids water reducer comprises, by weight, unsaturated polyoxyethylene ether 32.5% to 33.6%, unsaturated carboxylic acid 1.7% to 2.5%, functional monomer 3.25% to 3.36%, cross-linking agent 0.08% to 0.13%, oxidizing agent 0.12% to 0.32%, reducing agent 0.09% to 0.17%, chain transferring agent 0.03% to 0.06%, alkalinity modifier 0.86% to 1.22%, and water 60%. The water reducer in the invention has quite strong adaptability for sandstone with high silt content, good effect on mud resisting, large initial dispersibility, low cost and good slump retaining performance. Moreover, the preparation method in the invention reacts at normal temperature; has short reaction time, low energy consumption, low cost, high security coefficient, and no need to control the temperature in the whole production process; and is simple, without pollution, and suitable for commercial production.

Description

technical field [0001] The invention relates to the field of water reducers, in particular to a mud-slump-resistant polycarboxylate water reducer and a preparation method thereof. Background technique [0002] Polycarboxylate high-performance water-reducing agent is a new type of green and environment-friendly water-reducing agent. It has the advantages of large degree of freedom in molecular structure design, less environmental pollution, adjustable functions, and high water-reducing rate. It has been widely used in recent years. in concrete engineering. However, most of the traditional polycarboxylate superplasticizers are prepared by free radical polymerization by heating and heating method. Most of them need boiler heating during production, which consumes a lot of energy. After the polymerization reaction, the system needs to be cooled to a certain temperature before neutralizing the alkaline solution. To adjust the pH value, the whole production process takes a long t...

AI Technical Summary

Problems solved by technology

However, ordinary polycarboxylate superplasticizers are very sensitive to the mud content in sand and gravel, and the superplasticizer is easily absorbed by the soil, resulting in a decrease in the effective ratio of the water reducer that can function. Therefore, as the mud content increases , the dispersion performance and slump retention ability of polycarboxylate superplasticizer are obviously reduced, and the working performance of concrete is deteriorated

In addition, long-term transportation can also easily lead to excessive loss of concrete slump, which affects the construction performance of concrete, especially in hot weather seasons, the phenomenon of concrete slump loss is more obvious

In view of these problems, by increasing the amount of water-reducing agent or adding water to reshape the concrete before construction, the concrete can restore better working performance, but increasing the amount of water-reducing agent in the initial stage of mixing will cause concrete segregation and bleeding, which will affect the flexibility of concrete. and will greatly increase the production cost of concrete, while adding water will easily lead to an increase in the actual water-binder ratio of concrete, seriously affecting the strength of concrete, and may even cause quality accidents in concrete engineering

[0004] Aiming at the adverse effects of sand and gravel with high mud content on the performance of polycarboxylate water reducers, patent applications CN102643395A, CN103897116A, CN104177561A, CN102923989A, CN103641963A, etc. have all synthesized water reducers with anti-mud effect, but these water reducers are large Some are synthesized under heating or high temperature conditions, and some are synthesized in several steps. The process is relatively complicated and the cost is high. At the same time, the actual anti-mud effect of some water reducing agents is not very significant.

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