A low-sensitivity anti-mud cross-branched polycarboxylate water reducer and its preparation method

Abstract

The invention discloses a low-sensitivity anti-mud crossed branched chain type polycarboxylate superplasticizer and a preparation method thereof. The polycarboxylate superplasticizer comprises, by weight, the raw materials of 10-60 parts of 4-hydroxyl vinyl polyoxyethylene ether, 0-40 parts of allyl polyoxyethylene polyether, 0-40 parts of methyl allyl ether polyoxyethylene polyether, 0-40 parts of isopentenyl polyoxyethylene polyether, 6-10 parts of unsaturated monocarboxylic acid, 3-6 parts of unsaturated carboxylic ester monomers, 2-6 parts of 2-(dimethylamino)ethyl methacrylate, 2-6 parts of dibutyl maleate, 1-5 parts of unsaturated amphoteric quaternary phosphonium, 0.2-0.8 part of oxidant, 0.2-1.0 part of first reducing agent, 0.02-0.06 part of second reducing agent, 0.2-0.6 part of chain transfer agent and an appropriate quantity of a potassium hydroxide water solution and a sodium hydroxide water solution and an appropriate amount of deionized water. Lateral chains of the polycarboxylate superplasticizer are distributed more uniformly, are good in slump loss resistance, and the polycarboxylate superplasticizer has excellent low-sensitivity performance for the amount change of the doped polycarboxylate superplasticizer.

Description

technical field [0001] The invention belongs to the technical field of concrete water reducers, in particular to a low-sensitivity anti-mud cross-branched polycarboxylate water reducer and a preparation method thereof. Background technique [0002] Polycarboxylate superplasticizer has excellent dispersibility, and can make concrete achieve better fluidity at a lower dosage. It is widely used in highways, bridges, dams, tunnels, high-rise buildings and other projects. With the continuous development of polycarboxylate technology, the water-reducing rate of polycarboxylate water-reducing agent continues to increase. Although the increase in water-reducing rate can reduce the amount of polycarboxylate water-reducing agent and reduce costs, it also improves the water-reducing rate of polycarboxylate water-reducing agent. The sensitivity of the water agent is manifested in the construction process. The reasonable dosage of polycarboxylate superplasticizer is lowered a little, whi...

AI Technical Summary

Problems solved by technology

With the continuous development of polycarboxylate technology, the water-reducing rate of polycarboxylate water-reducing agent continues to increase. Although the increase in water-reducing rate can reduce the amount of polycarboxylate water-reducing agent and reduce costs, it also improves the water-reducing rate of polycarboxylate water-reducing agent. The sensitivity of the water agent is manifested in the construction process. The reasonable dosage of polycarboxylate superplasticizer is lowered a little, which will lead to insufficient fluidity or rapid loss of fresh concrete. The reasonable dosage should be increased a little. It is easy to cause concrete segregation and slurry bleeding, which makes the control of concrete production more difficult, that is, it is sensitive to the dosage

[0003] In addition, a large number of engineering examples and studies have shown that, compared with naphthalene-based, melamine-based and sulfamic acid-based water-reducers, polycarboxylate-based water-reducers are more sensitive to the clay content of aggregates, mainly manifested as polycarbonate-based water-reducers. The water-reducing and dispersing ability of the carboxylic acid-based water-reducing agent is severely reduced, and the slump-preserving effect is poor, resulting in a decrease in the strength of hardened concrete, etc.

Although it can be alleviated by increasing the amount of water reducing agent, it is easy to cause problems such as excessively long setting time of concrete and lower compressive strength ratio, and greatly increase the cost

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