Low-sensitivity anti-mud polycarboxylic acid water reducing agent and preparation method thereof

Abstract

The invention discloses a low-sensitivity anti-mud polycarboxylic acid water reducing agent and a preparation method thereof. The pH value is 6.0-6.5, and the solid content is 45-55%. The water reducing agent is composed of the following components in parts by weight: 90-130 parts of 4-hydroxybutylvinyl polyoxyvinyl ether with the molecular weight of 2000-5000, 6-10 parts of unsaturated monocarboxylic acid, 3-6 parts of unsaturated carboxylate monomer, 1-5 parts of unsaturated amphoteric quaternary alkylphosphonium salt, 0.2-0.8 part of oxidizer, 0.2-1.0 part of reducer, 0.02-0.06 part of catalyst, 0.2-0.6 part of chain-transfer agent, a right amount of potassium hydroxide water solution, a right amount of sodium hydroxide water solution and a right amount of deionized water. The polycarboxylic acid water reducing agent has the advantages of more uniform side chain distribution and favorable slump retaining effect, and has excellent low sensitivity to the doping amount changes.

Description

technical field [0001] The invention belongs to the technical field of concrete water reducers, and in particular relates to a low-sensitivity anti-mud type 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, w...

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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