High-slump-retaining coagulation-retarding type polycarboxylate water reducing agent and preparation and application thereof

Abstract

The invention discloses a high-slump-retaining coagulation-retarding type polycarboxylate water reducing agent and a preparation method and application thereof. The water reducing agent is prepared from, by molar part, 10-30 parts of small-molecule unsaturated carboxylic acid, 3-8 parts of ester of small-molecule unsaturated carboxylic acid, 1-5 parts of salt of small-molecule unsaturated carboxylic acid, 2-6 parts of polyethylene glycol diacrylate, 1-5 parts of an unsaturated polyether macromonomer, 8-20 parts of an acrylamide monomer, an initiator and a chain transferring agent, wherein theacrylamide monomer is a group consisting of three monomers including acrylamide (AM), 2-acrylamide-2-methylpropanesulfonic acid (AMPS) and 2-acryloylamino-2-phenylethanesulfonic acid (AMSS). The molecular structure of the water reducing agent is designed according to the construction demands for workability and slump retaining performance, and the high-slump-retaining coagulation-retarding type polycarboxylate water reducing agent with excellent comprehensive performance is finally obtained. During construction, a high water reducing rate can be achieved by applying a low dosage of the water reducing agent, the construction can be guaranteed, the slump retaining performance is excellent, the slump is basically not changed within 3 hours, and the water reducing agent has wide applicabilityin concrete construction.

Description

technical field [0001] The invention belongs to the field of concrete admixtures, and in particular relates to a polycarboxylate water reducer and its preparation and application. [0002] Background technique: [0003] With the rapid development of my country's economy and the improvement of construction levels, the rapid rise of high-speed railways, highway bridges, traffic tunnels, urban rail transit, and large buildings, concrete structures are becoming large, complex, high-rise, and have diverse construction conditions. Therefore, higher requirements are put forward for the strength, construction performance and durability of concrete, and almost all of them require the use of pumped concrete, which also maintains a better performance of concrete in the long-distance pumping process. Fluidity and slump retention, otherwise it will cause the slump loss of the freshly mixed concrete and make it impossible to construct, which will cause great economic losses to the constructi...

AI Technical Summary

Problems solved by technology

The technical idea of ​​the present invention is to introduce different functional monomers, synthesize polycarboxylic acid macromolecules with specific structures, and adjust the ratio of each functional monomer so that the prepared polycarboxylic acid water reducer has both long-term slump retention and The advantage of high water reducing rate can meet the stringent requirements of concrete construction at present, so as to overcome the shortcomings of poor slump retention in the later stage of ordinary polycarboxylate water reducing agents in the prior art

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