A high slump retarding polycarboxylate superplasticizer and its preparation and application

Abstract

The invention discloses a high slump retarding polycarboxylate water reducer and its preparation method and application. The water reducer is prepared from the following raw materials in molar parts: 10-30 parts of small molecule unsaturated carboxylic acid, 3‑8 parts of esters of small molecular unsaturated carboxylic acids, 1‑5 parts of salts of small molecular unsaturated carboxylic acids, 2‑6 parts of polyethylene glycol diacrylate, 1‑5 parts of unsaturated polyether macromonomers , 8-20 parts of acrylamide monomer, initiator and chain transfer agent; wherein said acrylamide monomer is acrylamide (AM), 2-acrylamide-2-methylpropanesulfonic acid (AMPS), 2 ‑acrylamido‑2‑phenylethanesulfonic acid (AMSS) is a group of three monomers. The molecular structure of the superplasticizer is designed according to the ease and slump retention of the construction requirements, and finally a high-slump retention and retardation polycarboxylate superplasticizer with excellent comprehensive performance is obtained. In construction, a low dosage can achieve a higher water reducer The water rate can ensure the construction, and the slump retention is excellent, and the slump is basically not lost within 3 hours, and it has wide applicability in 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. Background technique: [0002] 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 construction unit....

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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