Self-compensating shrinkage and slump-retaining copolymer and preparation method thereof

Abstract

The invention relates to the technical field of building materials, in particular to a self-compensating shrinkage and slump-retaining copolymer and a preparation method thereof. The copolymer is prepared from 2-3 parts of acrylic acid, 1-2 parts of sodium allylsulfonate, 2.5-4 parts of methoxy polyethylene glycol monomaleate with mass concentration of 60%, 30-35 parts of alkylene alkenyl polyoxyethylene ether, 1.5-2.5 parts of ammonium persulfate, 3-5 parts of a NaOH solution with mass concentration of 30% and 50-60 parts of water by reaction in accordance with a certain technological process. Slow-release slump retaining and self-compensation shrinkage are realized by conversion of a methoxy polyethylene glycol monomaleate-cement calcium aluminate intercalation hydration product into mono-sulfur hydrated calcium sulfoaluminate; 0.2%-0.5% by mass of a cementing material is mixed with concrete or a concrete product, the slump loss of the concrete in one hour is lower than 10%, the compressive strength ratio in one to three days is higher than 160%, the compressive strength ratio in 28 d is 140%-150%, and the shrinkage ratio in 28 d is lower than 80%, workability and volume stability of the concrete are remarkably improved, and the copolymer is applicable to various types of concrete and products.

Description

technical field [0001] The invention relates to the technical field of building materials, in particular to a self-compensating shrinkage slump-preserving copolymer. Background technique [0002] Water reducer is a concrete admixture that can reduce the amount of mixing water while maintaining the slump of concrete basically unchanged. Most of them are anionic surfactants, such as lignosulfonate, naphthalenesulfonate formaldehyde polymer, etc. After being added to the concrete mixture, it can disperse the cement particles, improve its workability, reduce the unit water consumption, improve the fluidity of the concrete mixture; or reduce the unit cement consumption and save cement. [0003] According to the water reducing and strengthening ability of the water reducing agent, it is divided into ordinary water reducing agent (also known as plasticizer, the water reducing rate is not less than 8%, represented by lignosulfonate), high-efficiency water reducing agent (also known...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide a self-compensating shrinkage slump-preserving copolymer and its preparation method to solve the problems of the slow-release slump-preserving effect of the water reducing agent in the prior art.