Hyperbranched water-reducing and viscosity-reducing concrete admixture, preparation method and application thereof

Abstract

The invention discloses a hyperbranched water-reducing and viscosity-reducing type concrete admixture, a preparation method and application thereof. The preparation method of the hyperbranched water-reducing and viscosity-reducing type concrete admixture comprises the steps: through chemical reaction of a monomer A and a monomer B, introducing another double bond to the tail end of the monomer A to prepare a double-end-group alkylene macromonomer; and carrying out addition polymerization reaction on the double-end-group alkylene macromonomer, the monomer A and the monomer C to prepare the hyperbranched water-reducing viscosity-reducing concrete admixture. According to the invention, the hyperbranched water-reducing and viscosity-reducing concrete admixture prepared by the invention contains a plurality of comb-shaped structure PCE, so that a large number of anchoring groups can be exposed, the fluidity of concrete can be greatly improved, and the viscosity of concrete can be greatly reduced; the preparation method is mild in synthesis condition, the monomer source is wide, the yield is high, the mixing amount is low, the water-reducing rate is high, and the viscosity reduction is good; and the admixture can be widely applied to various types of concrete.

Description

technical field [0001] The invention relates to the field of concrete admixtures, in particular to a hyperbranched water-reducing and viscosity-reducing concrete admixture and its preparation method and application. Background technique [0002] At present, the conventional admixtures used to improve the working performance of concrete include polycarboxylate water reducers. Based on the theory of adsorption and steric hindrance effect, the anchoring group on the main chain of polycarboxylate superplasticizer is adsorbed on the surface of cement particles, and its long hydrophilic side chain produces steric hindrance effect, thus playing the role of dispersing cement particles. However, the side chain of polycarboxylate superplasticizer is easy to curl, the growth of steric hindrance effect is limited, and its bulk viscosity is high. After mixing, it will increase the viscosity of concrete, which is difficult to meet the requirements of polycarboxylate superplasticizer in ac...

AI Technical Summary

Problems solved by technology

At present, there are mainly two types of synthetic methods for hyperbranched admixtures: the first type uses carboxyl groups (anchor groups) as active points, and introduces hyperbranched structures into comb-shaped polycarboxylic acid molecules under the premise of sacrificing adsorption capacity. The other type is usually to use special monomers or complex chemical reactions to prepare hyperbranched admixtures, which have the disadvantages of expensive monomers, many reaction steps, and poor controllability.

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