Slump-retaining concrete water reducing agent and preparation method thereof

Abstract

The invention relates to a slump-retaining concrete water reducing agent and a preparation method thereof. The water reducing agent comprises the following raw materials in parts by weight: 80-90 parts of a branched modified water reducing agent, 2-3 parts of a small molecular polymer, 8-9 parts of a slump-retaining auxiliary agent and 60-80 parts of water, in the preparation process of the water reducer, a branched monomer is introduced for branched modification, so that the generation of early calcium hydroxide can be inhibited, gaps are filled, and the mechanical strength is enhanced. Meanwhile, the strong adsorption capacity of phosphonic acid groups is utilized, the plastic viscosity of a system is effectively reduced, adsorption to a water reducing agent and mixing water is reduced, the dispersing performance is improved, the viscosity of concrete is reduced, the cement hydration process is delayed through the retarding effect of the phosphonic acid groups, and the long-time flow retention capacity is shown. According to the invention, a plurality of branched chains are grafted on cement, and the branched chains not only can provide a steric hindrance effect, but also can release polycarboxylic acid with a dispersion effect in a high-alkalinity environment of cement hydration to control slump loss.

Description

technical field [0001] The invention belongs to the technical field of concrete admixtures, and in particular relates to a slump-preserving concrete water reducer and a preparation method thereof. Background technique [0002] Concrete water reducer is currently the largest and most widely used concrete admixture. Its function is to significantly reduce the amount of water added when mixing concrete, and at the same time greatly improve the fluidity and strength of concrete when it is freshly mixed, thereby improving the quality of the project. [0003] Traditional superplasticizers such as polyester and polyether superplasticizers still have the disadvantages of high water-cement ratio, low concrete fluidity, small compactness, large cement dosage, and poor concrete strength and durability. There is also a problem that the water reducing agent cannot fully reflect its excellent water reducing performance due to the large amount of water reducing agent and the weak slump re...

AI Technical Summary

Problems solved by technology

However, the traditional polycarboxylate superplasticizer is very sensitive to the mud content in the aggregate, which shows that as the mud content increases, the dispersion performance and dispersion retention performance of the polycarboxylate superplasticizer decrease significantly, resulting in Concrete's workability is greatly reduced

Increasing the amount of polycarboxylate superplasticizer can improve the initial fluidity of concrete, but the loss of concrete is too fast, which affects the slump performance

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