An air-entraining controllable polycarboxylate water reducer for pure machine-made sand concrete and its preparation method

Abstract

The invention belongs to the field of concrete additives, and concretely relates to an air entrainment-controllable polycarboxylic water reducer used for purely machine-made sand concrete, and a preparation method thereof. The preparation method comprises the following steps: carrying out an esterification reaction on an alkylphenol polyoxyethylene monomer and an unsaturated carboxylic acid to generate an unsaturated carboxylic acid-alkylphenol polyoxyethylene esterification product monomer, carrying out an aqueous solution copolymerization reaction on the unsaturated carboxylic acid-alkylphenol polyoxyethylene esterification product monomer, an unsaturated polyether monomer and an unsaturated sulfonic acid monomer through an oxidation-reduction initiation system, and adding a proper amount of a molecular weight control agent to control the molecular weight in order to obtain the air entrainment-controllable polycarboxylic water reducer. The water reducer prepared in the invention has the advantages of high water reduction rate, good adaptability, small bubble diameters, stable sealing property and controllable air entrainment when applied to the purely machine-made sand concrete, and well solves the problems of difficult air entrainment, poor bubble stability and large concrete pumping loss of the purely machine-made sand concrete.

Description

Technical field

[0001] The invention belongs to the field of concrete admixtures, and in particular relates to an air-entraining controllable polycarboxylic acid water-reducing agent for pure machine-made sand concrete and a preparation method thereof. Background technique

[0002] Polycarboxylic acid water reducer has the advantages of strong designability of molecular structure, simple production process, high water reduction rate, good slump retention performance, strong adaptability to other materials, and green and pollution-free production process, so it is used in construction engineering. It has been widely used and replaced the traditional naphthalene-based water-reducing agent to become the most used admixture in engineering, the highest technical content, and the most significant economic and environmental benefits. As a surface active agent, polycarboxylic acid water-reducing agent has certain air-entraining performance. However, due to the large size of the bubbles i...

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