Air-entraining type polycarboxylate superplasticizer and preparation method thereof

Abstract

The invention discloses an air-entraining type polycarboxylate superplasticizer and a preparation method thereof, and belongs to the technical field of concrete admixtures, wherein the air-entrainingtype polycarboxylate superplasticizer comprises the following raw materials: 20-40 parts of a polyether macromonomer, 5-20 parts of a vinyl micromonomer, 1-10 parts of tea saponin, 0.1-0.5 part of a catalyst, 1-6 parts of an initiator and the balance being water. The excellent foaming and foam stabilizing capabilities of the natural nontoxic product tea saponin are utilized, so that the compatibility problem of the polycarboxylate superplasticizer compound air-entraining agent and the problem of poor stability of the air content in concrete are fundamentally solved. The air-entraining type polycarboxylate superplasticizer product provided by the invention is good in air-entraining performance, high in water reducing rate and high in concrete air content retention rate, and the long-term and durable performance of concrete can be remarkably improved.

Description

technical field [0001] The invention belongs to the technical field of concrete admixtures, in particular to an air-entraining polycarboxylate water reducer and a preparation method thereof. Background technique [0002] Polycarboxylate superplasticizer is an admixture used in cement-based materials, which can significantly improve the working performance, mechanical properties and durability of cement-based materials, and has become an indispensable component in concrete. Some researchers have pointed out that polycarboxylate superplasticizers have a comb structure, and based on the designability of their molecular structure, some functional monomers or structures can be introduced to endow polycarboxylate superplasticizers with more new functions, such as improving polycarboxylate superplasticizers. The slump-preserving performance, air-entraining performance, shrinkage-reducing performance, slow-release performance and so on of the acid superplasticizer. At present, the ...

AI Technical Summary

Problems solved by technology

The traditional air-entraining method is to add air-entraining agent in the concrete mixing process, or to use ordinary lignosulfonate superplasticizer with air-entraining function, but the effect of these two methods in actual engineering has certain shortcomings

Compounding air-entraining agents in admixtures, especially rosin and saponin air-entraining agents, is prone to incompatibility problems between air-entraining agents and other admixture systems, and admixture stratification occurs, which affects the use efficiency of admixtures

The use of lignosulfonate water reducer, due to its poor water reducing effect, in order to meet the working performance of engineering concrete, use a large amount of lignosulfonate water reducer, and it is easy to cause the transitional retardation of concrete, affecting the performance of concrete. construction progress and project quality

[0004] Air-entraining agents such as compound rosin and saponins commonly used at present have the problem of incompatibility with other admixture systems, and are prone to stratification of admixtures, which affects the use efficiency of admixtures

The use of lignosulfonate water reducer, due to its poor water reducing effect, in order to meet the working performance of engineering concrete, use a large amount of lignosulfonate water reducer, and it is easy to cause the transitional retardation of concrete, affecting the performance of concrete. construction progress and project quality

Polyoxyethylene ether side chains, small air-entraining unsaturated monomers (styrene and ethyl acetate) are used as air-entraining functional monomers, some monomers have low supersolubility or insoluble in water, oil-soluble functional monomers during polymerization Difficult to fully polymerize, prone to floating and delamination problems, affecting product performance and concrete performance

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