Preparation method for slump retaining agent for polycarboxylate superplasticizer

Abstract

The invention particularly relates to a preparation method for a slump retaining agent for a polycarboxylate superplasticizer. The preparation method comprises the following steps: (1) mixing and uniformly stirring maleic anhydride, methyl alcohol and p-toluenesulfonic acid, raising the temperature, stirring at constant temperature, and cooling to room temperature to obtain HMA; (2) mixing and uniformly stirring a polyether macromonomer, the HMA, sodium methallyl sulfonate and deionized water to prepare a solution, adding an oxidizing agent, stirring, adding a reducing agent and a chain transfer agent, continuous stirring, and adding an appropriate amount of deionized water to obtain an inter-polymer slump retaining agent. The preparation method has the main advantages that 1, the concrete workability is remarkably improved, the wrapping property is improved, the pumpability is improved, and the slump loss of concrete is remarkably reduced; 2, the slump retaining agent is decomposable in a cement-hydrated alkaline environment, and carboxyl is released, so that the adsorption capacity is improved, and the aim of improving the dispersing capacity of a copolymer is achieved; 3, feeding is carried out at a time by using a one-step method, the dropwise adding process is eliminated, heating is not needed, and the reaction period is short.

Description

technical field [0001] The invention belongs to the field of building materials, and in particular relates to a preparation method of a slump-retaining agent for a polycarboxylate water reducer. Background technique [0002] At present, the high-fluidity design of concrete, long-distance transportation and pumping during use have become important features of the concrete industry, but the loss of concrete slump has always been the technical bottleneck that restricts the rapid and efficient construction of concrete and long-distance transportation, and even affects The performance of freshly mixed concrete can cause durability problems, leading to a decline in the long-term performance of concrete structures, and even more serious safety problems. The use of concrete admixtures is an effective technical means to improve the fluidity of concrete and reduce slump loss. [0003] Polycarboxylate superplasticizer is a research hotspot in the field of concrete admixtures, and it i...

AI Technical Summary

Problems solved by technology

This process has high requirements for water, resulting in the complexity and instability of the preparation process

[0006] Although the above-mentioned patents relate to concrete slump-retaining agents or slump-retaining water reducers, there is currently no slump-retaining agent with wide adaptability, strong compatibility, simple process, and excellent performance.

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