Preparation method of polycarboxylic superplasticizer containing polyurea structure

Abstract

The invention provides a preparation method of a polycarboxylic superplasticizer containing a polyurea structure. The preparation method is characterized in that acrylic acid, a polyoxyethylene ethermacromonomer containing an alkenyl group at one end, a polyurea macromonomer containing an alkenyl group at one end are reacted in the presence of an initiator and a chain transfer agent to obtain thepolycarboxylic superplasticizer containing the polyurea structure. The polycarboxylic superplasticizer containing the polyurea structure, prepared through the preparation method, has improved concrete dispersibility, and also has an improved concrete slump retention property.

Description

technical field [0001] The invention relates to the field of water reducers for concrete, in particular to a preparation method of a polycarboxylate water reducer containing a polyurea structure. Background technique [0002] Since the beginning of the 21st century, polycarboxylate high-performance water reducers have been gradually used in nuclear power, It has been favored by people in major projects such as water conservancy and has become a hot spot and direction for the development of water reducing agent technology. However, many engineering difficulties have been encountered during the application of polycarboxylate superplasticizers, the most prominent of which is the loss of concrete slump. Due to the large difference in concrete raw materials, during the process of concrete transportation and construction, the phenomenon of excessive loss of concrete slump often occurs, which increases the difficulty of concrete construction and quality control. During the constr...

AI Technical Summary

Problems solved by technology

However, many engineering difficulties have been encountered during the application of polycarboxylate superplasticizers, the most prominent of which is the loss of concrete slump

Due to the large difference in concrete raw materials, during the transportation and construction of concrete, the phenomenon of rapid loss of concrete slump often occurs, which increases the difficulty of concrete construction and quality control

During the construction process, the method of adding water and reshaping is often used to make the concrete have good fluidity, which is easy to pump and pour. However, adding water and reshaping will change the water-cement ratio and air content of the concrete, reduce the impermeability of the concrete, and make the concrete Intensity is severely affected

In addition, by increasing the amount of water reducing agent or adding water reducing agent to reshape the concrete before construction, the concrete can restore better working performance, but increasing the amount of water reducing agent in the initial stage of mixing will cause segregation and bleeding of concrete. Destroy the uniformity of concrete, make the strength of each part of concrete have a large difference, reduce the flexural and compressive strength of concrete

These methods have not effectively solved the problem of excessive concrete collapse.

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