Viscosity modifier for controlling bleeding of concrete by utilization of high-molecular-weight polycarboxylic acid and application thereof

Abstract

The invention discloses a viscosity modifier for controlling bleeding of concrete by the utilization of high-molecular-weight polycarboxylic acid. The viscosity modifier is mainly formed by compounding high-molecular-weight polycarboxylic acid and common-molecular-weight polycarboxylic acid. The molecular weight of the high-molecular-weight polycarboxylic acid is 600-2000 thousand, and the molecular weight of the common-molecular-weight polycarboxylic acid is 200-700 thousand. In the viscosity modifier, solid content of the common-molecular-weight polycarboxylic acid is 6-20%, and the high-molecular-weight polycarboxylic acid accounts for 1-20%. The viscosity modifier can be effectively applied to manufacturing of concrete of C50 and above (including C50, C55, C60, C70 and C80) and the above premixed concrete. By directly compounding of 1-20% high-molecular-weight polycarboxylic acid and common-molecular-weight polycarboxylic acid and without influencing water-reducing rate and antisag property, viscosity of the premixed concrete is effectively enhanced, and bleeding and segregation are controlled. In addition, the problem of compatibility between traditional VMA and a polycarboxylate superplasticizer is fundamentally solved.

Description

Technical field [0001] The invention relates to a viscosity modifier for controlling concrete bleeding by using high molecular weight polycarboxylic acid. Background technique [0002] In the past ten years, with the rapid development of domestic infrastructure, including civil, municipal, railway, port, airport, nuclear power plant, water conservancy projects, etc., the application of polycarboxylate superplastic water reducer in ready-mixed concrete has exceeded the total reduction 52% of the water dosage, and the proportion of developed countries that accounted for 75% of the total water reducer is rapidly increasing. Although it has the advantages of high water reduction rate, good collapse retention performance, low concrete shrinkage rate, and green environmental protection, polycarboxylic acid water-reducing agent is used in some occasions, such as high-strength, self-compacting and other high-fluidity concrete construction. Insufficient cohesion will cause bleeding and s...

AI Technical Summary

Problems solved by technology

However, due to the unsatisfactory solubility of these viscosity modifiers and polycarboxylate superplasticizers, they cannot be added to the superplasticizer system in advance, otherwise they will easily precipitate and cause stratification

In recent years, it has been reported that acrylic acid is mainly used to obtain a new type of concrete viscosity modifier through oxidation-reduction radical polymerization with acrylamide, but this type of product has not been widely used in the market, and the reason is still unclear