A kind of high-efficiency shrinkage-reducing anti-cracking agent and preparation method thereof

Abstract

The present invention discloses an efficient shrinkage-reducing anti-cracking agent and a preparation method thereof, the efficient shrinkage-reducing anti-cracking agent comprises a shrinkage-reducing component and an expansion component, the shrinkage-reducing component is a shrinkage-reducing agent is a comb-shaped copolymer shrinkage-reducing agent, the expansion component is a calcium oxide type expander, and the mass ratio of the shrinkage-reducing component to the expansion component is 35: 65-45: 55. The shrinkage-reducing component is absorbed on the surface of the expansion component by spray drying, the expansion component is used as an anti-blocking insulating material to achieve fine powder production of the liquid shrinkage-reducing component, the shrinkage-reducing component is used as a waterproof insulation material to delay early hydration of the expansion component, and ultimately coordination and integration of expansion and shrinkage educing is achieved; by powder production and application, injuries of volatile organic solvents on workers during single use of the shrinkage-reducing agent can be avoided, the effective content of the product can be increased, the efficient shrinkage-reducing anti-cracking agent has a significant anti-cracking effect under conditions of low dosage, and helps are provided for expansion of the use range of anti-cracking materials.

Description

technical field [0001] The invention relates to a concrete admixture, in particular to a high-efficiency shrinkage-reducing and anti-cracking agent and a preparation method thereof. Background technique [0002] The shrinkage of concrete and the resulting cracking are a stubborn problem of the quality of concrete engineering, and it is also a problem that the academic and engineering circles have been concerned about. In recent years, with the continuous development of chemical admixture technology and the extensive use of various ground mineral admixtures, contemporary high-performance concrete characterized by low water-to-binder ratio and large content of mineral admixtures has begun to gradually replace high-performance concrete. Traditional concrete, characterized by water-to-binder ratio and high cement content, plays a leading role in construction projects and is widely used. Due to the composition and structural characteristics of high-performance concrete itself, t...

AI Technical Summary

Problems solved by technology

The addition of fiber only improves the tensile strength of concrete, prevents the expansion and extension of cracks to a certain extent, mainly plays the role of dispersing or homogenizing shrinkage stress, and cannot fundamentally eliminate the occurrence of cracks

Expansion agent is to compensate concrete shrinkage by generating expansion crystals through hydration reaction. Although it can compensate early shrinkage or produce micro-expansion, it can only achieve a suitable compensation effect when it is added in an appropriate amount (8% to 12%). When it is high, it will cause a large loss of concrete strength, and when the dosage is small, the compensation effect cannot be fully exerted, and the crack resistance effect is poor

In order to achieve the anti-cracking effect, the current amount of expansion agent in concrete is generally 8% to 12% of the total amount of cementitious materials, which brings high costs to long-distance transportation, resulting in limited sales of existing expansion agents. Conducive to the application and promotion of expansion agent

At present, the shrinkage reducing agents used at home and abroad are mostly polyether and polyether derivatives. Although they can reduce the shrinkage of concrete, they are mostly liquid products with few active ingredients. To achieve the required shrinkage reduction effect, a large amount needs to be mixed into concrete. Invisibly increases the cost of concrete, and the liquid shrinkage reducing agent is highly volatile, which seriously affects the health of workers and directly limits its promotion and application in China

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