Polycarboxylic acid water reducer for finish concrete and preparation method of water reducer

Abstract

The invention discloses a preparation method of a polycarboxylic acid water reducer for finish concrete. The preparation method comprises the following steps: (1) allowing diethylenetriamine and maleic anhydride to react under the action of a catalyst to prepare a bright red viscous pre-polymer solution; and (2) copolymerizing the pre-polymer solution, unsaturated polyoxyethylene ether, a sulfoacid monomer and unsaturated carboxylic acid under the action of a redox initiation system and a chain transfer agent to prepare a polycarboxylic acid type water reducer for finish concrete. The water reducer and one or more of a defoaming agent, an air entraining agent, a retarder and a viscosity adjusting agent are compounded and then doped into concrete to prepare finish concrete which is high in construction performance, excellent in wrapping property and can be used for realizing the mirror effect.

Description

technical field [0001] The invention belongs to the technical field of concrete admixtures in building materials, and in particular relates to a polycarboxylate water-reducer for fair-faced concrete, a preparation method thereof, and clear-water concrete prepared by using the water-reducer. Background technique [0002] With the vigorous development of national infrastructure, the construction of urban bridges has increased significantly, and people's requirements for the appearance and quality of urban roads and bridges have become more and more stringent. At present, many master builders in the world use the fair-faced concrete process in their design schemes, such as I.M. Pei, Tadao Ando, ​​etc., all use fair-faced concrete in large quantities in their designs. Foreign countries began to use fair-faced concrete as early as the Japanese Olympic Stadium in the 1960s, and later developed to the exterior walls of the Sydney Opera House, the National Grand Theater of Japan, th...

AI Technical Summary

Problems solved by technology

At present, ordinary polycarboxylate water-reducers are used in most of the clear-water concrete preparations. The use of this type of water-reducer often has the following problems: when the polycarboxylate water-reducer used in pumping concrete is used , good workability of fresh concrete can be obtained, but it is often achieved by introducing air bubbles, which will eventually cause more apparent air bubbles in the concrete. If defoamers are added on this basis, the initial workability of fresh concrete will be lost , affecting the construction quality of concrete, causing problems such as missing corners and construction holes; and if the concrete is made larger, it is easy to make the concrete segregate and bleed, resulting in severe delamination and serious color difference in the appearance of the concrete

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