Early-strength polycarboxylate superplasticizer and preparation method thereof

Abstract

The invention discloses an early-strength polycarboxylate superplasticizer and a preparation method thereof. The water reducer is prepared from raw materials in parts by weight as follows: 200 parts of unsaturated polyether, 10-30 parts of acrylic acid, 1-3 parts of an amide derivative, 0.1-0.5 parts of mohr's salt, 0.5-1.5 parts of a chain transfer agent, 0.2-0.8 parts of L-ascorbic acid, 0.8-4 parts of an oxidizing agent, 230 parts of deionized water and 12-20 parts of a 30% sodium hydroxide solution. The unsaturated polyether with a larger molecular weight is used, that is, a long side chain is introduced into a polycarboxylate superplasticizer molecule, quaternary amine and amide functional groups exist on a main chain, early hydration of hydration products, namely C3A and C3S, can be promoted, crystallization of Ca(OH)2 and forming of ettringite can be accelerated, the concrete setting time can be effectively shortened, the compactness of an early microstructure is improved, the early mechanical property of cement grout can be substantially improved, and the polycarboxylate superplasticizer promotes early-strength development of concrete and shows excellent early-strength performance from a macroscopic view.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to an early-strength polycarboxylate water reducer and a preparation method thereof. Background technique [0002] The construction of various industrial and civil buildings, highway and railway bridges, airport runways, mine construction, hydraulic structures, marine development, geothermal engineering, and military projects cannot do without concrete. Compared with other building materials, concrete has the advantages of easy raw materials It has the characteristics of wide application range, low energy loss and long service life. [0003] With the acceleration of the construction of concrete engineering projects, the consumption of precast concrete products is also showing a growing trend. Compared with ordinary concrete, precast concrete requires concrete to have a better early strength development rate to improve the formwork turnover rate or meet the st...

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Problems solved by technology

[0005] The research on early-strength polycarboxylic acid-based water reducers has become a research hotspot. At present, many research institutions are conducting research on this, such as CN201210554672. The preparation method of carboxylic acid-based water-reducers is generally formed by aqueous solution polymerization of oxidation-reduction bodies. During the reaction process, various materials need to be added dropwise at the same time, and under heating conditions. The process is not easy to control, and most of the product performance cannot be achieved. At the same time meet the requirements of setting time and early strength of special concrete (such as subway segment concrete)

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