Preparation method of early-strength dispersing type water reducing agent and concrete prefabricated part of early-strength dispersing type water reducing agent

Abstract

A preparation method of an early-strength dispersing type water reducing agent for concrete is characterized by comprising the following steps: preparing a dispersing monomer: adding 10-15 parts by mass of maleic anhydride, 30-40 parts by mass of 4-hydroxyphenylboronic acid pinacol ester and 100 parts by mass of acetone into a high-pressure reaction kettle, mixing, then adding 1-2 parts by mass of toluenesulfonic acid and 0.5-1.5 parts by mass of methyl hydroquinone, and uniformly stirring to obtain the dispersing monomer; the temperature is increased to 100-110 DEG C, the pressure is increased to 0.25-0.3 MPa, the pressure is kept for 60-120 minutes, and the dispersed monomer is obtained after pressure relief and cooling. A benzene ring structure is introduced into the water reducing agent, has a three-dimensional steric hindrance effect, is not prone to entering the interior of a gelling mineral structure, is only adsorbed on the surface of the gelling mineral structure, and is small in concentration loss, so that the dispersity is improved. Besides, monomers obtained after hydroxyl esterification are cross-linked, and a long branch chain is formed on a main chain, so that molecules of the water reducing agent have the long branch chain, the steric hindrance effect of a system is improved, a net-shaped space is enhanced, and more molecules can play a dispersing role.

Description

technical field [0001] The invention relates to a manufacturing method of an early-strength dispersion type water-reducing agent and a concrete prefabricated part added with an early-strength dispersion type water-reducing agent, belonging to the technical field of building materials. Background technique [0002] Precast concrete components have the advantages of green construction, advanced control of building quality, standardized production, etc., and are an important way to realize the industrialization of construction. The conventional method to improve the early strength of precast concrete is thermal curing, special cement and concrete early strength agent. The thermal curing method has high energy consumption. The advantages of small loss and excellent durability of the prepared concrete have become the mainstream additives, while the concrete prepared by the existing early-strength superplasticizer has rapid loss of dispersibility and fluidity, poor construction per...

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Problems solved by technology

Conventional methods to improve the early strength of precast concrete are thermal curing, special cement and concrete early strength agent. The thermal curing method consumes a lot of energy. The polycarboxylate water reducer has low dosage, good adaptability to cement, and low slump. The advantages of small loss and excellent durability of the prepared concrete have become the mainstream additives, while the existing early-strength water-reducers prepare concrete with rapid loss of dispersion and fluidity, poor construction performance, poor early-strength strength retention, and In view of the large temperature difference in many places in our country and the slow development of early strength in complex environments, it is necessary to increase the steam curing temperature and steam curing time of prefabricated components to improve the production efficiency and energy consumption of prefabricated components.

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