Polycarboxylic retarding high-performance water reducing agent for preparing concrete of middle and low strength grade

Abstract

The invention discloses a polycarboxylic retarding high-performance water reducing agent used for preparing concrete of middle and low strength grade. According to the weight percentage of the effective solid content, the water reducing agent comprises 9-15% of low air-entrained mother liquor, 0.5-3.0% of retarder, 0.01-0.03% of foam stabilizer, 0.03-0.10% of air-entraining agent, 0.02-0.08% of thickener, 0.05-0.20% of activator and the balance of water. The preparation method comprises the following steps of: weighing all compositions by the weight percentage of each effective solid content, putting and slowly mixing the compositions in a reaction kettle for 10-30min, thus obtaining the concrete. By adjusting the proportion of all compositions, the polycarboxylic retarding high-performance water reducing agent can meet the usage requirements of the concrete of middle and low strength grade (C15-C40), has the advantages of wide doping range, high water reducing ratio, good retarding effect, low chlorine and alkali content, low concrete shrinkage ratio, greenness, environmental protection and the like, and can prepare the green and economic high-performance concrete.

Description

technical field [0001] The invention belongs to the field of chemical building materials and construction, and in particular relates to a polycarboxylate-based slow-setting high-efficiency water reducer for preparing medium and low-strength concrete. Creep concrete, self-compacting and vibration-free concrete, high-durability concrete, low-heat mass concrete, etc. Background technique [0002] At present, the types of high-efficiency water reducers widely used in China are mainly naphthalenesulfonic acid formaldehyde condensates, sulfamic acid salts, and melamine. These water reducers all have certain limitations. The slump loss of concrete mixed with naphthalene-based and melamine-based high-efficiency water-reducers is fast, while sulfamate-based water-reducers are likely to cause separation and bleeding of concrete. In recent years, the various performance requirements of concrete in civil structures have been continuously improved, which puts forward higher requirement...

AI Technical Summary

Problems solved by technology

However, the price of polycarboxylic acid products is relatively expensive, the compatibility with other admixtures is poor, the dosage is too low to control, the air content of fresh concrete is too large, and the compressive strength is low, which greatly limits the use of polycarboxylate-based water reducers. Popularization and Application of Commercial Concrete of Medium and Low Strength Grades (C15~C40)

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