Efficient retarding and water reducing agent for highway concrete and preparation method thereof

Abstract

The invention relates to the technical field of water reducing agents, in particular to an efficient retarding water reducing agent for highway concrete and a preparation method thereof. The efficient retarding and water reducing agent for the highway concrete is prepared from the following components: isobutene alcohol polyoxyethylene ether, maleic anhydride, alpha methacrylic acid, allyl trimethyl ammonium chloride, ammonium persulfate, ascorbic acid, calcium lignosulphonate, hydrogen peroxide, an acid regulator, an alkali regulator and distilled water. Through molecular design, much -COO- is introduced into molecules of the polycarboxylate superplasticizer, so that the retarding effect of the superplasticizer is enhanced, and alpha-methacrylic acid is used for replacing acrylic acid, so that the self-polymerization degree of a monomer is reduced. By adding the reducing agent ascorbic acid, the temperature of the reaction system is reduced from about 80 DEG C to room temperature, and the energy consumption is reduced under the condition that the performance is basically unchanged. By adding the modified calcium lignosulphonate, the synthesis cost of the polycarboxylate superplasticizer is greatly reduced under the condition of small performance loss.

Description

technical field [0001] The invention relates to the technical field of water reducing agents, in particular to a high-efficiency retarding water reducing agent for road concrete and a preparation method thereof. Background technique [0002] Concrete construction often requires delaying the setting time of concrete to facilitate construction operations and ensure the quality of concrete. Concrete construction in hot weather, high temperature, accelerated concrete setting, accelerated slump loss, and soon lost fluidity will bring difficulties to construction and affect project quality, so concrete is required to have a longer setting time. The construction of mass concrete needs to prolong the setting time of concrete, delay the exothermic process of hydration, and reduce the cracks caused by temperature stress, all of which require the addition of retarders to improve the performance of concrete. [0003] Retarder is an admixture that can prolong the setting time of concret...

AI Technical Summary

Problems solved by technology

[0004] With the development of the economy, the scale of domestic investment in infrastructure construction continues to increase. The construction of infrastructure requires a large amount of concrete, and sand and gravel are an important part of concrete, so that the consumption of sand and gravel is also increasing year by year. Commonly used high-quality river sand is in short supply on a large scale. Many places have begun to use river sand or machine-made sand with high mud content, which has caused the existing polycarboxylate water reducer to be unsuitable and seriously reduced the quality of concrete. This is mainly because the mud contained in the sand is mainly composed of clay such as montmorillonite and kaolin, which has strong adsorption to polycarboxylate superplasticizer, and its saturated adsorption capacity is about 3-4 times that of cement. When the concrete contains a large amount of mud, the clay in the mud will absorb a large amount of polycarboxylate superplasticizer, resulting in a sharp decrease in fluidity and accelerated loss of concrete.

[0005] The existing slow-setting superplasticizers for highway concrete have disadvantages in the use process. First, the retarding effect is not ideal, and the production cost is also high; Adsorption capacity of acid water reducer