Efficient concrete water reducer and preparation method thereof

Abstract

The invention provides an efficient concrete water reducer and a specific preparation method thereof. The preparation method comprises the following specific steps of grafting and modifying through sodium lignin sulfonate and maleic anhydride, then copolymerizing with crylic acid and polyoxyethylene monomethyl ether acrylate so as to obtain an intramolecularly compounded efficient concrete water reducer product with an anion structure and a nonionic structure. The concrete water reducer has prominent advantages that the amount of admixture is less and is 0.2-0.5% of the weight of binding material, the decrement rate is high and is more than or equal to 35%, has good enhancing effect on concrete, has large gas generating amount and uniform bubbles, does not react with aggregate due to low alkalinity, does not erode the passive film on the surface of a rebar due to low content of chlorine. The raw material of the concrete water reducer adopts waste residue of papermaking, so that the concrete water reducer has low cost and good degradability, and no harmful contaminants are generated and left in the whole production process.

Description

technical field [0001] The invention belongs to the field of concrete admixtures, and relates to a high-efficiency concrete water reducer and a preparation method thereof. Background technique [0002] So far, the development of water reducers has gone through three stages: the first generation of ordinary water reducers represented by lignosulfonate, the second generation of high-efficiency water reducers represented by naphthalene series, and At present, the third-generation high-performance water reducer stage represented by polycarboxylic acid series. The water-reducing effect of lignosulfonate is general. At present, the water-reducing agent varieties in my country are still dominated by the second-generation naphthalene series products, which have high alkalinity, and formaldehyde and other harmful raw materials are used in the production process. After being formulated into concrete, harmful substances such as formaldehyde and naphthalene remaining in the water reduci...

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Problems solved by technology

Its dosage is low (the general dosage is 0.15%~0.25% of the weight of the cementitious material, which is only 1 / 4 of the naphthalene series), and the water reducing rate is high (the water reducing rate can generally reach 25%~40%); concrete mixing It has the advantages of good fluidity and flow retention, low slump loss, and great potential for concrete reinforcement. However, due to its high cost and poor compoundability with other concrete admixtures, its popularization is limited.

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