Modified starch water reducing agent and preparation method and use method thereof

Abstract

The invention discloses a modified starch water reducing agent and a preparation method and a use method thereof; with natural starch as a main raw material, the modified starch water reducing agent is prepared through oxidative degradation and grafting copolymerization reaction with a mixed monomer and has the characteristics of high water reducing rate, strong adaptability, good delayed coagulation effect and good compatibility with other additives, the water reducing rate can reach 26-28%, and the delayed coagulation time is 3-4 hours. When the product prepared by the method is in cooperation use with a polycarboxylate-type water reducing agent, can increase the delayed coagulation time of the polycarboxylate-type water reducing agent to reach 4-5 hours, can effectively prevent the polycarboxylate-type water reducing agent from generating water overflowing, segregation and other phenomena, and improves the adaptability of the polycarboxylate-type water reducing agent on mud-containing dinas.

Description

【Technical field】

[0001] The invention belongs to the technical field of concrete water-reducer, and relates to a modified starch water-reducer used in concrete construction and its preparation method and use method. 【Background technique】

[0002] Concrete water reducing agent is an admixture that must be used in the production and construction of modern concrete. Its function is to reduce the water consumption during concrete mixing under the condition of ensuring the fluidity of the new concrete, and to promote the hydration reaction of cement in concrete. Improve the strength and service life of concrete. The main concrete water reducers currently used in my country are the second generation water reducer naphthalene sulfonate formaldehyde condensate, sulfonated melamine formaldehyde condensate and sulfamate condensate, the third generation water reducer polycarboxylate water reducer Agents are being promoted and applied. The output of the second-generation water reduce...