CN-122010595-A - Concrete external curing agent for extremely high temperature environment, preparation method and application

Abstract

The invention discloses a concrete external curing agent for extremely high temperature environment, a preparation method and application thereof, belonging to the technical field of building material chemical additives, wherein (3-mercaptopropyl) trimethoxysilane modified cellulose nanocrystals, nonionic polyurethane associative thickeners, styrene, butyl acrylate, methyl methacrylate, hydrophilic functional monomers, crosslinking functional monomers, reactive emulsifiers, anionic emulsifiers and nonionic emulsifiers are added in the preparation of the concrete external curing agent for extremely high temperature environment, the concrete external curing agent for the extremely high temperature environment, which is prepared by the invention, has excellent construction performance under the high temperature environment, and has good high temperature resistant curing performance in the application stage.

Inventors

• FENG KE
• TIAN YU
• SHI XIN
• WU WEI
• Lian Yanli
• WANG YONGMEI
• ZHAO MINGMIN
• MA YUHAO
• SUI XIAOHUI
• ZHONG XIAORONG

Assignees

• 河北长安育才科技股份有限公司
• 河北交通职业技术学院

Dates

Publication Date

20260512

Application Date

20260409

Claims (9)

1. 1. The concrete external curing agent for the extremely high temperature environment is characterized by comprising, by mass, 10-30 parts of silane modified cellulose nanocrystal dispersion liquid, 15.8 parts of initiator solution, 100-120 parts of pre-emulsion, 0.2 part of photoinitiator, 1-1.5 parts of nonionic polyurethane associative thickener and 0.2 part of defoamer; The raw materials of the silane modified cellulose nanocrystal dispersion liquid comprise, by mass, 2 parts of cellulose nanocrystals, 98 parts of water and 1.0-2.0 parts of (3-mercaptopropyl) trimethoxy silane; the initiator solution comprises, by mass, 0.5 part of a water-soluble thermal decomposition initiator and 0.3 part of a buffering agent, wherein the water-soluble thermal decomposition initiator is ammonium persulfate, and the buffering agent is sodium bicarbonate; the pre-emulsion comprises the following raw materials in parts by mass, namely 25 parts of water, 2.5 parts of composite emulsifier and 100 parts of monomer mixture; the composite emulsifier comprises the following raw materials in parts by mass, namely 1.1 parts of reactive emulsifier, 0.9 part of anionic emulsifier and 0.5 part of nonionic emulsifier; The raw materials of the monomer mixture comprise, by mass, 50-55 parts of styrene, 38-43 parts of butyl acrylate, 4 parts of methyl methacrylate, 1.5 parts of hydrophilic functional monomers and 1.0-1.5 parts of crosslinkable functional monomers.
2. 2. The external curing agent for concrete in extremely high temperature environment according to claim 1, wherein the preparation method of the silane modified cellulose nanocrystal dispersion is that cellulose nanocrystals are added into water and uniformly dispersed to prepare the cellulose nanocrystal dispersion, the pH is adjusted to 4.5 by dilute hydrochloric acid, and (3-mercaptopropyl) trimethoxysilane is added for reaction under heating condition to obtain the silane modified cellulose nanocrystal dispersion.
3. 3. The concrete external curing agent for extremely high temperature environments according to claim 2, wherein the cellulose nanocrystals are carboxylated cellulose nanowhiskers.
4. 4. The external curing agent for concrete in extremely high temperature environment according to claim 1, wherein the crosslinkable functional monomer is hydroxyethyl methacrylate.
5. 5. The external curing agent for concrete in extremely high temperature environment according to claim 1, wherein the hydrophilic functional monomer is acrylic acid.
6. 6. The external curing agent for concrete in extremely high temperature environment according to claim 1, wherein the reactive emulsifier is 1-allyloxy-3- (4-nonylphenol) -2-propanol polyoxyethylene (10) ether ammonium sulfate, the anionic emulsifier is nonylphenol polyoxyethylene (4) ether ammonium sulfate, and the nonionic emulsifier is dodecylphenol polyoxyethylene ether.
7. 7. The external curing agent for concrete in extremely high temperature environment according to claim 1, wherein the photoinitiator is benzoyl methyl ether and the antifoaming agent is selected from mineral oil antifoaming agents.
8. 8. A method for preparing the external curing agent for concrete for extremely high temperature environments according to any one of claims 1 to 7, characterized by comprising the steps of: Weighing the raw materials according to mass fraction; Mixing a reactive emulsifier, an anionic emulsifier, a nonionic emulsifier and water, stirring and dissolving, adding styrene, butyl acrylate, methyl methacrylate, a hydrophilic functional monomer and a crosslinking functional monomer, and uniformly stirring to form a pre-emulsion; Adding a water-soluble thermal decomposition buffer to water to form an initiator solution; Adding 1/3 volume of initiator solution into silane modified cellulose nanocrystal dispersion liquid, adding the pre-emulsion and the rest 2/3 volume of initiator solution after reaction, reacting under heating, cooling to room temperature after the reaction is finished, adding photoinitiator, performing curing reaction under ultraviolet condition, and regulating pH to 8 after the curing reaction is finished to obtain in-situ polymerized emulsion; adding diluted nonionic polyurethane associative thickener solution into the in-situ polymerized emulsion, stirring uniformly, adding defoamer, and filtering to obtain the concrete external curing agent for the extremely high temperature environment.
9. 9. Use of the concrete external curing agent for extremely high temperature environments according to any one of claims 1 to 7 for preparing concrete for application in extremely high temperature environments.

Description

Concrete external curing agent for extremely high temperature environment, preparation method and application Technical Field The invention belongs to the technical field of building material chemical additives, and particularly relates to a concrete external curing agent for an extremely high-temperature environment, a preparation method and application. Background Concrete curing is a key link for ensuring the mechanical property and long-term durability of the concrete. For the conventional environment, various mature external curing technologies such as film coating water spraying, spraying curing agent and the like have been developed. The concrete external curing agent based on film forming and water retaining mechanisms has been widely used in the fields of bridges, road surfaces, house buildings and the like because of the advantages of convenient construction, water saving, high efficiency and the like. However, as the foundation construction of China deeply develops to the western region with complex geological conditions, tunnel engineering is often faced with the extreme construction environment of high rock temperature, high air temperature, strong heat radiation and low humidity, and constitutes a serious challenge for the existing concrete curing technology. According to the published tunnel engineering measured data (such as a deep buried tunnel of a Sichuan-Tibetan railway and a high-temperature tunnel of Xinjiang), the surrounding rock temperature of the face can be maintained above 80 ℃ for a long time, the air temperature in a tunnel exceeds 50 ℃, and the relative humidity is less than 30%, so that typical high-temperature dry heat and cave effect are formed. In order to adapt to the spraying operation of the reverse slope structures such as tunnel vault and side wall, the curing agent needs to have lower initial viscosity to ensure sprayability. However, the extremely high temperature can cause the film layer of the conventional curing agent to be rapidly softened and the viscosity to be rapidly reduced, so that the curing agent cannot be effectively hung on a vertical or inclined basal plane, and serious sagging and flowing phenomena are generated. This not only results in a great deal of waste of materials, but also makes the concrete surface incapable of forming a complete and continuous sealing maintenance film. The water evaporation kinetics is obviously enhanced under the high-temperature environment, and the barrier property of the film layer of the conventional curing agent is greatly reduced under the action of heat. Meanwhile, severe heat radiation can directly damage the integrity of the organic polymer film, so that the organic polymer film loses the water retention function, water is rapidly dissipated from the surface of the concrete, and a necessary condition cannot be provided for continuous hydration of cement. The concrete curing agent sold in the market at present is designed aiming at normal temperature or mild climatic conditions, and the heat-resistant upper limit and rheological property of a formula system cannot meet the extreme working conditions. Although attempts have been made to improve the workability by increasing the solids content or adding conventional thickeners, there are often cases where, in this case, either the spray atomization is sacrificed or the long-lasting sag resistance and water retention at dynamic high temperatures are not maintained. Therefore, the development of the high-performance concrete external curing agent which is specially used in an extremely high-temperature environment, can be easily sprayed in a construction stage, can be strongly adhered to a complex vertical surface in an application stage, does not flow, can effectively lock water to inhibit evaporation, and has become urgent market demands in special fields such as tunnel engineering and the like. Disclosure of Invention In order to solve the technical problems, the invention provides the concrete external curing agent for the extremely high temperature environment, the preparation method and the application thereof, and the concrete external curing agent for the extremely high temperature environment provided by the invention is the concrete external curing agent with excellent thixotropic property, sagging resistance and water retention in the construction and application stages of the high temperature environment. The invention provides a concrete external curing agent for extremely high temperature environment, which comprises, by mass, 10-30 parts of silane modified cellulose nanocrystal dispersion liquid, 15.8 parts of initiator solution, 100-120 parts of pre-emulsion, 0.2 part of photoinitiator, 1-1.5 parts of nonionic polyurethane associative thickener (HEUR thickener) and 0.2 part of defoamer; The raw materials of the silane modified cellulose nanocrystal dispersion liquid comprise, by mass, 2 parts of cellulose nanocrystals, 98 parts of water and 1.0-2.0 par