CN-121974726-A - Concrete curing agent with double water-retaining structure and preparation method and application thereof

CN121974726ACN 121974726 ACN121974726 ACN 121974726ACN-121974726-A

Abstract

The invention relates to the technical field of building materials and concrete additives, in particular to a concrete curing agent with a double water-retaining structure, and a preparation method and application thereof. The curing agent is arranged on the surface and the shallow surface layer of concrete and comprises a surface closed membrane structure and a double water-retaining structure of an internal permeable network structure, and comprises a film-forming emulsion matrix, a composite functional component and a self-healing active component, wherein the composite functional component comprises a carrier and a water-retaining unit loaded on the carrier. The carrier and the water-retaining unit are preassembled by designing special composite functional components, so that the carrier and the water-retaining unit can be used as a transport tool in the application process, and the carrier carries the self-healing active components to directionally permeate into the shallow surface layer of the concrete, thereby constructing a double water-retaining structure consisting of a compact surface sealing film and an internal three-dimensional water-retaining-repairing network on the surface and in the interior of the concrete.

Inventors

Huang Chuqing
RUAN YAOMING
LI ZHIHONG
Fu Buxin
RUAN WENQIN
HUANG CHUNJIANG

Assignees

深圳市鑫陆基建材有限公司

Dates

Publication Date: 20260505
Application Date: 20260302

Claims (11)

1. The concrete curing agent with the double water-retaining structure is characterized in that the curing agent is arranged on the surface and the shallow surface layer of concrete and comprises a double water-retaining structure with a surface closed membrane structure and an internal permeable network structure; the curing agent comprises a film-forming emulsion matrix for forming the surface closed film structure, a composite functional component for constructing the internal permeable network structure and a self-healing active component for inducing secondary hydration reaction at microcracks; The composite functional component comprises a carrier and a water-retaining unit loaded on the carrier.
2. The concrete curing agent according to claim 1, wherein the curing agent comprises, by weight, 30-50 parts of a film-forming emulsion matrix, 5-15 parts of a composite functional component, 3-10 parts of a self-healing active component and 25-50 parts of water; The film-forming emulsion matrix is at least one of styrene-acrylic emulsion, pure acrylic emulsion or silicone-acrylic emulsion.
3. The concrete curing agent according to claim 1 or 2, wherein the carrier in the composite functional component is an organosiloxane or polyether surfactant; And/or the water-retaining unit in the composite functional component is a hydrophilic polymer grafted or physically adsorbed on the carrier, preferably, the hydrophilic polymer is at least one of hydroxypropyl methylcellulose, polyvinyl alcohol or polyvinylpyrrolidone.
4. A concrete curing agent according to claim 3, wherein the hydrophilic polymer is replaced by a smart polymer having a Low Critical Solution Temperature (LCST) or humidity responsiveness, preferably the smart polymer comprises poly (N-isopropylacrylamide) or a copolymer thereof, poly (dimethylaminoethyl methacrylate) based copolymer.
5. A concrete curing agent according to claim 3, wherein said composite functional component is prepared in advance by dissolving or swelling said hydrophilic polymer in a part of water, adding a carrier, and reacting for 1-3 hours under stirring at 50-70 ℃ to form a composite.
6. A concrete curing agent according to claim 1 or 2, characterized in that the self-healing active component is a micro-or nano-sized inorganic material containing SiO 2 and/or Al 2 O 3 , the particle size distribution D90 of which is not more than 20 μm.
7. A method for preparing a concrete curing agent according to any one of claims 1 to 6, comprising the steps of: s1, preparing self-healing active slurry, namely mixing the self-healing active component, part of water and a dispersing agent, and performing high-speed shearing and dispersing to obtain uniformly dispersed slurry A; s2, preparing a curing agent base solution, namely mixing the film-forming emulsion matrix, the composite functional component and the rest water, and uniformly stirring to obtain a base solution B; S3, structural compounding, namely slowly adding the slurry A into the base solution B under the stirring condition, and uniformly mixing; And S4, adjusting and post-treating, namely adjusting the pH value of the mixed system to 7.5-9.0 by using a pH regulator, adding a defoaming agent and a preservative, uniformly stirring, and filtering to obtain a finished product.
8. The method according to claim 7, wherein in step S1, the high-speed shearing dispersion is performed at a rotational speed of 2000 to 5000 rpm for a dispersion time of not less than 30 minutes; And/or in the step S1, the dispersing agent is at least one selected from polyphosphate, polycarboxylate, polyacrylate, naphthalene sulfonate condensate and nonionic surfactant, and preferably the dispersing agent is polycarboxylate dispersing agent or sodium hexametaphosphate; and/or in the step S4, the defoaming agent is at least one selected from mineral oil defoaming agents, organic silicon defoaming agents and polyether defoaming agents, and preferably, the defoaming agent is polyether modified organic silicon defoaming agent; And/or in the step S4, the preservative is at least one selected from isothiazolinone, benzisothiazolinone and formaldehyde releasing preservative, and preferably, the preservative is 1, 2-benzisothiazolin-3-one (BIT).
9. Use of the concrete curing agent having a double water retention structure according to any one of claims 1 to 6 in concrete construction curing.
10. The application of the composite water-retaining agent according to claim 9, wherein the application method comprises the steps of spraying the curing agent on the surface of concrete before and after final setting of the concrete to form a film layer, and enabling the curing agent to permeate into a concrete shallow surface layer through the self-healing active component carried by the composite functional component to jointly construct the double water-retaining structure and realize restoration preparation of microcracks.
11. The use according to claim 10, wherein the primary coating is applied with a secondary cross-spray process, the primary coating forming the base film layer and the primary permeate, the secondary cross-spray process being applied to compensate for the porosity and strengthen the permeate network, the total amount of the two sprays being 150-250g/m 2 .

Description

Concrete curing agent with double water-retaining structure and preparation method and application thereof Technical Field The invention relates to the technical field of building materials and concrete additives, in particular to a concrete curing agent with a double water-retaining structure, and a preparation method and application thereof. Background Early maintenance after concrete pouring is a key link for guaranteeing strength development, durability and volume stability. The traditional watering and film-covering maintenance modes have the inherent defects of water resource waste, low efficiency, environmental restriction, interference with subsequent construction and the like. For this reason, chemical curing agents have been developed, which prevent excessive evaporation of water by forming a protective layer on the surface of concrete, and are an important curing means in modern concrete engineering. In the prior art, a film-forming curing agent is disclosed, and the core mechanism is that a layer of continuous and waterproof physical film is formed on the surface of concrete. For example, CN1171831C discloses an aqueous liquid film type concrete curing agent which is mainly composed of an acrylic polymer emulsion, a wax emulsion and various auxiliaries (film forming auxiliaries, wetting agents, etc.). The product focuses on optimizing film forming performance and aims to form a colorless and waterproof high-efficiency maintenance film. However, the protective efficacy of such curing agents is entirely dependent on the integrity of the surface film. In an actual engineering environment, the film layer is extremely easy to generate local damage due to construction treading, abrasion or material shrinkage stress, once damaged, concrete below the film layer is lost to be protected, so that local maintenance is invalid, moisture is concentrated and lost from the damaged part, and even local drying shrinkage is possibly aggravated. Still another category is the functional additive curing agent, the design concept of which focuses on introducing chemical substances having specific functions into the surface or interior of concrete to improve the bulk properties of the concrete. For example, CN101565284a describes a multifunctional shrinkage-reducing crack-resistant curing agent consisting of shrinkage-reducing compounds, permeation aids, film formers, etc. The product aims to reduce the shrinkage stress by reducing the surface tension of the concrete capillary pore solution through the shrinkage reducing compound, and has certain film forming and penetrating capacities. However, this solution relies mainly on the single action (shrinkage reduction) of the chemical additives, the film-forming and permeation functions of which are more so as to assist the infiltration of the additives. Comprehensive analysis shows that the film-forming curing agent and the functional additive curing agent have the following limitations that the structure is single, the reliability is insufficient, the single film layer is fragile and vulnerable, and the single internal additive cannot effectively prevent the rapid water loss on the surface. Isolated function, lack of synergy, the components tend to act independently (e.g., film formation only, shrinkage only, permeation only). Passive protection, intelligent deficiency, static and passive action mechanism of the existing product. Therefore, developing a high-performance curing agent which can actively construct a multistage cooperative and intelligent response protection structure on the concrete surface layer so as to integrate long-acting water retention, active self-repairing and dynamic durability improvement into a whole has become an urgent need and clear direction for technical development in the field. Disclosure of Invention Aiming at the problems of curing agents in the prior art, the invention provides a concrete curing agent with a multistage synergistic structure from the design of molecules and microstructures. The invention designs a special composite functional component, and preassembles the carrier and the water-retaining unit, so that the carrier can be used as a transport tool in the application process, and the carrier carries the self-healing active component to directionally permeate into the shallow surface layer of the concrete, thereby constructing a double water-retaining structure consisting of a compact surface sealing film and an internal three-dimensional water-retaining-repairing network on the surface and in the interior of the concrete. In order to realize the above inventive concept, the present invention adopts the following technical scheme: In a first aspect, a concrete curing agent with a dual water-retaining structure is provided, wherein the curing agent is arranged on the surface and the shallow surface layer of concrete, and comprises a surface closed membrane structure and a dual water-retaining structure with an internal perme