An organic activated nano metakaolin modified cement-based rapid repair material, a preparation method and application thereof

Abstract

The application discloses an organic activated nano-partial kaolin modified cement-based rapid repairing material and a preparation method and application thereof, and belongs to the technical field of building materials. The rapid repairing material comprises the following components in percentage by weight: 37.1-40.4% of Portland cement, 39.8-40.8% of sand, 0.4-2.9% of nano-partial kaolin, 0.02-0.08% of triethanolamine, 1.2-2.04% of butyl benzene copolymer emulsion SBE, 0.79-3.11% of aluminum sulfate octadecahydrate and the balance of water. The repairing material is constructed by introducing the aluminum sulfate octadecahydrate, the triethanolamine, the nano-partial kaolin and the butyl benzene copolymer emulsion, a multi-component synergistic system is formed, the early strength is high, the interface bonding performance is excellent, the rapid hardening can meet the open traffic demand, the debonding and cracking of the repairing layer are inhibited, and the durability is good. The material has good fluidity and suitable construction time, raw materials are easy to obtain, the cost is low, the process is simple, and the material is suitable for engineering popularization and application.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, and in particular to an organically activated nano-kaolin-modified cement-based rapid repair material, its preparation method, and its application. Background Technology

[0002] During long-term service, cement concrete structures are susceptible to defects such as cracking, spalling, exposed reinforcement, and interface debonding due to the combined effects of material degradation, repeated loading, and environmental factors (such as freeze-thaw cycles, wet-dry cycles, and chloride corrosion). These defects severely impact the structure's load-bearing capacity and durability. If these defects are not repaired promptly and effectively, cracks and damage will further expand, significantly shortening the service life of the concrete structure and potentially causing serious safety hazards. With the continuous expansion of existing infrastructure, repairing and reinforcing existing concrete structures to restore their service performance has become an unavoidable trend in the engineering field. For a considerable period in the future, the volume of concrete structure repair and maintenance work will continue to grow, even exceeding the scale of new construction projects.

[0003] Among existing rapid concrete repair materials, special cementitious materials such as magnesium phosphate cement and sulfoaluminate cement have attracted attention due to their rapid early strength development. However, these materials still have certain limitations in practical engineering applications. For example, the magnesium phosphate cement system has a violent cementitious reaction, a large heat release, and an extremely short setting time, which places high demands on construction time and operating conditions, making it easy to encounter problems with difficulty in controlling the construction window. Moreover, the material cost is relatively high, which is not conducive to its widespread application in large-scale repair projects. Although sulfoaluminate cement has the characteristic of rapid setting and hardening, its early reaction is also relatively rapid, and its later strength development and volume stability are greatly affected by the mix proportion and curing conditions. Its long-term service performance still needs further optimization.

[0004] In contrast, ordinary Portland cement, as the most widely used cementitious material, has advantages such as a wide availability of raw materials, low cost, stable performance, and good compatibility with existing concrete structures. It also boasts mature construction experience and a comprehensive technical standard system in engineering practice. Based on the Portland cement system, by rationally controlling its early hydration process and introducing functional components, it is possible to achieve rapid early strength development of repair materials while maintaining good workability and long-term durability. This is more conducive to meeting the comprehensive requirements of safety, economy, and scalability for rapid repair materials in practical engineering. Therefore, using Portland cement as the basic cementitious system is one of the important technical routes to achieve high-performance rapid repair materials for concrete.

[0005] Although silicate cement systems have good engineering applicability, their early hydration reaction rate is relatively slow, and relying solely on traditional mix proportions is insufficient to meet the requirements of rapid repair projects for early strength and construction efficiency. Therefore, it is necessary to optimize the hydration process and microstructure evolution of silicate cement through multi-component synergistic regulation. Summary of the Invention

[0006] This invention provides an organically activated nano-metakaolin-modified cement-based rapid repair material with rapid early strength development, controllable construction performance, and high interfacial bonding strength with old concrete, as well as its preparation method and application, to overcome the above-mentioned problems.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] This invention provides an organically activated nano-kaolin-modified cement-based rapid repair material, comprising the following components by weight percentage:

[0009] Silicate cement: 39.23%–41.56%;

[0010] Sand 41.98% ~ 42.70%;

[0011] Nano-metakaolinite 0.42%–2.99%;

[0012] Triethanolamine 0.02%–0.09%;

[0013] Styrene-butadiene copolymer emulsion (SBE) 1.27%–1.70%;

[0014] Aluminum sulfate octadechydrate: 0.43%–1.69%;

[0015] The remainder is water.

[0016] Furthermore, the nano-metakaolin is a two-dimensional nanomaterial with a sheet thickness of less than 50 nm, obtained by dehydrating kaolin at 600-900℃ to form metakaolin, and then physically cutting it.

[0017] Furthermore, the sand is medium-coarse river sand with a fineness modulus of 2.63.

[0018] Another aspect of the present invention provides a method for preparing the aforementioned organically activated nano-kaolin-modified cement-based rapid repair material, comprising the following steps:

[0019] S1: Weigh each component according to the proportions;

[0020] S2: Dissolve triethanolamine and aluminum sulfate octadecade in water, stir evenly, add nano-metakaolin, and perform ultrasonic dispersion treatment to obtain an organically activated nano-metakaolin suspension.

[0021] S3: Add the styrene-butadiene copolymer emulsion to the suspension obtained in S2, and stir manually for 1-2 minutes until well mixed;

[0022] S4: Mix the mixture obtained in S3 with silicate cement under low-speed stirring to form a slurry;

[0023] S5: Add sand to the slurry obtained in S4, mix at low speed first, then switch to high speed to obtain the rapid repair material.

[0024] Furthermore, in S2, the ultrasonic dispersion frequency is 40kHz, the power is 150W, and the time is 10-20min.

[0025] Furthermore, in S4, the low-speed stirring speed is 120±5 r / min, and the time is 30 s.

[0026] Furthermore, in S5, the high-speed stirring speed is 285±10 r / min, and the time is 90 s. The stirring time and stirring method can be adjusted according to the actual system preparation requirements.

[0027] In another aspect, this invention provides the application of the aforementioned organically activated nano-kaolin-modified cement-based rapid repair material in the repair and reinforcement of concrete structures.

[0028] The beneficial effects of this invention are:

[0029] (1) The repair material of the present invention constructs a multi-component synergistic system by introducing aluminum sulfate octadecahydrate, triethanolamine, nano-metakaolin, and styrene-butadiene copolymer emulsion, realizing multi-scale synergistic regulation from chemical activation and physical nucleation to polymer toughening. Among them, aluminum sulfate octadecahydrate provides active ions to promote the rapid formation of early hydration products; triethanolamine regulates ion release behavior and improves nanoparticle dispersion through complexation and adsorption, avoiding excessive local reaction; nano-metakaolin serves as a highly active nucleation substrate, accelerating and refining hydration products; and styrene-butadiene copolymer emulsion forms a polymer film network in the system, enhancing overall toughness and interfacial adhesion. The components complement each other and work synergistically, significantly improving early strength and interfacial adhesion to the old concrete matrix while ensuring construction performance, thus achieving synergistic optimization of the material's overall service performance.

[0030] (2) Based on the above synergistic mechanism, this repair material can form a hardened body with sufficient early strength within a few hours to meet the requirements of rapid traffic opening. At the same time, the polymer network formed by the styrene-butadiene copolymer emulsion, combined with the dense matrix constructed by hydration products and nanomaterials, effectively improves the structure and performance of the interface transition zone, effectively improves the bonding strength with the old concrete, thereby inhibiting debonding and cracking of the repair layer and ensuring the long-term durability of the repair project.

[0031] (3) The appropriate amount of triethanolamine added to this material can reasonably control the reaction rate. Combined with the lubrication and water retention of the styrene-butadiene copolymer emulsion, this repair material can achieve high early strength while maintaining good fluidity and suitable working time, which is beneficial for mixing, pouring and molding in on-site construction.

[0032] (4) This invention uses ordinary silicate cement as the main cementing material. The raw materials are widely available and the cost is low. The preparation process is simple and does not require special equipment. It is easy to promote and apply under conventional construction conditions and has good economic efficiency and engineering applicability. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] The materials involved in this patent are as follows:

[0035] P·O 42.5 silicate cement was produced by Dalian Haiou Cement Plant; the sand was medium-coarse river sand with a fineness modulus of 2.63; nano-metakaolin was purchased from Inner Mongolia Chaopai Building Materials Technology Co., Ltd.; nano-metakaolin is a two-dimensional nanomaterial with a layer thickness of less than 50nm, obtained by dehydrating kaolin as raw material at an appropriate temperature (600-900 ℃) to form a low-crystallinity transition phase - metakaolin, and finally by physical cutting and other techniques; triethanolamine was purchased from Sinopharm Chemical Reagent Co., Ltd., and was an analytical grade product; aluminum sulfate octahydrate was purchased from Sinopharm Chemical Reagent Co., Ltd., and was an analytical grade product; styrene-butadiene copolymer emulsion (SBE) was provided by BASF Germany (purchased through Shanghai Yijin Foreign Trade Co., Ltd.), model BASF STYROFAN® ECO 7623, with a density of approximately 0.9-1.05 g / cm³. 3 .

[0036] The principles involved in this patent are as follows:

[0037] Triethanolamine (TEA), a commonly used organic admixture, can regulate the hydration process of the aluminate phase in cement, promoting early hydration reactions under appropriate conditions and accelerating early strength development. Aluminum sulfate octadechydrate (AS), readily soluble in water, releases active aluminum sources and sulfate ions, effectively promoting the formation of early hydration products and accelerating the establishment of the structural system. Nano-metakaolin (NMK), with its high specific surface area and active surface characteristics, can serve as a heterogeneous nucleation substrate for cement hydration products, accelerating the hydration reaction process, and can also optimize the pore structure and interfacial transition zone through micro-filling, improving the material's density and mechanical properties. Furthermore, styrene-butadiene copolymer emulsion (SBE), a commonly used polymer modifier, can form a polymer film structure during hydration when introduced into cement-based systems, improving the adhesion and deformation coordination of repair materials and contributing to enhanced interfacial bonding quality between the repair layer and the original concrete matrix. By introducing TEA, AS, NMK and SBE into the silicate cement system and rationally designing their synergistic effects, the early strength, interfacial bonding performance and overall service performance of the repair material can be synergistically improved while taking into account the construction performance.

[0038] Specifically, aluminum sulfate octadeca dissolves rapidly in water during the mixing process, releasing Al. 3+ and SO4 2- This invention provides a highly active aluminum source and sulfate ions for silicate cement systems, significantly promoting the formation of early hydration products and the rapid establishment of the framework structure. Unlike existing technologies that use sulfate or aluminum salt accelerators alone, in this invention, aluminum sulfate octadechydrate is not used as a single accelerator component, but participates in the hydration reaction process under the synergistic regulation of triethanolamine. The two form a synergistic accelerator system, achieving controllability and high efficiency in the early hydration reaction. Triethanolamine can regulate the Al content in the liquid phase through complexation, adsorption, and other mechanisms. 3+ The effective concentration of the material alleviates the problem of excessively rapid local reaction caused by its instantaneous release, making the early hydration reaction more uniform in time and space, thereby avoiding flash solidification or sudden drop in workability, ensuring that the repair material has good workability and meets the needs of on-site repair operations.

[0039] After dissolving in the mixing water, triethanolamine (TEA) preferentially distributes on the surface of NMK sheets and in the surrounding liquid phase region through adsorption and complexation. On one hand, it reduces the surface energy between NMK particles, weakening their aggregation tendency in the aqueous phase and thus improving the dispersion of nano-metakaolin. On the other hand, TEA also affects the Ca in the liquid phase... 2+ And Al 3+The complexation and slow-release effects of isohydrated ions create a relatively stable and sustainable ion-enriched environment on the NMK surface, which is conducive to the continuous nucleation and growth of cement hydration products on its surface. Furthermore, in this controlled ion environment, nano-metakaolin, with its high specific surface area and two-dimensional layered structure, becomes an important "structural amplifier" for the cement hydration reaction. The active sites enriched on the NMK surface preferentially adsorb Ca in the hydration environment co-regulated by aluminum sulfate octadecade and TEA. 2+ Al 3+ and SO4 2- The presence of hydrated ions makes it easier for cement hydration products to nucleate and grow on their surface, thus transforming "chemical setting" into "structural setting." Unlike traditional micro-fine mineral admixtures that only play a filling or late-stage reaction role, NMK in the system of this invention mainly participates in the early structural construction process, significantly accelerating the formation of the microstructure framework and refining the morphology of hydration products.

[0040] The styrene-butadiene copolymer (SBE) emulsion is dispersed in cement paste as polymer particles. During early hydration, it does not directly participate in the gelation reaction. Instead, it gradually aggregates and forms a film between the hydration product particles and nano-metakaolin sheets as hydration products are generated. The polymer film formed during this process creates a flexible bridging structure between the inorganic framework composed of nano-metakaolin and hydration products. This not only enhances the bonding performance and deformation coordination of the repair material but also, to a certain extent, buffers the adverse effects of the rapid reaction caused by aluminum sulfate octadecade on the system's performance. Unlike existing technologies that simply utilize polymers to improve bonding performance, in this invention, SBE, NMK, and early hydration products work synergistically to form a composite structure of inorganic framework and polymer network in the early stages of repair, thus balancing early strength and crack resistance, and improving the overall service life of the repair material.

[0041] Example 1

[0042] An organically activated nano-kaolin-modified cement-based rapid repair material, the raw material ratio of which is (by weight):

[0043] Silicate cement (P·O·42.5): 95 parts (40.24%);

[0044] Sand: 100 parts (42.35%);

[0045] Nano-metakaolin (NMK): 5 parts (2.12%)

[0046] Triethanolamine (TEA): 0.1 part (0.04%);

[0047] Aluminum sulfate octadechydrate (AS): 2 parts (0.85%);

[0048] Styrene-butadiene copolymer emulsion (SBE): 4 parts (1.69%);

[0049] Water: 30 parts (12.71%);

[0050] Total weight: 236.1 portions;

[0051] An organically activated nano-kaolin-modified cement-based rapid repair material is prepared according to the following method:

[0052] S1: Weigh each component raw material accurately according to the above proportions;

[0053] TEA and AS were added to the mixing water and stirred thoroughly to dissolve them completely, forming a uniform organic additive solution. NMK was then added to the solution and ultrasonic treatment was carried out under continuous dispersion conditions. The dispersion was performed using an ultrasonic cleaner with an ultrasonic frequency of 40kHz and an ultrasonic power of 150W for 10-20 minutes, thereby obtaining a uniformly dispersed organic activated nano-kaolin suspension.

[0054] S2: Add SBE to the suspension above and stir manually for 1-2 minutes to obtain a mixture;

[0055] S3: Add the mixture and cement to the cement mortar mixer at the same time, and perform preliminary mixing at low speed for 30 seconds. The mixing speed is 120±5r / min, so that the cement particles and the suspension can be fully contacted and form a uniform slurry.

[0056] S4: While maintaining a low stirring speed (120±5 r / min), continuously add fine aggregate (sand) to the uniform slurry; after the addition is complete, increase the stirring speed to 285±10 r / min and continue stirring for 90 s to obtain a uniform cement-based mixture; the stirring process parameters can be adjusted according to the actual preparation requirements.

[0057] Example 2:

[0058] An organically activated nano-kaolin-modified cement-based rapid repair material, the raw material composition of which is as follows (by weight):

[0059] Silicate cement (P·O·42.5): 93 parts (39.7%);

[0060] Sand: 100 parts (42.70%)

[0061] Nano-metakaolin (NMK): 7 parts (2.99%);

[0062] Triethanolamine (TEA): 0.2 parts (0.09%);

[0063] Aluminum sulfate octadechydrate (AS): 1 part (0.43%);

[0064] Styrene-butadiene copolymer emulsion (SBE): 3 parts (1.28%);

[0065] Water: 30 parts;

[0066] Total weight: 234.2 portions;

[0067] The preparation method is the same as in Example 1.

[0068] Example 3:

[0069] An organically activated nano-kaolin-modified cement-based rapid repair material, the raw material ratio of which is (by weight):

[0070] Silicate cement (P·O·42.5): 99 parts (41.56%);

[0071] Sand: 100 parts (41.98%)

[0072] Nano-metakaolin (NMK): 1 part (0.42%);

[0073] Triethanolamine (TEA): 0.2 parts (0.08%);

[0074] Aluminum sulfate octadechydrate (AS): 4 parts (1.68%);

[0075] Styrene-butadiene copolymer emulsion (SBE): 4 parts (1.68%);

[0076] Water: 30 parts;

[0077] Total weight: 238.2 portions;

[0078] The preparation method is the same as in Example 1.

[0079] Example 4:

[0080] An organically activated nano-kaolin-modified cement-based rapid repair material, the raw material ratio of which is (by weight):

[0081] Silicate cement (P·O·42.5): 93 parts (39.23%);

[0082] Sand: 100 parts (42.19%)

[0083] Nano-metakaolin (NMK): 7 parts (2.95%);

[0084] Triethanolamine (TEA): 0.05 parts (0.02%);

[0085] Aluminum sulfate octadechydrate (AS): 4 parts (1.69%);

[0086] Styrene-butadiene copolymer emulsion (SBE): 3 parts (1.27%);

[0087] Water: 30 parts;

[0088] Total weight: 237.1 portions;

[0089] The preparation method is the same as in Example 1.

[0090] Example 5:

[0091] An organically activated nano-kaolin-modified cement-based rapid repair material, the raw material ratio of which is (by weight):

[0092] Silicate cement (P·O·42.5): 93 parts (39.54%);

[0093] Sand: 100 parts (42.52%)

[0094] Nano-metakaolin (NMK): 7 parts (2.98%);

[0095] Triethanolamine (TEA): 0.2 parts (0.09%);

[0096] Aluminum sulfate octadechydrate (AS): 1 part (0.43%);

[0097] Styrene-butadiene copolymer emulsion (SBE): 4 parts (1.70%);

[0098] Water: 30 parts;

[0099] Total weight: 235.2 portions;

[0100] The preparation method is the same as in Example 1.

[0101] Comparative Example 1:

[0102] TEA is not added in this comparative example;

[0103] This comparative example uses the following formula to prepare cement-based repair materials (by weight):

[0104] AS: 2 parts, SBE: 4 parts, NMK: 5 parts, cement: 95 parts, water: 30 parts, sand: 100 parts.

[0105] The preparation method is the same as in Example 1.

[0106] Comparative Example 2:

[0107] Compared with Example 3, no AS was added in this comparative example;

[0108] This comparative example uses the following formula to prepare cement-based repair materials (by weight):

[0109] TEA: 0.1 parts, SBE: 4 parts, NMK: 5 parts, cement: 95 parts, water: 30 parts, sand: 100 parts.

[0110] The preparation method is the same as in Example 1.

[0111] Comparative Example 3:

[0112] Compared to Example 3, no SBE was added in this comparative example;

[0113] This comparative example uses the following formula to prepare cement-based repair materials (by weight):

[0114] TEA: 0.1 parts, AS: 2 parts, NMK: 5 parts, cement: 95 parts, water: 30 parts, sand: 100 parts.

[0115] The preparation method is the same as in Example 1.

[0116] Comparative Example 4:

[0117] Compared to Example 3, no NMK was added in this comparative example;

[0118] This comparative example uses the following formula to prepare cement-based repair materials (by weight):

[0119] TEA: 0.2 parts, AS: 2 parts, SBE: 4 parts, cement: 100 parts, water: 30 parts, sand: 100 parts.

[0120] The preparation method is the same as in Example 1.

[0121] The specific components of each set of comparative examples are shown in Table 1:

[0122] Table 1. Ingredient list of quick repair materials for examples and comparative examples

[0123]

[0124] The performance parameters of the organic activated nano-kaolin cement mortar rapid repair materials prepared in Examples 1-3 and the cement-based repair materials (in the form of cement mortar) prepared in Comparative Examples 1-7 were tested:

[0125] Experiment 1: Flowability Test

[0126] Flowability reflects the plasticity of cement mortar. As a rapid road repair material, good flowability can facilitate construction and reduce construction difficulty. In this experiment, the flowability of the mortar was determined according to "GB / T 2419-2005 Test Method for Flowability of Cement Mortar" and "GB / T 8077-2023 Test Method for Homogeneity of Concrete Admixtures".

[0127] The test procedure is as follows: First, fill the prepared cement mortar into the conical mold of the cement mortar flowability tester. After smoothing the surface, lift the mold and turn on the flowability tester (commonly known as the "jumping table"). After vibrating 25 times, the mortar will flow into a round cake shape. Measure the maximum diameter of 2-3 different directions with a ruler and take the average value as the flowability of the cement mortar.

[0128] Experiment 2: Flexural and compressive strength tests of repair materials

[0129] This invention follows the national standard "Test Method for Strength of Cement Mortar (ISO Method)" (T 0506—2005), and describes Example 1. The organic activated nano-kaolin cement mortar rapid repair material prepared in 3 and the cement mortar prepared in comparative examples 1-7 were used to prepare standard specimens through a triple mold for performance testing. The performance test results are shown in Table 1. The size of the standard specimen is 40mm × 40mm × 160mm.

[0130] Experiment 3: Bond strength test between repair material and ordinary concrete

[0131] The interfacial bond strength was evaluated by splitting tensile test, and the ordinary concrete was C30 concrete that had been poured more than 60 days in advance.

[0132] The test data are shown in Table 2, and Table 3 shows the specifications for "Rapid Repair Materials for Cement Concrete in Highway Engineering".

[0133] Table 2. Test Results of Technical Indicators for Organically Activated Nano-Kaolin Cement Mortar Rapid Repair Material

[0134]

[0135] Table 3 Specification Indicators for "Rapid Repair Materials for Cement Concrete in Highway Engineering"

[0136]

[0137] As shown in Table 2, the experimental data of this invention, obtained by adding TEA, AS, SBE, and NMK to the organic activated nano-metakaolin-modified cement mortar rapid repair materials in Examples 1-3 of this invention, all meet the specifications of the "Rapid Repair Materials for Cement Concrete in Highway Engineering". Furthermore, the rapid repair materials prepared in Examples 1-5 of this invention have a 1-day compressive strength of over 30 MPa, exhibiting rapid early strength development, indicating that the repair materials prepared by this scheme can quickly form load-bearing capacity. Among them, Example 1 exhibits the highest bond strength, which is 1.2 to 1.5 times higher than that of Comparative Examples 1-4, due to the synergistic effect between the components.

[0138] Comparative Example 1 contained NMK, SBE, and AS, but no TEA. Its early strength (1-day compressive strength 25.6 MPa, flexural strength 9.1 MPa, bond strength 0.66 MPa) was lower than that of Example 1. Due to the lack of synergistic promotion of early hydration by TEA and AS, a strength-supporting framework could not be formed quickly. Moreover, more importantly, it can regulate the aluminum ion release rate through complexation, avoiding excessively rapid reaction and ensuring a uniform and stable hydration process, which is key to stable strength development.

[0139] Comparative Example 2 lacks the key coagulating component AS, resulting in insufficient active aluminum source and sulfate ions in the system, and a small amount of early hydration products are generated. Therefore, the strength indicators are significantly reduced. The product of Comparative Example 4 has a 1-day compressive strength of only 20.6 MPa, a flexural strength of only 5.6 MPa, and a bond strength of only 0.54 MPa.

[0140] Comparative Example 3 contained TEA, AS, and NMK, but no SBE. The synergistic effect of TEA and AS in promoting coagulation, along with the nucleation and filling effect of NMK, resulted in high early compressive strength. However, due to the lack of a flexible polymer network formed by SBE, the material's flexibility and bond strength were insufficient, with a 1-day flexural strength of 8.3 MPa and a bond strength of only 0.62 MPa. This limited the interfacial deformation coordination and long-term durability.

[0141] Comparative Example 4 contained TEA, AS, and SBE, but lacked NMK. Its 1-day compressive strength was 27.6 MPa, flexural strength was 7.4 MPa, and bond strength was 0.71 MPa, significantly lower than the examples, indicating that NMK plays an irreplaceable role in this formulation. Under the dispersion regulation of TEA, the highly active surface of NMK provided abundant heterogeneous nucleation sites for hydration products, accelerating and refining the formation of early microstructures, achieving structure-promoting coagulation, while its micro-filling effect further optimized the system density.

[0142] In summary, the core advantage of this solution lies in the synergistic function of its multiple components. TEA and AS work together to promote coagulation while ensuring the uniformity of the reaction; TEA also optimizes the dispersion of NMK, allowing it to fully exert its nucleation and filling effects; SBE constructs a polymer network within the formed inorganic framework, enhancing the coordination of adhesion and deformation. All four components used in this formulation are indispensable, working together to achieve an overall improvement in the early strength, workability, and long-term durability of the repair material.

[0143] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An organically activated nano-metakaolin-modified cement-based rapid repair material, characterized in that, By weight percentage, it includes the following components: Silicate cement: 39.23%–41.56%; Sand 41.98% ~ 42.70%; Nano-metakaolinite 0.42%–2.99%; Triethanolamine 0.02%–0.09%; Styrene-butadiene copolymer emulsion (SBE) 1.27%–1.70%; Aluminum sulfate octadechydrate: 0.43%–1.69%; The remainder is water.

2. A method for preparing the organically activated nano-metakaolin-modified cement-based rapid repair material according to claim 1, characterized in that, Includes the following steps: S1: Weigh each component according to the above ratio; dissolve triethanolamine and aluminum sulfate octadeca in water, stir evenly, add nano-metakaolin, and perform ultrasonic dispersion treatment to obtain organic activated nano-metakaolin suspension; S2: Add the styrene-butadiene copolymer emulsion to the organic activated nano-kaolin suspension obtained in S1, stir evenly to obtain a mixture; S3: Mix the mixture obtained in S2 with silicate cement under low-speed stirring to form a slurry; S4: Add sand to the slurry obtained in step S3, mix at low speed first, then switch to high speed to obtain the rapid repair material.

3. The method for preparing organically activated nano-metakaolin-modified cement-based rapid repair material according to claim 2, characterized in that, In S1, the ultrasonic dispersion frequency is 40kHz, the power is 150W, and the time is 10-20min.

4. The method for preparing organically activated nano-metakaolin-modified cement-based rapid repair material according to claim 2, characterized in that, In S3, the low-speed stirring speed is 120±5 r / min for 30 s.

5. The method for preparing organically activated nano-metakaolin-modified cement-based rapid repair material according to claim 2, characterized in that, In S4, the high-speed stirring speed is 285±10 r / min, and the time is 90 s.

6. The application of the organically activated nano-kaolin-modified cement-based rapid repair material according to claim 1 in the repair and reinforcement of concrete structures.

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