A polymer cement mortar for repairing, reinforcing and protecting concrete structures and a method for its production

Abstract

The application provides a polymer cement mortar for repairing, reinforcing and protecting concrete structures and a preparation method thereof, and relates to the technical field of cement mortar. The polymer cement mortar comprises the following components in parts by weight: inorganic cementing material 200-500 parts, synthetic resin 10-30 parts, slow-release rust inhibitor 1-5 parts, aggregate 500-800 parts, powder filler 20-100 parts, composite shrinkage inhibitor 1-10 parts and 40-250 parts of water. The slow-release rust inhibitor with a double control release system is adopted, the porous carrier thereof provides a first heavy physical slow release, and delays the initial release of the rust inhibitor; the carboxymethyl chitosan derivative coating layer located on the outer layer of the porous carrier has pH responsiveness, is stable in an alkaline environment with pH>12, and is ruptured when a corrosion factor invades to cause the local microenvironment pH to drop below 9, so that the high-concentration rust inhibitor is released in a targeted manner, and intelligent long-acting protection is realized.

Description

Technical Field

[0001] This application relates to the field of cement mortar technology, and in particular to a polymer cement mortar for repairing, reinforcing and protecting concrete structures and a method for preparing the same. Background Technology

[0002] Polymer cement mortar is widely used for the repair and reinforcement of concrete structures, especially for the repair of corrosion in reinforced concrete structures, due to its advantages such as high bonding strength, good impermeability, corrosion resistance, and relatively moderate cost.

[0003] However, the current method of adding rust inhibitors to repair mortar is mostly to add them directly in one go, which has obvious drawbacks. In the early stages of repair, the concentration of rust inhibitor is too high, which may interfere with the cement hydration process and affect the early strength development and interfacial bonding performance of the mortar. During long-term service, especially under harsh environments such as chloride corrosion and carbonation, the concentration of rust inhibitor is insufficient due to its large consumption, and it cannot provide continuous and effective protection for the reinforcing steel. This can easily lead to the durability of the repaired structure being far lower than the design expectations.

[0004] While some literature has reported slow-release techniques for rust inhibitors, such as loading the rust inhibitor onto a porous carrier to delay release through physical adsorption and pore diffusion, these techniques can only slow down the release rate and cannot achieve on-demand release. Summary of the Invention

[0005] To address the issue that rust inhibitors in existing repair mortars cannot be released on demand, this application provides a polymer cement mortar for the repair, reinforcement, and protection of concrete structures, and a method for its preparation.

[0006] In a first aspect, this application provides a polymer cement mortar for repairing, reinforcing, and protecting concrete structures, employing the following technical solution: A polymer cement mortar for repairing, reinforcing and protecting concrete structures comprises the following components in parts by weight: 200-500 parts inorganic cementitious material, 10-30 parts synthetic resin, 1-5 parts slow-release rust inhibitor, 500-800 parts aggregate, 20-100 parts powder filler, 1-10 parts composite shrinkage inhibitor and 40-250 parts water.

[0007] This invention adds a slow-release rust inhibitor to polymer cement mortar, which has a dual protective effect. It can actively release the rust inhibitor according to environmental changes (pH value, chloride ion concentration) to achieve long-term protection.

[0008] Optionally, the slow-release rust inhibitor comprises a porous carrier, a rust inhibitor loaded in the porous carrier, and a polymer coating layer covering the outer surface of the porous carrier, wherein the polymer coating layer is a pH-responsive material.

[0009] This invention utilizes a porous carrier to slow down the initial release rate of the rust inhibitor, while... When carbonization or corrosion factors invade and cause a drop in the local microenvironment pH, the polymer coating layer responds by swelling and rupturing, releasing a high concentration of rust inhibitor in a targeted manner. This achieves true secondary release and long-term slow-release intelligent protection, increasing protection efficiency by more than 50% over the lifespan.

[0010] Optionally, the porous carrier is a mesoporous silica nanosphere with a pore size of 2-50 nm or a carbon nanosphere with a pore size of 2-50 nm.

[0011] Optionally, the pH-responsive material is a carboxymethyl chitosan derivative, methyl methacrylate-methacrylic acid copolymer, or calcium alginate-chitosan complex.

[0012] Optionally, the pH-responsive material is a carboxymethyl chitosan derivative.

[0013] Optionally, the carboxymethyl chitosan derivative is prepared using the following method: First, chitosan powder is added to a polyol / water mixed solution containing sodium hydroxide, and stirred and swollen at 20~40℃ for 1~2 hours to obtain alkalized chitosan slurry. The mass ratio of chitosan to sodium hydroxide is 1:0.5~2.0, and the volume ratio of polyol to water in the polyol / water mixed solution is 1:0.5~3. The polyol is selected from at least one of ethylene glycol, propylene glycol, and glycerol. Then, chloroacetic acid is added to the alkalized chitosan slurry, and the mixture is heated to 50-65°C and reacted for 2-6 hours to carry out carboxymethylation reaction, wherein the mass ratio of chloroacetic acid to chitosan is 0.5-2.5:1; After the reaction is completed, the solution is cooled to room temperature, and the pH of the reaction solution is adjusted to 7.0-8.0 with acid to precipitate carboxymethyl chitosan. The acid is selected from at least one of hydrochloric acid, acetic acid, and citric acid, and the concentration is 0.5-2.0 mol / L. After separation of the precipitate, it is washed 2 to 4 times with an ethanol aqueous solution with a volume concentration of 70% to 80% to remove unreacted alkali, chloroacetic acid and by-product salts; the washed product is dried to constant weight at a temperature of 40 to 60°C, pulverized and sieved to obtain a white or light yellow powdery carboxymethyl chitosan derivative.

[0014] Optionally, the rust inhibitor is a compound of organic amine rust inhibitor and molybdate rust inhibitor.

[0015] Optionally, the organic amine rust inhibitor is selected from at least one of ethanolamine, diethanolamine, triethanolamine, cyclohexylamine, and benzoic acid amine; the molybdate rust inhibitor is selected from at least one of sodium molybdate, calcium molybdate, and zinc molybdate.

[0016] Optionally, the mass ratio of the organic amine rust inhibitor to the molybdate rust inhibitor is preferably 1:0.5~2.

[0017] Optionally, the mass ratio of the organic amine rust inhibitor to the molybdate rust inhibitor is 1:1.

[0018] Optionally, the slow-release rust inhibitor is prepared using the following method: The rust inhibitor was dissolved in a solvent, mesoporous silica nanospheres were added, and the mixture was ultrasonically dispersed and impregnated for 12-24 hours. After centrifugation and drying, a carrier loaded with the rust inhibitor was obtained. The carboxymethyl chitosan derivative is dissolved in water, and the carrier carrying the rust inhibitor is added. A uniform coating layer is formed on the surface of the carrier by spray drying.

[0019] Optionally, the mesoporous silica nanospheres have a particle size of 50-500 nm, a pore size of 2-10 nm, and a specific surface area of ​​200-1000 m². 2 / g.

[0020] Optionally, the mass ratio of the rust inhibitor to the mesoporous silica nanospheres is (0.2~2.0):1.

[0021] Optionally, the inlet air temperature of the spray dryer is 120–180°C, the outlet air temperature is 60–80°C, and the atomization pressure is 0.1–0.5 MPa.

[0022] Optionally, it also includes 2 to 10 parts of a gradient structure forming agent, wherein the gradient structure forming agent is composed of long fibers, short fibers, organic thixotropic agents and inorganic thixotropic agents in a mass ratio of 1 to 6: 0.3 to 3: 0.3 to 3: 0.1 to 1.

[0023] The gradient structure forming agent provided by this invention can spontaneously form a gradient of fiber orientation distribution from the base layer to the surface during the construction and troweling process, effectively alleviating the difference in elastic modulus and shrinkage, and forming a wide range of gradually strengthening zone from the base layer to the surface of the repair layer. Therefore, the mortar layer transitions smoothly from the relatively rigid layer in contact with the base layer to the relatively flexible layer on the surface, which can suppress cracking and peeling.

[0024] Optionally, the long fiber is selected from one or more of polyvinyl alcohol fiber, polypropylene fiber, and glass fiber, and the fiber length is 4mm to 15mm.

[0025] Optionally, the short fibers are selected from one or more of wood fibers and cellulose fibers, and the fiber length is 10μm~200μm.

[0026] Optionally, the long fibers are polyvinyl alcohol fibers with a length of 6 mm and / or 12 mm; the short fibers are wood fibers with a length of 10 μm to 200 μm.

[0027] Optionally, the inorganic thixotropic agent is a magnesium aluminum silicate thixotropic agent; the organic thixotropic agent is starch ether or thixotropic gel.

[0028] Optionally, it may also include 5 to 50 parts of a healing active factor, wherein the healing active factor includes one or more of organosilicon and inorganic silicate.

[0029] This invention utilizes a healing active factor that can undergo a complexation reaction with calcium ions dissolved from cement when it comes into contact with water, forming insoluble calcium salts that block cracks and promote material healing. Therefore, it can seal cracks formed during service and enable the material to self-heal.

[0030] Optionally, the composite shrinkage inhibitor is composed of a polyether-type shrinkage reducer, an expansion agent, and crack-resistant fibers.

[0031] This invention uses a composite shrinkage inhibitor to comprehensively suppress and reduce plastic shrinkage and drying shrinkage of repair mortar, avoiding cracking problems during the curing and trial use of repair mortar, and improving weather resistance and durability.

[0032] Optionally, the inorganic cementitious material comprises silicate cement and highly active micro powder in a mass ratio of 15~40:1~10.

[0033] Optionally, the highly active micro powder includes one or more of silica fume, nano-silica, and slag micro powder.

[0034] This invention improves the density of silicate cement by adding highly active micro powder, which utilizes the filling effect of the micro powder and the activity of pozzolanic ash to refine the pores.

[0035] Optionally, it also includes: 0.3 to 3 parts of water-reducing agent, 0.2 to 1.5 parts of defoamer, and 0.3 to 3 parts of thickener.

[0036] This invention uses water-reducing agents, defoamers, and thickeners to reduce water consumption, improve workability, increase mortar density, and promote cement hydration.

[0037] Optionally, the synthetic resin is an ethylene-vinyl acetate copolymer, which provides flexibility and adhesion.

[0038] Optionally, the aggregate is quartz sand.

[0039] Optionally, the powder filler is 200-500 mesh calcium carbonate or 150-1000 mesh quartz powder.

[0040] Secondly, this application provides a method for preparing polymer cement mortar for repairing, reinforcing, and protecting concrete structures, comprising the following steps: Mix all components except water evenly to obtain a dry powder; The dry powder is mixed with water in a certain proportion and stirred evenly to obtain the final product.

[0041] When constructing the polymer cement mortar provided by this invention, the following steps are generally adopted: after removing the release agent and other substances that affect the adhesion from the base layer and cleaning it, the mixed mortar is applied in a single layer to the repair area. Utilizing its unique rheological properties and gradient structure forming ability, a gradient layer is automatically formed during construction.

[0042] In summary, this application includes at least one of the following beneficial effects: 1. The rust-inhibiting component in the polymer cement mortar of the present invention employs a slow-release rust inhibitor with a dual-controlled release system. Its porous carrier provides the first layer of physical slow release, delaying the initial release of the rust inhibitor. The carboxymethyl chitosan derivative coating layer located on the outer layer of the porous carrier is pH-responsive and stable in an alkaline environment with pH > 12. When Cl is included... - H + CO3 2- When corrosive factors, including those mentioned above, invade and cause the local microenvironment pH to drop below 9, the coating layer ruptures, releasing a high concentration of rust inhibitor in a targeted manner, thus achieving intelligent and long-lasting protection.

[0043] 2. This invention uses a gradient structure forming agent to spontaneously form a fiber orientation gradient and mechanical property gradient from the base layer to the surface during construction, effectively alleviating the difference in elastic modulus and shrinkage, and inhibiting cracking and peeling; at the same time, combined with a healing active factor, it can form insoluble calcium salt to seal the crack when it comes into contact with water after the crack is generated, thus realizing the self-healing of the material.

[0044] 3. The polymer cement mortar provided by this invention can achieve a gradient transition in mechanical properties with the base material, significantly reducing interfacial stress while maintaining excellent workability, early strength, and long-term durability; it can achieve the gradient effect that traditional multi-layer construction can only achieve with a single layer, simplifying the process; in addition, the cement mortar also has high compressive and flexural strength, high bond strength, low shrinkage, and good impermeability; cement-based materials are more environmentally friendly than reactive resins and have better fire resistance and durability. Attached Figure Description

[0045] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0046] Unless otherwise specified, all raw materials used in the following preparation examples, embodiments, and comparative examples are commercially available products. Specifically, the ordinary silicate cement strength grade is PO 42.5; silica fume was purchased from Elken; granulated blast furnace slag powder was purchased from Shanghai Baosteel New Building Materials, with an activity index of S95; the synthetic resin is ethylene-vinyl acetate copolymer; the aggregate is graded silica sand, 40-140 mesh; the powder filler is 300 mesh calcium carbonate; the water-reducing agent is a polycarboxylate water-reducing agent; the defoamer is an organosilicon defoamer; and the thickener is hydroxypropyl methylcellulose. Preparation Example 1:

[0047] Preparation Example 1 provides a slow-release rust inhibitor, which is prepared by the following method: (1) Preparation of carboxymethyl chitosan derivatives: 10g of chitosan powder (degree of deacetylation ≥90%) was added to an ethylene glycol / water mixed solution containing 8g of sodium hydroxide (ethylene glycol to water volume ratio of 1:1, total volume 200mL), and stirred at 30℃ for 1.5 hours to obtain alkalized chitosan slurry. Then add 15g of chloroacetic acid to the above slurry, heat to 60℃ and react for 4 hours; after the reaction is completed, cool to room temperature, and adjust the pH of the reaction solution to 7.5 with 1.0 mol / L hydrochloric acid to precipitate carboxymethyl chitosan; After separation of the precipitate, it was washed three times with a 75% (v / v) ethanol aqueous solution. The washed product was dried at 50°C to constant weight and then pulverized through a 200-mesh sieve to obtain a white or light yellow powdery carboxymethyl chitosan derivative.

[0048] (2) Loading rust inhibitor: Triethanolamine and sodium molybdate were compounded at a mass ratio of 1:1 to serve as a rust inhibitor. 10g of the rust inhibitor was dissolved in 100mL of deionized water, and 10g of mesoporous silica nanospheres (Jiangsu Xianfeng Nanomaterials Technology Co., Ltd., 101016) were added. The mixture was ultrasonically dispersed for 30 minutes, impregnated at room temperature for 18 hours, centrifuged, and dried at 60℃ for 12 hours to obtain a carrier loaded with the rust inhibitor.

[0049] (3) Formation of a coating layer: Dissolve 5g of the carboxymethyl chitosan derivative obtained in step (1) in 100mL of deionized water, add 10g of the carrier of the rust inhibitor obtained in step (2), stir evenly, and then spray dry using a spray dryer; spray drying conditions: inlet air temperature 150℃, outlet air temperature 70℃, atomization pressure 0.3 MPa, collect the dried powder to obtain the slow-release rust inhibitor. Preparation Example 2:

[0050] Preparation Example 2 provides a compound contraction inhibitor, prepared using the following method: Mix polyether-type shrinkage inhibitor, calcium sulfoaluminate-based expansion agent, and polypropylene crack-resistant fiber in a mass ratio of 2:2:1, place them in a high-speed mixer, and stir at 400 rpm for 10-20 minutes until uniformly mixed to obtain a composite shrinkage inhibitor. Example 1:

[0051] Example 1 provides a polymer cement mortar, comprising the following components by weight: 300 parts of ordinary silicate cement, 70 parts of granulated blast furnace slag powder, 20 parts of synthetic resin, 4 parts of slow-release rust inhibitor (prepared in Preparation Example 1), 600 parts of aggregate, 50 parts of powder filler, 0.8 parts of water-reducing agent, 0.8 parts of defoamer, 0.5 parts of thickener, 5 parts of composite shrinkage inhibitor (prepared in Preparation Example 2), and 150 parts of water.

[0052] Preparation method: (1) Mix all components except water in a dry powder mixer at high speed for 15 minutes until the mixture is uniform to obtain dry powder; (2) At the construction site, mix the dry powder with water in proportion and use a mixer to stir for 3 to 5 minutes until uniform to obtain polymer cement mortar. Example 2:

[0053] Example 2 provides a polymer cement mortar, which differs from Example 1 in the amount of components used. Specifically, by weight, it includes: 150 parts of ordinary silicate cement, 20 parts of silica fume, 30 parts of granulated blast furnace slag powder, 10 parts of synthetic resin, 1 part of slow-release rust inhibitor (prepared in Example 1), 600 parts of aggregate, 50 parts of powder filler, 0.8 parts of water-reducing agent, 0.8 parts of defoamer, 0.5 parts of thickener, 5 parts of composite shrinkage inhibitor (prepared in Example 2), and 180 parts of water.

[0054] The preparation method is the same as in Example 1. Example 3:

[0055] Example 3 provides a polymer cement mortar, which differs from Example 1 in the amount of components used. Specifically, by weight, it includes: 400 parts of ordinary silicate cement, 50 parts of silica fume, 50 parts of granulated blast furnace slag powder, 30 parts of synthetic resin, 5 parts of slow-release rust inhibitor (prepared in Example 1), 600 parts of aggregate, 50 parts of powder filler, 0.8 parts of water-reducing agent, 0.8 parts of defoamer, 0.5 parts of thickener, 5 parts of composite shrinkage inhibitor (prepared in Example 2), and 150 parts of water.

[0056] The preparation method is the same as in Example 1. Example 4:

[0057] Example 4 provides a polymer cement mortar, which differs from Example 1 in that a healing active factor is added to the components. The healing active factor is sodium silicate powder, specifically including, by weight: 300 parts of ordinary silicate cement, 20 parts of silica fume, 50 parts of granulated blast furnace slag powder, 20 parts of synthetic resin, 4 parts of slow-release rust inhibitor (prepared in Preparation Example 1), 600 parts of aggregate, 50 parts of powder filler, 0.8 parts of water-reducing agent, 0.8 parts of defoamer, 0.5 parts of thickener, 5 parts of composite shrinkage inhibitor (prepared in Preparation Example 2), 10 parts of healing active factor, and 140 parts of water.

[0058] The preparation method is the same as in Example 1. Example 5:

[0059] Example 5 provides a polymer cement mortar, which differs from Example 4 in that a gradient structure forming agent is added to the components. Specifically, by weight, it includes: 300 parts of ordinary silicate cement, 20 parts of silica fume, 50 parts of granulated blast furnace slag powder, 20 parts of synthetic resin, 4 parts of slow-release rust inhibitor (prepared in Preparation Example 1), 600 parts of aggregate, 50 parts of powder filler, 0.8 parts of water-reducing agent, 0.8 parts of defoamer, 0.5 parts of thickener, 5 parts of composite shrinkage inhibitor (prepared in Preparation Example 2), 10 parts of healing active factor, 8 parts of gradient structure forming agent, and 90 parts of water.

[0060] The gradient structure forming agent is composed of the following components: 2 parts of long fiber PVA fiber (6 mm in length, 20-30 μm in diameter) and 2 parts of PVA fiber (12 mm in length, 20-30 μm in diameter); 1 part of short fiber wood fiber (50-150 μm in length, 10-20 μm in diameter); 0.8 parts of inorganic thixotropic agent magnesium aluminum silicate; and 0.4 parts of organic thixotropic agent glutenin.

[0061] The preparation method is the same as in Example 1.

[0062] Comparative Example 1: Comparative Example 1 provides a polymer cement mortar, which differs from Example 1 in that it lacks a slow-release rust inhibitor and a composite shrinkage inhibitor in its components, specifically comprising, by weight: 300 parts of ordinary silicate cement, 70 parts of granulated blast furnace slag powder, 20 parts of synthetic resin, 600 parts of aggregate, 50 parts of powder filler, 0.8 parts of water-reducing agent, 0.8 parts of defoamer, 0.5 parts of thickener, and 150 parts of water.

[0063] The preparation method is the same as in Example 1.

[0064] Comparative Example 2: Comparative Example 2 provides a polymer cement mortar, which differs from Example 1 in that the slow-release rust inhibitor is replaced by an equal mass of rust inhibitor (triethanolamine and sodium molybdate in a 1:1 mass ratio, without carrier loading and coating), specifically comprising, by weight: 300 parts of ordinary silicate cement, 70 parts of granulated blast furnace slag powder, 20 parts of synthetic resin, 600 parts of aggregate, 50 parts of powder filler, 0.8 parts of water-reducing agent, 0.8 parts of defoamer, 0.5 parts of thickener, 5 parts of composite shrinkage inhibitor (prepared in Preparation Example 2), and 150 parts of water.

[0065] The preparation method is the same as in Example 1. Performance testing:

[0066] The performance of the polymer cement mortars of Examples 1-5 and Comparative Examples 1-2 was tested. The test methods and results are as follows. The test results are shown in Table 1.

[0067] (1) 28-day compressive strength of cement mortar: The reference standard is GB / T 17671-2021 "Test Method for Strength of Cement Mortar"; (2) Flexural strength of cement mortar at 28 days: The reference standard is GB / T 17671-2021 "Test Method for Strength of Cement Mortar"; (3) 28-day bond strength of cement mortar: The reference standard is JCT 2381-2016 "Repair Mortar"; (4) 28-day shrinkage rate of cement mortar: The reference standard is GB / T 29417-2012 "Test method for drying shrinkage cracking performance of cement mortar and concrete"; (5) Chloride ion permeability coefficient: The reference standard is ASTM C1202; (6) Corrosion weight loss rate of steel bars (salt spray test): According to ASTM B117, the steel bars were exposed in a salt spray chamber for 60 days and the corrosion weight loss rate of steel bars was tested. The reduction rate was calculated based on ordinary mortar without rust inhibitor. (7) Crack reduction rate (dynamic load test): Four-point bending dynamic loading was adopted, with a loading frequency of 2Hz and a cycle of 100,000 times. The number and width of cracks on the surface of the repair layer were observed, and the crack reduction rate was calculated based on Comparative Example 1.

[0068] Table 1 Performance Test Results

[0069] As can be seen from the data in Table 1, compared with the steel weight loss rate of Comparative Example 1, the steel corrosion weight loss rate of Example 1 was reduced by as much as 85%, while that of Comparative Example 2 was only 35%. This may be because ordinary rust inhibitors are rapidly consumed in the early stage, resulting in insufficient protection in the later stage. However, the pH-responsive slow-release rust inhibitor of the present invention can achieve on-demand release, targeting the release when corrosive factors invade, thereby providing long-term and efficient steel protection. In addition, the strength of Example 1 is higher than that of Comparative Example 2, and the 28-day shrinkage rate is significantly lower than that of Comparative Example 2. This indicates that the present invention avoids the interference of a large amount of rust inhibitor added at the beginning to cement hydration through slow-release design, thereby reducing its negative impact on the early strength development of mortar. At the same time, the composite shrinkage inhibitor significantly reduces the shrinkage of polymer cement mortar.

[0070] In Example 4, after the addition of the healing active factor, the chloride ion permeability coefficient and shrinkage rate were slightly lower than those in Example 1, indicating that the healing active factor can react with cement hydration products to generate insoluble substances that fill micropores, thereby improving density and reducing permeability and shrinkage. Furthermore, the crack reduction rate in Example 4 was slightly higher than that in Example 1, demonstrating the self-repairing ability of the healing active factor for microcracks and its ability to inhibit crack propagation under dynamic loads.

[0071] Example 5 showed a crack reduction rate of up to 85%, significantly higher than the 58% of Example 4, demonstrating the remarkable effect of the gradient structure-forming agent. Through the synergistic effect of long and short fibers and the thixotropic agent, a gradient distribution of fiber orientation and mechanical properties was formed in the mortar, effectively mitigating differences in elastic modulus and shrinkage, and significantly inhibiting cracking and spalling. Furthermore, Example 5 also exhibited a low 28-day shrinkage rate, while demonstrating excellent compressive and flexural strength, indicating that the gradient structure-forming agent not only inhibited macroscopic cracking but also optimized the internal microstructure, thereby reducing shrinkage and improving mechanical properties.

[0072] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A polymer cement mortar for repairing, reinforcing, and protecting concrete structures, characterized in that, It comprises the following components by weight: 200-500 parts inorganic cementitious material, 10-30 parts synthetic resin, 1-5 parts slow-release rust inhibitor, 500-800 parts aggregate, 20-100 parts powder filler, 1-10 parts composite shrinkage inhibitor and 40-250 parts water.

2. The polymer cement mortar for repairing, reinforcing, and protecting concrete structures according to claim 1, characterized in that, The slow-release rust inhibitor is composed of a porous carrier, a rust inhibitor loaded in the porous carrier, and a polymer coating layer covering the outer surface of the porous carrier. The polymer coating layer is a pH-responsive material.

3. The polymer cement mortar for repairing, reinforcing, and protecting concrete structures according to claim 2, characterized in that, The pH-responsive material is a carboxymethyl chitosan derivative, methyl methacrylate-methacrylic acid copolymer, or calcium alginate-chitosan complex.

4. The polymer cement mortar for repairing, reinforcing, and protecting concrete structures according to claim 1, characterized in that, It also includes 2 to 10 parts of a gradient structure forming agent, which is composed of long fibers, short fibers, organic thixotropic agents and inorganic thixotropic agents in a mass ratio of 1 to 6: 0.3 to 3: 0.3 to 3: 0.1 to 1.

5. The polymer cement mortar for repairing, reinforcing, and protecting concrete structures according to claim 4, characterized in that, The long fibers are selected from one or more of polyvinyl alcohol fibers, polypropylene fibers, and glass fibers, and the fiber length is 4mm to 15mm.

6. The polymer cement mortar for repairing, reinforcing, and protecting concrete structures according to claim 4, characterized in that, The short fibers are selected from one or more of wood fibers and cellulose fibers, and the fiber length is 10μm~200μm.

7. The polymer cement mortar for repairing, reinforcing, and protecting concrete structures according to claim 1, characterized in that, It also includes 5 to 50 parts of healing active factors, which include one or more of organosilicon and inorganic silicates.

8. The polymer cement mortar for repairing, reinforcing, and protecting concrete structures according to claim 1, characterized in that, The inorganic cementitious material comprises silicate cement and highly active micro powder in a mass ratio of 15~40:1~10.

9. The polymer cement mortar for repairing, reinforcing, and protecting concrete structures according to claim 1, characterized in that, Also includes: Water-reducing agent 0.3-3 parts, defoamer 0.2-1.5 parts, thickener 0.3-3 parts.

10. A method for preparing polymer cement mortar for repairing, reinforcing, and protecting concrete structures as described in any one of claims 1-9, characterized in that, Includes the following steps: Mix all components except water evenly to obtain a dry powder; The dry powder is mixed with water in a certain proportion and stirred evenly to obtain the final product.

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