An airport concrete composite reinforcing material and a method for preparing the same

Abstract

The application provides an airport concrete composite reinforcing material and a preparation method thereof. The airport concrete composite reinforcing material of the application, through accurate proportioning of raw materials and synergistic effect of functional components, aims at the core use pain points of deterioration of the airport concrete pavement caused by long-term impact and wear of the aircraft dynamic load, environmental medium erosion and extreme temperature variation, realizes all-round improvement of the performance of the pavement surface layer functional layer, and simultaneously considers construction adaptability and environmental protection, and has significant technical advantages compared with traditional pavement materials and repair agents. The application further provides a preparation method of the airport concrete composite reinforcing material.

Description

Technical Field

[0001] This invention belongs to the field of airport pavement repair technology, specifically relating to an airport concrete composite reinforcement material and its preparation method. Background Technology

[0002] Cement concrete pavement, with its core advantages of high strength, strong load-bearing capacity, and excellent impact resistance, has become the preferred structural material for core aviation transportation infrastructure such as airport runways, taxiways, and aprons. Its performance directly affects the operational safety and traffic efficiency of airport flights. Airport concrete pavement is exposed to the open natural environment for a long time, and must withstand the high-frequency dynamic load impact and crushing from passenger aircraft takeoffs and landings, as well as the continuous effects of complex environmental factors such as wind and rain erosion, drastic temperature and humidity changes, freeze-thaw cycles, and salt spray corrosion. As a key part that directly contacts aircraft wheelsets, bears load impacts, and interacts with the external environment, the pavement surface faces far more stringent usage tests than ordinary road and bridge pavements. Due to the molding process and material characteristics, the surface of airport concrete pavement inherently contains a large number of interconnected pores, and its cement paste-based structure results in low surface hardness and insufficient wear resistance. Under the combined effects of repeated friction and impact from aircraft wheelsets and environmental factors, it is highly susceptible to defects such as dusting, micro-cracking, abrasion erosion, and surface peeling. Such surface defects directly lead to a decline in core functional indicators of the pavement, such as anti-skid sway value and structural depth, significantly reducing the friction coefficient between the pavement and aircraft wheel sets, increasing safety hazards during aircraft takeoff and landing, and also significantly shortening the functional service life of the airport pavement, forcing it to enter the maintenance stage prematurely. Under the continuous action of the natural environment and aircraft dynamic loads, harmful media such as rainwater, chloride ions, and sulfates can easily penetrate into the concrete through the interconnected pores of the pavement surface. This not only causes carbonization and freeze-thaw damage inside the concrete, but also corrodes the internal steel reinforcement structure, reducing the overall structural strength and durability of the pavement. The deterioration of the internal structure further accelerates the damage to the surface functional layer, forming a vicious cycle of surface damage, media penetration, internal deterioration, and further surface damage, significantly increasing the difficulty and cost of later maintenance of airport pavements.

[0003] Currently, the main method for repairing and strengthening surface defects of airport concrete pavements is the traditional method of adding a thick layer of concrete. This method requires laying a concrete layer of more than 30cm to restore pavement function, which not only consumes a large amount of raw materials such as cement and sand, resulting in high labor and construction costs, but also has a long maintenance cycle, causing long-term closure of airport runways and taxiways, seriously affecting the normal operation of the airport and causing huge economic losses and social impact. Although some conventional pavement surface reinforcement materials can achieve simple protection, they generally have poor permeability. They can only adhere to the pavement surface and cannot penetrate into the functional layer of 5-12mm to fill the pores. This makes it difficult to fundamentally solve the core problems of insufficient wear resistance and impermeability of the pavement surface, and it cannot simultaneously improve the pavement's comprehensive durability performance such as freeze-thaw resistance and salt spray corrosion resistance. The reinforcement effect is short-lived, and damage is likely to occur again later.

[0004] In summary, developing a surface reinforcement and repair material specifically for airport pavements to address the insufficient durability caused by poor wear resistance and numerous interconnected pores in existing airport concrete pavements, achieving deep penetration and dense filling of pores, improving overall durability and adaptability to extreme conditions, simplifying construction processes, shortening maintenance cycles, and expanding the material's functional adaptability to meet the repair needs of airport pavements in different regions and under different conditions, thereby reducing the overall maintenance cost of airport pavements, has become a pressing technical challenge in the fields of airport engineering and concrete materials. Summary of the Invention

[0005] This invention aims to at least solve one of the aforementioned technical problems existing in the prior art. To this end, this invention provides a composite reinforcement material for airport concrete, aiming to solve the problems of poor wear resistance of existing airport concrete pavement surfaces, poor durability due to interconnected pores, and high maintenance costs after the surface functional layer affects operational safety.

[0006] This invention also provides a method for preparing a composite reinforcement material for airport concrete.

[0007] The first aspect of the present invention provides an airport concrete composite reinforcement material, wherein the raw materials for preparation, by weight, include: Industrial solid waste activated compound: 100 parts Silica sol: 70-90 parts Nano silica: 20-30 parts Magnesium fluorosilicate: 30-40 parts Organosilicon: 5-8 parts Accelerator: 2-3 parts Surfactant: 0.3-0.5 parts Silanized-ZnO grafted modified bamboo fiber: 5-8 parts, Perfluorinated elastic microsphere synergistic film-forming agent: 25-35 parts.

[0008] The airport concrete composite reinforcement material of this invention, through precise proportioning of raw materials and synergistic effects of functional components, addresses the core pain points of airport concrete pavements, such as long-term degradation due to impact and wear from aircraft dynamic loads, environmental erosion, and extreme temperature changes. It achieves a comprehensive improvement in pavement surface performance while also considering construction adaptability and environmental friendliness. Compared to traditional pavement repair materials and agents, it has significant technical advantages, with the following specific benefits: Using 100 parts of industrial solid waste active compound as the base cementitious core, replacing the traditional pure cement system, it not only reduces the carbon emissions of material production through the resource utilization of industrial solid waste, but also leverages the active activation characteristics of solid waste-based materials to form a synergistic hydration reaction with silica sol and nano silica, generating more CSH gel, densifying the concrete pavement matrix structure, improving the early and long-term strength of pavement repair, and enhancing the pavement's resistance to corrosion from media such as sulfates and salt spray, making it suitable for the use needs of airports in special areas such as coastal areas and chemical plant areas.

[0009] The combination of silica sol, nano-silica, and magnesium fluorosilicate, along with the surface tension regulating effect of organosilicon, allows the material to rapidly penetrate into the functional layer of the airport concrete pavement, reaching a depth of 5-12 mm. It reacts with the hydration products in the concrete, densifying the surface layer, connecting pores, and sealing microcracks. Simultaneously, the filling effect of nano-silica and the film-forming properties of silica sol work synergistically to significantly improve the density of the pavement surface, fundamentally solving the problems of dusting and erosion on the airport pavement surface. This maintains the stability of the pavement's structural depth and anti-skid values, ensuring the friction coefficient requirements for aircraft takeoff and landing, and improving airport operational safety.

[0010] Silanized-ZnO grafted modified bamboo fiber, as a functional reinforcing component, exhibits significantly enhanced interfacial bonding with the cement matrix and polymer phase after silanization treatment. Nano-ZnO grafting further improves the stability of the fiber in alkaline cement environments, preventing fiber degradation and failure. The modified bamboo fiber is uniformly dispersed in the material system, effectively dispersing the dynamic load impact stress from aircraft takeoff and landing, reducing pavement surface wear and cracking. Simultaneously, combined with the film-forming and wear-resistant properties of perfluorinated elastic microspheres and film-forming agents, it significantly reduces the wear of airport pavements, extends the functional service life of the pavement, and solves the pain point of rapid damage to the surface of traditional pavements due to heavy-load friction.

[0011] The hydrophobic properties of organosilicon and perfluorinated elastic microspheres, combined with the synergistic film-forming agent, form a dense hydrophobic protective film on the pavement surface. This, along with the low-porosity structure formed after the material penetrates and compacts, effectively prevents harmful media such as water and chloride ions from penetrating into the concrete, significantly reducing the penetration depth and migration coefficient of chloride ions. Simultaneously, the dense structure of the material and the toughening effect of the elastic microspheres enhance the pavement concrete's resistance to freeze-thaw cycles. After multiple freeze-thaw cycles, the pavement can still maintain low mass loss and a high dynamic modulus of elasticity, preventing surface peeling and cracking caused by freeze-thaw cycles, thus meeting the environmental requirements of airports in cold and rainy regions.

[0012] The perfluorinated elastic microspheres and synergistic film-forming agent combine the high-temperature resistance and UV resistance of fluorinated materials with the low-temperature flexibility of elastic microspheres. This allows pavement materials to maintain stable performance under conditions such as instantaneous high temperatures from aircraft exhaust plumes and extreme low temperatures in cold regions, without softening, cracking, or peeling. Meanwhile, the nano-ZnO in the silanized-ZnO grafted modified bamboo fiber has UV shielding properties, which can delay the photo-aging degradation of the material system, improve the outdoor weather resistance of the material, extend the service life of pavement materials, and reduce the frequency of maintenance of airport pavements.

[0013] The material's raw material ratios are scientifically formulated, enhancing the pavement's surface hardness, wear resistance, and impermeability without adversely affecting core structural properties such as rebound value, compressive strength, and flexural strength. The pavement's structural strength remains stable after construction. Furthermore, core operational indicators such as anti-skid sway value and texture depth show no significant changes after material application, eliminating the need for additional adjustments to pavement surface characteristics and ensuring rapid commissioning of the airport pavement. The material system exhibits excellent dispersibility among its components, and the addition of surfactants further enhances its wettability on concrete pavements, allowing for convenient application methods such as spraying and brushing without complex on-site mixing. Simultaneously, the material forms a film quickly, rapidly creating a reinforced protective layer on the pavement surface, significantly shortening the maintenance period and reducing the impact of pavement construction on airport operations, demonstrating both technical feasibility and economic practicality.

[0014] According to some embodiments of the present invention, the airport concrete composite reinforcement material of the present invention, by weight, comprises the following raw materials: Industrial solid waste activated compound: 100 parts Silica sol: 75-85 parts Nano silica: 25-30 parts Magnesium fluorosilicate: 35-40 parts Organosilicon: 5-8 parts Accelerator: 2-2.5 parts Surfactant: 0.3-0.5 parts Silanized-ZnO grafted modified bamboo fiber: 5-8 parts, Perfluorinated elastic microsphere synergistic film-forming agent: 30-35 parts.

[0015] According to some embodiments of the present invention, the industrial solid waste active compound is composed of cement, steel slag powder, metakaolin and composite activator.

[0016] According to some embodiments of the present invention, the mass ratio of the cement, steel slag powder, metakaolin and composite activator is (5~7):(2~3):1.

[0017] According to some embodiments of the present invention, the mass ratio of the cement, steel slag powder, metakaolin and composite activator is any value among 5:2:1, 5:3:1, 6:2:1, 6:3:1, 7:2:1, and 7:3:1, such as 6:2:1, or any range of the two, such as 5:2:1 to 6:3:1.

[0018] According to some embodiments of the present invention, the cement in the industrial solid waste active compound is P·I silicate cement, P·II silicate cement or P·O silicate cement.

[0019] According to some embodiments of the present invention, the particle size of steel slag powder in the industrial solid waste active compound is ≤5μm.

[0020] According to some embodiments of the present invention, the composite activator is a mixture of sodium hydroxide, sodium sulfate and triethanolamine in a mass ratio of 1:1:(1~5).

[0021] Sodium hydroxide, a strongly alkaline inorganic activator, is the core trigger for activating the activity of industrial solid waste. Its key function is to provide a strongly alkaline environment (pH > 12), disrupting the crystal structure of dicalcium silicate and tricalcium silicate in cement and aluminosilicates in metakaolin, causing the originally stable mineral lattice to dissociate and release a large amount of chemically reactive active components such as SiO2, Al2O3, and CaO, providing the material basis for subsequent hydration reactions. Sodium sulfate enhances the hydration reaction and strength development. Triethanolamine, an organic alcohol amine complexing activator, also has the functions of catalyzing hydration, optimizing interfaces, and improving component compatibility. When the three are compounded in a ratio of 1:1:(1~5), sodium hydroxide initiates alkaline activation, sodium sulfate enhances hydration and densification, and triethanolamine catalyzes and optimizes the interface, achieving a synergistic effect of inorganic activation and organic regulation. This not only solves the problems of low activation efficiency and slow strength development of industrial solid waste by a single activator, but also avoids the defects of poor material volume stability and later strength reduction caused by excessive inorganic activator. Ultimately, the early strength, long-term durability, and density of the industrial solid waste active compound are greatly improved. The prepared airport concrete pavement composite reinforcement material can fully meet the core performance requirements of airport pavement such as heavy load, impermeability, wear resistance, and freeze-thaw resistance.

[0022] According to some embodiments of the present invention, the preparation method of the industrial solid waste active compound material may be: mixing cement, steel slag powder, metakaolin and composite activator.

[0023] According to some embodiments of the present invention, the silica sol is sodium-type HY silica sol.

[0024] According to some embodiments of the present invention, the organosilicon is hexamethylcyclotrisiloxane or decamethylcyclopentasiloxane.

[0025] According to some embodiments of the present invention, the coagulant is calcium chloride, calcium nitrate, sodium sulfate, or sodium aluminate.

[0026] According to some embodiments of the present invention, the surfactant is sodium dodecyl sulfonate.

[0027] According to some embodiments of the present invention, the preparation method of the silanized-ZnO grafted modified bamboo fiber is as follows: the bamboo fiber is subjected to silanization treatment, and the silanized bamboo fiber is immersed in 5-10wt% nano-ZnO dispersion for reaction, so that nano-ZnO is covalently grafted onto the fiber surface.

[0028] According to some embodiments of the present invention, the temperature of the reaction is 60-80°C.

[0029] According to some embodiments of the present invention, the temperature of the reaction is any value among 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C, 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C, and 80°C, such as 70°C, or a range of any two, such as 65°C to 75°C.

[0030] According to some embodiments of the present invention, the reaction time is 2-3 hours.

[0031] According to some embodiments of the present invention, the reaction time is any value among 2h, 2.1h, 2.2h, 2.3h, 2.4h, 2.5h, 2.6h, 2.7h, 2.8h, 2.9h, and 3h, such as 2.5h, or a range formed by any two, such as 2.2h to 2.8h. According to some embodiments of the present invention, the raw materials for preparing the perfluorinated elastic microsphere synergistic film-forming agent include fluorinated modified monomers, polymeric monomers, modified functional additives and polyurethane elastomer microspheres, wherein the fluorinated modified monomer is perfluorooctyl ethyl acrylate, the polymeric monomer is a mixture of hydroxyethyl methacrylate, butyl acrylate and styrene, and the modified functional additive is polyethylene glycol monomethyl ether acrylate.

[0032] According to some embodiments of the present invention, the mass ratio of hydroxyethyl methacrylate, butyl acrylate and styrene in the polymer monomers is 1:(2~3):1.

[0033] Hydroxyethyl methacrylate contains hydroxyl-containing active functional groups, which can form hydrogen bonds with the hydroxyl groups of the cement matrix, improving the adhesion between the emulsion and the concrete pavement. It also provides crosslinking sites for the polymerization system, enhancing film density. Butyl acrylate is a soft monomer that imparts excellent flexibility and low-temperature flexibility to the polymer emulsion, solving the problem of low-temperature brittleness and making it suitable for airport pavement conditions in cold regions. Styrene is a hard monomer that can improve the hardness, abrasion resistance, and high-temperature resistance of the polymer film, while also enhancing the emulsion's resistance to UV aging.

[0034] According to some embodiments of the present invention, in the raw materials for preparing the perfluorinated elastic microsphere synergistic film-forming agent, the amount of fluorinated modified monomer added is 5-10 wt% of the total mass of the polymeric monomers. After copolymerization with the main monomers, the fluorinated modified monomers introduce fluorocarbon chains into the polymer molecular chains, significantly improving the hydrophobicity, salt spray corrosion resistance, and weather resistance of the emulsion, reducing the surface energy of the pavement, and reducing the penetration of moisture and chloride ions.

[0035] According to some embodiments of the present invention, in the raw materials for preparing the perfluorinated elastic microsphere synergistic film-forming agent, the amount of modified functional additive added is 1-2 wt% of the total mass of the polymer monomers. Its function is to improve the hydrophilicity and cement compatibility of the polymer emulsion, optimize the emulsion's penetration ability on the concrete surface, synergistically crosslink with the hydroxyl groups of hydroxyethyl methacrylate, further enhance the density of the polymer film, strengthen its impermeability and wear resistance, and has no compatibility conflict with fluorinated monomers, thus not affecting the hydrophobic effect.

[0036] According to some embodiments of the present invention, in the raw materials for preparing the perfluorinated elastic microsphere synergistic film-forming agent, the amount of polyurethane elastomer microspheres added is 1-2 wt% of the total mass of the polymer monomers.

[0037] The preparation method of the perfluorinated elastic microsphere synergistic film-forming agent can be as follows: (1) Preparation of the pre-dispersion system: Add sodium dodecyl sulfate (SO4) emulsifier to deionized water, turn on a high-speed disperser and stir for 20-40 minutes at a speed of 2500-3000 rpm to ensure that the emulsifier is completely dissolved and a homogeneous emulsion system is formed. Hydroxyethyl methacrylate, butyl acrylate, styrene, and perfluorooctyl ethyl acrylate are added sequentially, and high-speed dispersion is continued for 30-40 minutes to ensure that the monomers are uniformly dispersed in the aqueous system and form a stable O / W type emulsion.

[0038] (2) Seed polymerization reaction: The above O / W type emulsion was transferred into a constant temperature reactor, and nitrogen gas was introduced to replace the air in the reactor (to eliminate the interference of oxygen on the polymerization reaction) to maintain a nitrogen atmosphere; Heat the mixture to 70-80℃, dissolve the initiator ammonium persulfate or azobisisobutyronitrile in a small amount of deionized water, and slowly drop it into the reactor at a rate of 1-2 drops / second. After the addition is complete, keep the mixture at the temperature for 3 hours, then turn on the stirrer (800-900 rpm) to promote the uniform polymerization reaction. During the reaction, the particle size of the polymer particles is monitored by a particle size analyzer and controlled between 100 and 300 nm. If the particle size is too large, the stirring speed can be increased appropriately; if the particle size is too small, a small amount of emulsifier can be added to adjust it.

[0039] (3) Elastic microsphere composite: Add polyurethane elastomer microspheres to an ultrasonic disperser and ultrasonically disperse them with a small amount of deionized water for 20-30 minutes (power 500W) to break up the microsphere agglomerates and form a uniform microsphere dispersion. The amount of polyurethane elastomer microspheres added is 1 wt% of the total mass of the polymer monomers.

[0040] Slowly add the microsphere dispersion to the polymerization reactor, cool to 60-70℃, maintain a stirring speed of 600-700 rpm, and keep the reaction at this temperature for 2 hours to allow the polyurethane elastomer microspheres and fluorinated polymer emulsion to fully combine and form a polymer matrix-elastic microsphere composite system. During this period, take samples to observe the state of the system to ensure that there is no stratification or precipitation. If stratification occurs, a small amount of emulsifier can be added or the stirring speed can be increased.

[0041] (4) Post-processing: Slowly add a neutralizing agent (triethanolamine) to the reactor to adjust the pH of the system to 7.5-8, stir for 30-40 minutes to reduce the corrosiveness of the system to the cement pavement, and at the same time improve the compatibility of the film-forming agent with the cement matrix. Continue to maintain the temperature at 60-70℃ and stir for 1-2 hours to carry out the maturation reaction and make the composite system more stable. Turn off the heating device and allow it to cool naturally to room temperature. Filter the system with a 100-mesh filter to remove any unreacted impurities or agglomerates, resulting in a uniform milky white emulsion, which is the perfluorinated elastic microsphere synergistic film-forming agent.

[0042] A second aspect of the present invention provides a method for preparing the airport concrete composite reinforcement material of the first aspect of the present invention, comprising the following steps: S1: Add nano-silica and surfactant to water and disperse by ultrasonication to obtain nano-silica dispersion; S2: The silanized-ZnO grafted modified bamboo fiber is immersed in the perfluorinated elastic microsphere synergistic film-forming agent to obtain a fiber dispersion; S3: The fiber dispersion, industrial solid waste active compound, silica sol, magnesium fluorosilicate, organosilicon, and coagulant are added to the nano-silica dispersion and stirred to obtain the airport concrete composite reinforcement material. The preparation method of this invention involves ultrasonic dispersion of nano-silica, which effectively prevents particle agglomeration and improves its dispersion uniformity in the system, fully leveraging its role in filling and dense pores at the nanoscale. Modified bamboo fiber is pre-impregnated with a film-forming agent to create a dispersion, ensuring thorough bonding between the fiber and the agent, improving fiber dispersibility in the material system, and enhancing the synergistic toughening and wear-resistant effects of both. A stepwise mixing process is employed to ensure the sequential and thorough integration of each functional component, guaranteeing the reactivity of core components such as industrial solid waste active compound, silica sol, and magnesium fluorosilicate, achieving synergistic effects among the components, and improving the overall impermeability, wear resistance, and freeze-thaw resistance of the material.

[0043] The preparation method of this invention has simple process steps, no complex equipment requirements, and is easy to industrialize and mass-produce. The resulting material has good dispersibility and stable performance, and can be directly adapted to airport pavement construction methods such as spraying and brushing, thereby improving construction efficiency.

[0044] According to some embodiments of the present invention, in step S1, the power of ultrasonic dispersion is 400-600W.

[0045] According to some embodiments of the present invention, in step S1, the ultrasonic dispersion time is 20-40 min.

[0046] According to some embodiments of the present invention, in step S3, the stirring speed is 1500-2500 rpm. Attached Figure Description

[0047] Figure 1 It is one of the on-site construction drawings for a specific test area at the airport.

[0048] Figure 2 This is the second on-site construction drawing of a specific test area at the airport.

[0049] Figure 3 This is a schematic diagram of the process of cutting a sample block of the old concrete pavement at the airport.

[0050] Figure 4 This is a sample image of the old concrete pavement at the airport. Detailed Implementation

[0051] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0052] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0053] Unless otherwise specified, "room temperature" in this invention means 25℃±5℃.

[0054] Unless otherwise specified, "about" in this invention means that the allowable error is within ±2%.

[0055] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0056] In the example: The cement was P·I52.5R silicate cement, purchased from Henan Haonai Building Materials Co., Ltd.

[0057] The steel slag powder has a particle size of ≤5μm and was purchased from Fujian Gangyuan Powder Materials Co., Ltd.

[0058] The metakaolin was purchased from Jinyu.

[0059] The polyurethane elastomer microspheres were purchased from Covestro.

[0060] Nano-silica was purchased from Merck.

[0061] HY silica sol was purchased from Hubei Jingcheng Chemical (HY represents high-purity silica substrate).

[0062] Example 1 An airport concrete composite reinforcement material, prepared by weight, comprises the following raw materials: Industrial solid waste activated compound: 100 parts Silica sol: 80 parts Nano silica: 28 parts Magnesium fluorosilicate: 38 parts Organosilicon: 6 parts Accelerator: 2.2 parts, Surfactant: 0.4 parts Silanized-ZnO grafted modified bamboo fiber: 6 parts, Perfluorinated elastic microsphere synergistic film-forming agent: 32 parts.

[0063] The industrial solid waste active compound material is composed of cement, steel slag powder, metakaolin and composite activator.

[0064] The mass ratio of cement, steel slag powder, metakaolin, and composite activator is 5:2:1.

[0065] The composite activator is a mixture of sodium hydroxide, sodium sulfate and triethanolamine in a mass ratio of 1:1:2.

[0066] The preparation method of industrial solid waste active compound material is as follows: first, prepare the composite activator, and then mix the composite activator with cement, steel slag powder, metakaolin and the composite activator.

[0067] The silica sol is sodium-type HY silica sol.

[0068] The organosilicon is hexamethylcyclotrisiloxane.

[0069] The coagulant is calcium chloride.

[0070] The surfactant is sodium dodecyl sulfonate.

[0071] The preparation method of silanized-ZnO grafted modified bamboo fiber is as follows: 10g of tripropyltrimethoxysilane is mixed with 20g of bamboo fiber to complete the silanization treatment. The silanized bamboo fiber is then immersed in a 5wt% nano-ZnO dispersion and reacted at 70℃ for 2h.

[0072] The preparation method of the perfluorinated elastic microsphere synergistic film-forming agent is as follows: (1) Preparation of the pre-dispersion system: Add sodium dodecyl sulfate (SO4) emulsifier to deionized water, turn on a high-speed disperser and stir for 30 minutes at 2500 rpm to ensure that the emulsifier is completely dissolved and a homogeneous emulsion system is formed. Hydroxyethyl methacrylate, butyl acrylate, styrene (mass ratio 1:2:1), and perfluorooctyl ethyl acrylate were added sequentially, and high-speed dispersion was continued for 40 min to ensure uniform dispersion of the monomers in the aqueous system, forming a stable O / W type emulsion. In the preparation of the perfluoro-based elastic microsphere synergistic film-forming agent, the amount of fluorinated modified monomer added was 5-10 wt% of the total mass of the polymerized monomers. The amount of polyethylene glycol monomethyl ether acrylate added was 1 wt% of the total mass of the polymerized monomers.

[0073] (2) Seed polymerization reaction: The above O / W type emulsion was transferred into a constant temperature reactor, and nitrogen gas was introduced to replace the air in the reactor (to eliminate the interference of oxygen on the polymerization reaction) to maintain a nitrogen atmosphere; Heat the mixture to 75°C, dissolve the initiator ammonium persulfate or azobisisobutyronitrile in a small amount of deionized water, and slowly drop it into the reactor at a rate of 1 drop / second. After the drop is complete, keep the mixture at the temperature for 3 hours, then turn on the stirrer (800 rpm) to promote the uniform polymerization reaction. During the reaction, the particle size of the polymer particles is monitored by a particle size analyzer and controlled between 100 and 300 nm. If the particle size is too large, the stirring speed can be increased appropriately; if the particle size is too small, a small amount of emulsifier can be added to adjust it.

[0074] (3) Elastic microsphere composite: Polyurethane elastomer microspheres were added to an ultrasonic disperser and ultrasonically dispersed with a small amount of deionized water for 20 minutes (power 500W) to break up the microsphere agglomerates and form a uniform microsphere dispersion. The amount of polyurethane elastomer microspheres added was 1 wt% of the total mass of the polymer monomers.

[0075] The microsphere dispersion was slowly added to the polymerization reactor and cooled to 60°C. The stirring speed was maintained at 600 rpm, and the reaction was carried out for 2 hours to allow the polyurethane elastomer microspheres and fluorinated polymer emulsion to fully combine and form a polymer matrix-elastic microsphere composite system. During the process, the system was sampled and the state was observed to ensure that there was no stratification or precipitation. If stratification occurred, a small amount of emulsifier could be added or the stirring speed could be increased.

[0076] (4) Post-processing: Slowly add a neutralizing agent (triethanolamine) to the reactor to adjust the pH of the system to 7.5, stir for 30 minutes to reduce the corrosiveness of the system to the cement pavement, and at the same time improve the compatibility of the film-forming agent with the cement matrix; Continue to maintain the temperature at 60℃ and stir for 1 hour to carry out the maturation reaction and make the composite system more stable. Turn off the heating device and allow it to cool naturally to room temperature. Filter the system with a 100-mesh filter to remove any unreacted impurities or agglomerates, resulting in a uniform milky white emulsion, which is the perfluorinated elastic microsphere synergistic film-forming agent.

[0077] The method for using composite reinforcement materials for airport concrete pavements includes the following steps: S1: Add nano-silica and surfactant to water according to the ratio, and disperse by ultrasonication at 500W for 20 minutes to obtain nano-silica dispersion; S2: Silanized-ZnO grafted modified bamboo fiber is immersed in a perfluorinated elastic microsphere synergistic film-forming agent to obtain a fiber dispersion; S3: Add fiber dispersion, industrial solid waste active compound, silica sol, magnesium fluorosilicate, organosilicon and coagulant to nano silica dispersion, stir at 2000 rpm for 10 minutes to obtain the airport pavement concrete composite reinforcement material of the present invention.

[0078] Example 2 An airport concrete composite reinforcement material differs from Example 1 in that the raw material ratio is different.

[0079] The raw materials for preparation are, by weight: Industrial solid waste activated compound: 100 parts Silica sol: 75 parts Nano silica: 25 parts Magnesium fluorosilicate: 35 parts Organosilicon: 5 parts Accelerator: 2 parts Surfactant: 0.3 parts Silanized-ZnO grafted modified bamboo fiber: 5 parts Perfluorinated elastic microsphere synergistic film-forming agent: 30 parts.

[0080] Example 3 An airport concrete composite reinforcement material differs from Example 1 in that the raw material ratio is different.

[0081] The raw materials for preparation are, by weight: Industrial solid waste activated compound: 100 parts Silica sol: 85 parts Nano silica: 30 parts Magnesium fluorosilicate: 40 parts Organosilicon: 8 parts Accelerator: 2.5 parts Surfactant: 0.5 parts Silanized-ZnO grafted modified bamboo fiber: 8 parts Perfluorinated elastic microsphere synergistic film-forming agent: 35 parts.

[0082] Comparative Example 1 An airport concrete composite reinforcement material differs from Example 1 in that it does not contain silanized-ZnO grafted modified bamboo fiber.

[0083] Comparative Example 2 An airport concrete composite reinforcement material differs from Example 1 in that it does not contain a perfluorinated elastic microsphere synergistic film-forming agent.

[0084] Performance testing The testing is divided into on-site construction and indoor testing.

[0085] On-site construction is being carried out in a specific test area at Changsha Huanghua Airport, such as... Figure 1 and Figure 2 As shown.

[0086] The indoor test was conducted in the laboratory using sections of old concrete pavement from Changsha Huanghua Airport. The sectioning process was as follows: Figure 3 As shown, the extracted sample block is as follows Figure 4 As shown.

[0087] The testing method involves taking concrete test blocks from the old airport pavement and testing the performance of the concrete test blocks before and after applying the composite reinforcement material to the airport concrete pavement in the examples and comparative cases.

[0088] The testing was based on the following standards: Civil Aviation Airport Pavement On-site Testing Procedures (MH / T5110-2015); Technical Specification for Construction of Cement Concrete Surface Layer in Civil Airports (MH5006-2015); "Design Specification for Cement Concrete Pavement of Civil Airports" (MH5004-2010); Civil Airport Flight Technical Standards (MH5001-2013); "Specifications for Field Testing of Highway Subgrade and Pavement" (JTG3450-2019); Highway Technical Condition Assessment Standard (JTG5210-2018); Test Procedures for Cement and Cement Concrete in Highway Engineering (JTG3420—2020); Standard for Test Methods of Long-Term Performance and Durability of Concrete (GB / T50082-2024); Standard for Test Methods of Physical and Mechanical Properties of Concrete GB / T50081-2019.

[0089] All test values ​​are results after the composite reinforcement material was sprayed. The blank control group consisted of airport concrete pavement / blocks without any reinforcement material sprayed (consistent with the blank group in the silica infiltration agent test). The spraying amount was uniformly 1.5 kg / m². 2 (Consistent with the construction parameters of the silica penetrant).

[0090] The results are shown in Tables 1 to 3.

[0091] Table 1 Surface performance test indicators and values

[0092] As can be seen from Table 1, in terms of Mohs hardness, the blank control group was 7.0, while Examples 1-3 reached 8.7-9.2, showing a significant improvement in hardness. Although Comparative Examples 1 (8.2) and 2 (8.0) were higher than the blank group, they were much lower than the examples. This indicates that the composite reinforcing material of the present invention can significantly improve the surface hardness of the pavement. The combination of silanized-ZnO grafted modified bamboo fiber and perfluorinated elastic microspheres as a synergistic film-forming agent is the key to improving surface hardness. The absence of either of these two components would lead to a significant decrease in the hardness improvement effect.

[0093] Regarding the anti-skid pendulum value (20℃), the blank control group had a value of 65~71 BPN, while Examples 1-3 had a value of 71~73 BPN, slightly higher than the blank group and remaining stable; Comparative Examples 1-2 had a value of 69~70 BPN, slightly lower than the examples but still within the safe range. This indicates that the material of the present invention, while increasing hardness, did not reduce the anti-skid performance of the pavement, but rather slightly optimized it, ensuring the friction coefficient requirements for aircraft takeoff and landing. Furthermore, the comparative examples without key functional components showed a weaker improvement in anti-skid performance.

[0094] Regarding the construction depth, the blank control group had a depth of 0.40~0.48mm, Examples 1-3 had a depth of 0.44~0.46mm, and Comparative Examples 1-2 had a depth of 0.41~0.42mm. All samples fell within the range of the blank group. This indicates that the material of the present invention does not change the construction depth of the pavement surface after spraying, requiring no additional adjustment to the pavement surface characteristics, and can be put into operation directly. The bonding between the material and the pavement surface does not damage the original surface structure characteristics.

[0095] As shown in Table 1, the composite reinforcing material of the present invention can significantly improve the surface hardness of airport concrete pavement, while accurately maintaining the stability of core operational indicators such as pavement anti-skid value and texture depth, thus meeting the surface functional requirements of airport pavement. The synergistic effect of silanized-ZnO grafted modified bamboo fiber and perfluorinated elastic microspheres as a film-forming agent is the core factor for the significant improvement in surface hardness. The absence of either of them would severely weaken the surface strengthening effect.

[0096] Table 2 Mechanical performance test indicators and values

[0097] Table 2 shows that the rebound values ​​of the blank control group were 29.8~39.1, and those of Examples 1-3 were 34.8~36.2, which were more stable and in the high range of the blank group; the values ​​of Comparative Examples 1-2 were 32.9~33.6, which were lower than those of the examples. This indicates that after the material of the present invention is sprayed, the surface density of the pavement concrete is improved, making the rebound value more stable and optimized. This reflects the compaction effect of the material on the surface substrate after penetration, while the lack of key functional components will lead to a decrease in the compaction effect.

[0098] Regarding compressive strength, the blank control group had a strength of 63.4 MPa, while Examples 1-3 showed a strength of 64.5-65.8 MPa, a slight increase. Comparative Examples 1-2 showed a strength of 63.6-63.8 MPa, essentially the same as the blank group. This indicates that the material of this invention does not adversely affect the compressive strength of the pavement; on the contrary, it achieves a slight increase in compressive strength through hydration reaction and pore filling. The comparative examples without key components showed no significant improvement.

[0099] Regarding flexural strength, the blank control group had a strength of 5.8 MPa, while Examples 1-3 showed a significant improvement of 6.2-6.4 MPa. Comparative Examples 1 (5.9 MPa) and 2 (5.8 MPa) showed almost no improvement. This indicates that the silanized-ZnO grafted modified bamboo fiber has a significant toughening effect and can effectively improve the flexural strength of the pavement. The flexural strength of Comparative Example 2, which lacks this component, remained unchanged, confirming the optimizing effect of modified bamboo fiber on the flexural performance of the pavement.

[0100] As shown in Table 2, the airport concrete composite reinforcement material of the present invention will not adversely affect the core structural mechanical properties of airport concrete pavement. On the contrary, it can slightly improve compressive strength, significantly improve flexural strength, and optimize the stability of rebound value, thus achieving the technical goal of surface strengthening and structural stability. Among them, silanized-ZnO grafted modified bamboo fiber is the key to improving flexural strength, and the combination of perfluorinated elastic microspheres, film-forming agent and other components helps to improve surface density. The absence of these two components will lead to the basic disappearance of the mechanical property improvement effect.

[0101] Table 3 Durability performance test indicators and values

[0102] In Table 3: The surface abrasion resistance (surface / side) of the blank control group was 3.85 kg / m. 2 Side profile 2.16kg / m 2 Examples 1-3: Surface area 1.18~1.42 kg / m² 2 Side profile: 0.48~0.60 kg / m 2 Wear resistance decreased by over 60%; comparative examples 1-2 showed a wear resistance of 2.58~2.86 kg / m². 2 Side profile: 1.45~1.68 kg / m 2 The wear resistance consumption is significantly higher than that of the previous example. This indicates that the material of the present invention can significantly improve the wear resistance of pavement. The stress dispersion effect of silanized-ZnO grafted modified bamboo fiber and the film-forming wear-resistant properties of the perfluorinated elastic microsphere synergistic film-forming agent form a synergy, which is the core of the improved wear resistance. The absence of both will lead to a significant decrease in wear resistance.

[0103] Regarding chloride ion penetration depth / migration coefficient, the blank group had a penetration depth of 48.5 mm and a migration coefficient of 24.1 × 10⁻⁶. - 12 m 2 / s; Examples 1-3: penetration depth 17.2~20.3mm, migration coefficient 7.6~9.5×10 -12 m 2 / s, the index decreased by more than 50%; comparative examples 1-2 had a penetration depth of 32.6~35.8mm and a migration coefficient of 18.5~20.2×10 -12 m 2 / s, far worse than the example. This indicates that the material of the present invention can significantly reduce chloride ion penetration capacity and greatly improve the pavement's resistance to salt spray corrosion and chloride ion erosion. The material's dual effect of densely filling pores after penetration and hydrophobic protective membrane effectively blocks chloride ion migration, while the lack of key components will lead to a significant weakening of the anti-permeability effect.

[0104] Regarding the carbonation depth (7 days), the blank group had a depth of 1.5 mm, Examples 1-3 all had a depth of 0 mm, and Comparative Examples 1-2 had a depth of 0.8-1.0 mm. This demonstrates that the material of the present invention can completely prevent the carbonation reaction of the concrete surface within 7 days. The dense surface structure of the material isolates carbon dioxide from contact with the concrete, while the absence of key components leads to a decrease in the carbonation protection effect.

[0105] Regarding freeze-thaw resistance (150 freeze-thaw cycles), the blank group showed a mass loss of 5.6% and a dynamic modulus of elasticity remaining of 58.5%; Examples 1-3 showed a mass loss of 0.7-1.0% and a dynamic modulus of elasticity remaining of 94.8-97.2%, exhibiting excellent freeze-thaw stability; Comparative Examples 1-2 showed a mass loss of 3.2-3.8% and a dynamic modulus of elasticity remaining of 70.5-75.6%, significantly lower than the examples. This demonstrates that the material of this invention significantly improves the pavement's resistance to freeze-thaw cycles. The dense porous structure, the toughening effect of the elastic microspheres, and the hydrophobic protection effectively prevent surface damage caused by freeze-thaw cycles. The absence of these two elements would significantly reduce freeze-thaw resistance.

[0106] Regarding high-temperature resistance (baking at 200℃ for 50 cycles), the blank group showed localized peeling and cracking; Examples 1-3 showed no significant changes; Comparative Example 1 showed slight powdering, and Comparative Example 2 showed localized micro-cracks and peeling. This indicates that the material of the present invention possesses excellent high-temperature resistance. The high-temperature resistance of the fluorine-based film-forming agent combined with the ultraviolet shielding properties of nano-ZnO ensures the material's stable performance under high-temperature conditions. However, the absence of key components would lead to a decrease in high-temperature resistance and weather resistance.

[0107] As shown in Table 3, the airport concrete composite reinforcement material of the present invention has achieved a comprehensive and significant improvement in the durability of airport concrete pavement. It exhibits excellent performance in core durability indicators such as wear resistance, chloride ion penetration resistance, carbonation resistance, freeze-thaw resistance, and high temperature resistance, and can be adapted to various complex working conditions such as coastal areas, cold regions, and high temperatures. The synergistic effect of silanized-ZnO grafted modified bamboo fiber and perfluorinated elastic microsphere film-forming agent is the core of improving durability performance. The absence of either one will lead to a significant weakening of the durability performance improvement effect, which confirms the scientific nature of the raw material ratio and functional component synergistic design of the present invention.

[0108] As can be seen from the comprehensive data in Tables 1-3, the airport concrete composite reinforcement material of the present invention, through the precise proportion of each raw material and the synergistic effect of the functional components, significantly improves the surface hardness, wear resistance, and overall durability of the pavement, while precisely maintaining the pavement's anti-skid value, structural depth, and other core operational indicators. Moreover, it does not adversely affect the pavement's rebound value, compressive strength, flexural strength, and other structural mechanical properties; on the contrary, it achieves slight optimization. This solves the technical pain points of traditional repair materials that strengthen the surface but damage the original properties or have poor durability, and the strengthening effect is short-lived.

[0109] Meanwhile, the test data of Comparative Examples 1-2 fully demonstrate that the silanized-ZnO grafted modified bamboo fiber and the perfluorinated elastic microsphere synergistic film-forming agent are the core functional components of the material of this invention. The combined use of the two achieves a synergistic effect of toughening, wear resistance and protection. The absence of any component will lead to a significant decrease in the strengthening and durability of the material, further verifying the rationality and necessity of the raw material ratio and component design of this invention.

[0110] It should be noted that the airport concrete composite reinforcement material of the present invention can penetrate into the surface layer of the concrete pavement by 5-12mm through the openings and pores of the surface concrete. The products after the reaction can densely fill the 5-12mm surface functional layer, greatly improving the impermeability of the surface functional layer, making it difficult for water and harmful ions to enter, and greatly improving the durability properties such as freeze resistance and salt corrosion resistance.

[0111] The airport concrete composite reinforcement material of the present invention, after the openings and pores of the surface concrete are densely filled, the cracks are sealed, the hardness of the concrete pavement surface is improved, the wear resistance of the surface functional layer is significantly improved, the friction coefficient affecting pavement safety is stabilized, and the problems such as dust and ash generation are solved.

[0112] The airport concrete composite reinforcement material of the present invention extends the surface functional life after penetrating and strengthening the surface functional layer by 5-12mm. Compared with the currently common practice of adding 30cm of concrete to the surface to restore the pavement surface function, it can not only reduce maintenance costs, but also greatly reduce maintenance time, and has significant technical, economic and social benefits.

[0113] The present invention has been described in detail above with reference to the embodiments. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A composite reinforcement material for airport concrete, characterized in that, The raw materials for preparation, by weight, include: Industrial solid waste activated compound: 100 parts Silica sol: 70-90 parts Nano silica: 20-30 parts Magnesium fluorosilicate: 30-40 parts Organosilicon: 5-8 parts Accelerator: 2-3 parts Surfactant: 0.3-0.5 parts Silanized-ZnO grafted modified bamboo fiber: 5-8 parts, Perfluorinated elastic microsphere synergistic film-forming agent: 25-35 parts.

2. The airport concrete composite reinforcement material according to claim 1, characterized in that, The industrial solid waste active compound material is composed of cement, steel slag powder, metakaolin and composite activator.

3. The airport concrete composite reinforcement material according to claim 2, characterized in that, The mass ratio of the cement, steel slag powder, metakaolin, and composite activator is (5~7):(2~3):

1.

4. The airport concrete composite reinforcement material according to claim 2, characterized in that, The composite activator is a mixture of sodium hydroxide, sodium sulfate and triethanolamine in a mass ratio of 1:1:(1~5).

5. The airport concrete composite reinforcement material according to claim 1, characterized in that, The organosilicon is hexamethylcyclotrisiloxane or decamethylcyclopentasiloxane.

6. The airport concrete composite reinforcement material according to claim 1, characterized in that, The preparation method of the silanized-ZnO grafted modified bamboo fiber is as follows: the bamboo fiber is subjected to silanization treatment, and the silanized bamboo fiber is immersed in 5-10wt% nano ZnO dispersion to react, so that nano ZnO is covalently grafted onto the fiber surface.

7. The airport concrete composite reinforcement material according to claim 6, characterized in that, The reaction temperature is 60-80℃, and the reaction time is 2-3 hours.

8. The airport concrete composite reinforcement material according to claim 1, characterized in that, The raw materials for preparing the perfluorinated elastic microsphere synergistic film-forming agent include fluorinated modified monomers, polymeric monomers, modified functional additives, and polyurethane elastomer microspheres. The fluorinated modified monomer is perfluorooctyl ethyl acrylate, the polymeric monomer is a mixture of hydroxyethyl methacrylate, butyl acrylate, and styrene, and the modified functional additive is polyethylene glycol monomethyl ether acrylate.

9. The airport concrete composite reinforcement material according to claim 8, characterized in that, In the polymer monomers, the mass ratio of hydroxyethyl methacrylate, butyl acrylate and styrene is 1:(2~3):

1.

10. A method for preparing an airport concrete composite reinforcement material as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1: Add nano-silica and surfactant to water and disperse by ultrasonication to obtain nano-silica dispersion; S2: The silanized-ZnO grafted modified bamboo fiber is immersed in the perfluorinated elastic microsphere synergistic film-forming agent to obtain a fiber dispersion; S3: The fiber dispersion, industrial solid waste active compound, silica sol, magnesium fluorosilicate, organosilicon and coagulant are added to the nano silica dispersion and stirred to obtain the airport concrete composite reinforcement material.

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