Rapid repairing material for cement concrete pavement and construction method thereof

Abstract

The invention relates to the technical field of pavement patching materials, and particularly discloses a cement concrete pavement rapid patching material and a construction method thereof. The rapid repairing material for the cement concrete pavement comprises repairing concrete and an interface reinforcing agent in a mass ratio of 100: (8-15), the repairing concrete comprises the following raw materials: 40-55 parts of composite sulphoaluminate cement, 5-12 parts of polyurethane elastic microbeads, 3-8 parts of a composite expanding agent, 25-40 parts of graded quartz sand, 1-2 parts of a water reducing agent and 20-30 parts of water. The interface reinforcing agent is prepared from the following raw materials: 20 to 35 parts of silane modified epoxy resin, 10 to 20 parts of graphene oxide dispersion liquid, 15 to 30 parts of curing agent, 1 to 2 parts of organic tin catalyst and 30 to 50 parts of absolute ethyl alcohol. The pavement rapid repairing material provided by the invention can significantly improve the bonding force between a repairing layer and an original pavement, and effectively prevents the problem of cracking and falling of the repairing layer.

Description

Technical Field

[0001] This application relates to the field of road repair materials technology, and more specifically, it relates to a rapid repair material for cement concrete pavements and its construction method. Background Technology

[0002] Cement concrete pavement, widely used in modern road engineering, plays a crucial role in the construction of various highways, urban roads, and airport runways due to its significant advantages such as high strength, good stability, and high durability. However, with increasing traffic volume, heavier vehicle loads, and longer service life, cement concrete pavements inevitably develop various defects, such as cracks, potholes, and misalignments, severely affecting pavement performance and driving safety. Therefore, timely and effective repair of damaged cement concrete pavements has become a key aspect of ensuring normal road operation. From early simple partial excavation and repaving to the later adoption of various new repair materials and processes, cement concrete pavement repair technology has continuously developed and improved, aiming to achieve fast, efficient, and durable repair results while minimizing traffic disruption.

[0003] In existing technologies, there are many types of materials used for repairing cement concrete pavements, including ordinary cement mortar, polymer-modified cement mortar, and epoxy resin repair materials. Ordinary cement mortar has a low cost, but it has disadvantages such as high shrinkage, high brittleness, and poor adhesion to the original pavement. Polymer-modified cement mortar improves the performance of ordinary cement mortar to some extent, increasing its flexibility and adhesion, but its construction process is relatively complex, and its durability still needs improvement. Epoxy resin repair materials have advantages such as high bonding strength and fast curing speed, but they are expensive and have harsh requirements for the construction environment, which limits their large-scale application.

[0004] However, existing repair materials generally suffer from a key problem in practical applications: poor bonding strength between the repair layer and the original concrete pavement, leading to cracking and detachment. This is mainly due to differences in material composition and physical and mechanical properties between the repair material and the original concrete pavement, making it difficult to form a good bond at the interface. Furthermore, if the original pavement is not properly treated during construction, such as failing to thoroughly remove loose particles or roughen it, the bonding effect between the repair layer and the original pavement will be further weakened, thus affecting the repair quality and service life. Therefore, developing a rapid repair material for cement concrete pavements and its construction method that can effectively solve the above problems is of significant practical importance. Summary of the Invention

[0005] In order to overcome the key problems of existing cement concrete pavement repair materials, such as poor bonding force between the repair layer and the original concrete pavement, insufficient bonding strength, and easy cracking and detachment, and to effectively improve the repair quality and service life, and achieve fast, efficient and durable pavement repair effect, this application provides a cement concrete pavement rapid repair material and its construction method.

[0006] The rapid repair material and construction method for cement concrete pavement provided in this application adopt the following technical solution: Rapid repair material for cement concrete pavement, comprising repair concrete and interface reinforcing agent in a mass ratio of 100:(8-15); The repaired concrete comprises the following raw materials in parts by weight: 40-55 parts of composite sulfoaluminate cement, 5-12 parts of polyurethane elastic microspheres, 3-8 parts of composite expansion agent, 25-40 parts of graded quartz sand, 1-2 parts of water-reducing agent and 20-30 parts of water. The interface strengthening agent comprises the following raw materials in parts by weight: 20-35 parts of silane-modified epoxy resin, 10-20 parts of graphene oxide dispersion, 15-30 parts of curing agent, 1-2 parts of organotin catalyst, and 30-50 parts of anhydrous ethanol.

[0007] By adopting the above technical solution, the rapid repair material for cement concrete pavement of this application effectively solves the problem of insufficient bond strength between existing repair materials and the original concrete pavement through the synergistic effect of the repair concrete and the interface reinforcing agent. The filling effect of the nanoparticles of composite sulfoaluminate cement in the repair concrete can refine the pores, making the repair concrete structure more compact. At the same time, nano-calcium carbonate can chemically bond with the silane groups in the interface reinforcing agent, enhancing the interfacial chemical bonding force and improving the bond strength between the repair layer and the original pavement at the microscopic level. The silane-modified epoxy resin in the interface reinforcing agent retains the strong adhesion of epoxy resin and penetrates into the micropores of the original concrete surface through the silane groups, forming mechanical anchoring and further enhancing the bonding effect. This dual effect of chemical bonding and mechanical anchoring greatly improves the bond strength between the repair layer and the original concrete pavement, effectively preventing the repair layer from cracking and falling off.

[0008] In terms of crack resistance, this repair material also performs exceptionally well. The polyurethane elastic microspheres in the repair concrete absorb shrinkage stress, and their pretreated silane groups form molecular-level anchors with the epoxy resin of the interface agent, reducing the deformation difference between the repair layer and the interface, thereby lowering the risk of cracks caused by deformation incompatibility. The sheet-like structure of the graphene oxide dispersion enhances the mechanical properties of the interface layer, and the composite expansive agent, through the synergistic expansion effect of ettringite and magnesium oxide, compensates for the drying shrinkage of the repair concrete, further reducing crack formation. Graded quartz sand optimizes the skeleton structure, reduces porosity, makes the repair concrete denser, and enhances its crack resistance. The synergistic effect of these components effectively improves the crack resistance of the repair material and extends the service life of the repaired pavement.

[0009] The repair material described in this application achieves rapid and efficient road repair. The composite sulfoaluminate cement in the repair concrete exhibits rapid hardening properties, reaching a certain strength in a short time, reducing road closure time and minimizing traffic disruption. The rapid curing properties of the interface reinforcement agent also enable the repair layer to quickly form a tight bond with the original pavement, accelerating the construction progress. Simultaneously, the construction method is simple and easy to implement; the steps of base treatment, application of the interface reinforcement agent, pouring of repair concrete, and curing are convenient, further improving repair efficiency and meeting the needs of modern road engineering for rapid repair. It also overcomes the shortcomings of existing cement concrete pavement repair materials, such as poor bonding strength between the repair layer and the original concrete pavement, insufficient adhesion strength, and susceptibility to cracking and detachment.

[0010] Optionally, the composite sulfoaluminate cement is prepared using the following method: Sulfoaluminate cement and nano-calcium carbonate are mixed at a mass ratio of (9-9.5):1 and stirred in a mixer at a speed of 300-500 r / min for 20-40 min to obtain composite sulfoaluminate cement.

[0011] By adopting the above technical solution, composite sulfoaluminate cement is prepared by mixing sulfoaluminate cement and nano-calcium carbonate at a mass ratio of (9-9.5):1. The addition of nano-calcium carbonate modifies the sulfoaluminate cement; the small size and surface effect of the nanoparticles enable them to better fill the pores of cement hydration products, refine the pore structure, and improve the density of the cement paste. This increased density not only enhances the strength of the repaired concrete but also provides more favorable conditions for chemical bonding with the silane groups in the interface reinforcing agent, further improving the adhesion performance between the repair layer and the original pavement, effectively solving the problem of insufficient bond strength.

[0012] Optionally, the polyurethane elastic microspheres have a particle size of 0.2-0.8 mm, and their surface is pretreated with γ-aminopropyltriethoxysilane. The pretreatment method is as follows: immerse the polyurethane elastic microspheres in a 2%-5% (w / w) γ-aminopropyltriethoxysilane ethanol solution for 1-2 hours, filter, and then dry.

[0013] By employing the above technical solution, a suitable particle size range allows polyurethane elastic microspheres to be uniformly dispersed in the repaired concrete, fully leveraging their ability to absorb shrinkage stress. After surface pretreatment, the silane groups on the polyurethane elastic microspheres can form molecular-level anchors with the epoxy resin of the interface agent. This molecular-level connection reduces the deformation difference between the repair layer and the interface, enhancing the bonding force at the interface. When the repaired concrete shrinks or is subjected to external forces, the polyurethane elastic microspheres can alleviate stress through their own elastic deformation, thereby effectively preventing crack formation and improving the crack resistance of the repair material.

[0014] Optionally, the composite expanding agent is prepared by compounding calcite-type expanding agent and magnesium oxide expanding agent in a mass ratio of (2-3):1.

[0015] By adopting the above technical solution, the ettringite-based expansive agent can generate significant expansion in the early stages, rapidly compensating for the early shrinkage of the repaired concrete; while the magnesium oxide expansive agent can continue to expand slowly in the later stages, further compensating for the long-term shrinkage of the repaired concrete. The synergistic effect of the two allows the composite expansive agent to effectively compensate for the drying shrinkage of the repaired concrete at different stages, reducing cracks caused by shrinkage, improving the crack resistance and durability of the repair material, and solving the problem of easy cracking and detachment of existing repair materials.

[0016] Optionally, the graded quartz sand is made by mixing fine sand with a particle size of 0.15-0.6 mm and medium sand with a particle size of 0.6-1.2 mm in a mass ratio of 1:(1.5-2).

[0017] Optionally, the silane-modified epoxy resin is prepared by the following method: Bisphenol A type epoxy resin and γ-glycidoxypropyltrimethoxysilane were mixed at a mass ratio of (5-8):1 and reacted at 70-90℃ for 1.5-3h. After cooling to room temperature, silane-modified epoxy resin was obtained.

[0018] By adopting the above technical solution and undergoing the aforementioned modification treatment, the silane-modified epoxy resin retains the strong adhesion of epoxy resin while introducing silane groups. These silane groups possess permeability, allowing them to penetrate into the micropores of the original concrete surface. They react chemically with hydroxyl and other groups in the concrete, forming chemical bonds and simultaneously creating mechanical anchorage within the micropores. This significantly enhances the bond strength between the interface reinforcement agent and the original concrete pavement. This dual bonding mechanism effectively solves the problem of poor adhesion between existing repair materials and the original pavement, improving repair quality.

[0019] Optionally, the concentration of the graphene oxide dispersion is 0.5-2 g / L.

[0020] Optionally, the curing agent comprises a polyamide curing agent and butyl acrylate in a mass ratio of (4-6):1.

[0021] By adopting the above technical solution, the polyamide curing agent can chemically react with the epoxy resin, enabling the interface reinforcing agent to cure rapidly and form an interface layer with a certain strength. The addition of butyl acrylate imparts a certain degree of flexibility to the interface layer, which can alleviate stress concentration caused by factors such as temperature changes. This composite curing agent not only ensures the rapid curing of the interface reinforcing agent but also improves the flexibility of the interface layer, allowing it to better adapt to the deformation of the repair layer and the original pavement, enhancing the adhesion between the repair layer and the original pavement, and solving the problem of easy cracking and detachment of existing repair materials.

[0022] Optionally, the organotin catalyst is dibutyltin dilaurate.

[0023] By adopting the above technical solution, the organotin catalyst is dibutyltin dilaurate. Dibutyltin dilaurate can effectively catalyze the reaction between silane-modified epoxy resin and the curing agent, accelerating the curing speed of the interface reinforcement agent and improving construction efficiency. Simultaneously, it ensures the full progress of the reaction, enabling the interface reinforcement agent to form a stable interface layer, enhancing the bond strength between the interface layer and the original concrete pavement and the repair concrete, helping to solve the problem of insufficient bond strength and ensuring repair quality.

[0024] Secondly, this application provides a construction method for a rapid repair material for cement concrete pavement, employing the following technical solution: The construction method for rapid repair materials for cement concrete pavements, using the aforementioned rapid repair materials, includes the following steps: S1. Base treatment: Remove loose concrete from the damaged area of ​​the road surface, clean the surface impurities with a wire brush, and blow away the dust with an air compressor to ensure that the base surface is dry. S2. Repair treatment: Apply the interface reinforcement agent evenly to the base surface and let it stand for 5-15 minutes; then pour the repair concrete on the base surface coated with the interface reinforcement agent, vibrate it to make it dense, and smooth the surface. S3. Curing: Cover the repair layer with geotextile, maintain the ambient temperature at 15-30℃, and open the road to traffic after 2-5 hours of curing.

[0025] The above-described method involves removing loose concrete from the damaged area of ​​the road surface, cleaning surface impurities with a wire brush, and blowing away dust with an air compressor to ensure the base surface is dry, providing favorable conditions for the application of the interface reinforcement agent. After applying the interface reinforcement agent, allow it to stand for 5-15 minutes to allow it to fully penetrate the original concrete surface. Then, pour the repair concrete onto the base layer coated with the interface reinforcement agent, vibrate it to compact it, and smooth the surface to ensure a tight bond between the repair concrete and the base layer. In the curing step, cover the repair layer with geotextile, maintain an ambient temperature of 15-30℃, and allow it to cure for 2-5 hours before reopening to traffic. This curing method allows the repair material to reach a certain strength in a shorter time while minimizing the impact of curing time on traffic, achieving rapid and efficient road repair and solving the problems of long construction cycles and significant traffic disruption associated with existing repair technologies.

[0026] In summary, this application has the following beneficial effects: 1. This application designs a formula and synergistic mechanism for repair concrete and interface reinforcing agents, effectively solving the problem of insufficient bond strength between existing repair materials and the original concrete pavement. The nano-calcium carbonate composite sulfoaluminate cement in the repair concrete, through the filling effect of nanoparticles, makes the structure more compact and chemically bonds with the silane groups in the interface reinforcing agent; the silane-modified epoxy resin in the interface reinforcing agent, with its silane groups penetrating into the micropores of the original concrete surface to form mechanical anchoring. This dual strengthening effect of chemical and mechanical processes significantly improves the adhesion between the repair layer and the original pavement, effectively preventing cracking and detachment of the repair layer.

[0027] 2. This application addresses the problem of cracking in repair materials by innovatively incorporating polyurethane elastic microspheres, a composite expansive agent, and graded silica sand into the repair concrete. The polyurethane elastic microspheres absorb shrinkage stress, and their pretreated silane groups form molecular-level anchors with the interface agent, reducing deformation differences. The composite expansive agent effectively compensates for drying shrinkage through the synergistic expansion of ettringite and magnesium oxide. The graded silica sand optimizes the skeleton structure and reduces porosity. The synergistic effect of these three components significantly improves the crack resistance of the repair material and extends the service life of the repaired pavement.

[0028] 3. The construction method described in this application features close coordination between all stages, from base treatment to maintenance, achieving rapid and efficient road repair. Base treatment ensures good adhesion of the interface reinforcement agent; after applying the interface reinforcement agent, it is allowed to stand to fully penetrate; the repair concrete is poured and vibrated to ensure tight bonding; finally, a specific maintenance method is used to allow the repair material to reach the strength required for opening to traffic in a short period. This series of measures effectively overcomes the problems of long construction cycles and significant traffic disruption associated with existing repair technologies, while also solving the technical bottlenecks of poor bonding strength between the repair layer and the original concrete pavement, and easy cracking and detachment. Detailed Implementation

[0029] The present application will be further described in detail below with reference to the embodiments.

[0030] In the construction method described in this application, a cement concrete panel is used to simulate the road surface to be repaired. The cement concrete panel has a design strength grade of C40, a thickness of 250mm, and a surface depth of 70-80mm with a single area of ​​less than 0.1m. 2 Irregular pits (without penetrating cracks, and no settlement or voids in the underlying structure); the surface moisture content of the cement concrete panel is ≤8% (tested using a portable moisture content meter), and the compressive strength of the cement concrete panel is ≥30MPa (tested using the rebound method).

[0031] Example Example 1 Rapid repair material for cement concrete pavement, comprising repair concrete and interface reinforcement in a mass ratio of 100:8.

[0032] The raw material composition and dosage of the repair concrete are shown in Table 1. Among them, the graded quartz sand is made by mixing fine sand with a particle size of 0.15-0.6mm and medium sand with a particle size of 0.6-1.2mm at a mass ratio of 1:1.5, and the mud content of both fine sand and medium sand is ≤0.5%; the composite expansive agent is made by compounding calcite-type expansive agent and magnesium oxide expansive agent at a mass ratio of 2:1; the water-reducing agent is a polycarboxylate-based water-reducing agent.

[0033] Repair concrete is prepared by the following method: (1) Weigh sulfoaluminate cement and nano calcium carbonate at a mass ratio of 9:1, add them to a mixer with a speed of 300 r / min, and stir for 40 min until they are evenly mixed to obtain composite sulfoaluminate cement; select polyurethane elastic microspheres with a particle size of 0.2 mm, soak them in a 2% mass fraction γ-aminopropyltriethoxysilane ethanol solution for 1 h, filter them, and dry them in a 60℃ oven until they are constant weight for later use; weigh calcite-type expansion agent and magnesium oxide expansion agent at a mass ratio of 2:1, mix and stir for 5 min until they are evenly mixed to obtain composite expansion agent.

[0034] (2) Add composite sulfoaluminate cement, pretreated polyurethane elastic microspheres, composite expansion agent and graded quartz sand to the forced mixer in sequence, and dry mix for 2 minutes to obtain the mixture; then add water-reducing agent and water to the mixture, adjust the mixer speed to 400 r / min, and mix for 3 minutes to obtain the repair concrete.

[0035] The raw material composition and dosage of the interface strengthening agent are shown in Table 1. The concentration of the graphene oxide dispersion is 2 g / L. The curing agent includes polyamide curing agent and butyl acrylate in a mass ratio of 4:1. The organotin catalyst is dibutyltin dilaurate.

[0036] The interface strengthening agent was prepared by the following method: (1) Weigh bisphenol A type epoxy resin and γ-glycidoxypropyltrimethoxysilane at a mass ratio of 5:1, add them to a reaction vessel equipped with a stirring device, heat to 70°C, keep warm and stir for 3 hours, and cool to room temperature to obtain silane modified epoxy resin; weigh polyamide curing agent and butyl acrylate at a mass ratio of 4:1, mix and stir for 10 minutes until uniform to obtain curing agent.

[0037] (2) Add anhydrous ethanol to the mixing tank and start stirring at 200 r / min. Then add silane-modified epoxy resin and graphene oxide dispersion in sequence and stir for 15 min until the liquid is evenly mixed. Continue to add curing agent and dibutyltin dilaurate, adjust the speed to 300 r / min and stir for 20 min to obtain the interface strengthening agent.

[0038] The construction method for rapid repair materials for cement concrete pavements, using the repair concrete and interface reinforcing agent prepared above, includes the following steps: S1. Base treatment: Remove loose concrete from the damaged area of ​​the road surface, clean the surface impurities with a wire brush, blow away the dust with an air compressor, ensure that there are no visible impurities at the bottom and side walls of the pit, and ensure that the base surface is dry. S2. Repair treatment: Weigh the repair concrete and interface reinforcement agent according to the mass ratio of 100:8. Apply the interface reinforcement agent evenly to the base surface. The number of applications should be adjusted according to the amount of interface reinforcement agent. The interval between each application should be 2 minutes. After application, let it stand for 5 minutes. Then pour the repair concrete onto the base surface coated with interface reinforcement agent, vibrate it to make it dense, and smooth the surface. S3. Curing: Cover the repair layer with geotextile, maintain the ambient temperature at 15℃, and open the road to traffic after 5 hours of curing.

[0039] Example 2 Rapid repair material for cement concrete pavement, comprising repair concrete and interface reinforcement in a mass ratio of 100:12.

[0040] The raw material composition and dosage of the repair concrete are shown in Table 1. Among them, the graded quartz sand is a mixture of fine sand with a particle size of 0.15-0.6mm and medium sand with a particle size of 0.6-1.2mm at a mass ratio of 1:1.8, and the mud content of both fine sand and medium sand is ≤0.5%; the composite expansive agent is a compound of calcite-type expansive agent and magnesium oxide expansive agent at a mass ratio of 2.5:1; and the water-reducing agent is a polycarboxylate-based water-reducing agent.

[0041] Repair concrete is prepared by the following method: (1) Weigh sulfoaluminate cement and nano calcium carbonate at a mass ratio of 9.25:1, add them to a mixer with a speed of 400 r / min, and stir for 30 min until they are evenly mixed to obtain composite sulfoaluminate cement; select polyurethane elastic microspheres with a particle size of 0.5 mm, soak them in a 3.5% mass fraction γ-aminopropyltriethoxysilane ethanol solution for 1.5 h, filter them, and dry them in a 60℃ oven until they are constant weight for later use; weigh calcite-type expansion agent and magnesium oxide expansion agent at a mass ratio of 2.5:1, mix and stir for 5 min until they are evenly mixed to obtain composite expansion agent.

[0042] (2) Add composite sulfoaluminate cement, pretreated polyurethane elastic microspheres, composite expansion agent and graded quartz sand to the forced mixer in sequence, and dry mix for 2 minutes to obtain the mixture; then add water-reducing agent and water to the mixture, adjust the mixer speed to 400 r / min, and mix for 3 minutes to obtain the repair concrete.

[0043] The raw material composition and dosage of the interface strengthening agent are shown in Table 1. The concentration of the graphene oxide dispersion is 1 g / L. The curing agent includes polyamide curing agent and butyl acrylate in a mass ratio of 5:1. The organotin catalyst is dibutyltin dilaurate.

[0044] The interface strengthening agent was prepared by the following method: (1) Weigh bisphenol A type epoxy resin and γ-glycidoxypropyltrimethoxysilane at a mass ratio of 6.5:1, add them to a reaction vessel equipped with a stirring device, heat to 80°C, keep warm and stir for 2 hours, and cool to room temperature to obtain silane modified epoxy resin; weigh polyamide curing agent and butyl acrylate at a mass ratio of 5:1, mix and stir for 10 minutes until uniform to obtain curing agent.

[0045] (2) Add anhydrous ethanol to the mixing tank and start stirring at 200 r / min. Then add silane-modified epoxy resin and graphene oxide dispersion in sequence and stir for 15 min until the liquid is evenly mixed. Continue to add curing agent and dibutyltin dilaurate, adjust the speed to 300 r / min and stir for 20 min to obtain the interface strengthening agent.

[0046] The construction method for rapid repair materials for cement concrete pavements, using the repair concrete and interface reinforcing agent prepared above, includes the following steps: S1. Base treatment: Remove loose concrete from the damaged area of ​​the road surface, clean the surface impurities with a wire brush, blow away the dust with an air compressor, ensure that there are no visible impurities at the bottom and side walls of the pit, and ensure that the base surface is dry. S2. Repair treatment: Weigh the repair concrete and interface reinforcement agent according to the mass ratio of 100:12. Apply the interface reinforcement agent evenly to the base surface. The number of applications should be adjusted according to the amount of interface reinforcement agent. The interval between each application should be 2 minutes. After application, let it stand for 10 minutes. Then pour the repair concrete onto the base surface coated with interface reinforcement agent, vibrate it to make it dense, and smooth the surface. S3. Curing: Cover the repair layer with geotextile, maintain the ambient temperature at 22℃, and open the road to traffic after 3 hours of curing.

[0047] Example 3 Rapid repair material for cement concrete pavement, comprising repair concrete and interface reinforcement in a mass ratio of 100:15.

[0048] The raw material composition and dosage of the repair concrete are shown in Table 1. Among them, the graded quartz sand is made by mixing fine sand with a particle size of 0.15-0.6mm and medium sand with a particle size of 0.6-1.2mm at a mass ratio of 1:2, and the mud content of both fine sand and medium sand is ≤0.5%; the composite expansive agent is made by compounding ettringite-type expansive agent and magnesium oxide expansive agent at a mass ratio of 3:1; the water-reducing agent is a polycarboxylate-based water-reducing agent.

[0049] Repair concrete is prepared by the following method: (1) Weigh sulfoaluminate cement and nano calcium carbonate at a mass ratio of 9.5:1, add them to a mixer with a speed of 500 r / min, and stir for 20 min until they are mixed evenly to obtain composite sulfoaluminate cement; select polyurethane elastic microspheres with a particle size of 0.8 mm, soak them in a 5% mass fraction γ-aminopropyltriethoxysilane ethanol solution for 2 h, filter them, and dry them in a 60℃ oven until they reach constant weight for later use; weigh calcite-type expansion agent and magnesium oxide expansion agent at a mass ratio of 3:1, mix and stir for 5 min until they are uniform to obtain composite expansion agent.

[0050] (2) Add composite sulfoaluminate cement, pretreated polyurethane elastic microspheres, composite expansion agent and graded quartz sand to the forced mixer in sequence, and dry mix for 2 minutes to obtain the mixture; then add water-reducing agent and water to the mixture, adjust the mixer speed to 400 r / min, and mix for 3 minutes to obtain the repair concrete.

[0051] The raw material composition and dosage of the interface strengthening agent are shown in Table 1. The concentration of the graphene oxide dispersion is 0.5 g / L. The curing agent includes polyamide curing agent and butyl acrylate in a mass ratio of 6:1. The organotin catalyst is dibutyltin dilaurate.

[0052] The interface strengthening agent was prepared by the following method: (1) Weigh bisphenol A type epoxy resin and γ-glycidoxypropyltrimethoxysilane at a mass ratio of 8:1, add them to a reaction vessel equipped with a stirring device, heat to 90°C, keep warm and stir for 1.5h, and cool to room temperature to obtain silane modified epoxy resin; weigh polyamide curing agent and butyl acrylate at a mass ratio of 6:1, mix and stir for 10min until uniform to obtain curing agent.

[0053] (2) Add anhydrous ethanol to the mixing tank and start stirring at 200 r / min. Then add silane-modified epoxy resin and graphene oxide dispersion in sequence and stir for 15 min until the liquid is evenly mixed. Continue to add curing agent and dibutyltin dilaurate, adjust the speed to 300 r / min and stir for 20 min to obtain the interface strengthening agent.

[0054] The construction method for rapid repair materials for cement concrete pavements, using the repair concrete and interface reinforcing agent prepared above, includes the following steps: S1. Base treatment: Remove loose concrete from the damaged area of ​​the road surface, clean the surface impurities with a wire brush, blow away the dust with an air compressor, ensure that there are no visible impurities at the bottom and side walls of the pit, and ensure that the base surface is dry. S2. Repair treatment: Weigh the repair concrete and interface reinforcement agent according to the mass ratio of 100:15. Apply the interface reinforcement agent evenly to the base surface. The number of applications should be adjusted according to the amount of interface reinforcement agent. The interval between each application should be 2 minutes. After application, let it stand for 15 minutes. Then pour the repair concrete onto the base surface coated with interface reinforcement agent, vibrate it to make it dense, and smooth the surface. S3. Curing: Cover the repair layer with geotextile, maintain the ambient temperature at 30℃, and open the road to traffic after 2 hours of curing.

[0055] Table 1. Raw material composition and dosage (kg) of the repaired concrete and interface strengthening agent in Examples 1-3.

[0056] Example 4 The rapid repair material for cement concrete pavement differs from that in Example 1 in that it repairs a different type of concrete. Specifically, the components and preparation method of the repair concrete in this example are as follows: The raw material dosage for repairing concrete is the same as in Example 1. The graded quartz sand is a mixture of fine sand with a particle size of 0.15-0.6 mm and medium sand with a particle size of 0.6-1.2 mm at a mass ratio of 1:1.5, and the mud content of both fine and medium sand is ≤0.5%. The composite expansive agent is a mixture of ettringite-type expansive agent and magnesium oxide expansive agent at a mass ratio of 2:1. The water-reducing agent is a polycarboxylate-based water-reducing agent.

[0057] Repair concrete is prepared by the following method: (1) Weigh sulfoaluminate cement and nano calcium carbonate at a mass ratio of 5:1, add them to a mixer with a speed of 300 r / min, and stir for 40 min until they are evenly mixed to obtain composite sulfoaluminate cement; select polyurethane elastic microspheres with a particle size of 0.2 mm, soak them in a 2% mass fraction γ-aminopropyltriethoxysilane ethanol solution for 1 h, filter them, and dry them in a 60℃ oven until they are constant weight for later use; weigh calcite-type expansion agent and magnesium oxide expansion agent at a mass ratio of 2:1, mix and stir for 5 min until they are evenly mixed to obtain composite expansion agent.

[0058] (2) Add composite sulfoaluminate cement, pretreated polyurethane elastic microspheres, composite expansion agent and graded quartz sand to the forced mixer in sequence, and dry mix for 2 minutes to obtain the mixture; then add water-reducing agent and water to the mixture, adjust the mixer speed to 400 r / min, and mix for 3 minutes to obtain the repair concrete.

[0059] Example 5 The rapid repair material for cement concrete pavement differs from that in Example 1 in that it repairs different types of concrete. Specifically, the polyurethane elastic microspheres in the concrete repair component of this example have not been pretreated with γ-aminopropyltriethoxysilane.

[0060] Example 6 The difference between this rapid repair material for cement concrete pavement and Example 1 lies in the interface reinforcing agent. Specifically, the curing agent in the interface reinforcing agent of this example is a separate polyamide curing agent.

[0061] Comparative Example Comparative Example 1 The difference between this rapid repair material for cement concrete pavement and Example 1 is that commercially available VAE emulsion-type interface agent is used instead of its interface reinforcing agent in this comparative example.

[0062] Comparative Example 2 The difference between the rapid repair material for cement concrete pavement and Example 1 is that the repair concrete in this comparative example uses an equal amount of silicate cement instead of composite sulfoaluminate cement.

[0063] Comparative Example 3 The difference between the rapid repair material for cement concrete pavement and Example 1 is that polyurethane elastic microspheres were not added to the repair concrete in this comparative example, and the difference was made up using composite sulfoaluminate cement.

[0064] Comparative Example 4 The difference between the rapid repair material for cement concrete pavement and Example 1 is that the interface reinforcing agent in this comparative example uses an equal amount of unmodified epoxy resin instead of silane-modified epoxy resin.

[0065] Performance testing Test samples: cement concrete panels repaired in Examples 1-6 and Comparative Examples 1-4.

[0066] 1. Interfacial tensile bond strength testing The tensile bond strength (7 days after repair) between the repaired cement concrete panel and the repair layer was tested according to the method specified in JC / T907-2002 "Concrete Interface Treatment Agent".

[0067] 2. Crack resistance test The repaired cement concrete panel sample was placed in a freeze-thaw chamber for 220 freeze-thaw cycles, and the presence of cracks between the base layer and the repair layer was recorded. The sample was then made into a beam specimen and subjected to a three-point bending test using a universal testing machine. The load was applied until cracks appeared in the sample, and the magnitude of the load at the time of cracking was recorded to determine the crack resistance.

[0068] 3. Durability and resistance to shedding test The repaired cement concrete panel sample was placed in a freeze-thaw chamber for 220 freeze-thaw cycles. Then, a road material accelerated loading tester (MLS-66) was used to simulate the effect of heavy vehicle tires rolling over it. After the tester was started to simulate rolling for 10,000 cycles, it was observed whether the interface between the repair layer and the original concrete was separated.

[0069] The test results are shown in Table 2.

[0070] Table 2 Test Results

[0071] As can be seen from Table 2, the repaired concrete and interface reinforcing agent in Examples 1-3 of this application have a good synergistic effect and high tensile bond strength, all reaching above 2.6 MPa, which is significantly higher than that of the comparative example; and have a high cracking load, and no cracks or spalling occurred in the experiment, indicating that the repair material provided by this application can effectively solve the problem of insufficient bond strength between the repair layer and the base layer, and easy cracking and detachment.

[0072] In Example 4, the high proportion of nano-calcium carbonate in the composite sulfoaluminate cement led to particle agglomeration, resulting in a decrease in density and a strength reduction to 2.13 MPa. In Example 5, the polyurethane microspheres were not pretreated, and in Example 6, a single polyamide curing agent was used. Both examples showed slightly lower strengths than Example 1 due to insufficient interfacial bonding or stress coordination.

[0073] Comparative Example 1 used a commercially available VAE emulsion interface agent, without the penetration anchoring of silane-modified epoxy resin and the reinforcement of graphene oxide, relying solely on physical bonding, resulting in the lowest strength (0.96 MPa). Due to the extremely low bonding strength, cracks easily initiated along the interface, causing a sharp drop in load. Comparative Example 2 showed low overall strength and weak crack resistance of the silicate cement repair layer (11.6 kN). Comparative Example 3 lacked polyurethane microspheres, failing to alleviate shrinkage stress, and its cracking load was only 15.8 kN.

[0074] Comparative Example 2 used silicate cement instead of composite sulfoaluminate cement. Without the filling and chemical bonding sites of nano-calcium carbonate, the density was poor and the strength was only 1.23 MPa. After freeze-thaw, the interface deteriorated further, and the repair layer became unstable and fell off after compaction.

[0075] Comparative Example 4 used unmodified epoxy resin, which lacked the ability to penetrate silane groups, resulting in insufficient mechanical anchoring and a strength of 1.17 MPa. Comparative Example 3 did not add polyurethane microspheres, which did not directly affect the bonding, but the interface deformation coordination was poor, and the strength was slightly higher (1.52 MPa) but still far lower than that of the examples.

[0076] In summary, the experimental data fully demonstrates that this application, through the synergistic effect of composite sulfoaluminate cement, modified epoxy interface agent and elastic microspheres, and composite expansion agent, effectively solves the technical problems of poor bonding strength, insufficient adhesion strength, and easy cracking and detachment between the repair layer and the original concrete. The data from the embodiments are all superior to those from the comparative examples, fully verifying the effectiveness of the technical solution of this application.

[0077] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A rapid repair material for cement concrete pavement, characterized in that, Includes repair concrete and interface reinforcement with a mass ratio of 100:(8-15); The repaired concrete comprises the following raw materials in parts by weight: 40-55 parts of composite sulfoaluminate cement, 5-12 parts of polyurethane elastic microspheres, 3-8 parts of composite expansion agent, 25-40 parts of graded quartz sand, 1-2 parts of water-reducing agent and 20-30 parts of water. The interface strengthening agent comprises the following raw materials in parts by weight: 20-35 parts of silane-modified epoxy resin, 10-20 parts of graphene oxide dispersion, 15-30 parts of curing agent, 1-2 parts of organotin catalyst, and 30-50 parts of anhydrous ethanol.

2. The rapid repair material for cement concrete pavement according to claim 1, characterized in that, The composite sulfoaluminate cement is prepared by the following method: Sulfoaluminate cement and nano-calcium carbonate are mixed at a mass ratio of (9-9.5):1 and stirred in a mixer at a speed of 300-500 r / min for 20-40 min to obtain composite sulfoaluminate cement.

3. The rapid repair material for cement concrete pavement according to claim 1, characterized in that, The polyurethane elastic microspheres have a particle size of 0.2-0.8 mm, and their surface is pretreated with γ-aminopropyltriethoxysilane. The pretreatment method is as follows: the polyurethane elastic microspheres are immersed in a 2%-5% (w / w) γ-aminopropyltriethoxysilane ethanol solution for 1-2 hours, filtered, and then dried.

4. The rapid repair material for cement concrete pavement according to claim 1, characterized in that: The composite expanding agent is composed of calcite-type expanding agent and magnesium oxide expanding agent in a mass ratio of (2-3):

1.

5. The rapid repair material for cement concrete pavement according to claim 1, characterized in that: The graded quartz sand is made by mixing fine sand with a particle size of 0.15-0.6 mm and medium sand with a particle size of 0.6-1.2 mm in a mass ratio of 1:(1.5-2).

6. The rapid repair material for cement concrete pavement according to claim 1, characterized in that, The silane-modified epoxy resin was prepared using the following method: Bisphenol A type epoxy resin and γ-glycidoxypropyltrimethoxysilane were mixed at a mass ratio of (5-8):1 and reacted at 70-90℃ for 1.5-3h. After cooling to room temperature, silane-modified epoxy resin was obtained.

7. The rapid repair material for cement concrete pavement according to claim 1, characterized in that: The concentration of the graphene oxide dispersion is 0.5-2 g / L.

8. The rapid repair material for cement concrete pavement according to claim 1, characterized in that: The curing agent comprises a polyamide curing agent and butyl acrylate in a mass ratio of (4-6):

1.

9. The rapid repair material for cement concrete pavement according to claim 1, characterized in that: The organotin catalyst is dibutyltin dilaurate.

10. A construction method for a rapid repair material for cement concrete pavement, characterized in that, The application of the rapid repair material for cement concrete pavement according to any one of claims 1-9 includes the following steps: S1. Base treatment: Remove loose concrete from the damaged area of ​​the road surface, clean the surface impurities with a wire brush, and blow away the dust with an air compressor to ensure that the base surface is dry. S2. Repair treatment: Apply the interface reinforcement agent evenly to the base surface and let it stand for 5-15 minutes; then pour the repair concrete on the base surface coated with the interface reinforcement agent, vibrate it to make it dense, and smooth the surface. S3. Curing: Cover the repair layer with geotextile, maintain the ambient temperature at 15-30℃, and open the road to traffic after 2-5 hours of curing.

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