Airfield pavement micro-crack disease repair method based on multi-proportion capillary crystalline material

Abstract

The invention discloses an airfield pavement micro-crack disease repairing method based on a multi-proportion capillary crystalline material. The airfield pavement micro-crack disease repairing method comprises material composition and proportion design and a construction technological process. The material composition and proportion design comprises basic components and a multi-proportion scheme; the basic component comprises active Portland cement, nanoscale silica fume, redispersible latex powder, capillary crystalline master batch, a water reducing agent and a fiber reinforcing agent; the active Portland cement provides early strength and a hydration reaction basis; pores are filled with the nanoscale silica fume, so that the compactness and the impermeability are improved; the flexibility and temperature stress resistance of the material are enhanced through the redispersible latex powder; and the active ingredients of calcium silicate and calcium aluminate contained in the capillary crystalline master batch encounter water to generate crystals to fill cracks. Self-repairing of the pavement is achieved, the service life of the pavement is prolonged through the self-repairing function, and follow-up maintenance and repairing work is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of rapid repair and durability improvement of airport concrete pavement, and specifically to a method for repairing micro-cracks on airport pavement based on multi-proportion infiltration crystallization materials. Background Art

[0002] Airport concrete pavements, also known as airport cement concrete pavements or rigid pavements, are the primary structural form in critical areas such as airport runways, taxiways, and aprons. Using cement concrete as its surface material, it possesses high strength, durability, and stability, capable of withstanding the massive loads and repeated impacts of aircraft takeoffs and landings. Airport concrete pavements not only provide a solid landing platform for aircraft, ensuring efficient airport operations, but also, through their excellent durability and adaptability, support the long-term development of airports and their ability to withstand various extreme climatic conditions. Therefore, the design and construction of concrete pavements are crucial in airport construction and maintenance.

[0003] However, when existing technologies are actually used, airport pavements are subjected to long-term impacts from aircraft takeoffs and landings, heavy-load rolling, and extreme climates, which can easily lead to surface microcracks (width ≤ 3mm), resulting in water seepage, decreased structural strength, and the risk of FOD (foreign object damage); the defects of traditional repair methods include: long repair cycles: the pavement needs to be closed for large-scale chiseling and cast-in-place concrete, affecting airport operations; poor material adaptability: ordinary repair materials have insufficient bonding strength with the original concrete, making them prone to secondary cracking; insufficient durability: they cannot withstand long-term environmental erosion such as freeze-thaw cycles and chemical corrosion. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for repairing micro-cracks on airport pavements based on multi-ratio infiltration crystallization materials, so as to solve the problem raised in the above background technology that airport pavements are subjected to the impact of aircraft takeoff and landing, heavy-load rolling and extreme climate for a long time, which is prone to surface micro-cracks (width ≤ 3mm), leading to water seepage, decreased structural strength and FOD (foreign object damage) risks; the defects of traditional repair methods include: long repair cycle: the pavement needs to be closed for large-scale chiseling and cast-in-place concrete, affecting airport operations; poor material adaptability: ordinary repair materials have insufficient bonding strength with the original concrete and are prone to secondary cracking; insufficient durability: unable to resist long-term environmental erosion problems such as freeze-thaw cycles and chemical corrosion.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: including material composition and proportion design and construction process flow;

[0006] The material composition and proportion design includes basic components and multiple proportion schemes;

[0007] The basic components include active Portland cement, nano-scale silica fume, redispersible latex powder, infiltration crystallization masterbatch, water reducer and fiber reinforcement; the active Portland cement provides early strength and hydration reaction foundation; the nano-scale silica fume fills pores to improve density and impermeability; the redispersible latex powder enhances material flexibility and resistance to temperature stress; the active ingredients of calcium silicate and calcium aluminate contained in the infiltration crystallization masterbatch form crystals when exposed to water to fill cracks; the water reducer reduces the water-cement ratio and improves workability; and the polypropylene fiber and basalt fiber in the fiber reinforcement inhibit crack propagation.

[0008] The multi-ratio scheme includes surface penetration type and deep filling type;

[0009] The surface penetration type has a water-cement ratio of 0.25-0.30, and the penetration crystallization masterbatch accounts for 15%. The surface penetration type is a high-fluidity slurry that penetrates into the cracks through capillary action and forms a dense crystallization layer after solidification.

[0010] The water-cement ratio of the deep filling type is 0.30-0.35, the infiltration crystallization masterbatch accounts for 10%, and 5% expansion agent is added. The deep filling type is a low-fluidity slurry. The expansion agent is added to compensate for shrinkage to ensure that the crack filling density is ≥98%;

[0011] The construction process includes crack pretreatment, material preparation and construction, and curing and maintenance;

[0012] The crack pretreatment includes surface cleaning and interface treatment;

[0013] The material preparation and application include surface penetration type construction and deep filling type construction;

[0014] The solidification and curing include initial solidification and long-term curing.

[0015] Preferably, the active silicate cement accounts for 40%-50% of the basic components, the nano-scale silica fume accounts for 15%-20% of the basic components, the redispersible latex powder accounts for 5%-10% of the basic components, the osmotic crystallization masterbatch accounts for 10%-15% of the basic components, the water reducer accounts for 1%-2% of the basic components, and the fiber reinforcement accounts for 2%-5% of the basic components.

[0016] Preferably, the surface penetration type construction includes adding the material and water into a forced mixer according to the ratio, stirring for 3 minutes to a uniform slurry, and spraying with an airless sprayer along both sides of the crack extending 10 cm, with a spraying amount of 0.8-1.2 kg / m 2 , cover with polyethylene film immediately after spraying to prevent moisture evaporation.

[0017] Preferably, the deep filling construction includes stirring and then standing for 5 minutes, injecting the slurry into the cracks to return to the surface of the slurry, and then smoothing the surface and covering it with a waterproof cloth for curing for 30 minutes.

[0018] Preferably, the initial curing includes surface hardening 1 hour after construction, with a compressive strength of ≥5MPa, and a compressive strength of ≥20MPa after 24 hours, meeting the requirements for light load traffic.

[0019] Preferably, the long-term curing includes opening to traffic after 72 hours, the material strength reaches more than 85% of the original concrete, and water is sprayed daily during the curing period for moisture retention, which lasts for 7 days.

[0020] The phased work is carried out in the following steps:

[0021] S1, AGV small road surface automatic inspection S1 stage: In this stage, the small vehicle used for pavement crack disease identification automatically cruises on the airport pavement, and then enters the S2 stage;

[0022] S2, image recognition of defects: In this stage, the camera on the AGV begins to identify road surface defects and then enters the S3 stage;

[0023] S3: Determine whether cracks exist. In this stage, the industrial computer determines whether cracks exist on the pavement based on the pavement disease image fed back by the camera. If the judgment result is "yes", the process proceeds to S6; otherwise, the process proceeds to S4.

[0024] S4, the S4 stage of determining whether the inspection is complete: In this stage, the industrial computer determines whether the inspection task has reached the completion point. If the judgment result is "yes", it enters the S5 stage, otherwise it returns to the entrance of the S2 stage;

[0025] S5, the end of the inspection: In this stage, the industrial computer controls the AGV to return to the starting point, automatically shuts down, and waits for user instructions. The inspection is completed;

[0026] S6, RTK point positioning S6 stage: In this stage, the industrial computer controls RTK to obtain GPS point coordinates and upload them to the cloud, and then enters the S7 stage;

[0027] S7, high-pressure air cleaning of the road surface: In this stage, the industrial computer controls the air pump to clean the loose gravel on the road surface, and then enters the S8 stage;

[0028] S8, Linear laser scanning for crack length, width, and depth: In this stage, the industrial computer controls the linear laser scanning to obtain surface topography data within the crack range. Then, in S9, the amount of material required for crack repair is calculated and uploaded to the cloud.

[0029] S9, calculating the repair area of ​​the crack area: In this stage, the industrial computer obtains the surface morphology data of the pavement within the crack range based on linear laser scanning, calculates the amount of materials required for crack repair and the construction range, and then enters the S10 stage;

[0030] S10, determining whether the crack is a deep crack: In this stage, the industrial computer determines whether the crack is a deep crack based on the inspection data. If the judgment result is "yes", it enters the S11 stage, otherwise it enters the S13 stage;

[0031] S11, sending GPS coordinates to the deep repair material AGV repair vehicle S11 stage: In this stage, the industrial computer sends the repair instructions to the deep repair material AGV repair vehicle, and then enters the S12 stage;

[0032] S12, S12 stage of spraying deep repair materials: In this stage, the deep repair material AGV repair vehicle arrives at the repair site according to the GPS coordinates, and then the robot arm with a camera controls the nozzle to inject deep repair materials into the deep cracks. At the same time, the same type of deep repair material is sprayed within a range of 10 cm on both sides of the deep cracks. After reaching the expected amount, it automatically returns to the starting point, and then the system automatically returns to the S1 stage;

[0033] S13, sending GPS coordinates to the deep repair material AGV repair vehicle S13 stage: In this stage, the industrial computer sends the repair instructions to the shallow repair material AGV repair vehicle, and then enters the S14 stage;

[0034] S14, S14 stage of spraying shallow repair materials: In this stage, the shallow repair material AGV repair vehicle arrives at the repair site according to the GPS coordinates, and then the robotic arm with a camera controls the nozzle to inject deep repair materials into the shallow cracks. At the same time, the same type of shallow repair materials are sprayed within 20 cm on both sides of the deep cracks. After reaching the expected amount, it automatically returns to the starting point, and then the system automatically returns to the S1 stage.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention improves the operational efficiency of the airport, shortens the repair time, and reduces flight delays: Traditional repair methods require the closure of the pavement for large-scale construction, which seriously affects the takeoff and landing of flights. The method of the present invention has a short construction period, and the time that a single repair affects the takeoff and landing of flights can be shortened to less than 1 / 3 of the traditional method, or even shorter, thereby significantly reducing flight delays and improving the operational efficiency of the airport. The repaired pavement can meet the requirements for light-load traffic in a short period of time and can be fully open to traffic after 24 hours. This means that the airport pavement can resume its normal function more quickly, improve the utilization rate of the pavement, and bring more economic benefits to the airport;

[0037] The present invention also has mechanical properties: the repair material has high compressive strength and flexural strength, and can withstand the huge loads and repeated impacts during aircraft takeoff and landing, ensuring the stability and safety of the pavement. The repair material has excellent impermeability and can effectively prevent moisture and chemicals from penetrating into the interior of the pavement, thereby extending the service life of the pavement. At the same time, its freeze-thaw resistance is also significantly improved, and it can maintain the stability and durability of the pavement under extreme climatic conditions. The active ingredients in the repair material form crystals when they come into contact with water, which can continuously fill new microcracks and achieve self-repair of the pavement. This self-repair function not only extends the service life of the pavement, but also reduces subsequent maintenance and repair work. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The present invention is a construction process flow of a method for repairing micro-cracks on an airport pavement based on multi-ratio infiltration crystallization materials;

[0039] Figure 2 This is a diagram showing the phased working steps of the method for repairing micro-cracks on airport pavement based on multi-ratio infiltration crystallization materials of the present invention;

[0040] Figure 3 A schematic diagram of a construction inspection vehicle for a method of repairing micro-cracks on an airport pavement using multi-ratio infiltrated crystallization materials according to the present invention;

[0041] Figure 4 This is a schematic diagram of a construction repair vehicle for a method of repairing micro-cracks on an airport pavement using multi-proportion infiltration crystallization materials according to the present invention.

[0042] In the figure: 101, construction inspection trolley; 102, construction repair trolley; 2, blower pump; 3, front bracket; 5, second storage tank; 6, delivery pump; 7, scanning rod; 8, air outlet; 9, camera; 11, robotic arm; 12, nozzle with camera. DETAILED DESCRIPTION

[0043] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0044] See also Figure 1 The present invention provides a technical solution for a method of repairing micro-cracks on an airport pavement based on a multi-ratio infiltration crystallization material, including material composition and ratio design and a construction process flow.

[0045] Material composition and proportion design includes basic components and multiple proportion schemes;

[0046] The basic components include active silicate cement, nano-silica fume, redispersible latex powder, permeable crystallization masterbatch, water reducer and fiber reinforcement; active silicate cement accounts for 40%-50% of the basic components, and provides early strength and hydration reaction basis through active silicate cement; nano-silica fume accounts for 15%-20% of the basic components, and fills pores through nano-silica fume to improve density and impermeability; redispersible latex powder accounts for 5%-10% of the basic components, and enhances the flexibility and resistance to temperature stress of the material through redispersible latex powder; permeable crystallization masterbatch accounts for 10%-15% of the basic components, and the active ingredients of calcium silicate and calcium aluminate contained in the permeable crystallization masterbatch form crystals when they come into contact with water to fill cracks; water reducer accounts for 1%-2% of the basic components, and reduces the water-cement ratio through the water reducer to improve working performance; fiber reinforcement accounts for 2%-5% of the basic components, and the polypropylene fiber and basalt fiber in the fiber reinforcement inhibit crack expansion.

[0047] Multiple ratio solutions include surface penetration and deep filling types;

[0048] The water-cement ratio of the surface penetration type is 0.25-0.30, and the penetration crystallization masterbatch accounts for 15%. The surface penetration type is a high-fluidity slurry (expansion ≥300mm), which penetrates into the cracks through capillary action and forms a dense crystallization layer after solidification;

[0049] The water-cement ratio of the deep filling type is 0.30-0.35, the infiltration crystallization masterbatch accounts for 10%, and 5% expansion agent is added. The deep filling type is a low-fluidity slurry (expansion 180-220mm). The expansion agent is added to compensate for shrinkage to ensure that the crack filling density is ≥98%.

[0050] See also Figure 1 The construction process includes crack pretreatment, material preparation and construction, and curing and maintenance;

[0051] Crack pretreatment includes surface cleaning and interface treatment; surface cleaning includes using high-pressure air (pressure ≥0.6MPa) to blow along the direction of the crack to remove loose particles and oil stains. For cracks with a width ≥2mm, V-shaped cutting (slope 1:3, depth 5-8mm) is used to expand the contact area to 3-5 times the original crack width; interface treatment includes spraying interface agent (epoxy resin emulsion, solid content 50%) to enhance the bonding strength between the material and the original concrete (shear strength ≥3.5MPa).

[0052] Material preparation and application include surface penetration type construction and deep filling type construction; surface penetration type construction includes adding materials and water into a forced mixer (speed ≥ 60r / min) according to the proportion, stirring for 3 minutes to a uniform slurry, and using an airless sprayer (pressure 0.3-0.5MPa) to spray along both sides of the crack extending 10cm, with a spraying amount of 0.8-1.2kg / m 2 , immediately cover with polyethylene film after spraying to prevent water evaporation; deep filling construction includes standing for 5 minutes after stirring (to eliminate bubbles), injecting slurry into the cracks to return to the surface of the slurry, covering the surface with waterproof cloth for 30 minutes after scraping the surface, and covering the wet burlap bag for 24 hours after scraping the surface; curing and maintenance include initial curing and long-term maintenance. Initial curing includes surface hardening 1 hour after construction, compressive strength ≥5MPa, and compressive strength ≥20MPa after 24 hours, meeting the requirements for light load traffic; long-term maintenance includes opening traffic after 72 hours, and the material strength reaches more than 85% of the original concrete. Water is sprayed every day during the maintenance period for moisturizing for 7 days.

[0053] Technical principles: including the self-repair mechanism and synergistic enhancement effect of infiltration crystallization;

[0054] Self-repair mechanism of infiltration crystallization: The active calcium silicate and calcium aluminate in the infiltration crystallization material react with water to produce the following reaction:

[0055] 3CaO·SiO2+nH2O→xCaO·SiO2·yH2O+(3-x)Ca(OH)2

[0056] 3CaO·Al2O3+3CaSO4·2H2O+26H2O→3CaO·AlxO3·3CaSO4·32H2O

[0057] The ettringite crystals generated by the reaction have a needle-like structure, filling the pores inside the cracks to form a self-healing layer (with a thickness of up to 0.5-1mm).

[0058] Synergistic reinforcement effect: the effect produced by nano-silica fume, redispersible latex powder and polypropylene fiber; Nano-silica fume: consumes Ca(OH)2 through pozzolanic reaction to generate CSH gel, thereby improving the strength of the interface transition zone; Redispersible latex powder: forms a polymer film to wrap cement particles, thereby improving the flexural strength (28-day flexural strength ≥8MPa); Polypropylene fiber: bridges the crack tips, disperses stress concentration and inhibits crack expansion.

[0059] Example 1: Repair of longitudinal cracks on airport runway

[0060] Disease characteristics: crack width 1.5mm, depth 8mm, length 20m; concrete carbonization depth on both sides of the crack 3mm, pH value 9.2.

[0061] Repair plan: V-shaped cutting cracks, depth 6mm; after spraying the interface agent, inject deep filling material and vibrate to compact it; scrape the surface flat and cover with wet sacks for maintenance.

[0062] Repair effect: Traffic was opened after 24 hours, and the compressive strength was 22MPa; after 3 months of testing, crystals were generated inside the cracks, the impermeability was P15, and the flexural strength increased by 18%.

[0063] Example 2: Repair of freeze-thaw cracks on the apron of a northern airport

[0064] Disease characteristics: crack width 0.8mm, network distribution, area 5m 2 ; The number of freeze-thaw cycles reached 200 times, and the concrete mass loss rate was 1.2%.

[0065] Repair plan: Blow the cracks with high-pressure air and then spray the surface with penetrating material; cover with a moisturizing film and maintain for 48 hours.

[0066] Repair effect: After repair, the anti-freeze and thaw cycle is ≥350 times, and the quality loss rate is ≤0.5%; follow-up inspection after 1 year showed that no new cracks were found.

[0067] The present invention achieves the following breakthroughs in treating micro-cracks on airport pavements through the use of multi-ratio infiltration crystallization materials and targeted construction techniques:

[0068] Improved repair efficiency: The construction period is shortened to 1 / 3 of that of traditional methods, and a single repair affects flight takeoff and landing time ≤ 4 hours;

[0069] Functional integration: It combines rapid closure, self-repair and durability improvement, extending the pavement life by 5-8 years after repair;

[0070] Economic optimization: The repair cost per unit area is reduced by 40%, and the maintenance cost over the entire life cycle is reduced by 60%.

[0071] See also Figure 2-4 Process construction equipment:

[0072] It includes a construction inspection trolley 101 and a construction repair trolley 102, and the upper ends of the construction inspection trolley 101 and the construction repair trolley 102 are adapted to be equipped with a mobile power supply and an operation controller. The upper end of the construction inspection trolley 101 is fixedly installed with a blower pump 2, a front bracket 3 and a scanning rod 7 from the front to the back. The front bottom support of the construction trolley 1 is fixedly installed with an air outlet 8, and the air outlet 8 is connected to the blower pump 2 through a connecting hose. A camera 9 is fixedly installed on the top front end of the front bracket 3, and a linear laser scanner 10 is fixedly installed on the rear side of the upper end of the scanning rod 7;

[0073] A delivery pump 6, a storage tank 5 and a robotic arm 11 are fixedly mounted on the upper end of the construction and repair trolley 102. A nozzle 12 with a camera is fixedly mounted on the upper end of the robotic arm 11, and the delivery pump 6 is connected to the storage tank 5 and the nozzle 12 with a camera through a connecting pipe.

[0074] See also Figure 2-4 The phased work is carried out in the following steps:

[0075] S1, AGV small road surface automatic inspection S1 stage: In this stage, the small vehicle used for pavement crack disease identification automatically cruises on the airport pavement, and then enters the S2 stage;

[0076] S2, image recognition of defects: In this stage, the camera on the AGV begins to identify road surface defects and then enters the S3 stage;

[0077] S3: Determine whether cracks exist. In this stage, the industrial computer determines whether cracks exist on the pavement based on the pavement disease image fed back by the camera. If the judgment result is "yes", the process proceeds to S6; otherwise, the process proceeds to S4.

[0078] S4, the S4 stage of determining whether the inspection is complete: In this stage, the industrial computer determines whether the inspection task has reached the completion point. If the judgment result is "yes", it enters the S5 stage, otherwise it returns to the entrance of the S2 stage;

[0079] S5, the end of the inspection: In this stage, the industrial computer controls the AGV to return to the starting point, automatically shuts down, and waits for user instructions. The inspection is completed;

[0080] S6, RTK point positioning S6 stage: In this stage, the industrial computer controls RTK to obtain GPS point coordinates and upload them to the cloud, and then enters the S7 stage;

[0081] S7, high-pressure air cleaning of the road surface: In this stage, the industrial computer controls the air pump to clean the loose gravel on the road surface, and then enters the S8 stage;

[0082] S8, Linear laser scanning for crack length, width, and depth: In this stage, the industrial computer controls the linear laser scanning to obtain surface topography data within the crack range. Then, in S9, the amount of material required for crack repair is calculated and uploaded to the cloud.

[0083] S9, calculating the repair area of ​​the crack area: In this stage, the industrial computer obtains the surface morphology data of the pavement within the crack range based on linear laser scanning, calculates the amount of materials required for crack repair and the construction range, and then enters the S10 stage;

[0084] S10, determining whether the crack is a deep crack: In this stage, the industrial computer determines whether the crack is a deep crack based on the inspection data. If the judgment result is "yes", it enters the S11 stage, otherwise it enters the S13 stage;

[0085] S11, sending GPS coordinates to the deep repair material AGV repair vehicle S11 stage: In this stage, the industrial computer sends the repair instructions to the deep repair material AGV repair vehicle, and then enters the S12 stage;

[0086] S12, S12 stage of spraying deep repair materials: In this stage, the deep repair material AGV repair vehicle arrives at the repair site according to the GPS coordinates, and then the robot arm with a camera controls the nozzle to inject deep repair materials into the deep cracks. At the same time, the same type of deep repair material is sprayed within a range of 10 cm on both sides of the deep cracks. After reaching the expected amount, it automatically returns to the starting point, and then the system automatically returns to the S1 stage;

[0087] S13, sending GPS coordinates to the deep repair material AGV repair vehicle S13 stage: In this stage, the industrial computer sends the repair instructions to the shallow repair material AGV repair vehicle, and then enters the S14 stage;

[0088] S14, S14 stage of spraying shallow repair materials: In this stage, the shallow repair material AGV repair vehicle arrives at the repair site according to the GPS coordinates, and then the robotic arm with a camera controls the nozzle to inject deep repair materials into the shallow cracks. At the same time, the same type of shallow repair materials are sprayed within 20 cm on both sides of the deep cracks. After reaching the expected amount, it automatically returns to the starting point, and then the system automatically returns to the S1 stage.

[0089] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0090] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for repairing microcracks on airport pavement using multi-ratio infiltration crystallization materials, characterized by: Including material composition and proportion design and construction process flow; The material composition and proportion design includes basic components and multiple proportion schemes; The basic components include active Portland cement, nano-scale silica fume, redispersible latex powder, infiltration crystallization masterbatch, water reducer and fiber reinforcement; the active Portland cement provides early strength and hydration reaction foundation; the nano-scale silica fume fills pores to improve density and impermeability; the redispersible latex powder enhances material flexibility and resistance to temperature stress; The calcium silicate and calcium aluminate active ingredients contained in the infiltration crystallization masterbatch generate crystals when in contact with water to fill cracks; the water-cement ratio is reduced by the water-reducing agent to improve working performance; and the polypropylene fiber and basalt fiber in the fiber reinforcement inhibit crack expansion; The multi-ratio scheme includes surface penetration type and deep filling type; The surface penetration type has a water-cement ratio of 0.55-0.85, and the penetration crystallization masterbatch accounts for 35%. The surface penetration type is a high-fluidity slurry that penetrates into the cracks through capillary action and forms a dense crystallization layer after solidification. The water-cement ratio of the deep filling type is 0.30-0.35, the infiltration crystallization masterbatch accounts for 10%, and 5% expansion agent is added. The deep filling type is a low-fluidity slurry. The expansion agent is added to compensate for shrinkage to ensure that the crack filling density is ≥98%; The construction process includes crack pretreatment, material preparation and construction, and curing and maintenance; The crack pretreatment includes surface cleaning and interface treatment; The material preparation and application include surface penetration type construction and deep filling type construction; The solidification and curing include initial solidification and long-term curing.

2. The method for repairing microcracks on airport pavement using multi-ratio infiltration crystallization materials according to claim 1, characterized in that: The active silicate cement accounts for 10%-20% of the basic components, the nano-scale silica fume accounts for 15%-20% of the basic components, the redispersible latex powder accounts for 5%-10% of the basic components, the osmotic crystallization masterbatch accounts for 10%-55% of the basic components, the water reducer accounts for 1%-2% of the basic components, and the fiber reinforcement accounts for 2%-5% of the basic components.

3. The method for repairing microcracks on airport pavement using multi-ratio infiltration crystallization materials according to claim 2, characterized in that: The surface penetration type construction includes stirring the mixture into a uniform slurry according to the proportion, and spraying it along both sides of the crack by extending 10 cm with an airless sprayer, with a spraying amount of 0.8-1.2 kg / m 2 , cover with polyethylene film immediately after spraying to prevent moisture evaporation.

4. The method for repairing microcracks on airport pavement using multi-ratio infiltration crystallization materials according to claim 3, characterized in that: The deep filling construction includes stirring and then standing for more than 5 minutes, injecting the slurry into the cracks until the slurry returns to the surface, and then smoothing the surface and covering it with waterproof cloth for curing for 30 minutes.

5. The method for repairing microcracks on airport pavement using multi-ratio infiltration crystallization materials according to claim 4, characterized in that: The initial curing time is 15 minutes, which can meet the requirements for aircraft passage.

6. The method for repairing microcracks on airport pavement using multi-ratio infiltration crystallization materials according to claim 5, characterized in that: The long-term maintenance includes opening to traffic after 3 hours, ensuring that the material strength reaches more than 85% of the original concrete, and spraying water daily for moisture retention during the maintenance period for 7 days.

7. The method for repairing microcracks on an airport pavement using a multi-ratio infiltration crystallization material according to any one of claims 1 to 6, characterized in that: The phased work includes the following steps: S1, AGV small road surface automatic inspection S1 stage: In this stage, the small vehicle used for pavement crack disease identification automatically cruises on the airport pavement, and then enters the S2 stage; S2, image recognition of defects: In this stage, the camera on the AGV begins to identify road surface defects and then enters the S3 stage; S3: Determine whether cracks exist. In this stage, the industrial computer determines whether cracks exist on the pavement based on the pavement damage image fed back by the camera. If the judgment result is "yes", the process proceeds to S6; otherwise, the process proceeds to S4. S4, stage S4: Determine whether the inspection is complete: In this stage, the industrial computer determines whether the inspection task has reached the completion point. If the judgment result is "yes", it enters stage S5; otherwise, it returns to the entrance of stage S2; S5, the end of the inspection: In this stage, the industrial computer controls the AGV to return to the starting point, automatically shuts down, and waits for user instructions. The inspection is completed; S6, RTK point positioning S6 stage: In this stage, the industrial computer controls RTK to obtain GPS point coordinates and upload them to the cloud, and then enters the S7 stage; S7, high-pressure air cleaning of the road surface: In this stage, the industrial computer controls the air pump to clean the loose gravel on the road surface, and then enters the S8 stage; S8, Linear laser scanning for crack length, width, and depth: In this stage, the industrial computer controls the linear laser scanning to obtain surface topography data within the crack range. Then, in S9, the amount of material required for crack repair is calculated and uploaded to the cloud. S9, calculating the repair area of ​​the crack area: In this stage, the industrial computer obtains the surface morphology data of the pavement within the crack range based on linear laser scanning, calculates the amount of materials required for crack repair and the construction range, and then enters the S10 stage; S10, Determining whether it is a deep crack: In this stage, the industrial computer determines whether the crack is a deep crack based on the inspection data. If the judgment result is "yes", it enters the S11 stage, otherwise it enters the S13 stage; S11, sending GPS coordinates to the deep repair material AGV repair vehicle S11 stage: In this stage, the industrial computer sends the repair instructions to the deep repair material AGV repair vehicle, and then enters the S12 stage; S12, S12 stage of spraying deep repair materials: In this stage, the deep repair material AGV repair vehicle arrives at the repair site according to the GPS coordinates, and then the robot arm with a camera controls the nozzle to inject deep repair materials into the deep cracks. At the same time, the same type of deep repair material is sprayed within a range of 10 cm on both sides of the deep cracks. After reaching the expected amount, it automatically returns to the starting point, and then the system automatically returns to the S1 stage; S13, sending GPS coordinates to the deep repair material AGV repair vehicle S13 stage: In this stage, the industrial computer sends the repair instructions to the shallow repair material AGV repair vehicle, and then enters the S14 stage; S14, S14 stage of spraying shallow repair materials: In this stage, the shallow repair material AGV repair vehicle arrives at the repair site according to the GPS coordinates, and then the robotic arm with a camera controls the nozzle to inject deep repair materials into the shallow cracks. At the same time, the same type of shallow repair materials are sprayed within 20 cm on both sides of the deep cracks. After reaching the expected amount, it automatically returns to the starting point, and then the system automatically returns to the S1 stage.

Images