Construction method for repairing airport pavement and sandwich composite structure

Abstract

The invention discloses a construction method for repairing a broken slab of an airport pavement and a sandwich composite structure. The construction method comprises the following steps: S1, prefabricating a cement concrete pavement slab serving as a main body of a new pavement slab according to parameters; s2, a cement laitance layer on the surface is removed, and an interface binder is brushed after the cement laitance layer is removed; s3, a wearing layer is poured, and a flexible and elastic polymer composite material is adopted; s4, performing anti-skid treatment on the upper surface of the wearing layer to form an anti-skid layer; s5, the damaged old pavement panel is removed; s6, the interface of the base layer is coated with the interface binder; s7, a bed slurry layer is arranged after the interface binder is brushed; s8, the prefabricated new pavement slab is installed on the bed mortar layer and leveled, and then joints are filled; s9, after standing maintenance, joint cutting is conducted, and joint sealing materials are filled; and S10, opening the traffic after cleaning the site. Compared with the prior art, according to the new pavement formed through construction, the combining capacity of the new pavement slab and the old pavement slab or the base layer serving as the base plane is high, and the overall abrasion resistance and durability are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of airport pavement repair, and more particularly to a construction method and sandwich composite structure for airport pavement repair. Background Technology

[0002] The cement concrete pavement slabs commonly used in domestic airports are prone to widespread defects such as broken slabs, chipped corners, chipped edges, and cracks under the long-term coupled effects of aircraft loads and complex environments, seriously threatening airport operational safety and efficiency. As airports gradually enter a period of large-scale maintenance, the load-bearing capacity and durability of most airport pavements can no longer meet the requirements for normal airport use, and repair and replacement are urgently needed.

[0003] Currently, common methods for repairing broken concrete slabs in airports include: overlaying with asphalt concrete, such as the "Airport Pavement Structure and Paving Method for Overlaying Asphalt Layer on Old Cement Airport Runways" disclosed in Chinese Invention Patent Application No. 202110489215.4; removing the old pavement slab and then casting and repaving with cement concrete or polymer concrete slabs, such as the "Construction Method for Repairing Airport Pavement Slabs Without Cutting Joints" disclosed in Chinese Invention Application No. 202411727488.8; and precast cement concrete slabs, such as the "A Method for Repairing Broken Airport Pavement Slabs" disclosed in Chinese Invention Application No. 202310555145.7.

[0004] However, all of the above methods have certain problems. For example, asphalt concrete overlays are prone to reflective cracking and are susceptible to rutting and shoving in high-temperature environments, affecting aircraft operational safety. Cast-in-place repaving of cement concrete has a long curing period and is difficult to hydrate at low temperatures, making it impossible to carry out construction without interrupting flight operations. To solve the problem of construction without interrupting flight operations, rapid-hardening cement and precast concrete paving slabs can be used. Although rapid-hardening cement has a short curing time, it is brittle and lacks long-term durability, quickly developing defects such as cracks and slab breaks, leading to secondary repairs. On the other hand, precast concrete paving slabs cannot guarantee the bonding strength between the new and old paving slabs, and cannot fundamentally solve the surface erosion defects such as honeycomb pitting and particle spalling caused by cement concrete paving slabs in low-temperature freeze-thaw environments, thus still having certain shortcomings. Summary of the Invention

[0005] The first technical problem to be solved by the present invention is to propose a construction method for airport pavement repair that enables strong bonding between the new pavement slab and the old pavement slab or base layer, and provides high wear resistance and durability, in light of the above-mentioned technical status.

[0006] The second technical problem to be solved by the present invention is to propose a sandwich composite structure constructed by the above-mentioned airport pavement repair construction method.

[0007] The technical solution adopted by this invention to solve the first technical problem mentioned above is: a construction method for repairing broken slabs on airport pavement, characterized by comprising the following steps: S1. Precast cement concrete pavement slab: Before construction, assess the damage to the old pavement, determine the repair parameters, and precast the cement concrete pavement slab as the main body of the new pavement slab according to the parameters. S2. Applying interface adhesive: After grinding or shot blasting the precast cement concrete pavement panel and cleaning it, apply a layer of interface adhesive. The interface adhesive is made of polymer resin material. S3. Casting the wear layer: After applying the interface adhesive, the wear layer is cast. The new paving panel has a surface functional layer. The wear layer, as a part of the surface functional layer, is made of a flexible and elastic polymer composite material. S4. Surface anti-slip treatment: The upper surface of the wear layer is treated with anti-slip treatment to form an anti-slip layer. The anti-slip layer is also part of the surface functional layer. The prefabricated new track panel is placed at room temperature for static curing. S5. Base surface milling: Remove the damaged old pavement slab down to the intact part or semi-rigid base layer to form the construction base surface; S6. Apply the interface adhesive a second time: Apply the interface adhesive to the substrate interface; S7. Laying the grout layer: After applying the interface adhesive, the grout layer is set. The grout layer is made of high-strength non-shrink cement or organic polymer composite material. S8. Install the new track panel: Install the prefabricated new track panel on the grout layer and level it, then fill the joints; S9. Curing, joint cutting and caulking: After the sandwich composite structure is made through S1 to S8, it is statically cured as a whole. After the grout layer reaches the predetermined strength, the joint is cut and caulking material is filled in. S10. Open to traffic after site clearance: Clear and inspect the site, and open to traffic once airworthiness conditions are met.

[0008] To further enhance the bonding performance between the new pavement panel and the old pavement panel or base layer, preferably, in step S1, when prefabricating the new pavement panel, a shear-resistant structure is provided on the bottom surface of the new pavement panel, and the shear-resistant structure is corrugated, stepped, or sawtooth.

[0009] Preferably, in step S1, when prefabricating new pavement panels, the joint design includes: making the joint between the new and old pavement panels a flat joint; making the joint between new pavement panels a tongue-and-groove joint; and simultaneously fabricating tie rods for longitudinal joints and dowel bars for transverse joints. Making the joint between the new and old pavement panels a flat joint facilitates the installation of dowel bars by slotting the sides of the original pavement panels during construction, ensuring the load-bearing capacity of the joint. Making the joint between the new pavement panels a tongue-and-groove joint, such as a trapezoidal or overlapping joint, enhances the interlocking and overall integrity between the panels, improving shear resistance and load transfer effect, which is superior to a flat joint. The diameter and spacing of the tie rods and dowel bars are determined according to specifications and calculations.

[0010] Preferably, in step S7, the slurry layer is made of the same flexible polymer composite material as the wear layer.

[0011] Preferably, in step S1, when prefabricating the new track panel, lifting components are pre-embedded in the new track panel; in step S5, after the new track panel is installed on the grout layer, the lifting components are removed, and the remaining lifting holes are filled and sealed with a resin adhesive of the same composition as the interface adhesive. Using the same resin material as the interface adhesive to fill the lifting holes forms a chemical bond, preventing the intrusion of moisture and corrosive substances.

[0012] Preferably, the anti-slip treatment in S8 includes at least one of the following methods: applying abrasive powder and grinding or grooving. By applying abrasive powder and grinding or grooving, an anti-slip layer with a specific structural depth is formed, reducing damage to the base layer from wheel impacts and improving comfort and safety during aircraft takeoff and landing.

[0013] Furthermore, the wear layer made in S7 and the anti-slip layer made in S8 are incorporating phase change materials for low-temperature ice melting and thermosensitive color-changing microspheres for high-temperature infrared cooling.

[0014] Preferably, the flexible polymer composite material used in the grout layer and the wear layer is polyurethane concrete. This polyurethane concrete is composed of a polymer resin material mixed with natural gravel or pebbles. The polymer resin material and the interfacial binder are the same material, and the polyurethane concrete can react with the interfacial binder to form a three-dimensional covalent bond structure. Using polyurethane concrete significantly improves interlayer bonding performance and crosslinking density, enhances the overall structural strength, durability, and load-bearing capacity, while also achieving rapid curing.

[0015] Furthermore, the interface adhesive has self-leveling properties, enabling it to penetrate the original cement concrete foundation pavement, block cracks, and react with aggregates to form a dense structure and composite whole.

[0016] The technical solution adopted by the present invention to solve the second technical problem mentioned above is: a sandwich composite structure for repairing broken slabs of airport pavement, characterized in that it is constructed by any one of the above-mentioned construction methods, and comprises, from bottom to top: The first adhesive layer is coated on the substrate and is an interface adhesive made of polymer resin material. The grout layer is disposed above the first adhesive layer and is made of high-strength non-shrink cement or organic polymer composite material; The new pavement panel, installed on the grout layer, includes a cement concrete pavement panel as the main body and a surface functional layer. The surface functional layer includes an abrasion layer and an anti-slip layer. The abrasion layer is disposed above the cement concrete pavement panel through a second adhesive layer. The second adhesive layer uses the same material as the first adhesive layer. The abrasion layer uses the same material as the grout layer. The anti-slip layer is disposed on or formed on the upper surface of the abrasion layer.

[0017] Compared with existing technologies, the advantages of this invention are as follows: It uses polymer resin materials as interface binders to treat and reinforce old pavement, solving the problem of insufficient bonding between new and old pavement panels or base layers, forming a strong overall composite structure; a flexible polymer composite material serves as the wear layer, solving the problem of poor wear resistance and durability of traditional cement concrete surfaces; a surface functional layer, forming a composite force with the new pavement panel to improve the pavement's load-bearing capacity and safety, exhibiting strong high-temperature resistance and corrosion resistance, forming a powerful protective layer to prevent the new pavement panel from being eroded by the external environment, while also possessing superior wear resistance and anti-slip properties, ensuring the safe use of the pavement; the use of fast-curing flexible polymer composite materials as the grout layer and wear layer allows for traffic reopening after only 2 hours of static curing after construction, significantly improving construction efficiency and meeting the airport's uninterrupted operation requirements; through the overall sandwich composite structure, while meeting quality, safety, and efficiency requirements, costs are reduced and controlled, thus ensuring the feasibility of large-scale application of this technology. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart of the construction method according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the sandwich composite structure according to an embodiment of the present invention; Figure 3 This is a top view (including steel mesh) of the new pavement panel according to an embodiment of the present invention. Figure 4 This is a bottom view of the new channel panel according to an embodiment of the present invention; Figure 5 This is a cross-sectional view of the overall construction of an embodiment of the present invention. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0020] like Figures 1 to 5 The figure shows a preferred embodiment of the construction method and sandwich composite structure for airport pavement repair according to the present invention.

[0021] The construction method of the present invention is as follows: Figure 1 As shown, it includes: S1. Precast cement concrete pavement slab: Before construction, assess the damage to the old pavement according to specifications, determine the demolition method (full thickness or partial thickness), and precast the cement concrete pavement slab, which will form the main body of the new pavement slab, by calculating the thickness, strength, reinforcement and other parameters. The new pavement slab also has a surface functional layer, including a wear layer and an anti-slip layer. The wear layer and anti-slip layer are precast in S3 and S4 respectively. The cement concrete pavement slab is precast in the factory strictly according to the dimensions and parameters to ensure flatness and ensure that the flexural strength of the test blocks cured under the same conditions is not less than 6MPa. During precasting, the bottom shear structure is completed and the tie rods and force transmission rods are precast and embedded. The thickness of the precast cement concrete pavement slab is 6-7cm thinner than the thickness of the broken slab to be repaired, so as to reserve space for the bottom grout layer constructed in S7 and the surface functional layers made in S3 and S4. S2. Apply interface adhesive: Grind or shot blast the precast cement concrete pavement panel to remove the surface cement laitance layer and expose the aggregate. After cleaning the top surface of the precast new pavement panel, apply interface adhesive. S3. Pouring the wearing layer: Pour the polyurethane concrete wearing layer within half an hour after the interface adhesive is applied. The thickness of the wearing layer is determined comprehensively based on the part of the pavement to be repaired and the design and specification requirements. After pouring, vibrate and level the surface. The flatness is ≤3mm. S4. Surface anti-slip treatment: After the wear layer has cured, the upper surface of the wear layer is ground with standard sand, and anti-slip treatment such as roughening or grooving is performed to form an anti-slip layer. The construction depth is determined according to relevant specifications or design basis. S5. Base surface milling: The old pavement slab is removed down to the intact part or semi-rigid base layer by cutting and breaking methods to form the construction base surface; S6. Second application of interface adhesive: Apply interface adhesive to the substrate. The interface adhesive is made of polymer resin material. S7. Laying the grout layer: Within half an hour after the interface adhesive is applied, lay a 2-3cm thick grout layer made of high-strength non-shrink cement or organic polymer composite material, preferably polyurethane concrete, for leveling. S8. Install new track panels: Install the prefabricated new track panels onto the grout layer through the lifting holes, and adjust the elevation using special equipment; S9. Curing, joint cutting and caulking: After the sandwich composite structure is made through S1 to S8, the whole structure is left to stand for 2 hours for curing. After the grout layer reaches the predetermined strength, the joint is cut and caulking material is filled in. S10. Open to traffic after site clearance: Clear and inspect the site, and open to traffic once airworthiness conditions are met.

[0022] The sandwich composite structure in this embodiment is as follows: Figure 2 As shown, from bottom to top, there are a first adhesive layer 2, a grout layer 3, and a prefabricated new track panel 4.

[0023] Based on the damage assessment results, the old pavement slab is either completely removed down to the base surface or partially removed down to a non-damaged position as the base surface 1 for subsequent construction. The first bonding layer 2 is an interface adhesive made of polymer resin material and is applied to the base surface 1. The grout layer 3 is made of flexible polymer composite material and is placed above the first bonding layer 2. The new pavement slab 4 is installed on the grout layer 3 and includes a cement concrete pavement slab 41 as the main body and a surface functional layer 42. The surface functional layer 42 includes an abrasion layer 421 and an anti-slip layer 422. The abrasion layer 421 is placed above the cement concrete pavement slab 41 through a second bonding layer 43. The second bonding layer 43 uses the same material as the first bonding layer 2, the abrasion layer 421 uses the same material as the grout layer 3, and the anti-slip layer 422 is placed or formed on the upper surface of the abrasion layer 421.

[0024] The interface adhesive used in the first adhesive layer 2 and the second adhesive layer 43 is a polymer resin material with high viscosity, high fluidity, and high permeability, such as polyurethane resin, epoxy resin, polyester resin, acrylic resin, vinyl resin, etc., with polyurethane resin being preferred. Its performance must meet the following requirements: curing time ≤ 120 minutes, and waterproof performance reaching P10 level or above.

[0025] The flexible polymer composite material used in the grout layer 3 and the wear layer 421 is preferably polyurethane concrete. Polyurethane concrete is composed of a polymer resin material mixed with a certain gradation of natural gravel or pebbles. This polymer resin material is the same as the material used in the interface adhesive. The polyurethane concrete and the interface adhesive can undergo a specific chemical reaction in a short time to form a three-dimensional covalent bond structure, improving the interfacial crosslinking density and bonding performance. The polyurethane concrete must meet the following requirements: curing in 2 hours at normal low temperature, compressive strength ≥ 28 MPa, flexural tensile strength ≥ 18 MPa, and no significant performance degradation at high temperatures above 70℃.

[0026] The thickness, reinforcement, and other parameters of the precast new pavement panel 4 need to be determined through finite element analysis and theoretical calculations based on elastic foundation composite slabs. The material can utilize aggregate from the demolition of abandoned airport pavement, and by adding and controlling the placement and concentration of nanomaterials, the interface transition zone between the recycled aggregate and cement mortar can be strengthened, achieving a gradient functional design and effectively dispersing stress. The preferred process is vacuum-assisted vibration molding, which applies low-frequency vibration and vacuum negative pressure during casting to eliminate air bubbles, shorten demolding time, and improve precast efficiency. If reinforcement is required, single-layer or double-layer steel mesh 44 can be used, with steel bar diameters of 6-20mm and spacing of 10-30cm. Alternatively... Figure 3 As shown, circular or rectangular lifting holes 49 are provided in the new pavement panel 4, with pre-embedded lifting components (such as circular or figure-eight shaped steel bars, threaded pre-embedded lifting components) inside, at a depth of 5-12cm. Each pavement panel has 2-12 holes, preferably 4. After installation, the lifting components are removed, and the panel is filled and sealed with a resin adhesive with essentially the same composition as the interface adhesive. Figure 4 As shown, the bottom surface of the new track panel 4 is provided with serrated rectangular or trapezoidal cross-section joint grooves as shear-resistant structures 411, arranged in parallel with a spacing of 1~10cm and a depth of 3~10mm, preferably trapezoidal cross-section. The top surface is roughened to improve the interface shear resistance. Preferably, directional self-healing microcapsules are added to the new track panel, which can release a healing agent for automatic repair when microcracks appear.

[0027] like Figure 5 As shown, for the joint design, longitudinal joints are equipped with tie rods 46, and transverse joints are equipped with dowel bars 45. Their diameter and spacing are determined according to specifications and calculations, and they are prefabricated simultaneously with the new pavement panel 4. The prefabricated new pavement panel 4 and the old pavement panel adopt a flat joint 47 + dowel bar 45 structure. During construction, holes are drilled and grooves are made on the side of the original pavement panel in advance to place the steel dowel bars 45 or tie rods 46. Before placement, anchoring adhesive can be applied to enhance the load-bearing capacity of the joint. The prefabricated new pavement panel 4 and the new pavement panel 4 adopt a tongue and groove joint 48 + dowel bar 45 structure. The tongue and groove joint 48 can be trapezoidal or lapped, with trapezoidal being preferred. The joint is filled with polyurethane concrete of the same type as the wearing layer 421, or with a resin material with better fluidity, to ensure the integrity of the load-bearing structure.

[0028] The performance requirements for the new panel 4 are: compressive strength ≥ 30MPa, and flexural tensile strength ≥ 6MPa.

[0029] The wear layer 421 is made of polyurethane concrete. Preferably, phase change material (PCM) and thermochromic microspheres are incorporated to achieve automatic ice melting at low temperatures and infrared cooling reflection at high temperatures. An anti-slip layer 422 with a specific structural depth is formed by spreading standard sand and then grinding or grooving; the coefficient of friction is determined based on the location of the paving slab.

[0030] After cutting the seams using specialized equipment, sealant is injected, and the upper 1 / 4 to 1 / 5 of the plate thickness is sealed with elastic polymer sealants such as polyurethane and silicone. Surface preparation utilizes milling machines, sweepers, and mud sweepers; seam cutting is done using a seam cutting machine, achieving mechanized and automated operations with high efficiency and minimal pollution. After the sandwich composite structure is installed on base surface 1, the tensile strength must be ≥ 3MPa, or damage to the foundation concrete layer must occur.

Claims

1. A construction method for repairing broken slabs on airport pavement, characterized in that, Includes the following steps: S1. Precast cement concrete pavement slab: Before construction, assess the damage to the old pavement, determine the repair parameters, and precast the cement concrete pavement slab as the main body of the new pavement slab according to the parameters. S2. Applying interface adhesive: After grinding or shot blasting the precast cement concrete pavement panel and cleaning it, apply a layer of interface adhesive. The interface adhesive is made of polymer resin material. S3. Casting the wear layer: After applying the interface adhesive, the wear layer is cast. The new paving panel has a surface functional layer. The wear layer, as a part of the surface functional layer, is made of a flexible and elastic polymer composite material. S4. Surface anti-slip treatment: The upper surface of the wear layer is treated with anti-slip treatment to form an anti-slip layer. The anti-slip layer is also part of the surface functional layer. The prefabricated new track panel is left to stand for curing. S5. Base surface milling: Remove the damaged old pavement slab down to the intact part or semi-rigid base layer to form the construction base surface; S6. Apply the interface adhesive a second time: Apply the interface adhesive to the substrate interface; S7. Laying the grout layer: After applying the interface adhesive, the grout layer is set. The grout layer is made of high-strength non-shrink cement or organic polymer composite material. S8. Install the new track panel: Install the prefabricated new track panel on the grout layer and level it, then fill the joints; S9. Curing, joint cutting and caulking: After the sandwich composite structure is made through S1 to S8, it is statically cured as a whole. After the grout layer reaches the predetermined strength, the joint is cut and caulking material is filled in. S10. Open to traffic after site clearance: Clear and inspect the site, and open to traffic once airworthiness conditions are met.

2. The construction method according to claim 1, characterized in that, In S1, when prefabricating a new track panel, a shear-resistant structure is provided on the bottom surface of the new track panel. The shear-resistant structure is corrugated, stepped, or sawtooth.

3. The construction method according to claim 1, characterized in that, In step S1, when prefabricating the new channel panel, joint design is performed: Make the joint between the new and old pavement panels a flat joint; The joints between the new deck panels are made into tongue and groove joints. Simultaneously, tie rods for longitudinal joints and force transmission rods for transverse joints are manufactured.

4. The construction method according to claim 1, characterized in that, In step S7, the slurry layer is made of the same flexible polymer composite material as the wear layer.

5. The construction method according to claim 1, characterized in that, In step S1, when prefabricating the new track panel, a lifting component is pre-embedded in the new track panel; in step S5, after the new track panel is installed on the grout layer, the lifting component is removed, and the remaining lifting hole is filled and sealed with a resin liquid with the same composition as the interface adhesive.

6. The construction method according to claim 1, characterized in that, The anti-slip treatment in S8 includes at least one of the following methods: sprinkling surface sand and grinding or grooving.

7. The construction method according to claim 1, characterized in that, The wear layer made in S7 and the anti-slip layer made in S8 incorporate phase change materials for low-temperature ice melting and thermosensitive color-changing microspheres for high-temperature infrared cooling.

8. The construction method according to claim 1, characterized in that, The flexible polymer composite material used in the grout layer and the wear layer is polyurethane concrete. The polyurethane concrete is made by mixing polymer resin material with natural gravel or pebbles. The polymer resin material and the interface binder are the same material. The polyurethane concrete can react with the interface binder to form a three-dimensional covalent bond structure.

9. The construction method according to claim 1, characterized in that, The interface adhesive has self-leveling properties, enabling it to penetrate the original cement concrete foundation pavement, block cracks, and react with aggregates to form a dense structure and composite whole.

10. A sandwich composite structure for repairing broken slabs of airport pavement, characterized in that, Constructed by the construction method described in any one of claims 1 to 9, comprising, from bottom to top: The first adhesive layer is coated on the substrate and is an interface adhesive made of polymer resin material. The grout layer is disposed above the first adhesive layer and is made of high-strength non-shrink cement or organic polymer composite material; The new pavement panel, installed on the grout layer, includes a cement concrete pavement panel as the main body and a surface functional layer. The surface functional layer includes an abrasion layer and an anti-slip layer. The abrasion layer is disposed above the cement concrete pavement panel through a second adhesive layer. The second adhesive layer uses the same material as the first adhesive layer. The abrasion layer uses the same material as the grout layer. The anti-slip layer is disposed on or formed on the upper surface of the abrasion layer.

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