Steel bridge deck pavement method based on magnetic force effect

Abstract

The invention provides a steel bridge deck pavement method based on a magnetic force effect, which comprises the following three steps of: paving a magnetic response epoxy anti-sliding waterproof bonding layer on a steel bridge deck, then paving a magnetic epoxy resin asphalt concrete layer, and finally paving an asphalt mastic macadam mixture layer. The magnetic response epoxy anti-sliding waterproof bonding layer adopts the magnetic response epoxy adhesive cement and the aggregate to form an adhesive cement-aggregate-adhesive cement sandwich structure, and the strength and the shearing strength of the bonding layer are enhanced by means of the magnetic adsorption effect between the magnetic polymer microspheres and the magnetic blocks. The magnetic epoxy resin asphalt concrete layer also generates interlayer magnetic adsorption with the'adhesive cement-aggregate-adhesive cement 'sandwich structure through internal magnetic polymer microsphere-magnetic blocks, and the magnetic epoxy resin asphalt concrete layer and the'adhesive cement-aggregate-adhesive cement' sandwich structure jointly form a'double-magnetic effect functional layer 'and are tightly connected through the magnetic adsorption effect, so that the overall cohesiveness and anti-sliding performance of the pavement system are effectively enhanced, and the pavement system is suitable for being used in the field of pavement. The durability and the service life of the steel bridge deck pavement can be improved, and the driving safety is guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of road construction materials technology, specifically relating to a method for paving steel bridge decks based on magnetic effects. Background Technology

[0002] With the continuous advancement of urbanization and the increasing traffic volume, urban steel bridge decks have become an important transportation infrastructure. Due to the unique structure of steel bridge decks, they face a series of problems such as waterproofing, skid resistance, and fatigue resistance. Traditional steel bridge deck paving methods typically use ordinary asphalt concrete or polymer-modified asphalt concrete. However, these methods are susceptible to the effects of moisture, vehicle loads, and climate change during long-term use, leading to problems such as loosening, cracking, and insufficient skid resistance in the pavement layer, thus affecting the service life of the bridge deck and traffic safety. Therefore, overcoming the defects of loosening, cracking, and insufficient skid resistance in steel bridge deck pavement layers is an urgent engineering challenge that needs to be addressed in steel bridge deck paving methods.

[0003] In order to overcome the defects of traditional steel bridge deck paving, the use of new materials and technologies to improve steel bridge deck paving has become a hot topic in bridge engineering technology research in recent years. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a steel bridge deck paving method based on magnetic effects. The aim is to significantly improve the strength, anti-slip performance, and durability of steel bridge deck paving by introducing magnetic materials, thereby solving the defects of existing steel bridge deck paving.

[0005] To achieve the above objectives, the solution of the present invention is: A method for paving a steel bridge deck based on magnetic effect involves laying a magnetically responsive epoxy anti-slip and waterproof adhesive layer, a magnetic epoxy resin asphalt concrete layer, and an asphalt mastic aggregate mixture layer sequentially from bottom to top on the steel bridge deck.

[0006] The magnetically responsive epoxy anti-slip and waterproof adhesive layer is composed of magnetically responsive epoxy mortar and aggregate. The magnetically responsive epoxy mortar contains magnetic polymer microspheres, epoxy resin, curing agent, reactive diluent and toughening agent, and the aggregate contains magnetic blocks and crushed stone.

[0007] The magnetic epoxy resin asphalt concrete layer includes magnetically responsive epoxy mortar, asphalt, aggregates, magnetic blocks, and fillers.

[0008] The magnetic polymer microspheres and magnetic blocks in the magnetically responsive epoxy adhesive form a strong adsorption effect under the action of magnetic force, and form a bonding structure through magnetic adsorption, which greatly improves the strength and anti-slip performance of the epoxy adhesive layer.

[0009] Furthermore, the magnetically responsive epoxy adhesive comprises, by weight parts: 25-58.3 parts magnetic polymer microspheres, 50-58.3 parts epoxy resin, 30-33.3 parts curing agent, 4-4.7 parts reactive diluent, and 3-3.7 parts toughening agent.

[0010] Furthermore, the preparation of the magnetically responsive epoxy adhesive includes: Toughening agent is added to epoxy resin and stirred, followed by reactive diluent and stirred, then magnetic polymer microspheres are added and stirred, and finally curing agent is added and stirred evenly to obtain magnetically responsive epoxy adhesive.

[0011] Furthermore, the magnetic polymer microspheres have a core-shell structure: the core is a micron-sized Fe3O4 structure obtained by agglomerating nano-sized Fe3O4 magnetic particles with an average particle size of 10-20 μm; the shell is a copolymer resin prepolymer with an average thickness of 1-5 μm, and the saturation magnetization of the magnetic polymer microspheres is 10-20 emu / g.

[0012] Furthermore, the magnetic polymer microspheres are prepared by in-situ polymerization, specifically including the following steps: (a): Preparation of copolymer resin prepolymer: Preparation of suspension mixture: Mix urea, melamine and formaldehyde solution with deionized water to obtain suspension mixture; pH adjustment: The pH of the suspension mixture was adjusted to 9 using sodium hydroxide solution; Water bath heating and stirring: Use a magnetic stirrer to heat and stir, and start stirring for a time when the temperature rises to 70°C to obtain a copolymer resin prepolymer solution; (b): Preparation of magnetic polymer microspheres: Water bath heating and stirring: Nano-sized iron oxide is mixed with the copolymer resin prepolymer solution to obtain a mixture. The mixture is placed in a water bath and stirred continuously. Adjusting pH: While stirring, use citric acid solution to adjust the pH of the mixture to 2.5-3.0; Separation and washing: After cooling to room temperature, the product was separated and washed repeatedly with deionized water and anhydrous ethanol. After drying, the surface was coated with a copolymer resin prepolymer to obtain core-shell structured magnetic polymer microspheres. Furthermore, the epoxy resin is E44 epoxy resin, which is a thermosetting resin with characteristics such as high strength, corrosion resistance, high temperature resistance and wear resistance.

[0013] The curing agent is an amine-based curing agent, selected from one or more of polyamide 650 or polyamide 651. The cured product has good heat resistance and mechanical properties, and the curing time at 60℃ is about 96 hours.

[0014] Both the epoxy resin and the curing agent are produced by Hunan Baxiongsi New Materials Co., Ltd.

[0015] The active diluent is a butyl glycidyl ether with an epoxy group, produced by Henan Huineng Resin Co., Ltd., and its main function is to improve the flowability of magnetically responsive epoxy paste.

[0016] The toughening agent is thermoplastic resin polypropylene (PP), produced by Hanpin Paint Industry (Shandong) Co., Ltd., and its function is to improve the toughness of magnetically responsive epoxy adhesive.

[0017] Furthermore, the diameter of both the magnetic blocks and the crushed stone in the aggregate is 3-5 mm, with a mass ratio of 3:7; the magnetic blocks are neodymium iron boron waste, and the remanence of the magnetic blocks is 0.5-1 kOe; the crushed stone is basalt. The crushed stone is produced by Jiangsu Yabang Mining Co., Ltd.; the magnetic blocks are produced by Hengshui Beirui Metal Trading Co., Ltd., and their magnetic force is insufficient to cause the blocks to agglomerate but can adsorb magnetically responsive epoxy mortar.

[0018] Further, the magnetic epoxy resin asphalt concrete layer comprises, by weight, 3-3.3 parts magnetically responsive epoxy mortar, 3-3.3 parts asphalt, aggregate, 21.17-21.39 parts coarse magnetic blocks, 6.42-6.51 parts fine magnetic blocks, and 7-8 parts filler; the aggregate comprises 49.42-49.91 parts coarse aggregate and 14.98-15.19 parts fine aggregate; the total porosity of the magnetic epoxy resin asphalt concrete layer is 4.0%.

[0019] Furthermore, the asphalt is 70# base asphalt, produced by China Petroleum & Chemical Corporation Refining & Sales Co., Ltd.

[0020] Both coarse and fine aggregates are discontinuously graded. The coarse aggregate has a particle size of 2.36-13.2 mm and is basalt from Jiangsu Yabang Mining Co., Ltd. The fine aggregate has a particle size of 0.075-2.36 mm and is limestone from Chibi Yuanda Mining Co., Ltd. Both coarse and fine magnetic blocks are made from NdFeB waste. The coarse magnetic blocks have a particle size of 2.36-13.2 mm, while the fine magnetic blocks have a particle size of 0.075-2.36 mm. Both coarse and fine magnetic blocks possess a certain degree of magnetism, but their magnetic force is insufficient to cause adsorption and aggregation between blocks. However, they can adsorb magnetically responsive epoxy resin. They are produced by Hengshui Beirui Metal Trading Co., Ltd.

[0021] The filler is limestone powder, produced by Shanghai Huchang Building Materials Co., Ltd.

[0022] Furthermore, the steel bridge deck paving method based on magnetic effect includes the following steps: (1) Spray a 2mm thick magnetically responsive epoxy mortar onto the steel bridge deck; (2) Lay another layer of aggregate; (3) Then spray the magnetic responsive epoxy mortar onto the aggregate, with a spraying amount of 0.45±0.03kg / m², to form a magnetic responsive epoxy anti-slip waterproof bonding layer with a sandwich structure of "magnetic responsive epoxy mortar-aggregate-magnetic responsive epoxy mortar". (4) Lay a magnetic epoxy resin asphalt concrete layer on top of the magnetically responsive epoxy anti-slip waterproof bonding layer, and compact it after spreading; (5) Lay an asphalt mastic stone mixture layer on top of the magnetic epoxy resin asphalt concrete layer, and compact it after paving to obtain a steel bridge deck based on magnetic effect.

[0023] The thickness of the magnetically responsive epoxy anti-slip and waterproof adhesive layer is 6-8cm, the thickness of the magnetic epoxy resin asphalt concrete layer is 4-6cm, and the thickness of the asphalt mastic aggregate mixture layer is 5-8cm.

[0024] The asphalt mastic aggregate (SMA) layer conforms to the standard "Technical Specification for Construction of Asphalt Pavement of Highway" (JTGF40-2004). The design parameters of each layer comply with the "Technical Specification for Design and Construction of Steel Bridge Deck Pavement of Highway" (JTG / T3364-02-2019).

[0025] Among them, the magnetically responsive epoxy anti-slip waterproof adhesive layer uses magnetically responsive epoxy mortar and aggregate to form a "mortar-aggregate-mortar" sandwich structure. By means of the magnetic adsorption between magnetic polymer microspheres and magnetic blocks, the strength and shear strength of the adhesive layer are enhanced.

[0026] Specifically, the upper magnetic epoxy resin asphalt concrete layer also generates interlayer magnetic adsorption through the internal magnetic polymer microspheres-magnetic blocks and the "mortar-aggregate-mortar" sandwich structure. Together, they form a "dual magnetic effect functional layer" that is tightly connected through the magnetic adsorption effect, effectively enhancing the overall adhesion and anti-slip performance of the pavement system.

[0027] Due to the adoption of the above solution, the beneficial effects of the present invention are: 1. This invention constructs a magnetically responsive epoxy anti-slip and waterproof adhesive layer with a sandwich structure of "magnetically responsive epoxy mortar-aggregate-magnetically responsive epoxy mortar," which, together with the magnetic epoxy resin asphalt concrete layer, forms a "dual magnetic effect functional layer." The magnetic polymer microspheres contained in the upper and lower sandwich layers can mutually adsorb with the magnetic blocks in the aggregate, forming an internal, integrated magnetic adsorption system. This system, through close adsorption with the steel bridge deck, forms a dual mechanism of "chemical bonding-physical magnetic attraction," thereby significantly improving interfacial bonding performance. Furthermore, the upper layer of this sandwich structure, the magnetic epoxy resin asphalt concrete layer, also contains magnetic polymer microspheres and magnetic blocks, which can generate an interlayer magnetic effect with the lower structure. Thus, the upper and lower layers jointly achieve synergistic enhancement of the "dual magnetic effect functional layer," significantly improving the interfacial bonding performance and anti-slip capability of the entire pavement system.

[0028] 2. The core-shell structured micron-sized magnetic polymer microspheres prepared by this invention possess numerous advantages, including large specific surface area, large pore volume, strong adsorption capacity, protection of the core, and good magnetic properties and dispersibility. This enhances the "carrying and transporting" ability of ordinary nano-sized Fe3O4 particles, specifically, the ability to carry and transport epoxy asphalt mortar, thereby reducing the segregation of epoxy asphalt mortar. The epoxy asphalt mortar can be uniformly adsorbed onto the sprinkled magnetic blocks, overcoming the deficiency of insufficient "carrying and transporting" ability caused by the smooth surface of traditional micron-sized Fe3O4 particles. 3. This invention introduces the magnetic adsorption effect of magnetic materials. Through the magnetic adsorption between magnetic polymer microspheres and magnetic blocks, the bonding force between the anti-slip waterproof adhesive layer and the asphalt concrete layer is significantly improved. In addition, the magnetic effect between the magnetic responsive epoxy anti-slip waterproof adhesive layer and the magnetic epoxy resin asphalt concrete layer will also generate a magnetic adsorption effect with the steel bridge deck, which significantly improves the strength, anti-slip performance, durability and driving safety of the entire steel bridge deck pavement system. It can effectively reduce the frequency of steel bridge deck maintenance and repair, thereby reducing long-term maintenance costs.

[0029] 4. In addition to traditional bonding, the steel bridge deck, the magnetically responsive epoxy anti-slip and waterproof adhesive layer, and the magnetic epoxy resin asphalt concrete layer of this invention form a tightly connected integral structure through layer-by-layer magnetic adsorption. This pavement system achieves efficient and reliable bonding with the steel bridge deck, breaking through the technical limitations of traditional pure epoxy asphalt bonding, and has significant engineering application value.

[0030] 5. This invention utilizes neodymium iron boron waste as a magnetic block to provide magnetic field conditions, realizing solid waste utilization, reducing material costs, laying the foundation for practical engineering applications, and providing an innovative solution to the defects of steel bridge deck pavement. By introducing a magnetic effect into the steel bridge deck pavement layer, the bonding strength, anti-slip performance, and durability of the pavement layer can be significantly improved.

[0031] 6. The construction process of this invention is no different from the traditional one, except that the raw materials have been replaced. The construction is simple and highly feasible. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the steel bridge deck paving structure based on the magnetic effect of the present invention.

[0033] Figure 2 This is a schematic diagram illustrating the magnetic effect principle of the steel bridge deck pavement structure of the present invention.

[0034] Figure 3 This is a microscopic image of the magnetic polymer microspheres obtained using an optical microscope (640x magnification) in Example 1 of this invention.

[0035] Figure 4 This is a schematic diagram of the microstructure of the magnetic polymer microspheres obtained by thermal field emission scanning electron microscopy (1Kx) in Embodiment 1 of the present invention.

[0036] Figure 5 This is a schematic diagram of the microstructure of the magnetic polymer microspheres obtained by thermal field emission scanning electron microscopy (2Kx) in Embodiment 1 of the present invention.

[0037] Figure 6 This is a schematic diagram of the microstructure of the magnetic polymer microspheres obtained by thermal field emission scanning electron microscopy (10Kx) in Embodiment 1 of the present invention.

[0038] Figure 7 This is a schematic diagram of the microstructure of the magnetic polymer microspheres obtained by thermal field emission scanning electron microscopy (30Kx) in Embodiment 1 of the present invention.

[0039] Figure reference numerals: 1-Magnetic responsive epoxy mortar, 11-Magnetic polymer microspheres, 2-Aggregate, 21-Magnetic block (black), 22-Crushed stone (gray). Detailed Implementation

[0040] This invention provides a method for paving steel bridge decks based on magnetic effects.

[0041] like Figure 1 and Figure 2 As shown, in the magnetically responsive epoxy resin anti-slip and waterproof adhesive layer, the magnetic polymer microspheres 11 contained in the upper and lower layers of magnetically responsive epoxy mortar 1 can mutually adsorb with the magnetic blocks 21 contained in the aggregate 2, thereby forming an integral adsorption system. This system achieves tight adsorption with the steel bridge deck. In this structure, between the magnetically responsive epoxy resin anti-slip and waterproof adhesive layer and the steel bridge deck, in addition to the traditional adhesive force F... 粘 In addition, a magnetic force F is superimposed. 磁 Adsorption. Together, these two factors constitute a dual mechanism of "adhesion-magnetic attraction," significantly improving interfacial adhesion performance.

[0042] Furthermore, the magnetic polymer microspheres 11 and magnetic blocks 21 contained in the magnetic epoxy resin asphalt concrete layer can form a new adsorption system with the magnetic polymer microspheres 11 and magnetic blocks 21 in the waterproof adhesive layer. Together, they constitute a "dual magnetic effect functional layer," achieving tight magnetic adsorption between layers. This cross-layer magnetic force creates an effective magnetic connection between the adhesive layer and the concrete layer, thereby enhancing the overall pavement structure's bonding performance and anti-slip capability.

[0043] In summary, in addition to traditional bonding, the steel bridge deck, the magnetically responsive epoxy anti-slip and waterproof adhesive layer, and the magnetic epoxy resin asphalt concrete layer form a tightly bonded integral structure through layer-by-layer magnetic adsorption. This pavement system achieves efficient and reliable bonding with the steel bridge deck, overcoming the technical limitations of traditional pure epoxy asphalt bonding and possessing significant engineering application value.

[0044] The present invention will be further described below with reference to specific embodiments. These embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following embodiments.

[0045] Example 1 (Optimal Example): The steel bridge deck paving method based on magnetic effect in this embodiment is as follows: a magnetically responsive epoxy anti-slip and waterproof adhesive layer, a magnetic epoxy resin asphalt concrete layer, and an asphalt mastic crushed stone mixture layer are laid sequentially on top of the steel bridge deck.

[0046] The magnetically responsive epoxy anti-slip and waterproof adhesive layer consists of magnetically responsive epoxy mortar 1 and aggregate 2. The preparation of magnetically responsive epoxy mortar 1 includes: (The stirring time is taken as an example when preparing 135.15g of magnetically responsive epoxy mortar 1. The actual stirring time depends on the amount of mortar required for the project.) Add 3.35 parts of polypropylene (toughening agent) to 54.15 parts of E44 epoxy resin and stir until homogeneous for 20 seconds; then add 4.35 parts of butyl glycidyl ether (reactive diluent) and stir until homogeneous for 20 seconds; continue to add 41.65 parts of magnetic polymer microspheres 11 and stir until homogeneous for 30 seconds; finally add 31.65 parts of polyamide 650 (curing agent) and stir until homogeneous for 30 seconds to obtain magnetically responsive epoxy paste 1.

[0047] In fact, the magnetic polymer microspheres 11 are prepared by in-situ polymerization (taking 5 g of modified nano Fe3O4 particles as an example), specifically including the following steps: (a): Preparation of copolymer resin prepolymer: Preparation of suspension mixture: 5.28g urea, 12.24g melamine and 37.78g formaldehyde solution (37%) were mixed with deionized water (dilution ratio 1:4) to obtain suspension mixture; pH adjustment: The pH of the suspension mixture was adjusted to 9 using a 5% NaOH solution; Water bath heating and stirring: Use a magnetic stirrer to heat and stir for 30 minutes (1025 rpm) when the temperature reaches 70℃ to obtain a copolymer resin prepolymer solution; at this time, melamine, urea and formaldehyde have completed the addition reaction, and the solution is clear and transparent, yielding the prepolymer. After the reaction is complete, cool to room temperature for later use.

[0048] (b): Preparation of magnetic polymer microspheres: Water bath heating and stirring: Mix 5g of nano-sized Fe3O4 with the copolymer resin prepolymer solution, place the mixture in a 65℃ water bath, and continuously stir mechanically for 2.5h (350rpm) using a digital display DC electric stirrer. Adjusting pH: While stirring, adjust the pH of the mixture to 2.7 using a citric acid solution; Separation and washing: After cooling to room temperature, the product is separated by magnetic separation and washed alternately with deionized water and anhydrous ethanol to remove residual copolymer resin prepolymer monomers and unreacted substances such as citric acid. Cleaning and drying: The microspheres were repeatedly washed with deionized water and anhydrous ethanol to remove acidic residues. After drying in an oven, magnetic polymer microspheres 11 with a core-shell structure were obtained. The core consisted of micron-sized Fe3O4 particles with an average particle size of 15 μm; the shell was a copolymer resin prepolymer with an average thickness of 3 μm. The saturation magnetization of the magnetic polymer microspheres 11 was 10 emu / g.

[0049] Aggregate 2 includes magnetic blocks 21 and crushed stone 22, both with a diameter of 3-5 mm and a mass ratio of 3:7; magnetic blocks 21 are neodymium iron boron waste with a remanence of 0.5 kOe; crushed stone 22 is basalt.

[0050] The magnetic epoxy resin asphalt concrete layer comprises, by weight, 3.15 parts magnetically responsive epoxy mortar, 2.15 parts 70# base asphalt, 49.67 parts coarse aggregate, 15.09 parts fine aggregate, 21.28 parts coarse magnetic blocks, 6.47 parts fine magnetic blocks, and 7.5 parts limestone powder.

[0051] Both coarse and fine aggregates are discontinuously graded. The coarse aggregate has a particle size of 2.36-13.2 mm and is composed of basalt. The fine aggregate has a particle size of 0.075-2.36 mm and is composed of limestone. Both coarse magnetic blocks and fine magnetic blocks are neodymium iron boron waste. The coarse magnetic blocks have a particle size of 2.36-13.2 mm, and the fine magnetic blocks have a particle size of 0.075-2.36 mm.

[0052] The steel bridge deck paving steps based on magnetic effect in this embodiment are as follows: <1> A 7cm thick magnetically responsive epoxy anti-slip and waterproof adhesive layer is laid on top of the steel bridge deck, following these steps: (1) First, spray a 2mm thick layer of magnetically responsive epoxy mortar 1 onto the steel bridge surface; (2) Lay another layer of aggregate 2, including magnetic blocks 21 and crushed stone 22, with a mass ratio of 3:7; (3) Then spray the magnetically responsive epoxy mortar 1 onto the magnetic block 21 and the crushed stone 22, with a spraying amount of 0.45±0.03kg / m. 2 A magnetically responsive epoxy anti-slip and waterproof adhesive layer is formed by a sandwich structure of "magnetically responsive epoxy mortar - aggregate - magnetically responsive epoxy mortar". <2> A 5cm thick layer of magnetic epoxy resin asphalt concrete is laid on top of the magnetically responsive epoxy anti-slip and waterproof adhesive layer. After the layer is laid, it is compacted. The gradation design of the magnetic epoxy resin asphalt concrete is shown in Table 1, and the mix proportion design is shown in Table 2. <3> A 7cm thick layer of asphalt mastic aggregate was laid on top of the magnetic epoxy resin asphalt concrete layer, and then compacted to obtain a steel bridge deck pavement structure based on the magnetic effect. All design parameters meet the requirements of the "Technical Specification for Design and Construction of Highway Steel Bridge Deck Pavement" (JTG / T3364-02-2019).

[0053] The asphalt mastic macadam mixture layer is laid according to the "Technical Specification for Construction of Highway Asphalt Pavement". Before opening to traffic after compaction, the skid resistance coefficient, smoothness and other indicators must be tested. The road can only be opened to traffic after the specifications are met.

[0054] Example 2: The steel bridge deck paving method based on magnetic effect in this embodiment is as follows: a magnetically responsive epoxy anti-slip and waterproof adhesive layer, a magnetic epoxy resin asphalt concrete layer, and an asphalt mastic crushed stone mixture layer are laid sequentially on top of the steel bridge deck.

[0055] The magnetically responsive epoxy anti-slip and waterproof adhesive layer consists of magnetically responsive epoxy mortar 1 and aggregate 2. The preparation of magnetically responsive epoxy grout 1 includes: (The stirring time is taken as an example when preparing 112g of magnetically responsive epoxy grout 1. The actual stirring time depends on the amount of grout required for the project.) Add 3 parts of polypropylene (toughening agent) to 50 parts of E44 epoxy resin and stir until homogeneous for 20 seconds; then add 4 parts of butyl glycidyl ether (reactive diluent) and stir until homogeneous for 20 seconds; then add 25 parts of magnetic polymer microspheres 11 and stir until homogeneous for 30 seconds; finally add 30 parts of polyamide 651 (curing agent) and stir until homogeneous for 30 seconds to obtain magnetically responsive epoxy paste 1.

[0056] In fact, the magnetic polymer microspheres 11 are prepared by in-situ polymerization (taking 5 g of modified nano Fe3O4 particles as an example), specifically including the following steps: (a): Preparation of copolymer resin prepolymer: Preparation of suspension mixture: 5.28g urea, 12.24g melamine and 37.78g formaldehyde solution (37%) were mixed with deionized water (dilution ratio 1:3) to obtain suspension mixture; pH adjustment: The pH of the suspension mixture was adjusted to 9 using a 5% NaOH solution; Water bath heating and stirring: Use a magnetic stirrer to heat and stir for 30 minutes (1025 rpm) when the temperature reaches 70℃ to obtain a copolymer resin prepolymer solution; at this time, melamine, urea and formaldehyde have completed the addition reaction, and the solution is clear and transparent, yielding the prepolymer. After the reaction is complete, cool to room temperature for later use.

[0057] (b): Preparation of magnetic polymer microspheres: Water bath heating and stirring: Mix 5g of nano-sized Fe3O4 with the copolymer resin prepolymer solution, place the mixture in a 65℃ water bath, and continuously stir mechanically for 2 hours (350rpm) using a digital display DC electric stirrer. Adjusting pH: While stirring, use citric acid solution to adjust the pH of the mixture to 2; Separation and washing: After cooling to room temperature, the product is separated by magnetic separation and washed alternately with deionized water and anhydrous ethanol to remove residual copolymer resin prepolymer monomers and unreacted substances such as citric acid. Cleaning and drying: The microspheres were repeatedly washed with deionized water and anhydrous ethanol to remove acidic residues. After drying in an oven, magnetic polymer microspheres 11 with a core-shell structure were obtained. The core consisted of micron-sized Fe3O4 particles with an average particle size of 10 μm; the shell was a copolymer resin prepolymer with an average thickness of 2 μm. The saturation magnetization of the magnetic polymer microspheres 11 was 20 emu / g.

[0058] Aggregate 2 includes magnetic blocks 21 and crushed stone 22, both with a diameter of 3-5 mm and a mass ratio of 3:7; magnetic blocks 21 are neodymium iron boron waste with a remanence of 0.5 kOe; crushed stone 22 is basalt.

[0059] The magnetic epoxy resin asphalt concrete layer comprises, by weight, 3 parts magnetic responsive epoxy mortar, 3 parts 70# base asphalt, 49.42 parts coarse aggregate, 14.98 parts fine aggregate, 21.17 parts coarse magnetic blocks, 6.42 parts fine magnetic blocks, and 7 parts limestone powder.

[0060] Both coarse and fine aggregates are discontinuously graded. The coarse aggregate has a particle size of 2.36-13.2 mm and is composed of basalt. The fine aggregate has a particle size of 0.075-2.36 mm and is composed of limestone. Both coarse magnetic blocks and fine magnetic blocks are neodymium iron boron waste. The coarse magnetic blocks have a particle size of 2.36-13.2 mm, and the fine magnetic blocks have a particle size of 0.075-2.36 mm.

[0061] The steel bridge deck paving steps based on magnetic effect in this embodiment are as follows: <1> A 6cm thick magnetically responsive epoxy anti-slip and waterproof adhesive layer is laid on top of the steel bridge deck, following these steps: (1) First, spray a 2mm thick layer of magnetically responsive epoxy mortar 1 onto the steel bridge surface; (2) Lay another layer of aggregate 2, including magnetic blocks 21 and crushed stone 22, with a mass ratio of 3:7; (3) Then spray the magnetically responsive epoxy mortar 1 onto the magnetic block 21 and the crushed stone 22, with a spraying amount of 0.45±0.03kg / m. 2 A magnetically responsive epoxy anti-slip and waterproof adhesive layer is formed by a sandwich structure of "magnetically responsive epoxy mortar - aggregate - magnetically responsive epoxy mortar". <2> A 6cm thick layer of magnetic epoxy resin asphalt concrete is laid on top of the magnetically responsive epoxy anti-slip and waterproof adhesive layer. After the layer is laid, it is compacted. The gradation design of the magnetic epoxy resin asphalt concrete is shown in Table 1, and the mix proportion design is shown in Table 2. <3> A 6cm thick layer of asphalt mastic aggregate was laid on top of the magnetic epoxy resin asphalt concrete layer, and then compacted to obtain a steel bridge deck pavement structure based on magnetic effect. All design parameters meet the requirements of the "Technical Specification for Design and Construction of Highway Steel Bridge Deck Pavement" (JTG / T3364-02-2019).

[0062] The asphalt mastic macadam mixture layer is laid according to the "Technical Specification for Construction of Highway Asphalt Pavement". Before opening to traffic after compaction, the skid resistance coefficient, smoothness and other indicators must be tested. The road can only be opened to traffic after the specifications are met.

[0063] Example 3: The steel bridge deck paving method based on magnetic effect in this embodiment is as follows: a magnetically responsive epoxy anti-slip and waterproof adhesive layer, a magnetic epoxy resin asphalt concrete layer, and an asphalt mastic crushed stone mixture layer are laid sequentially on top of the steel bridge deck.

[0064] The magnetically responsive epoxy anti-slip and waterproof adhesive layer consists of magnetically responsive epoxy mortar 1 and aggregate 2. The preparation of magnetically responsive epoxy mortar 1 includes: (The stirring time is taken as an example when preparing 158.3g of magnetically responsive epoxy mortar 1. The actual stirring time depends on the amount of mortar required for the project.) Add 3.7 parts of polypropylene (toughening agent) to 58.3 parts of E44 epoxy resin and stir until homogeneous for 20 seconds; then add 4.7 parts of butyl glycidyl ether (reactive diluent) and stir until homogeneous for 20 seconds; continue to add 58.3 parts of magnetic polymer microspheres 11 and stir until homogeneous for 30 seconds; finally add 33.3 parts of polyamide 650 (curing agent) and stir until homogeneous for 30 seconds to obtain magnetically responsive epoxy paste 1.

[0065] In fact, the magnetic polymer microspheres 11 are prepared by in-situ polymerization (taking 5g of modified nano Fe3O4 particles as an example), which specifically includes the following steps: (a): Preparation of copolymer resin prepolymer: Preparation of suspension mixture: 5.28g urea, 12.24g melamine and 37.78g formaldehyde solution (37%) were mixed with deionized water (dilution ratio 1:5) to obtain suspension mixture; pH adjustment: The pH of the suspension mixture was adjusted to 9 using a 5% NaOH solution; Water bath heating and stirring: Use a magnetic stirrer to heat and stir for 30 minutes (1025 rpm) when the temperature reaches 70℃ to obtain a copolymer resin prepolymer solution; at this time, melamine, urea and formaldehyde have completed the addition reaction, and the solution is clear and transparent, yielding the prepolymer. After the reaction is complete, cool to room temperature for later use.

[0066] (b): Preparation of magnetic polymer microspheres: Water bath heating and stirring: Mix 5g of nano-sized Fe3O4 with the copolymer resin prepolymer solution, place the mixture in a 65℃ water bath, and continuously stir mechanically for 3h (350rpm) using a digital display DC electric stirrer. Adjusting pH: While stirring, adjust the pH of the mixture to 3 using a citric acid solution; Separation and washing: After cooling to room temperature, the product is separated by magnetic separation and washed alternately with deionized water and anhydrous ethanol to remove residual copolymer resin prepolymer monomers and unreacted substances such as citric acid. Cleaning and drying: The microspheres were repeatedly washed with deionized water and anhydrous ethanol to remove acidic residues. After drying in an oven, magnetic polymer microspheres 11 with a core-shell structure were obtained. The core consisted of micron-sized Fe3O4 particles with an average particle size of 20 μm; the shell was a copolymer resin prepolymer with an average thickness of 5 μm. The saturation magnetization of the magnetic polymer microspheres 11 was 20 emu / g.

[0067] Aggregate 2 includes magnetic blocks 21 and crushed stone 22, both with a diameter of 3-5 mm and a mass ratio of 3:7; magnetic blocks 21 are neodymium iron boron waste with a remanence of 0.5 kOe; crushed stone 22 is basalt.

[0068] The magnetic epoxy resin asphalt concrete layer comprises, by weight, 3.3 parts magnetically responsive epoxy mortar, 3.3 parts 70# base asphalt, 49.91 parts coarse aggregate, 15.19 parts fine aggregate, 21.39 parts coarse magnetic blocks, 6.51 parts fine magnetic blocks, and 8 parts limestone powder.

[0069] Both coarse and fine aggregates are discontinuously graded. The coarse aggregate has a particle size of 2.36-13.2 mm and is composed of basalt. The fine aggregate has a particle size of 0.075-2.36 mm and is composed of limestone. Both coarse magnetic blocks and fine magnetic blocks are neodymium iron boron waste. The coarse magnetic blocks have a particle size of 2.36-13.2 mm, and the fine magnetic blocks have a particle size of 0.075-2.36 mm.

[0070] The steel bridge deck paving steps based on magnetic effect in this embodiment are as follows: <1> An 8cm thick magnetically responsive epoxy anti-slip and waterproof adhesive layer is laid on top of the steel bridge deck, following these steps: (1) First, spray a 2mm thick layer of magnetically responsive epoxy mortar 1 onto the steel bridge surface; (2) Lay another layer of aggregate 2, including magnetic blocks 21 and crushed stone 22, with a mass ratio of 3:7; (3) Then spray the magnetically responsive epoxy mortar 1 onto the magnetic block 21 and the crushed stone 22, with a spraying amount of 0.45±0.03kg / m. 2 A magnetically responsive epoxy anti-slip and waterproof adhesive layer is formed by a sandwich structure of "magnetically responsive epoxy mortar - aggregate - magnetically responsive epoxy mortar". <2> A 4cm thick layer of magnetic epoxy resin asphalt concrete is laid on top of the magnetically responsive epoxy anti-slip and waterproof adhesive layer. After the layer is laid, it is compacted. The gradation design of the magnetic epoxy resin asphalt concrete is shown in Table 1, and the mix proportion design is shown in Table 2. <3> An 8cm thick layer of asphalt mastic aggregate was laid on top of the magnetic epoxy resin asphalt concrete layer, and then compacted to obtain a steel bridge deck pavement structure based on the magnetic effect. All design parameters meet the requirements of the "Technical Specification for Design and Construction of Highway Steel Bridge Deck Pavement" (JTG / T3364-02-2019).

[0071] The asphalt mastic macadam mixture layer is laid according to the "Technical Specification for Construction of Highway Asphalt Pavement". Before opening to traffic after compaction, the skid resistance coefficient, smoothness and other indicators must be tested. The road can only be opened to traffic after the specifications are met.

[0072] Comparative Example 1: Epoxy Asphalt Waterproof Bonding Layer for Traditional Bridge Deck Paving This comparative example uses a traditional epoxy asphalt waterproof bonding layer, which does not contain magnetic components. The specific steps are as follows: conventional epoxy asphalt mortar is sprayed onto the steel bridge deck, followed by the laying of ordinary aggregate (such as basalt) to form a waterproof bonding layer. The material proportions and construction process refer to the standard "Technical Specification for Design and Construction of Highway Steel Bridge Deck Pavement" (JTG / T3364-02-2019). The lack of magnetic effect may result in insufficient interlayer adhesion and poor anti-slip performance.

[0073] Comparative Example 2: Traditional epoxy resin asphalt mixture layer This comparative example uses a traditional epoxy resin asphalt mixture, free of any magnetic components. Its material composition and proportions follow conventional design: epoxy resin, curing agent, 70# base asphalt, basalt coarse aggregate (particle size 2.36-13.2mm), limestone fine aggregate (particle size 0.075-2.36mm), and limestone powder. The design, mixing, and compaction processes of the mixture all comply with the relevant provisions for epoxy asphalt mixtures in the "Technical Specification for Design and Construction of Highway Steel Bridge Pavement" (JTG / T 3364-02-2019). Due to the complete lack of magnetically responsive elements such as magnetic polymer microspheres and coarse / fine magnetic blocks as in the examples, an enhanced magnetic bonding network cannot be formed internally. Therefore, when working together with the magnetically responsive epoxy anti-slip and waterproof adhesive layer, an interlayer magnetic adsorption effect cannot be generated, making it difficult to further improve interlayer bonding and synergistic deformation capabilities. Under extreme loads and complex environmental coupling effects, its overall durability and fatigue resistance may be inferior to the embodiments of this invention.

[0074] Comparative Example 3: Traditional Bridge Deck Pavement Composite Structure This comparative example uses a traditional bridge deck pavement composite structure, typically including an epoxy asphalt waterproof bonding layer, an ordinary asphalt concrete layer, and an asphalt mastic aggregate mixture layer, but all are made of non-magnetic materials. The pavement layer thickness, material design, and construction process follow the standard specification "Technical Specification for Design and Construction of Highway Steel Bridge Deck Pavement" (JTG / T3364-02-2019), but no magnetic response elements are introduced. Therefore, it is impossible to enhance interlayer adhesion and overall durability through magnetic force, potentially leading to detachment and fatigue damage.

[0075] The magnetic polymer microspheres 11 from Example 1 were subjected to the following experiments: like Figure 3As shown, under room temperature conditions (25°C, approximately 50% humidity, one atmosphere), dark-colored micron-sized Fe3O4 particles were clearly observed under an optical microscope to be encapsulated by brown transparent (i.e., the outer shell structure under the optical microscope is brown transparent) prepolymers, forming regular core-shell structured microspheres. These microspheres are much larger than the initial nano-Fe3O4 particles, indicating that the prepolymer successfully solidified on the particle surface and constructed a new physical entity. This morphological transformation from the nanoscale to the microscale physically greatly expands the external contour and total volume of the particles, providing a structural basis for a significant increase in specific surface area.

[0076] The prepolymer coating is not dense and smooth, but rather exhibits roughness and porosity. This stems from the rapid polycondensation and crosslinking of melamine-urea-formaldehyde resin under acidic conditions, which easily forms a rough, porous cured network. These microscopic irregularities and pore structures significantly increase the surface roughness and internal contact area of ​​the coating itself. Therefore, the increase in specific surface area comes not only from the dimensional changes caused by the core-shell structure, but more importantly from the high specific surface area and porous characteristics of the coating itself.

[0077] This encapsulation process effectively separates and immobilizes the originally highly agglomerated Fe3O4 nanoparticles within these porous microspheres, reducing their close contact and maintaining a high effective surface area. This increased specific surface area means that the material surface can provide more active sites, thereby significantly enhancing its adsorption performance and allowing the core-shell structured microspheres to fully function.

[0078] like Figures 4 to 7 As shown, under room temperature conditions (25°C, approximately 50% humidity, one standard atmosphere), the images at low magnification clearly reveal the overall morphology and distribution of the microspheres. It can be observed that the prepolymer successfully encapsulates nano-Fe3O4 into numerous independent, relatively uniform spherical or near-spherical structures, with particle sizes mainly distributed at the micrometer level. This regular spherical structure and good dispersibility demonstrate the effectiveness of the preparation process and, from a macroscopic scale, show that the physical surface area of ​​the material has been significantly increased compared to the tightly aggregated state of the original nanoparticles.

[0079] At medium magnification ( Figure 6The surface details of individual microspheres are clearly revealed. It is evident that the microsphere shell is not smooth and dense, but rather exhibits significant roughness and a porous structure. These nanoscale wrinkles and pores are typical characteristics of the rapid curing and cross-linking of melamine-urea-formaldehyde copolymer resin prepolymer under acidic conditions. This highly porous surface structure is the core reason for the dramatic increase in the material's specific surface area. It not only provides a huge outer surface but also creates abundant internal surfaces, thereby greatly increasing the active sites available for adsorption or reaction.

[0080] At high magnification, the image enters the nanoscale ( Figure 7 This allows for insight into the microscopic mechanisms of the encapsulation. At this resolution, finer nano-sized Fe3O4 particles can be observed firmly embedded within a porous prepolymer network, directly confirming the "sea-island" core-shell structure. This observation directly verifies that the prepolymer is encapsulated and deposited using nano-Fe3O4 as the core. The resulting three-dimensional network not only fixes the magnetic core but also, through its open porous structure, constitutes a high specific surface area, laying a solid structural foundation for enhancing the adsorption performance of the magnetic microspheres.

[0081] Table 1. Gradation Design of Magnetic Epoxy Resin Asphalt Concrete Table 2 Mix Proportion Design of Magnetic Epoxy Resin Asphalt Concrete Layer Table 3 Comparison of test results for the performance of magnetically responsive epoxy anti-slip and waterproof adhesive layers Table 4 Comparison of Performance Test Results of Magnetic Epoxy Resin Asphalt Concrete Layer Table 5 Comparison of performance test results of steel bridge deck pavement composite structures based on magnetic effect According to the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG 3410-2025), the test results of Example 1 and the comparative example (Tables 3, 4, and 5) show that the magnetically responsive epoxy anti-slip waterproof bonding layer prepared by the present invention is significantly superior to traditional epoxy asphalt waterproof bonding layer materials in terms of both bonding strength and shear strength, effectively improving the interfacial bonding performance and anti-slip capability between pavement layers.

[0082] Furthermore, the rutting dynamic stability of the magnetic epoxy resin asphalt concrete layer is higher than that of the traditional epoxy resin asphalt mixture layer, and far exceeds the specification requirements, demonstrating excellent high-temperature deformation resistance and heavy-load adaptability. Meanwhile, its superior performance advantages are further reflected in: First, excellent water damage resistance. The splitting tensile strength ratio measured in the experiment is significantly higher than the comparative example and the lower limit of the specification. This indicates that, under the combined action of the magnetic polymer microspheres and the copolymer resin shell, the internal bonding force of the mixture is strengthened, effectively blocking the intrusion and erosion of water, greatly reducing the risk of aggregate spalling, potholes, and other water damage due to loss of adhesion under freeze-thaw cycles, thus ensuring the long-term service performance and durability of the pavement layer in humid and rainy environments. Second, significantly improved low-temperature crack resistance. Its low-temperature flexural strain value is significantly better than that of traditional epoxy asphalt mixtures, meaning that this material has higher flexibility and deformation capacity under low-temperature conditions. This is thanks to the synergistic toughening effect of the magnetic components and the epoxy-asphalt system, which effectively alleviates the shrinkage stress caused by the sudden drop in temperature, thereby better suppressing the generation and propagation of low-temperature shrinkage cracks and greatly enhancing the adaptability and integrity of the pavement structure in cold regions or environments with large temperature differences.

[0083] Furthermore, the steel bridge deck pavement composite structure based on the magnetic effect also shows significant advantages in terms of fatigue life and maintenance cycle, and has better overall durability.

[0084] In summary, by introducing a "dual magnetic effect functional layer," this invention comprehensively enhances the mechanical and durability properties of steel bridge deck pavement structures, providing a reliable guarantee for their long-term service under complex loads and harsh environments.

[0085] The above description of the embodiments is intended to enable those skilled in the art to understand and use the present invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments. Improvements and modifications made by those skilled in the art based on the principles of the present invention, without departing from the scope of the invention, should be within the protection scope of the present invention.

Claims

1. A method for paving steel bridge decks based on magnetic effect, characterized in that, A magnetically responsive epoxy anti-slip and waterproof bonding layer, a magnetic epoxy resin asphalt concrete layer, and an asphalt mastic aggregate mixture layer are laid sequentially from bottom to top on the steel bridge deck. The magnetically responsive epoxy anti-slip and waterproof adhesive layer is composed of magnetically responsive epoxy mortar (1) and aggregate (2). The magnetically responsive epoxy mortar (1) contains magnetic polymer microspheres (11), epoxy resin, curing agent, reactive diluent and toughening agent. The aggregate (2) contains magnetic blocks (21) and crushed stone (22). The magnetic epoxy resin asphalt concrete layer includes magnetically responsive epoxy mortar (1), asphalt, aggregates, magnetic blocks (21), and fillers; The magnetically responsive epoxy adhesive (1) forms a bonded structure through magnetic adsorption between magnetic polymer microspheres (11) and magnetic blocks (21).

2. The steel bridge deck paving method based on magnetic effect according to claim 1, characterized in that, The magnetically responsive epoxy adhesive (1) comprises, by weight, 25-58.3 parts magnetic polymer microspheres (11), 50-58.3 parts epoxy resin, 30-33.3 parts curing agent, 4-4.7 parts reactive diluent, and 3-3.7 parts toughening agent.

3. The steel bridge deck paving method based on magnetic effect according to claim 1, characterized in that, The preparation of the magnetically responsive epoxy adhesive (1) includes: Toughening agent was added to epoxy resin and stirred, followed by reactive diluent and stirred, then magnetic polymer microspheres (11) were added and stirred, and finally curing agent was added and stirred evenly to obtain magnetic responsive epoxy paste (1).

4. The steel bridge deck paving method based on magnetic effect according to claim 1, characterized in that, The magnetic polymer microspheres (11) have a core-shell structure: the core is micron-sized iron oxide particles with an average particle size of 10-20 μm; the shell is a copolymer resin prepolymer with an average thickness of 1-5 μm; and the saturation magnetization of the magnetic polymer microspheres (11) is 10-20 emu / g.

5. The steel bridge deck paving method based on magnetic effect according to claim 1, characterized in that, The magnetic polymer microspheres (11) are prepared by in-situ polymerization, specifically including the following steps: (a): Preparation of copolymer resin prepolymer: Preparation of suspension mixture: Mix urea, melamine and formaldehyde solution with deionized water to obtain suspension mixture; pH adjustment: The pH of the suspension mixture was adjusted to 9 using sodium hydroxide solution; Water bath heating and stirring: Use a magnetic stirrer to heat and stir, and start stirring for a time when the temperature rises to 70°C to obtain a copolymer resin prepolymer solution; (b): Preparation of magnetic polymer microspheres: Water bath heating and stirring: Nano-sized iron oxide is mixed with the copolymer resin prepolymer solution to obtain a mixture. The mixture is placed in a water bath and stirred continuously. Adjusting pH: While stirring, use citric acid solution to adjust the pH of the mixture to 2.5-3.0; Separation and washing: After cooling to room temperature, the product was separated and washed repeatedly with deionized water and anhydrous ethanol. After drying, core-shell magnetic polymer microspheres (11) were obtained.

6. The steel bridge deck paving method based on magnetic effect according to claim 1, characterized in that, The epoxy resin is E44 epoxy resin, the curing agent is selected from one or more of polyamide 650 or polyamide 651, the reactive diluent is butyl glycidyl ether, and the toughening agent is polypropylene.

7. The steel bridge deck paving method based on magnetic effect according to claim 1, characterized in that, The diameter of the magnetic block (21) and the crushed stone (22) in the aggregate (2) is 3-5 mm, and the mass ratio is 3:7; the magnetic block (21) is neodymium iron boron waste, and the remanence of the magnetic block (21) is 0.5-1 kOe; the crushed stone (22) is basalt.

8. The steel bridge deck paving method based on magnetic effect according to claim 1, characterized in that, The magnetic epoxy resin asphalt concrete layer comprises, by weight, 3-3.3 parts magnetically responsive epoxy mortar (1), 3-3.3 parts asphalt, aggregate, 21.17-21.39 parts coarse magnetic blocks, 6.42-6.51 parts fine magnetic blocks, and 7-8 parts filler; the aggregate comprises 49.42-49.91 parts coarse aggregate and 14.98-15.19 parts fine aggregate.

9. The steel bridge deck paving method based on magnetic effect according to claim 8, characterized in that, The asphalt is 70# base asphalt; both the coarse and fine aggregates are discontinuously graded; the coarse aggregate has a particle size of 2.36-13.2 mm and is composed of basalt; the fine aggregate has a particle size of 0.075-2.36 mm and is composed of limestone; the filler is limestone powder; and / or, Both the coarse magnetic blocks and the fine magnetic blocks are NdFeB waste. The particle size of the coarse magnetic blocks is 2.36-13.2 mm, and the particle size of the fine magnetic blocks is 0.075-2.36 mm.

10. The steel bridge deck paving method based on magnetic effect according to claim 1, characterized in that, The laying steps are as follows: (1) Spray magnetically responsive epoxy mortar (1) onto the steel bridge deck. (2) Lay another layer of aggregate (2); (3) Then spray the magnetic responsive epoxy mortar (1) onto the aggregate to form a magnetic responsive epoxy anti-slip waterproof bonding layer with a sandwich structure of "magnetic responsive epoxy mortar-aggregate-magnetic responsive epoxy mortar". (4) Lay a magnetic epoxy resin asphalt concrete layer on top of the magnetically responsive epoxy anti-slip waterproof bonding layer, and compact it after spreading; (5) An asphalt mastic aggregate mixture layer is laid on top of the magnetic epoxy resin asphalt concrete layer, and compacted after paving to obtain a steel bridge deck based on the magnetic effect; and / or, The thickness of the magnetically responsive epoxy anti-slip and waterproof adhesive layer is 6-8cm. The thickness of the magnetic epoxy resin asphalt concrete layer is 4-6 cm. The thickness of the asphalt mastic-aggregate mixture layer is 5-8cm.

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