High-toughness asphalt mixture, preparation method of high-toughness asphalt mixture, viscous and tough abrasion composite layer and construction method of viscous and tough abrasion composite layer

Abstract

The invention provides a high-toughness asphalt mixture and a preparation method thereof as well as a viscous and tough abrasion composite layer and a construction method thereof, and relates to the technical field of asphalt materials. The high-toughness asphalt mixture is prepared from the following components in parts by mass: 6 to 7.5 parts of matrix asphalt, 8 to 12 parts of filler, 68 to 72 parts of aggregate, 0.2 to 0.4 part of polyester fiber and an SBS (Styrene Butadiene Styrene) modifier which accounts for 3 to 5 percent of the mass of the matrix asphalt. According to the high-toughness asphalt mixture provided by the invention, by adding the SBS modifier and the polyester fibers, the toughness, high-temperature stability and durability of the asphalt mixture are remarkably improved. The selection and proportion of the aggregate are assisted by the network structure of the polyester fiber, so that the proper void ratio of the mixture is ensured, the pavement drainage is facilitated, and the stability of the whole structure is also enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of asphalt materials, and in particular to a high-toughness asphalt mixture and a preparation method thereof, and a viscous-tough wear composite layer and a construction method thereof. Background Art

[0002] As the main structural form of highways, the performance and durability of asphalt pavement are directly related to driving safety and maintenance costs. Traditional asphalt pavement structures often use suspended dense mixtures. Although they have a high density, they are prone to rutting deformation and fatigue cracking under heavy traffic, making it difficult to meet the load-bearing requirements of high-grade roads. Moreover, for heavy-loaded pavements, the pressure of heavy-loaded vehicles on the road surface is much greater than that of ordinary vehicles, so higher strength and durability are required to withstand greater vertical loads and shear forces. In addition, since heavy-loaded vehicles travel at relatively low speeds, the road surface must also be able to cope with long-term static or low-speed dynamic loads, which places higher requirements on the viscoelasticity and thermal stability of the asphalt mixture.

[0003] However, existing conventional wearing layers are susceptible to spalling and water seepage due to the coupled effects of temperature stress and load. This leads to rapid degradation of the pavement structure, requiring milling and resurfacing every 3-5 years on average, significantly increasing lifecycle costs. Furthermore, existing pavement maintenance technologies suffer from weak adhesion between new and old layers, making it difficult to control reflective cracks. Furthermore, the construction process is easily affected by ambient temperature and interlayer contaminants, making efficient pavement maintenance and repair difficult.

[0004] Therefore, there is an urgent need to develop a new type of high-toughness asphalt mixture and visco-tough wear composite layer to improve the overall performance and durability of asphalt pavement. Summary of the Invention

[0005] In view of this, the present invention proposes a high-toughness asphalt mixture and a preparation method thereof, and an efficient and reliable viscous and tough wear composite layer and a construction method thereof, so as to improve construction efficiency and pavement durability.

[0006] In a first aspect, the present invention provides a high-toughness asphalt mixture, which comprises the following components, in parts by mass: 6 to 7.5 parts of base asphalt, 8 to 12 parts of filler, 68 to 72 parts of aggregate, 0.2 to 0.4 parts of polyester fiber, and an SBS modifier accounting for 3 to 5% of the mass of the base asphalt.

[0007] By adopting the above technical solution, the addition of SBS modifier improves the elasticity and durability of the matrix asphalt, making it have better rutting resistance under high temperature conditions, while also showing excellent crack resistance under low temperature conditions. The addition of polyester fiber further enhances the overall strength and stability of the mixture, effectively reducing the generation and development of road cracks. The combination of the two significantly improves the toughness of the asphalt mixture, enabling it to better resist the dynamic stress caused by traffic loads and reduce fatigue damage caused by repeated loading. In addition, the asphalt mixture formula of the present invention effectively improves the cohesion and adhesion of the mixture, ensuring a stronger bond between aggregate and asphalt, thereby reducing peeling and crack expansion caused by moisture damage.

[0008] Based on the above technical solution, preferably, the aggregate comprises, by weight percentage, 65-75% coarse aggregate and no more than 15% fine aggregate; The particle size of the coarse aggregate is 4.75-13.2 mm, and the particle size of the fine aggregate is 0.075-2.36 mm.

[0009] On the basis of the above technical solution, preferably, the void ratio of the high-toughness asphalt mixture is 4-6%.

[0010] By adopting this technical solution, a good skeleton structure is ensured within the mixture, enhancing the inter-material interlocking and stability, and effectively improving the road surface's resistance to rutting deformation. Furthermore, controlling the porosity of the high-toughness asphalt mixture to 4-6% ensures sufficient density to enhance resistance to water damage while providing appropriate pore space to allow for thermal expansion and contraction, reducing cracks caused by thermal stress.

[0011] In a second aspect, the present invention relates to a method for preparing the above-mentioned high-toughness asphalt mixture, comprising the following steps: S1. Prepare the corresponding components according to the mass fractions, heat the base asphalt, add the SBS modifier under stirring, continue stirring, then shear the mixture and place it in a constant temperature environment to develop to obtain modified asphalt; S2. Preheat the aggregate and filler, and under constant temperature stirring conditions, sequentially add the modified asphalt and polyester fiber of S1, and continue stirring to obtain a high-toughness asphalt mixture.

[0012] By adopting the above technical solution, first, in the S1 step, the matrix asphalt and the SBS modifier are fully stirred and sheared, which ensures that the modifier is evenly dispersed in the matrix asphalt, thereby obtaining a modified asphalt with more stable and enhanced performance. This treatment method can not only improve the durability and elasticity of the material, but also optimize its processing performance. Secondly, in the S2 step, by preheating the aggregate and filler, and adding modified asphalt and polyester fiber under constant temperature conditions, it is ensured that the good combination between the components is achieved, and the consistency and stability of the mixture are promoted. This method effectively improves the overall strength, rutting resistance and crack resistance of high-toughness asphalt mixture, thereby extending the service life of the road, reducing maintenance costs, and providing reliable protection for high-quality road construction.

[0013] In a third aspect, the present invention provides a high-toughness asphalt surface layer structure for an asphalt pavement, comprising a V-grooved layer, a tack layer, and a high-toughness asphalt surface layer laid from bottom to top; The V-shaped groove layer is a V-shaped groove opened in the road surface sub-layer, the ratio of the width to the depth of the V-shaped groove is 1.5-2.5:1, the depth is 3-6 mm, and the groove bottom angle is 65-75 degrees; The high-toughness asphalt surface layer is prepared from the above-mentioned high-toughness asphalt mixture.

[0014] By adopting this technical solution, the V-grooved layer design increases the contact area and interlocking ability between the new and old layers, effectively improving the interlayer bonding strength and shear resistance, reducing the occurrence of reflective cracks, and is more conducive to stress dispersion and improved interfacial bonding strength compared to traditional rectangular groove structures. The high-toughness asphalt mixture used in the high-toughness asphalt surface layer, especially the addition of SBS modifiers and polyester fibers, enhances the material's flexibility, wear resistance, and temperature sensitivity, making the road surface more resistant to deformation and damage when subjected to heavy traffic and environmental stresses.

[0015] On the basis of the above technical solution, preferably, the groove spacing between the V-shaped grooves is 1.0 to 1.5 times the groove width.

[0016] By adopting this technical solution, appropriate groove spacing ensures sufficient spatial distribution to enhance interlayer bonding, while avoiding the construction difficulties or insufficient material filling caused by too small spacing, and the weakening of the interlocking effect caused by too large spacing. This design not only improves the overall stability and shear strength of the structure, but also effectively distributes the pressure of traffic loads on the road surface, reducing the risk of damage caused by localized stress concentration, such as rutting and cracking, thereby further extending the service life of the road surface and improving driving safety and comfort. Furthermore, this optimization helps improve construction efficiency and quality, and reduces subsequent maintenance costs.

[0017] On the basis of the above technical solution, preferably, the V-shaped groove is filled with polymer-modified emulsified asphalt, and the polymer-modified emulsified asphalt is an emulsified asphalt material with a softening point greater than or equal to 85 and an adhesion grade not less than 4.

[0018] This technical solution effectively fills and seals the V-grooves, providing strong interlayer adhesion and shear strength, preventing delamination and damage caused by moisture intrusion. Furthermore, the high softening point of the filler material ensures stability under high-temperature conditions, reducing the risk of rutting and deformation. Its excellent adhesion ensures a tight bond between the new and old layers, further reducing the likelihood of reflective cracks.

[0019] On the basis of the above technical solution, preferably, the thickness of the high-toughness asphalt surface layer is 1.5~2 cm.

[0020] By adopting this technical solution, sufficient strength and wear resistance are guaranteed to effectively resist the influence of traffic loads and environmental factors. At the same time, its thickness range ensures good construction operability and adaptability, making it particularly suitable for urban roads or heavy-load sections that require efficient repair.

[0021] On the basis of the above technical solution, preferably, the material used for preparing the adhesive layer is a special non-stick wheel emulsified asphalt material with an adhesion grade of not less than 4 and a demulsification time of not more than 5 hours.

[0022] By adopting the above technical solution, not only good construction performance is achieved, but also tire adhesion problems that may be caused by traditional materials are avoided, ensuring paving quality and flatness.

[0023] On the basis of the above technical solution, preferably, the spreading amount of the adhesive layer is 0.4~0.6kg / m 2 .

[0024] By adopting the above technical solution, the bonding effect between the new and old layers is enhanced, interlayer damage caused by moisture infiltration is prevented, and unnecessary cost increases or performance waste caused by excessive thickness is avoided.

[0025] In a fourth aspect, the present invention relates to a construction method for the above-mentioned high-toughness asphalt surface layer structure of an asphalt pavement, comprising the following steps: S1. Use precision milling technology to create V-shaped grooves in the road sub-base. After cleaning, fill the grooves with polymer-modified emulsified asphalt. S2. Spray special non-stick wheel emulsified asphalt on the road surface treated in S1 and spread hot mix high-toughness asphalt mixture, laying the tack coat and high-toughness asphalt surface layer; S3. Use a steel wheel and rubber wheel combination roller to compact and complete the construction.

[0026] By adopting the above technical solutions, the simultaneous construction method significantly enhanced the bond strength between each layer and the consistency of the overall structure. In addition, this method greatly improved construction efficiency, shortened the construction period, and reduced the uncertainty risks caused by multiple operations.

[0027] On the basis of the above technical solution, preferably, in step S2, the paving temperature is 150-160°C; and in step S3, the final pressing temperature is not lower than 90°C.

[0028] The present invention provides a high-toughness asphalt mixture and a preparation method thereof, as well as a viscous-tough wear composite layer and a construction method thereof, which have the following beneficial effects compared to the prior art: (1) The high-toughness asphalt mixture provided by the present invention significantly improves the high-temperature stability and durability of the asphalt mixture by adding SBS modifier and polyester fiber. The selection and proportion of aggregates, combined with the network structure of polyester fiber, ensures an appropriate porosity in the mixture, which not only helps pavement drainage but also enhances the stability of the overall structure.

[0029] (2) The high-toughness asphalt mixture prepared by the present invention has a simple preparation method and ensures good fusion of various components, thereby improving the physical and mechanical properties of the mixture, making it more suitable for application in various road environments.

[0030] (3) The viscous and tough wear composite layer of the present invention is a V-grooved layer formed by fine milling to optimize water drainage and reduce water damage, while the tack layer and the high-toughness asphalt surface layer strengthen the bonding between the new and old pavements, thereby improving the integrity and durability of the pavement.

[0031] (4) The construction method of the viscous-tough wear composite layer of the present invention is simple and easy to implement. During construction, the precision milling technology is combined with the synchronous construction method to effectively prevent moisture penetration and improve the interface bonding strength. It not only ensures the flatness and density of the road surface and improves the durability of the road, but also further improves the construction efficiency and has certain economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 The visco-tough wear composite layer of Example 1 of the present invention; Figure 2 The visco-tough wear composite layer of Comparative Example 2 of the present invention; Figure 3 The visco-tough wear composite layer of Comparative Example 3 of the present invention; In the figure, 1 is the V-shaped slotted layer, 2 is the tack layer, 3 is the high-toughness asphalt surface layer, 4 is the pavement sub-layer; 5 is the rectangular slotted layer. DETAILED DESCRIPTION

[0034] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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.

[0035] When faced with heavy traffic or certain high-grade roads, traditional asphalt pavement structures often suffer from frequent reflective cracks and interlayer peeling due to insufficient interlayer adhesion, making it difficult to provide sufficient shear resistance. In addition, due to the limitations of the viscoelastic properties of conventional wearing layer materials, they are prone to peeling, water seepage and other defects under the coupling of temperature stress and load, resulting in rapid attenuation of the pavement structure depth, seriously affecting the service life of the road. At the same time, existing repair technologies and materials perform poorly in resisting rutting deformation and fatigue cracking, making it difficult to meet the high strength and long life requirements of high-grade roads. In view of the above problems, the inventors made the present invention through further exploration and research.

[0036] The inventors took the above factors into full consideration when designing the structure of the high-toughness asphalt surface layer 3 of the asphalt pavement. First, by using fine milling technology to treat and open V-shaped grooves on the underlying layer of the pavement, not only more physical locking points are provided in the structure and the contact area is increased, but also the adhesion and flexibility are improved by using high-performance polymer-modified emulsified asphalt in the material selection. This fundamentally solves the problem of insufficient bonding between the layers of the traditional pavement, ensures a firm bond between the new and old layers, significantly improves the interlayer bonding strength and shear resistance, and effectively prevents the occurrence of reflective cracks and interlayer peeling. Secondly, the high-toughness asphalt surface layer 3 significantly improves the overall flexibility, wear resistance and water damage resistance of the material by using a specific ratio of materials and strictly controlling the porosity: (1) The rubber segment in the molecular structure of the SBS modifier provides good elastic recovery for the matrix asphalt, while the hard segment enhances the thermal stability of the material. This combination enables the high-toughness asphalt mixture to maintain excellent flexibility and deformation resistance under different temperature conditions. (2) The addition of polyester fibers can assist in forming a three-dimensional network structure during the preparation of the mixture, effectively dispersing stress concentration points and preventing crack expansion. At the same time, the fibers can also absorb some energy and reduce local deformation caused by vehicle loads. (3) In addition, the porosity of the high-toughness asphalt surface layer 3 was specially considered during the design. This not only ensures sufficient density to enhance the ability to resist water damage, but also provides appropriate pore space to allow thermal expansion and contraction, reducing cracks caused by temperature stress. Reasonable porosity also ensures drainage performance, preventing moisture from invading and being retained inside the pavement structure, thereby avoiding peeling and water seepage caused by moisture. Finally, the simultaneous spraying of special non-stick wheel emulsified asphalt and paving of hot-mixed high-toughness asphalt mixture can ensure that the tack layer 2 material is tightly combined with the hot-mixed high-toughness asphalt mixture in the best condition, avoiding surface contamination or environmental impact caused by time difference, further improving construction efficiency and interlayer adhesion, and further ensuring high quality and flatness.

[0037] Before construction begins on the pavement subsoil, the existing pavement must be thoroughly cleaned, and any cracks, potholes, or other damaged areas must be repaired and reinforced to remove all dust, debris, and other contaminants, ensuring a smooth and stable pavement. Furthermore, material heating and insulation temperatures must be strictly controlled. The base asphalt must be heated to 160-180°C, and the aggregate must be preheated to the same temperature and maintained during transportation. Paving and compaction temperatures must be continuously monitored on-site to ensure paving temperatures are between 150-160°C and final compaction temperatures are no lower than 90°C. During construction, the pavement temperature must be maintained above 10°C, and construction must be avoided on rainy days. Specialized equipment should be used for uniform paving to avoid uneven thickness, with special attention paid to edge areas. Compaction should be carried out in layers, from initial compaction to secondary compaction to final compaction, ensuring adequate compaction in every area, especially at joints. Longitudinal and transverse joints should be treated using hot jointing techniques or specialized equipment to ensure density and flatness. During construction, the construction area should be closed and clearly marked. Newly paved pavement should be allowed to cool to below 50°C before being opened to traffic. Finally, newly paved pavement requires proper maintenance, such as covering with a moisture-retaining blanket or watering, to prevent premature cracking. Based on the above description, it's clear that all precautions and requirements during construction, unless otherwise noted in this article, follow standard procedures and are not detailed here.

[0038] The present invention will be further described below with reference to specific embodiments, and the scope of protection of the present invention is not limited by the following embodiments. Unless otherwise specified, the materials mainly involved in the following examples are conventional commercial products. Similar materials from other manufacturers may be used under the premise of meeting the technical requirements of the materials without changing the implementation effect and technical standards of this patent.

[0039] Table 1 Material source description The following are preparation examples of the present application, each of which provides a high-toughness asphalt mixture for preparing a high-toughness asphalt surface layer 3, all of which are prepared under the same environment.

[0040] Preparation Example 1 This preparation example provides a high-toughness asphalt mixture for preparing a high-toughness asphalt surface layer 3, comprising the following steps: Heat 6 kg of base asphalt to 160°C to achieve a suitable flow state; add 3% of the mass of the base asphalt as an SBS modifier under stirring conditions, continue stirring for 30 minutes, and then use a high-speed shearing machine to shear the mixture for 15 minutes; place the modified asphalt in a constant temperature environment for 2 hours.

[0041] 68 kg of aggregate (65% coarse aggregate, 15% fine aggregate) and 8 kg of filler were preheated to 160°C, added to the mixing equipment, and the equipment temperature was kept at 160°C. The prepared SBS modified asphalt was then added and stirred. Finally, 0.2 kg of polyester fiber was added in small amounts several times, with at least 20 seconds between each addition. Stirring was continued for 5 minutes to form a stable high-toughness asphalt mixture Z1.

[0042] Preparation Example 2 This preparation example provides a high-toughness asphalt mixture for preparing a high-toughness asphalt surface layer 3, comprising the following steps: Heat 6.5 kg of base asphalt to 180°C to achieve a suitable flow state; add 5% SBS modifier by mass of the base asphalt under stirring conditions, continue stirring for 60 minutes, and then use a high-speed shearing machine to shear the mixture for 30 minutes; place the modified asphalt in a constant temperature environment for 4 hours.

[0043] Preheat 70 kg of aggregate (70% coarse aggregate, 10% fine aggregate) and 10 kg of filler to 180°C, add them to the mixing equipment, and keep the equipment temperature at 180°C. Then add the prepared SBS modified asphalt and stir. Finally, add 0.3 kg of polyester fiber in small amounts several times, with at least 20 seconds between each addition. Continue stirring for 10 minutes to form a stable high-toughness asphalt mixture Z2.

[0044] Preparation Example 3 This preparation example provides a high-toughness asphalt mixture for preparing a high-toughness asphalt surface layer 3, comprising the following steps: Heat 7 kg of base asphalt to 180°C to achieve a suitable flow state; add 5% SBS modifier by mass of the base asphalt under stirring conditions, continue stirring for 60 minutes, and then use a high-speed shearing machine to shear the mixture for 30 minutes; place the modified asphalt in a constant temperature environment for 4 hours.

[0045] 72 kg of aggregate (75% coarse aggregate, 6% fine aggregate) and 12 kg of filler were preheated to 180°C, added to the mixing equipment, and the equipment temperature was kept at 180°C. The prepared SBS modified asphalt was then added and stirred. Finally, 0.4 kg of polyester fiber was added in small amounts several times, with at least 20 seconds between each addition. Stirring was continued for 10 minutes to form a stable high-toughness asphalt mixture Z3.

[0046] Preparation Example 4 This preparation example provides a high-toughness asphalt mixture for preparing a high-toughness asphalt surface layer 3, comprising the following steps: Heat 7.5 kg of base asphalt to 160°C to achieve a suitable flow state; add 3% of the mass of the base asphalt as an SBS modifier under stirring conditions, continue stirring for 30 minutes, and then use a high-speed shearing machine to shear the mixture for 15 minutes; place the modified asphalt in a constant temperature environment for 2 hours.

[0047] 72 kg of aggregate (72% coarse aggregate, 2% fine aggregate) and 12 kg of filler were preheated to 160°C, added to the mixing equipment, and the equipment temperature was kept at 160°C. The prepared SBS modified asphalt was then added and stirred. Finally, 0.4 kg of polyester fiber was added in small amounts several times, with at least 20 seconds between each addition. Stirring was continued for 5 minutes to form a stable high-toughness asphalt mixture Z4.

[0048] Preparation Comparative Example 1 The difference from Preparation Example 1 is that no polyester fiber is added, and the other steps remain unchanged to obtain ZD1.

[0049] Preparation Comparative Example 2 The difference from Preparation Example 1 is that 0.1 kg of polyester fiber is added, and the other steps remain unchanged to obtain ZD2.

[0050] Preparation Comparative Example 3 The difference from Preparation Example 1 is that 0.5 kg of polyester fiber was added, and the other steps remained unchanged to obtain ZD3.

[0051] Preparation Comparative Example 4 The difference from Preparation Example 1 is that 0.2 kg of polyester fiber is added at one time, and the other steps remain unchanged to obtain ZD4.

[0052] Preparation Comparative Example 5 The difference from Preparation Example 2 is that the base asphalt is modified with a commercially available EVA modifier, and the other steps remain unchanged to obtain ZD5.

[0053] Preparation Comparative Example 6 The difference from Preparation Example 2 is that 70 kg of aggregate (70% coarse aggregate, 20% fine aggregate) is used, and the other steps remain unchanged to obtain ZD6.

[0054] The following performance tests were performed on the above Preparation Examples 1 to 4 and Comparative Preparation Examples 1 to 6, including: 1. Porosity By measuring the maximum density that asphalt mixture can achieve under ideal conditions, the void ratio is calculated based on the difference between the actual density and the theoretical maximum density. The following steps are involved: a. Determine the bulk density of asphalt mixture using the surface drying method; b. Determine the theoretical maximum relative density of the asphalt mixture (usually by completely compacting all aggregates and asphalt in the mixture to the density in the air-free state); c. Calculate the void ratio using the formula: Void ratio = (1-bulk volume density / theoretical maximum relative density bulk volume density) × 100%.

[0055] 2. Determination of water permeability coefficient The test was carried out in accordance with the relevant records in the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" JTG E20-2011. 3. Water stability test The test was carried out in accordance with the relevant descriptions in the immersion Marshall test (JTG E20-2011).

[0056] The above performance test results are recorded in Table 2 below.

[0057] Table 2 Performance test results Comparing Preparation Example 1 with Comparative Examples 1-4, combined with the experimental data in Table 2, reveals that the void content of ZD1 significantly increased, while its water stability decreased. This indicates that the absence of polyester fiber resulted in a lack of internal support within the mixture, preventing effective filling between coarse and fine aggregates. This increased interstices between aggregates, resulting in a loose structure, which accelerated the separation of asphalt from aggregate after water intrusion. In ZD2, insufficient polyester fiber was added, resulting in a high void content, indicating that the interstices between aggregates were not fully filled, resulting in insufficient density. This indicates that a low fiber content fails to effectively block water penetration, leaving the asphalt-aggregate interface susceptible to erosion. In ZD3, excessive polyester fiber addition led to the formation of fiber agglomerates within the mixture, hindering uniform dispersion and causing localized "void concentrations," resulting in a decrease in overall impermeability. In ZD4, when the fibers were added all at once, the fibers easily formed localized clumping due to electrostatic adsorption or insufficient mechanical agitation. These agglomerates prevented effective filling between aggregates, leading to uneven void distribution and an increase in the overall void content. Z1 achieves a dense skeleton structure by optimizing aggregate grading and polyester fiber filling, reduces ineffective pores, and exhibits good water stability and low water permeability coefficient.

[0058] This demonstrates that controlling the polyester fiber addition rate between 0.2% and 0.4% and optimizing the process to "small, multiple additions," combined with the aggregate gradation relationship provided by the present invention, allows the high-toughness asphalt surface layer 3 to exhibit good waterproofing and excellent water stability, helping to avoid aggregate segregation during subsequent construction.

[0059] By comparing Preparation Example 2 and Comparative Example 5, and combining the test data results in Table 2, it can be seen that ZD5 exhibits a higher void ratio. Analysis shows that the reason may be that the EVA modifier has poorer fluidity and adhesion under high temperature conditions than the SBS modifier, resulting in it being unable to fully fill the voids between aggregates during the mixing process, thereby increasing the void ratio, and thus the water penetration path is not completely blocked, and the water permeability coefficient is significantly higher than that of Z2.

[0060] In addition, by comparing Preparation Example 2 and Comparative Example 6, and combining the test data results in Table 2, it can be seen that: there are too many fine aggregates in ZD6, which are easily accumulated in the gaps between the coarse aggregates, destroying the skeleton intercalation effect, making the mixture structure loose, and although it can block the effective pores, it increases the ineffective voids, resulting in a decrease in the overall density, and thus an increase in the water permeability coefficient. In addition, combined with Preparation Examples 1 to 4, it can be seen that: when the amount of fine aggregate is too low, such as Z4, the gaps between the aggregates increase, which leads to a decrease in the ability to resist water seepage. Therefore, the inventor further suggests: on the basis of controlling the coarse aggregate to 65~75% and the fine aggregate to no more than 15%, further limiting the proportion of fine aggregate to no less than 6% will help improve the comprehensive performance of the high-toughness asphalt surface layer 3.

[0061] The following are embodiments of the present application, which provide a structure and construction method for a high-toughness asphalt surface layer 3 of an asphalt pavement.

[0062] Example 1 like Figure 1 As shown, this embodiment provides a visco-tough wear composite layer, which is designed as shown in Table 3, including: Table 3 The construction method of this embodiment includes the following steps: S1. Use precision milling technology to create V-shaped grooves in the road sub-base. After cleaning, fill the grooves with polymer-modified emulsified asphalt. S2, at 150°C, spray special non-stick wheel emulsified asphalt on the road surface treated in S1 and spread hot-mix high-toughness asphalt mixture, laying tack coat 2 and high-toughness asphalt surface layer 3; S3. Use a steel wheel and rubber wheel combination roller to compact and complete the construction.

[0063] Example 2 This embodiment provides a visco-tough wear composite layer, which is designed as shown in Table 4 and includes: Table 4 The construction method of this embodiment includes the following steps: S1. Use precision milling technology to create V-shaped grooves in the road sub-base. After cleaning, fill the grooves with polymer-modified emulsified asphalt. S2, at 160°C, spray special non-stick wheel emulsified asphalt on the road surface treated in S1 and spread hot-mix high-toughness asphalt mixture, laying tack coat 2 and high-toughness asphalt surface layer 3; S3. Use a steel wheel and rubber wheel combination roller to compact and complete the construction.

[0064] Example 3 This embodiment provides a visco-tough wear composite layer, which is designed as shown in Table 5 and includes: Table 5 The construction method of this embodiment includes the following steps: S1. Use precision milling technology to create V-shaped grooves in the road sub-base. After cleaning, fill the grooves with polymer-modified emulsified asphalt. S2, at 160°C, spray special non-stick wheel emulsified asphalt on the road surface treated in S1 and spread hot-mix high-toughness asphalt mixture, laying tack coat 2 and high-toughness asphalt surface layer 3; S3. Use a steel wheel and rubber wheel combination roller to compact and complete the construction.

[0065] Example 4 This embodiment provides a visco-tough wear composite layer, which is designed as shown in Table 6 and includes: Table 6 The construction method of this embodiment includes the following steps: S1. Use precision milling technology to create V-shaped grooves in the road sub-base. After cleaning, fill the grooves with polymer-modified emulsified asphalt. S2, at 150°C, spray special non-stick wheel emulsified asphalt on the road surface treated in S1 and spread hot-mix high-toughness asphalt mixture, laying tack coat 2 and high-toughness asphalt surface layer 3; S3. Use a steel wheel and rubber wheel combination roller to compact and complete the construction.

[0066] Comparative Example 1 The difference from Example 1 is that in step S2, the adhesive layer 2 is spread first, and then the high-toughness asphalt surface layer 3 is laid.

[0067] Comparative Example 2 The difference from Example 1 is: Figure 2 As shown, the V-grooved layer 1 is missing and the construction method is adjusted accordingly.

[0068] Comparative Example 3 The difference from Example 2 is: Figure 3 As shown, rectangular grooves are used instead of V-grooves, and the construction method is adjusted accordingly.

[0069] Comparative Example 4 The difference from Example 3 is that the laying thickness of the high-toughness asphalt surface layer 3 is 2.1 cm, and the construction method is adjusted accordingly.

[0070] Comparative Example 5 The difference from Example 3 is that the laying thickness of the high-toughness asphalt surface layer 3 is 1.4 cm, and the construction method is adjusted accordingly.

[0071] Comparative Example 6 The difference from Example 4 is that the V-grooved layer 1 is not filled with polymer-modified emulsified asphalt, and the other steps remain unchanged.

[0072] Performance testing was performed on Examples 1-4 and Comparative Examples 1-6. Dynamic stability, low-temperature flexural strain, and interlayer bond strength were tested according to JTG E20-2011, "Testing Procedures for Asphalt and Asphalt Mixtures for Highway Engineering." Anti-skid performance and smoothness were tested according to JTG 3450-2019, "Field Testing Procedures for Highway Subgrade and Pavement." The performance test results are shown in Table 7.

[0073] Table 7 Performance test results The performance test results in Table 8 show that the asphalt pavements obtained in Examples 1 to 4 are all superior to those in Comparative Examples 1 to 6, indicating that the viscous-tough wear composite layer and its construction method of the present invention not only improve the overall bearing capacity and service life of the road, but also greatly reduce maintenance costs and improve driving safety and comfort.

[0074] Comparison of the pavement performance results of Example 1 and Comparative Example 1 shows that step-by-step construction can easily lead to problems such as interlayer thermal bonding failure and insufficient mixture compaction. The simultaneous construction method of the present invention helps to enhance interlayer bonding strength, thereby improving pavement stability and durability.

[0075] By comparing Example 1 and Comparative Example 2, and Example 2 and Comparative Example 3, it is further illustrated that the road surface is finely milled and further designed into a V-groove, resulting in better overall performance. This is because the V-groove formed by fine milling helps to strengthen the interface and provide an anti-skid texture, and the tip shape of the V-groove bottom easily forms a "hole effect", which can reduce stress concentration at the crack tip and delay crack expansion. The right-angled edges of the rectangular groove are prone to stress concentration problems. In addition, the right-angled groove wall of the rectangular groove is not tightly bonded to the filling material, which easily forms a weak interface, thereby increasing the risk of interlayer delamination.

[0076] By comparing Example 3 with Comparative Examples 4-5, it is shown that if the high-toughness asphalt surface layer 3 is too thick, it will easily lead to temperature segregation and deterioration of flatness, while if it is too thin, it will weaken the skeleton support and reduce the dynamic stability.

[0077] By comparing Example 4 and Comparative Example 6, it is shown that the V-shaped groove formed by the fine milling treatment can form mechanical bite by filling the groove with polymer-modified emulsified asphalt, which not only enhances the interlayer bonding strength and improves the load transfer efficiency, but also can better control the material distribution during the compaction process to ensure surface flatness.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements and changes in material sources made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high-toughness asphalt mixture, characterized in that: The composition comprises the following components in parts by mass: 6 to 7.5 parts of matrix asphalt, 8 to 12 parts of filler, 68 to 72 parts of aggregate, 0.2 to 0.4 parts of polyester fiber and 3 to 5% of the mass of the matrix asphalt by SBS modifier.

2. The high-toughness asphalt mixture according to claim 1, characterized in that: The aggregates, calculated by mass percentage, include: 65-75% coarse aggregate and no more than 15% fine aggregate; The particle size of the coarse aggregate is 4.75-13.2 mm, and the particle size of the fine aggregate is 0.075-2.36 mm.

3. The high-toughness asphalt mixture according to claim 1, characterized in that: The void ratio of the high-toughness asphalt mixture is 4-6%.

4. A method for preparing the high-toughness asphalt mixture according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1. Prepare the corresponding components according to the mass fractions, heat the base asphalt, add the SBS modifier under stirring, continue stirring, then shear the mixture and place it in a constant temperature environment to develop to obtain modified asphalt; S2. Preheat the aggregate and filler, and under constant temperature stirring conditions, sequentially add the modified asphalt and polyester fiber of S1, and continue stirring to obtain a high-toughness asphalt mixture.

5. A viscous-tough wear composite layer, characterized in that: It includes a V-shaped grooved layer (1), a tack layer (2) and a high-toughness asphalt surface layer (3) laid from bottom to top; The V-shaped groove layer (1) is a V-shaped groove opened in the road surface sub-layer, the ratio of the width to the depth of the V-shaped groove is 1.5-2.5:1, the depth is 3-6 mm, and the groove bottom angle is 65-75°; The high-toughness asphalt surface layer (3) is made from the high-toughness asphalt mixture according to any one of claims 1 to 3.

6. The viscous-tough wear composite layer according to claim 5, characterized in that: The groove spacing between the V-shaped grooves is 1.0 to 1.5 times the groove width.

7. The viscous-tough wear composite layer according to claim 6, characterized in that: The V-shaped groove is filled with polymer-modified emulsified asphalt, and the polymer-modified emulsified asphalt is an emulsified asphalt material with a softening point greater than or equal to 85 and an adhesion grade not less than grade 4.

8. The viscous-tough wear composite layer according to claim 5, characterized in that: The spreading amount of the adhesive layer (2) is 0.4~0.6kg / m 2 The material of the sticky layer is a special non-stick wheel emulsified asphalt material with an adhesion grade of not less than 4 and a demulsification time of not more than 5 hours; The thickness of the high-toughness asphalt surface layer (3) is 1.5-2 cm.

9. A method for constructing a viscous-tough abrasion composite layer according to any one of claims 5 to 8, characterized in that: The following steps are involved: S1. Use precision milling technology to create V-shaped grooves in the road sub-base. After cleaning, fill the grooves with polymer-modified emulsified asphalt. S2, spraying special non-stick wheel emulsified asphalt on the road surface treated in S1 and paving hot mix high-toughness asphalt mixture, laying the tack coat (2) and high-toughness asphalt surface layer (3); S3. Use a steel wheel and rubber wheel combination roller to compact and complete the construction.

10. The construction method of the adhesive-tough wear composite layer according to claim 9, characterized in that: In step S2, the paving temperature is 150-160°C; in step S3, the final pressing temperature is not lower than 90°C.

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