Method for repairing reflection cracks on road surface

Abstract

The invention discloses a method for repairing reflection cracks on a road surface, and relates to the technical field of road maintenance. The method comprises the following steps: detecting reflection crack diseases of a to-be-maintained road, and dividing the to-be-maintained road into a mild reflection crack disease road section and a severe reflection crack disease road section; aiming at a heavy reflection crack disease road section, firstly, a road surface layer is completely milled and planed, then, a self-leveling organic silicone sealant is adopted to carry out crack pouring pretreatment on the surface of a base layer, and then a stress absorption layer, asphalt stabilized macadam and an anti-crack asphalt mixture are additionally laid on the top of the base layer. Aiming at a light reflection crack disease road section, an upper surface layer in a road is milled firstly, then a two-component polyurethane elastomer material is adopted to carry out crack pouring pretreatment on the surface of a lower surface layer, and then basalt warp-knitted fiber cloth, asphalt stabilized macadam and an anti-crack asphalt mixture are additionally laid in sequence. Different repairing methods are adopted for light and heavy reflection cracks, the problem of road reflection crack diseases is more scientifically, reasonably and efficiently solved, the pavement use performance is improved, the maintenance period is shortened, and the service life is prolonged.

Description

Technical Field

[0001] This invention relates to the field of road maintenance technology, and in particular to a method for repairing reflective cracks in road surfaces. Background Technology

[0002] In my country, semi-rigid base course structures are commonly used for asphalt pavements on high-grade highways. While semi-rigid base course structures offer advantages such as high overall strength, good stability, and strong load-bearing capacity, they are prone to thermal shrinkage and drying cracks due to their inherent material properties. These cracks can then propagate upwards to the asphalt surface layer, forming reflective cracks. Reflective cracks not only disrupt the integrity and continuity of the asphalt pavement but also allow surface water and impurities to penetrate the base course, leading to potholes, pumping, and other defects, severely impacting the pavement's service quality. Therefore, addressing reflective cracking has become a critical issue in asphalt pavement maintenance.

[0003] Currently, the treatment of reflective cracks mainly involves methods such as filling cracks, sealing cracks, overlaying, and milling followed by repaving. While these methods can curb the development of reflective cracks to some extent, the timing and methods of crack treatment during maintenance rely heavily on engineering experience. There is a lack of classification criteria for road sections with different degrees of reflective cracking and targeted treatment methods, leading to unstable treatment results. Often, crack repairs fail prematurely due to delamination, cracking, and depressions, resulting in ineffective crack prevention measures. Summary of the Invention

[0004] This invention provides a method for repairing reflective cracks in road surfaces, addressing the current lack of classification criteria for road sections with varying degrees of reflective crack damage and the absence of targeted treatment for severely and mildly damaged sections during maintenance. This invention offers a more scientific, rational, and efficient solution to reflective crack problems on high-grade highways, improving pavement performance, reducing maintenance cycles, and extending pavement service life. Specifically, it is achieved through the following technical methods.

[0005] A method for repairing reflective cracks in road surfaces includes the following steps:

[0006] The road sections to be maintained were inspected for reflective cracking and classified into sections with mild reflective cracking and sections with severe reflective cracking.

[0007] For the road sections with severe reflective cracks, the road surface is milled until the base layer is exposed. Self-leveling silicone sealant is used to fill the cracks in the base layer for pretreatment. Stress-absorbing layer, asphalt-stabilized crushed stone layer and crack-resistant asphalt mixture layer are laid in sequence on the base layer.

[0008] For the road sections with mild reflective cracks, the upper and middle layers of the road are milled to expose the lower layer. A two-component polyurethane elastomer material is used to pre-treat the surface of the lower layer by filling cracks. Basalt warp-knitted fiber cloth, asphalt-stabilized crushed stone layer and crack-resistant asphalt mixture layer are laid sequentially on top of the lower layer.

[0009] Furthermore, the method for determining the road section with mild reflective crack damage is: 3-7 mild transverse cracks or 2-3 severe transverse cracks are distributed every 100 meters;

[0010] The method for determining the road section with severe reflective cracks is: at least 8 transverse cracks or at least 4 severe transverse cracks are distributed every 100 meters.

[0011] Furthermore, the mild transverse crack must simultaneously meet the following conditions: (1) the crack width is less than 3 mm; (2) the length of the main crack wall fragments is less than 40% of the main crack length; and (3) the core sample shows that the crack does not penetrate the entire pavement structure.

[0012] Furthermore, the severe transverse cracks can be defined as meeting one of the following conditions: (1) the crack width is greater than 3 mm; (2) the length of the main crack wall fragments is greater than 40% of the main crack length; (3) the core sample shows that the crack penetrates the entire pavement structure.

[0013] Furthermore, the stress-absorbing layer comprises, from bottom to top, a first rubber asphalt bonding layer, a glass fiber layer, a second rubber asphalt bonding layer, and a clean crushed stone layer.

[0014] Furthermore, both the first and second rubber asphalt bonding layers are processed using a hot-melt method; the base asphalt used in both layers is SK-90 asphalt, the rubber powder has a mesh size of 30, and the rubber powder accounts for 20% of the total mass of the base asphalt; the application rate of both layers is 1-1.75 kg / m³. 2 .

[0015] Furthermore, the glass fiber layer uses glass fibers with a length of 6 cm, a tensile strength ≥3000 MPa, an elastic modulus ≥70 GPa, an elongation at break greater than 3%, and a spreading rate of 0.11~0.13 kg / m². 2 .

[0016] Furthermore, the clean crushed stone layer uses clean crushed stone with a particle size of 5-10 mm and a spreading rate of 14-18 kg / m³. 2 The gravel coverage rate is 70-80%.

[0017] Furthermore, the mass per unit area of ​​the basalt warp-knitted fiber fabric is ≥300 g / m². 2 Both longitudinal tensile strength and transverse tensile strength are ≥50kN / m, and the ratio of longitudinal tensile strength to transverse tensile strength is 1.0-1.2.

[0018] Furthermore, the asphalt-stabilized crushed stone layer uses ATB-25 asphalt-stabilized crushed stone.

[0019] Furthermore, the asphalt-stabilized crushed stone layer has an asphalt-aggregate ratio of 3.5%, and its gradation composition consists of 0-3 mm aggregate, 3-6 mm aggregate, 6-11 mm aggregate, 11-17 mm aggregate, and mineral powder in a mass ratio of 24:35:6:31:4.

[0020] Furthermore, the crack-resistant asphalt mixture layer for the road section with mild reflective cracking is AC-13 basalt fiber asphalt mixture, and the crack-resistant asphalt mixture layer for the road section with severe reflective cracking is AC-20 SBS modified asphalt mixture and AC-13 basalt fiber asphalt mixture.

[0021] Furthermore, the AC-13 basalt fiber asphalt mixture has an asphalt-aggregate ratio of 5.1%, a basalt fiber content of 0.4%, a basalt fiber length of 9 mm, and a gradation composition of 0-5 mm aggregate, 5-10 mm aggregate, 10-15 mm aggregate and mineral powder in a mass ratio of 28:36:32:4.

[0022] Furthermore, the AC-20 SBS modified asphalt mixture has an asphalt-aggregate ratio of 4.2%, and its gradation composition consists of 0-4 mm aggregate, aggregates with particle sizes of 4-7 mm, 7-11 mm, 11-16 mm, and 16-26 mm, and mineral powder in a mass ratio of 22:27:14:25:9:3.

[0023] In the road pavement reflective crack repair method provided by the present invention, when detecting reflective crack defects in the road section to be maintained, a multi-functional road inspection vehicle and core drilling equipment are generally used, combined with manual investigation, to record the defect type and characteristics of the road section to be maintained, including but not limited to crack appearance, type, length, width, proportion of crack wall fragmentation, and crack penetration degree of core sample; then, according to the classification standard provided by the present invention, the road section to be maintained is divided into road sections with mild reflective crack defects and road sections with severe reflective crack defects.

[0024] The self-leveling silicone sealant used in the road surface reflective crack repair method provided by this invention is a common commercially available product; it is a single-component, room-temperature flowable crack repair material with low tensile modulus, high elasticity, and high displacement capacity. The main components of the self-leveling silicone sealant include polydimethylsiloxane, crosslinking agent, filler, plasticizer, coupling agent, and catalyst.

[0025] The two-component polyurethane elastomer material used in the above-mentioned road surface reflective crack repair method provided by the present invention is a common commercial product; it is a high-performance nanoscale two-component material that is liquid at room temperature and has strong stability and adhesion after curing.

[0026] Compared with existing technologies, the advantages of this invention are as follows: It classifies and grades road sections based on pavement distress detection results, proposes classification characteristics for road sections with mild and severe reflective cracking, and enhances the scientific rationality of the decision-making process for treating reflective cracking. It proposes different targeted treatment measures for road sections with mild and severe reflective cracking, which are widely applicable, have excellent treatment effects, and possess better stability and durability. This can significantly improve the performance of the pavement, maximize investment benefits, and effectively reduce maintenance costs. Attached Figure Description

[0027] Figure 1 A schematic flowchart illustrating the road surface reflective crack repair method provided by the present invention.

[0028] Figure 2 This is a schematic diagram comparing the pavement structure before and after the repair of a road section with severe reflective cracks, as presented in this invention.

[0029] Figure 3 This is a schematic diagram comparing the pavement structure before and after the repair of a road section with mild reflective cracks, as presented in this invention. Detailed Implementation

[0030] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example

[0032] This embodiment focuses on a major overhaul and maintenance project of a highway in Shaanxi Province. The original pavement structure, from top to bottom, consisted of: a top layer (4 cm fine-grained asphalt concrete (AC-13)), a middle layer (5 cm medium-grained asphalt concrete (AC-20)), a bottom layer (6 cm coarse-grained asphalt concrete (AC-25)), a 36 cm cement-stabilized crushed stone layer, and a 20 cm cement-lime stabilized soil layer. This pavement structure is a typical semi-rigid base pavement structure. By the maintenance period, the asphalt pavement had developed numerous reflective cracks.

[0033] For the aforementioned road sections requiring maintenance, this implementation provides a method for repairing reflective cracks in the road surface, with the following steps.

[0034] 1. A multi-functional road inspection vehicle and manual surveys were used to inspect each lane of the maintenance section, recording the types and characteristics of road defects in the section to be maintained. Defect characteristics include, but are not limited to, the appearance, type, length, width, and percentage of crack wall debris. Core samples were taken from transverse cracks, and the development of cracks within the core samples was observed and recorded.

[0035] 2. Based on the inspection results of the maintained road sections and the classification standards for reflective crack defects of road sections with mild and severe reflective crack defects, the reflective crack defects of the maintained road sections are divided.

[0036] The criteria for identifying road sections with mild reflective cracking are: 3-7 mild transverse cracks or 2-3 severe transverse cracks per 100 meters. The criteria for identifying road sections with severe reflective cracking are: at least 8 transverse cracks or at least 4 severe transverse cracks per 100 meters.

[0037] The mild transverse cracks must simultaneously meet the following conditions: (1) the crack width is less than 3 mm; (2) the length of the main crack wall fragments is less than 40% of the main crack length; (3) the core sample shows that the crack does not penetrate the entire pavement structure. The severe transverse cracks only need to meet one of the following conditions: (1) the crack width is greater than 3 mm; (2) the length of the main crack wall fragments is greater than 40% of the main crack length; (3) the core sample shows that the crack penetrates the entire pavement structure.

[0038] Based on on-site testing and statistics, nine transverse cracks were found within a continuous 100-meter section of road segment 1 selected for maintenance in this embodiment. Since the number of transverse cracks is greater than eight, this section was determined to be a severely reflective cracked road segment. Based on the test results, the road segment to be maintained was confirmed as a severely reflective cracked road segment.

[0039] In this embodiment, a continuous 100-meter section of road segment 2 to be maintained contains six transverse cracks. These six transverse cracks are wider than 3mm, and the length of the main crack wall fragments accounts for 30% to 50% of the total length. The reflective cracks in the core samples penetrate the entire pavement structure, indicating that all six transverse cracks are severe transverse cracks. Based on the test results, this road segment to be maintained is determined to be a severely reflective cracked road segment.

[0040] In this embodiment, section 3 of the road to be maintained, spanning 100 meters, exhibits seven transverse cracks. Two of these transverse cracks are wider than 3 mm, with the main crack wall fragments accounting for 20%-40% of the total length. Core samples show that these cracks penetrate the entire pavement structure, classifying them as severe transverse cracks. The other five transverse cracks are narrower than 3 mm, with the main crack wall fragments accounting for 20%-30% of the total length. Core samples show that these cracks do not penetrate the entire pavement structure, classifying them as mild transverse cracks. Based on the test results, this section is determined to be a mild reflective cracking defect.

[0041] In this embodiment, four transverse cracks are distributed within a continuous 100-meter section of road to be maintained. The width of these four transverse cracks is less than 3 mm, and the proportion of the main crack wall fragments is 10%-20%. Core samples show that the cracks do not penetrate the entire pavement structure, and the road is identified as having mild transverse cracks. Based on the test results, this road section is determined to be a mild reflective crack defect section.

[0042] 3. The treatment measures taken for the above-mentioned road sections with severe reflective cracking (section 1 and section 2) are as follows:

[0043] (1) Mill the existing road surface structure to be maintained, including the top layer (4 cm fine-grained asphalt concrete (AC-13)), the middle layer (5 cm medium-grained asphalt concrete (AC-20)) and the bottom layer (6 cm coarse-grained asphalt concrete (AC-25)) until the base layer is exposed.

[0044] An air compressor and a crack cleaning machine are used to clean the original base surface and crack openings, ensuring that the base surface is clean and dry and that stones and dirt in the cracks are completely removed.

[0045] (2) After the crack cleaning work is completed, the self-leveling silicone sealant (purchased from Dow Corning (Guangzhou) Silicone Co., Ltd., model: Dow Corning 890-SL) can be used to fill the cracks in the base layer at room temperature.

[0046] Specifically, insert the nozzle into the crack at a 45° angle and maintain a constant speed to ensure that the filling material fully fills the crack.

[0047] Half an hour after the grouting is completed or before the overall grouting work is finished, inspect the grouting area, mainly observing whether the grouting area is flat and sealed, and ensuring that there are no bubbles or leakage. If such phenomena exist, it is necessary to apply additional grout in time.

[0048] Self-leveling silicone sealant is a commonly used and commercially available, single-component, room-temperature flowable crack repair material with low tensile modulus, high elasticity, and high displacement capacity. Its main components include polydimethylsiloxane, crosslinking agents, fillers, plasticizers, coupling agents, and catalysts. It bonds tightly to the substrate material, exhibits good mechanical compatibility, and can significantly improve the crack resistance of the repaired area. Simultaneously, the self-leveling silicone sealant has high density and a certain degree of waterproofing, effectively preventing moisture from seeping into the crack.

[0049] (3) After the grouting is completed, a fiber rubber asphalt stress absorption layer is laid on top of the base layer, which includes, from bottom to top: the first rubber asphalt bonding layer, the glass fiber layer, the second rubber asphalt bonding layer, and the clean crushed stone layer.

[0050] A fiber-reinforced rubber asphalt chip seal layer is obtained by spreading the first rubber asphalt bonding layer, the glass fiber layer, the second rubber asphalt bonding layer, and the clean chip seal layer using a fiber-reinforced rubber asphalt chip seal vehicle.

[0051] The first and second rubber asphalt bonding layers were self-processed using a hot-melt method. The base asphalt used was No. 90 asphalt, the rubber powder had a mesh size of 30, the rubber powder content was 20%, and the spreading rate for both was 1.25 kg / m². 2 The spreading temperature should be 190℃.

[0052] The glass fiber has a length of 6 cm, a tensile strength of 3500 MPa, an elastic modulus of 72 GPa, an elongation at break of 3.4%, and a spreading rate of 0.12 kg / m. 2 .

[0053] The fiber rubber asphalt chip seal vehicle should travel at a constant speed of 3-5 km / h. During the spreading process, attention should be paid to controlling the horizontal and vertical overlap positions to avoid missed areas or excessive spreading at the overlaps.

[0054] Clean limestone with a particle size of 5-10 mm after washing, spread at a rate of 16 kg / m³. 2 The crushed stone coverage rate should be 80%, and the crushed stone discharge temperature should be 100℃. After the crushed stone is spread, the surface of the resulting product should be compacted 2-3 times using a rubber-tired roller.

[0055] In this embodiment, the fiber-reinforced rubber asphalt stress-absorbing layer uses 5-10 mm uniform-sized crushed stone with sharp edges, exhibiting good compatibility with asphalt mixtures. Furthermore, the crushed stone and rubber asphalt effectively dissipate the stress at the tip of reflective cracks, increasing the crack propagation path and reducing stress concentration effects, thus providing excellent stress absorption and dispersion. In addition, the presence of glass fibers in the fiber-reinforced rubber asphalt stress-absorbing layer significantly improves its overall crack resistance. Glass fibers possess high tensile strength and elongation at break, effectively preventing crack propagation.

[0056] (4) Add a lower layer of ATB-25 asphalt stabilized crushed stone mixture (asphalt stabilized crushed stone layer). ATB-25 asphalt stabilized crushed stone mixture has excellent shear, flexural and fatigue resistance properties, and as a lower layer, it can effectively inhibit the generation and development of reflective cracks.

[0057] The optimal asphalt-aggregate ratio for ATB-25 asphalt-stabilized crushed stone mixture is 3.5%, and the gradation composition is 0-3 mm aggregate, 3-6 mm aggregate, 6-11 mm aggregate, 11-17 mm aggregate and mineral powder in a mass ratio of 24:35:6:31:4.

[0058] The ATB-25 asphalt stabilized crushed stone mixture and its raw materials meet the relevant requirements of the "Technical Specification for Construction of Asphalt Pavement of Highway" (JTG F40-2004) (hereinafter referred to as the "Construction Specification"). The mixing, transportation, paving and compaction of the ATB-25 mixture are strictly carried out in accordance with the "Construction Specification".

[0059] (5) Adding an intermediate layer of AC-20 SBS modified asphalt mixture (crack-resistant asphalt mixture layer). AC-20 SBS modified asphalt mixture has excellent high and low temperature performance, water stability and fatigue resistance, and can effectively resist rutting, water damage and reflective cracking. Using this structure as an intermediate layer can effectively improve the fatigue resistance of the road, inhibit the development of reflective cracks and extend the service life of the pavement.

[0060] The optimal asphalt-aggregate ratio for AC-20 SBS modified asphalt mixture is 4.2%, and the gradation composition is 0-4 mm aggregate, 4-7 mm aggregate, 7-11 mm aggregate, 11-16 mm aggregate, 16-26 mm aggregate and mineral powder in a mass ratio of 22:27:14:25:9:3.

[0061] AC-20 SBS modified asphalt mixture and its raw materials all meet the relevant requirements of the "Construction Specification". The mixing, transportation, paving and compaction processes of AC-20 SBS modified asphalt mixture are strictly carried out in accordance with the "Construction Specification".

[0062] (6) Add AC-13 basalt fiber asphalt mixture as the top layer. AC-13 basalt fiber asphalt mixture has excellent crack resistance, high and low temperature performance, fatigue resistance and water stability. Using this structure as the top layer can effectively curb the development of reflective cracks to the road surface and greatly improve the service performance and service life of the road.

[0063] The optimal asphalt-aggregate ratio for AC-13 basalt fiber asphalt mixture is 5.1%, the fiber content is 0.4%, the fiber length is 9 mm, and the gradation composition is 0-5 mm aggregate, 5-10 mm aggregate, 10-15 mm aggregate and mineral powder in a mass ratio of 28:36:32:4.

[0064] AC-13 basalt fiber asphalt mixture and its raw materials all meet the relevant requirements of the "Construction Specification". The mixing, transportation, paving and compaction processes of AC-13 basalt fiber asphalt mixture are strictly carried out in accordance with the "Construction Specification".

[0065] 4. The treatment measures taken for the above-mentioned road sections with mild reflective cracking (sections 3 and 4) are as follows:

[0066] (1) Milling the existing road surface structure: surface layer (4 cm fine-grained asphalt concrete (AC-13)) and intermediate layer (5 cm medium-grained asphalt concrete (AC-20)).

[0067] An air compressor and a crack cleaning machine are used to clean the surface of the existing asphalt concrete layer and the openings of existing cracks, ensuring that the surface is clean and dry and that the stones and dirt inside the cracks are completely removed.

[0068] (2) After the crack cleaning work is completed, the two-component polyurethane elastomer material (purchased from Beijing Aishim Technology Co., Ltd., specification: Aishim TIT sealant) can be used to fill the cracks in the lower layer of asphalt pavement at room temperature.

[0069] Specifically, insert the nozzle into the crack at a 45° angle and maintain a constant speed to ensure that the filling material fully fills the crack.

[0070] Half an hour after the grouting is completed or before the overall grouting work is finished, inspect the grouting area, mainly observing whether the grouting area is flat and sealed, and ensuring that there are no bubbles or leakage. If such phenomena exist, it is necessary to apply additional grout in time.

[0071] Two-component polyurethane elastomer is a commercially available, high-performance, nanoscale two-component material. At room temperature, both components A and B are in liquid form. Before mixing and curing, both components exhibit good flowability and permeability, allowing for effective injection into cracks without the need for grooving or widening during construction. The mixture of components A and B cures rapidly, enabling quick traffic flow. Furthermore, the two-component polyurethane elastomer demonstrates good mechanical compatibility with the asphalt mixture matrix, exhibiting extremely stable properties after curing, and possessing excellent durability and adhesion.

[0072] (3) After the grouting is completed, basalt warp-knitted fiber cloth (purchased from Nanjing Daozhizun Composite Materials Co., Ltd.) is laid on top of the lower layer. The mass per unit area is 320 g / m². 2 The longitudinal and transverse tensile strengths are 58 kN / m and 53 kN / m, respectively, and the aspect ratio of the tensile strength is 1.09.

[0073] Before adding the basalt warp-knitted fiber, the required amount of basalt warp-knitted fiber should be arranged at the location of the maintenance section to ensure that the basalt warp-knitted fiber cloth can be laid immediately after the tack coat is applied.

[0074] After ensuring the road surface is flat, dry, and clean, determine the overlap positions of the basalt warp-knitted fiber cloth based on the width, length, and location of cracks, placing the overlaps as close as possible to the crack locations. The overlap widths for the longitudinal and transverse seams of the basalt warp-knitted fiber cloth are 5-10 cm and 10-15 cm, respectively. Within the marked area, apply the adhesive using an asphalt distributor. In this embodiment, No. 70 base asphalt is used, with a application rate of 1.2 kg / m². 2 .

[0075] After the tack coat is applied, basalt warp-knitted fiber cloth should be laid immediately. After laying, it should be rolled or brushed in a timely manner to ensure that the tack coat and basalt warp-knitted fiber cloth are tightly bonded. If wrinkles occur during the laying process, the wrinkles should be cut open with scissors or other tools, then overlapped and bonded tightly with hot asphalt.

[0076] (4) Add an intermediate layer of ATB-25 asphalt stabilized crushed stone mixture (asphalt stabilized crushed stone layer).

[0077] ATB-25 asphalt-stabilized crushed stone mixture has excellent shear, flexural, and fatigue resistance properties. Using this structure as the intermediate layer can effectively suppress the development of reflective cracks.

[0078] The optimal asphalt-aggregate ratio for ATB-25 asphalt-stabilized crushed stone mixture is 3.5%, and the gradation composition is 0-3 mm aggregate, 3-6 mm aggregate, 6-11 mm aggregate, 11-17 mm aggregate and mineral powder in a mass ratio of 24:35:6:31:4.

[0079] All indicators of the asphalt mixture and its raw materials meet the relevant requirements of the "Construction Specification". The mixing, transportation, paving and compaction of ATB-25 mixture are strictly carried out in accordance with the "Construction Specification".

[0080] (5) Add a top layer of AC-13 basalt fiber asphalt mixture (crack-resistant asphalt mixture layer).

[0081] AC-13 basalt fiber asphalt mixture possesses excellent crack resistance, high and low temperature performance, fatigue resistance, and water stability. Using this structure as the top layer can effectively inhibit the development of reflective cracks to the road surface, significantly improving pavement performance and lifespan.

[0082] The optimal asphalt-aggregate ratio for AC-13 basalt fiber asphalt mixture is 5.1%, the fiber content is 0.4%, the fiber length is 9 mm, and the gradation composition is 0-5 mm aggregate, 5-10 mm aggregate, 10-15 mm aggregate and mineral powder in a mass ratio of 28:36:32:4.

[0083] The mixture and its raw materials all meet the relevant requirements of the "Construction Specification". The mixing, transportation, paving and compaction of AC-13 basalt fiber asphalt mixture are strictly carried out in accordance with the "Construction Specification".

[0084] This invention discloses a comprehensive treatment method for reflective cracks in high-grade highways, which is scientific, reasonable, and targeted. It effectively addresses the lack of grading criteria and targeted treatment in the treatment of reflective cracks in semi-rigid base courses of high-grade highways. This application proposes a classification method for road sections with different degrees of reflective crack damage and adopts targeted treatment measures for these sections. This approach can more scientifically, rationally, and efficiently solve the problem of reflective crack damage in high-grade highways, improve pavement performance, extend pavement service life, and reduce pavement maintenance cycles.

[0085] This invention discloses a method for repairing reflective cracks in road pavements. The method categorizes reflective crack damage on roads to be maintained into mild and severe cases. For the severe and mild cases, silicone sealant and two-component polyurethane are used to fill and repair cracks in the base and subbase layers, respectively. Both silicone sealant and two-component polyurethane exhibit good mechanical compatibility with cement-stabilized crushed stone and asphalt mixtures, effectively inhibiting crack propagation and preventing moisture ingress. During the treatment of severe reflective crack sections, the base... The fiber-reinforced rubber asphalt stress-absorbing layer laid on top of the main layer not only possesses excellent stress absorption and dissipation properties but also exhibits good crack resistance and impermeability, effectively inhibiting and delaying the upward propagation of reflective cracks. In the treatment of sections with mild reflective cracking, the basalt warp-knitted fiber cloth laid on top of the lower layer possesses excellent crack resistance and waterproofing properties, effectively inhibiting and delaying the development of reflective cracks. The overlay of asphalt-stabilized crushed stone and crack-resistant asphalt mixture further improves the pavement's performance, delays the development of reflective cracks, and reduces the occurrence of fatigue cracks, rutting, water damage, and other defects. With the comprehensive guarantee of multiple treatment measures, the post-maintenance pavement service quality can be significantly improved, extending the road's service life.

[0086] The above detailed embodiments describe the implementation of the present invention; however, the present invention is not limited to the specific details described in the above embodiments. Within the scope of the claims and technical concept of the present invention, various simple modifications and changes can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

Claims

1. A method for repairing reflective cracks in road surface, characterized in that, Includes the following steps: The road sections to be maintained were inspected for reflective cracking and classified into sections with mild reflective cracking and sections with severe reflective cracking. For the road sections with severe reflective cracks, the road surface is milled until the base layer is exposed. Self-leveling silicone sealant is used to fill the cracks in the base layer for pretreatment. Stress-absorbing layer, asphalt-stabilized crushed stone layer and crack-resistant asphalt mixture layer are laid in sequence on the base layer. For the road sections with mild reflective cracks, the upper and middle layers of the road are milled to expose the lower layer. A two-component polyurethane elastomer material is used to pre-treat the surface of the lower layer by filling cracks. Basalt warp-knitted fiber cloth, asphalt-stabilized crushed stone layer and crack-resistant asphalt mixture layer are laid sequentially on top of the lower layer.

2. The method for repairing reflective cracks in road surfaces according to claim 1, characterized in that, The method for judging the road section with mild reflective cracks is: 3-7 mild transverse cracks or 2-3 severe transverse cracks are distributed every 100 meters; The method for determining the road section with severe reflective cracks is: at least 8 transverse cracks or at least 4 severe transverse cracks are distributed every 100 meters.

3. The method for repairing reflective cracks in road surfaces according to claim 1, characterized in that, The stress-absorbing layer comprises, from bottom to top: a first rubber asphalt bonding layer, a glass fiber layer, a second rubber asphalt bonding layer, and a clean crushed stone layer.

4. The method for repairing reflective cracks in road surfaces according to claim 3, characterized in that, Both the first and second rubber asphalt bonding layers are processed using a hot-melt method. The base asphalt used in both layers is SK-90 asphalt, and the rubber powder has a mesh size of 30. The rubber powder content accounts for 20% of the total mass of the base asphalt. The application rate of both the first and second rubber asphalt bonding layers is 1-1.75 kg / m³. 2 .

5. The method for repairing reflective cracks in road surfaces according to claim 3, characterized in that, The glass fiber layer uses glass fibers with a length of 6 cm, a tensile strength ≥3000 MPa, an elastic modulus ≥70 GPa, an elongation at break greater than 3%, and a spreading rate of 0.11-0.13 kg / m². 2 .

6. The method for repairing reflective cracks in road surfaces according to claim 3, characterized in that, The clean crushed stone layer uses clean crushed stone with a particle size of 5-10 mm and a spreading rate of 14-18 kg / m³. 2 The gravel coverage rate is 70-80%.

7. The method for repairing reflective cracks in road surfaces according to claim 1, characterized in that, The mass per unit area of ​​the basalt warp-knitted fiber fabric is ≥300 g / m². 2 Both longitudinal tensile strength and transverse tensile strength are ≥50kN / m, and the ratio of longitudinal tensile strength to transverse tensile strength is 1.0-1.

2.

8. The method for repairing reflective cracks in road surfaces according to claim 1, characterized in that, The asphalt-stabilized crushed stone layer uses ATB-25 asphalt-stabilized crushed stone.

9. The method for repairing reflective cracks in road surfaces according to claim 8, characterized in that, The asphalt-stabilized crushed stone layer has an asphalt-aggregate ratio of 3.5% and a gradation composition of 0-3 mm aggregate, 3-6 mm aggregate, 6-11 mm aggregate, 11-17 mm aggregate and mineral powder in a mass ratio of 24:35:6:31:

4.

10. The method for repairing reflective cracks in road surfaces according to claim 8, characterized in that, For road sections with mild reflective cracking, the crack-resistant asphalt mixture layer is AC-13 basalt fiber asphalt mixture; for road sections with severe reflective cracking, the crack-resistant asphalt mixture layer is AC-20 SBS modified asphalt mixture and AC-13 basalt fiber asphalt mixture. Furthermore, the AC-13 basalt fiber asphalt mixture has an asphalt-aggregate ratio of 5.1%, a basalt fiber content of 0.4%, a basalt fiber length of 9 mm, and a gradation composition of 0-5 mm aggregate, 5-10 mm aggregate, 10-15 mm aggregate and mineral powder in a mass ratio of 28:36:32:

4. Furthermore, the AC-20 SBS modified asphalt mixture has an asphalt-aggregate ratio of 4.2%, and its gradation composition consists of 0-4 mm aggregate, 4-7 mm aggregate, 7-11 mm aggregate, 11-16 mm aggregate, 16-26 mm aggregate and mineral powder in a mass ratio of 22:27:14:25:9:3.

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