Anti-cracking fabric for road interlayer structure and preparation method and application thereof

Abstract

The application relates to the field of road engineering technical materials, in particular to an anti-cracking fabric for a road interlayer structure and a preparation method and application thereof. The material contains, in mass parts, 95-100 parts of polypropylene resin, 3-5 parts of ultraviolet-resistant master batch, 1-2 parts of titanium dioxide, and 3-5 parts of shape memory polyurethane, and a three-dimensional anti-cracking fabric is prepared through a melt spinning process, a needle punching forming process and the like. The fabric can make the shear strength of a pavement and a base layer 1.5-1.8 MPa, the breaking strength of the fabric is greater than or equal to 15 kN / m, the permeability coefficient is less than or equal to 1*10 ‑9 cm / s, and the breaking strength retention rate after ultraviolet aging for 1000 hours is greater than or equal to 85%. Through raw material compounding and process synergistic optimization, the shear resistance, weather resistance, long-acting anti-cracking, interlayer adhesion and waterproof performance are simultaneously improved.

Description

Technical Field

[0001] This invention belongs to the field of road engineering technology materials, and particularly relates to a crack-resistant fabric for road interlayer structures, its preparation method and application. Background Technology

[0002] In road construction and operation systems, the interlayer structure serves as the core link connecting upper and lower structural layers, and its stability directly determines the road's traffic safety and service life. With the continuous increase in traffic volume, frequent passage of heavy vehicles, and the increasing frequency of extreme weather conditions, the stress impact and environmental erosion problems faced by interlayer structures are becoming increasingly prominent. Geotextiles, with their significant advantages such as light weight, high tensile strength, convenient construction, resistance to microbial erosion, and good corrosion resistance, have been widely used and promoted in road engineering.

[0003] However, in the long-term engineering practice and application, existing geotextile technologies have gradually revealed many technical defects that urgently need to be addressed, especially in terms of the synergistic improvement of important performance characteristics: First, insufficient shear strength; when faced with interlayer shear stress generated by repeated rolling of heavy vehicles, interlayer slippage and delamination are prone to occur, leading to a decrease in road structure stability. Second, lack of weather resistance; single anti-aging components are insufficient to resist the long-term effects of multiple environmental factors such as ultraviolet radiation, high and low temperature cycles, and rain and snow erosion, resulting in rapid material aging, performance degradation, and shortened service life. Third, short-term crack resistance; relying solely on fiber flexibility to disperse stress, lacking active stress buffering and crack inhibition mechanisms, it is difficult to achieve long-term crack resistance; under the long-term superposition of temperature stress and load stress, cracks are prone to recurrence and expansion. Fourth, weak interlayer bonding; resulting in weak bonding between geotextiles and upper and lower structural layers, failing to effectively transfer stress and affecting overall load-bearing capacity. Fifth, unreliable waterproofing function; insufficient density of the fiber network structure; the waterproof barrier formed after asphalt impregnation has pores, allowing moisture to easily penetrate into the base layer, causing a chain of problems such as base layer softening and strength reduction. These deficiencies in key properties severely limit the widespread application of geotextiles in high-grade roads and road engineering projects in complex environments.

[0004] In existing related technologies, some patents attempt to improve crack-resistant materials for roads, but there are still obvious limitations. For example, CN116749616B discloses a road base crack-resistant reinforcement material, which improves the tensile strength of the material by optimizing the fiber composition and ratio. However, this material has shortcomings in weather resistance design. It has not been specifically optimized for the erosion of material performance by natural environmental factors such as ultraviolet rays and temperature cycling. After long-term exposure, it is prone to aging and embrittlement, resulting in a decrease in crack resistance. At the same time, its interlayer bonding design is relatively simple, and it is prone to peeling from the upper and lower structural layers under high stress, making it difficult to meet the collaborative work requirements between complex road layers. CN113430714B provides a composite crack-resistant geotextile. This geotextile improves the overall tensile strength through multi-layer composite structure. However, in terms of crack resistance mechanism, it still relies on the physical constraint of traditional fibers and does not introduce new functional components and structural design to achieve active stress absorption and dispersion. Moreover, its water-sealing performance mainly depends on the density of the substrate itself and lacks a synergistic sealing design after bonding with asphalt. Moisture can easily seep in from the fiber gaps or interlayer interfaces, which cannot fundamentally solve the problem of road water damage.

[0005] Therefore, developing a crack-resistant fabric that combines high shear strength, excellent weather resistance, long-term crack resistance, strong interlayer adhesion, and reliable waterproofing has become an urgent technical need in the current road engineering field. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a crack-resistant fabric for road interlayer structures, its preparation method, and its application. The aim is to systematically solve the technical problems of existing geotextiles, such as insufficient shear strength, poor weather resistance, short-term crack resistance, weak interlayer bonding, and unreliable waterproofing. Through the selection of raw materials and synergistic optimization of processes, multiple performance characteristics are simultaneously improved.

[0007] This invention provides a crack-resistant fabric for road interlayer structures, comprising the following raw materials by weight: 95-100 parts polypropylene resin, 3-5 parts UV-resistant masterbatch, 1-2 parts titanium dioxide, and 3-5 parts shape memory polyurethane. The crack-resistant fabric is prepared by melt spinning to form a three-dimensional needle-punched structure, and its physical properties meet the following requirements: single filament fineness 4-13 dtex, breaking strength ≥15 kN / m, breaking elongation ≥30%, and permeability coefficient ≤1×10⁻⁶. -9 cm / s.

[0008] Polypropylene resin, as the base material of crack-resistant fabrics, accounts for the largest proportion of its usage, providing support for the overall structural strength and molding stability. A suitable range of polypropylene resin dosage ensures that the fabric has sufficient base material skeleton, guaranteeing the formation of continuous and uniform monofilaments during melt spinning, while avoiding excessive base material dosage that could lead to decreased fabric flexibility and limited crack resistance.

[0009] Furthermore, the melt index of the polypropylene resin is 1.5~3.0 g / 10min (230℃, 2.16 kg). This melt index range ensures that the resin has good processing fluidity, forming monofilaments of uniform thickness and stable strength during melt spinning, avoiding fluctuations in shear strength due to uneven monofilament properties; at the same time, it ensures that the monofilaments have both sufficient strength and flexibility, providing a substrate support for the high shear strength and long-term crack resistance of the three-dimensional needle-punched structure.

[0010] UV-resistant masterbatch is used to improve weather resistance. Its appropriate dosage range avoids problems such as insufficient anti-aging ability due to insufficient dosage, or cost waste and decreased compatibility with substrate due to excessive dosage, thus achieving a balance between weather resistance, economy and compatibility.

[0011] Titanium dioxide can form a basic synergistic anti-aging system with UV-resistant masterbatch, enhancing the fabric's resistance to ultraviolet rays. Simultaneously, it subtly strengthens the fiber structure through microparticle filling. Appropriate titanium dioxide dosage avoids both insufficient dosage leading to limited anti-aging and strengthening effects, and excessive dosage causing increased fiber brittleness and difficulties in spinning.

[0012] Furthermore, the titanium dioxide is nano-sized titanium dioxide with a particle size of 20-50 nm. The nano-sized particle size gives it a larger specific surface area, which, in synergy with the UV-resistant masterbatch, enhances weather resistance and further resists environmental erosion. At the same time, the filling effect of the nanoparticles strengthens the fiber structure and improves the overall shear resistance and durability of the fabric. Its excellent chemical stability also enhances the fabric's corrosion resistance, enabling its application in complex environments.

[0013] Shape memory polyurethane is crucial for achieving crack resistance in fabrics. When its dosage is too low, it cannot buffer stress and inhibit crack propagation through shape recovery effect when the road surface undergoes slight deformation or cracks. When its dosage is too high, its compatibility with the matrix decreases and the cost increases, failing to meet the application requirements of easily cracked and high-stress scenarios.

[0014] Furthermore, the shape memory polyurethane has a shape recovery rate of ≥90%, an elongation at break of ≥500%, and contains active epoxy groups at the ends of its molecular chains.

[0015] When road surfaces deform or crack due to temperature cycling and vehicle loads, shape memory polyurethane can quickly buffer stress impacts with a high shape recovery rate of ≥90%, dispersing concentrated stress throughout the fabric and actively inhibiting crack initiation and propagation. Its ≥500% elongation at break allows it to adapt to significant road surface deformation without damage, preventing short-term crack resistance and ensuring long-term continuous crack resistance. The active epoxy functional groups at the ends of the molecular chains can chemically react with the polypropylene molecular chains or active components in asphalt under the high temperatures of melt processing and road paving, forming chemical crosslinking points. This not only provides physical entanglement but also forms strong interfacial chemical bonds, thereby greatly enhancing interlayer adhesion and shear strength.

[0016] Furthermore, the glass transition temperature of the shape memory polyurethane is -30℃ to 5℃.

[0017] The glass transition temperature of shape memory polyurethane covers the ambient temperature of most regions within this temperature range, enabling shape memory polyurethane to maintain good flexibility and resilience at low winter temperatures and structural stability at high summer temperatures. This avoids the failure of shape memory function due to extreme temperatures and ensures long-term stable crack resistance under different climatic conditions.

[0018] Furthermore, the formation of the three-dimensional needle-punched structure includes: the monofilament obtained by the melt spinning method is processed into a fiber web by web forming, the fiber web is sprayed with a mixed oil agent, and then the fiber web is intertwined and entangled by pre-needling and main needle-punching processes in sequence, and the amount of mixed oil agent added is 5 to 10% of the total mass of the raw materials.

[0019] The appropriate addition of mixed oil during the formation of the three-dimensional needle-punched structure increases fiber lubrication, reduces needle-punching damage, promotes the formation of strong entanglement nodes, and enhances the overall structural integrity and shear resistance of the fabric. Simultaneously, the oil fills the tiny pores between fibers, and combined with the dense three-dimensional structure, allows the fabric to form a continuous, non-porous, impermeable layer after being impregnated with asphalt, significantly improving waterproof reliability, effectively blocking water penetration paths, and preventing softening of the substrate. The step-by-step process of pre-needling and main needle-punching further strengthens the fiber interweaving density, providing structural assurance for high shear strength and reliable waterproofing.

[0020] Furthermore, the mixed oil is a mixture of at least two of the following: silane coupling agent, oleate, butyl stearate, and mineral oil.

[0021] Silane coupling agents, acting as bonding reinforcement components, form a chemical bond between fibers and tack coat oil, as well as between upper and lower structural layers, significantly improving interfacial bonding strength and preventing interlayer delamination and slippage. Oleate esters and butyl stearate increase fiber lubricity, ensuring needle-punching quality and indirectly improving structural integrity and bonding foundation. Mineral oil enhances the spreadability and stability of the oiling agent, ensuring uniform coverage of the fiber surface so that each fiber can fully participate in the bonding reaction. The synergistic effect of these multiple components forms a lubricating, bonding, and stable interlayer bonding system, enabling the crack-resistant fabric to form a strong whole with the upper and lower layers. Appropriate dosage avoids both insufficient lubrication, bonding, and stability due to too low a dosage, and excessive dosage leading to oil accumulation, decreased fiber web quality, and poor compatibility with the substrate.

[0022] Furthermore, the pre-needling frequency of the three-dimensional acupuncture structure is 1000~1200 times / min, the main acupuncture frequency is 1300~1600 times / min, and the acupuncture depth is 2~5mm.

[0023] Pre-needling initially fixes the fiber web at a lower frequency to prevent fiber slippage caused by subsequent high-frequency needle punching. Main needle punching, with a higher frequency, deepens the reinforcement, resulting in tighter fiber entanglement and forming a high-strength three-dimensional skeleton, significantly improving shear resistance. The 2-5mm needle depth range in the three-dimensional needle-punched structure matches the frequencies of pre-needling and main needle punching. This approach prevents fiber slippage through shallow pre-needling while strengthening structural stability through deep main needle punching. This ensures that when the fabric is subjected to complex forces such as vehicle loads and temperature stress, it can resist shear forces through its dense structure and disperse stress and inhibit crack propagation through sufficient fiber entanglement, achieving a synergistic improvement in high shear strength, long-term crack resistance, and reliable waterproofing.

[0024] Furthermore, the UV-resistant masterbatch is composed of light stabilizers, UV absorbers, carrier resins, and dispersants.

[0025] The UV absorber actively absorbs UV energy and converts it into heat, preventing direct damage to the fabric. The light stabilizer inhibits the free radical chain reaction caused by UV radiation, delaying material aging and degradation. The carrier resin ensures the compatibility of the UV-resistant components with the polypropylene resin, and the dispersant ensures uniform dispersion, avoiding localized weaknesses in weather resistance. The UV-resistant masterbatch and titanium dioxide work synergistically to resist environmental erosion from UV radiation, high and low temperatures, rain, and snow, significantly delaying the decline in the fabric's mechanical properties and ensuring long-term stability in weather resistance.

[0026] This invention also provides a method for preparing a crack-resistant fabric, comprising the following steps:

[0027] Step 1: Mixing process: Polypropylene resin, UV-resistant masterbatch, titanium dioxide and shape memory polyurethane are mixed in the corresponding mass ratio, the mixing temperature is 120~150℃, the mixing time is 10~20min, and a uniformly mixed raw material mixture is obtained, which is then conveyed to the extrusion system through a screw extruder. Step 2: Melt spinning process: The raw material mixture is melted and extruded at 200℃~230℃, and after being metered by the spinning box, it is conveyed to the spinneret, where it is spun into multiple monofilaments. Step 3: Cooling and drawing process: The monofilament is cooled by side blowing air to form nascent fibers, and at the same time, the nascent fibers are drawn at high speed to obtain drawn fibers; Step 4: Web forming and needle punching process: The drawn fibers are adsorbed onto the forming mesh curtain to form a fiber web. A mixed oil agent is sprayed onto the fiber web at the same time, and then the web is subjected to pre-needling and main needle punching processes in sequence to make the fiber web intertwine and entangle to form a three-dimensional fabric. Step 5: Stretching and Shaping Process: The three-dimensional fabric is stretched laterally and then cut and wound into a crack-resistant fabric.

[0028] Furthermore, the appropriate mixing temperature in step one ensures that the polypropylene resin maintains good melt flowability while preventing excessively high temperatures from degrading and rendering functional components such as the UV-resistant masterbatch and shape memory polyurethane ineffective. Simultaneously, it promotes sufficient contact between the molecules of each component, improving compatibility. The appropriate mixing time ensures that the polypropylene resin, UV-resistant masterbatch, titanium dioxide, and shape memory polyurethane are uniformly dispersed in proportion, avoiding localized component enrichment or deficiency. This prevents problems such as weak weather resistance, fluctuating crack resistance, and insufficient shear strength in the fabric due to uneven mixing. This combination of temperature and time balances mixing efficiency with the formation of a uniform and stable raw material mixture, ensuring the smooth progress of subsequent processes such as melt spinning and needle punching, and guaranteeing the uniformity of monofilament fineness and the density of the three-dimensional structure of the crack-resistant fabric.

[0029] Furthermore, in step two, the spinneret has an orifice diameter of 0.2~0.4mm, and the orifices are evenly distributed in a regular hexagonal pattern. This structural design ensures the quality of the monofilaments and the uniformity of the fabric structure. The limited orifice diameter, combined with the melt spinning process, stably controls the monofilament fineness within 4~13 dtex, ensuring consistent monofilament strength and thus guaranteeing uniform shear strength. The evenly distributed regular hexagonal spinnerets ensure uniform stress during the extrusion of the molten raw material, resulting in regular monofilament cross-sections and consistent quality, avoiding localized reductions in fabric crack resistance, water resistance, and adhesion due to differences in monofilament properties.

[0030] Furthermore, in the melt spinning process described in step two, the temperature fluctuation range of the spinning box is ≤±2℃. Strict control of the spinning box temperature fluctuation ensures the consistency of monofilament performance. Stable temperature prevents localized degradation or uneven flowability of the raw materials, ensuring that the monofilaments extruded from the spinneret are of uniform thickness and consistent performance, and avoiding fluctuations in the fabric's localized shear resistance, crack resistance, and waterproofing performance due to differences in monofilament quality.

[0031] Furthermore, in step three, the wind speed of the side-blowing air is 0.5–1.2 m / s, the temperature is 15°C–25°C, and the cooling time is 3–5 s.

[0032] The appropriate wind speed and temperature of the side-blowing airflow prevent the nascent fibers from cooling too quickly and becoming brittle, or too slowly and sticking together. The appropriate cooling time ensures that the fibers are fully shaped, forming drawn fibers that combine strength and flexibility, providing high-quality fiber raw materials for subsequent needle punching, interlayer bonding, shear resistance and crack resistance.

[0033] Furthermore, in step three, the high-speed drawing speed is 4000~5000m / min, and the drawing ratio is 3~5 times. These speeds and drawing ratios, through mechanical stretching, enhance the crystallinity and orientation of the fibers, making the internal structure of the fibers denser and significantly improving strength and toughness. The reinforced fibers, acting as the skeleton of the three-dimensional needle-punched structure, directly improve the fabric's shear resistance and long-term tear resistance.

[0034] Furthermore, the spraying pressure of the mixed oil agent in step four is 0.1~0.3MPa, and the spraying method is bidirectional cross-spraying. The above-mentioned spraying pressure and spraying method can improve the interlayer adhesion and waterproof density. Precise spraying pressure ensures that the oil agent covers the fiber web with appropriate force, avoiding both insufficient pressure leading to uneven oil agent coverage and insufficient adhesion, and excessive pressure leading to excessive oil agent penetration and material waste; bidirectional cross-spraying allows the oil agent to be sprayed evenly from both sides, ensuring that the fiber surface and internal gaps are fully wetted with oil agent, improving the fiber entanglement effect and bonding foundation, while enhancing the density of the fabric structure and assisting in improving the waterproof function.

[0035] Furthermore, in the web-forming needle punching process described in step four, the operating speed of the formed mesh curtain is 1~3m / min, matching the needle punching frequency. This coordinated design of the mesh curtain speed and needle punching frequency ensures the quality of the needle punching process. The precise matching of the mesh curtain speed with the pre-needling and main needle punching frequencies ensures that each area of ​​the fiber web receives sufficient needle punching times and depth, guaranteeing tight fiber interweaving and entanglement to form a high-strength, high-density three-dimensional structure. This further enhances shear strength and waterproofing, avoiding performance defects caused by insufficient needle punching.

[0036] Furthermore, the transverse stretching temperature in step five is 120~160℃, and the holding time is 5~8 minutes. These stretching temperatures and holding times ensure that the fabric maintains good flexibility and plasticity during the stretching process, guaranteeing the formation of a structurally uniform and strength-stable finished product at a stretching ratio of 2.5~3.0. This process improves fiber orientation and crystallinity, further enhancing shear strength and breaking strength, while optimizing the fabric's structural density and assisting in improving waterproofing and interlayer bonding.

[0037] This invention also provides an application of crack-resistant fabric in road interlayer structures. Application scenarios include the interlayer reinforcement area between the base layer and the asphalt surface layer of newly built roads, the interlayer reinforcement area of ​​existing road maintenance, the crack treatment area of ​​old road reconstruction, the interlayer between highways and bridges, the interlayer between tunnels and roadbeds, and other road interlayer structures that require improved interlayer crack resistance.

[0038] This invention provides a method for applying crack-resistant fabric in road interlayer structures, comprising the following steps: Step 1: Base treatment: Remove loose soil, oil stains and loose particles from the base surface to ensure the surface is dry and flat; Step 2: Laying of crack-resistant fabric: Lay the crack-resistant fabric longitudinally between the base layer and the asphalt surface layer along the road, with an overlap width of ≥10cm. Use hot asphalt as tack coat to ensure effective bonding between the crack-resistant fabric and the base layer, and reinforce it by mechanical compaction. Step 3: Asphalt surface layer construction: Spray tack coat evenly on the surface of the crack-resistant fabric, then spread the hot-mix asphalt mixture and compact it, with the compaction temperature controlled at 130℃~150℃.

[0039] Furthermore, the amount of tack coat oil used in step three is 0.3–0.5 kg / m³. 2 .

[0040] The beneficial effects of this application are as follows: 1. This application introduces shape memory polyurethane and strictly controls its dosage, which not only ensures good compatibility with polypropylene resin substrate, but also gives full play to its high shape recovery rate and high elongation at break characteristics. Combined with a suitable glass transition temperature design, it realizes active buffering, dispersion and suppression of pavement deformation and cracks, laying a foundation for long-term crack resistance.

[0041] 2. This application uses a mixed oil agent with at least two components. By controlling the dosage, selecting appropriate spraying pressure and cross-spraying method, it not only optimizes the surface lubricity of the fiber and reduces fiber damage during the needle punching process, thus providing a guarantee for the formation of a dense three-dimensional structure, but also significantly improves the interfacial bonding strength between the crack-resistant fabric and the upper and lower structural layers, avoiding interlayer peeling and slippage.

[0042] 3. This application selects appropriate needle-punching frequency and depth for pre-needling and main needle-punching, which avoids fiber slippage and ensures the compactness and high strength of the three-dimensional structure.

[0043] 4. This application is not an independent improvement of a single component or process, but rather an organic whole formed through the synergy of various elements: the crack-resistant properties of shape memory polyurethane synergize with the three-dimensional support of the needle-punched structure to enhance crack and shear resistance; the lubrication and bonding functions of the mixed oil synergize with the needle-punching and spraying processes to optimize structural density and interlayer adhesion; the weather-resistant system of UV-resistant masterbatch and nano-sized titanium dioxide synergizes with the spinning and stretching processes to ensure long-term service stability; and the precise matching of the dosage of each raw material with process parameters such as mixing temperature, melting temperature, and stretching ratio ensures uniform mixing of raw materials, stable fiber forming, and controllable density. Ultimately, this achieves simultaneous optimization of high shear strength, excellent weather resistance, long-term crack resistance, strong interlayer adhesion, and reliable waterproofing. After laying the crack-resistant fabric of this application, the shear strength of the pavement and base layer can reach 1.5~1.8MPa. The breaking strength of the fabric of this application is ≥15kN / m, the breaking elongation is ≥30%, and the permeability coefficient is ≤1×10⁻⁶. -9 cm / s, after UV aging for 1000h, the fracture strength retention rate is greater than 85%, and the interlayer adhesion is greater than 0.8MPa. Detailed Implementation

[0044] The embodiments described in this invention are merely some, not all, of the embodiments described herein. All other embodiments obtained by those skilled in the art based on the embodiments described herein without inventive effort are within the scope of protection of this application.

[0045] Example 1 A crack-resistant fabric for road interlayer structures comprises the following raw materials by weight: 98 parts polypropylene resin, 4 parts UV-resistant masterbatch, 1.5 parts titanium dioxide, and 4 parts shape memory polyurethane. The polypropylene resin has a melt index of 2.2 g / 10 min (230℃, 2.16 kg). The UV-resistant masterbatch is a compound of light stabilizer, UV absorber, carrier resin, and dispersant. The shape memory polyurethane exhibits a shape recovery rate of 92%, an elongation at break of 550%, and a glass transition temperature of 0℃.

[0046] Preparation method: Step 1: Mixing process: By weight, mix polypropylene resin, UV-resistant masterbatch, titanium dioxide and shape memory polyurethane in the corresponding weight ratio, control the mixing temperature at 135℃ and the mixing time at 15min to obtain a uniformly mixed raw material mixture, and then convey it to the extrusion system through a screw extruder. Step 2: Melt spinning process: The raw material mixture is melt-extruded at 215℃. The temperature fluctuation of the spinning box is controlled within ±1.5℃. After being metered by the spinning box, it is conveyed to the spinneret (0.3mm orifice, with the spinneret orifices evenly distributed in a regular hexagonal shape), and multiple monofilaments are formed by spinning. Step 3: Cooling and drawing process: The monofilament is cooled by side blowing air with a wind speed of 0.8 m / s, a temperature of 20℃, and a cooling time of 4 seconds to form nascent fibers. At the same time, high-speed drawing is performed at a fiber speed of 4500 m / min with a drawing ratio of 4 times to obtain drawn fibers. Step 4: Web Forming and Needling Process: The drawn fibers are adsorbed onto the forming mesh curtain, which runs at a speed of 2m / min to form a fiber web; a mixed oil agent (composed of silane coupling agent, oleic acid ester, and mineral oil in a mass ratio of 2:3:5) is prepared at 7% of the total mass of raw materials and sprayed evenly onto the fiber web using a bidirectional cross-spraying method at a spray pressure of 0.2MPa; then, pre-needling is performed sequentially at a frequency of 1100 times / min and a needle-punching depth of 3mm, followed by main needle-punching at a frequency of 1450 times / min and a needle-punching depth of 4mm, so that the fiber web is interwoven and entangled to form a three-dimensional fabric; Step 5: Stretching and Shaping Process: The three-dimensional fabric is stretched laterally at 135℃ for 6 minutes, with a stretching ratio of 2.8 times. After stretching to the required dimensions, the edges are cut and the fabric is wound into a crack-resistant finished product.

[0047] The application of the above-mentioned crack-resistant fabric includes the following steps: Step 1: Base treatment: Remove loose soil, oil stains and loose particles from the surface of the newly built heavy-duty road base. Use grinding equipment to lightly grind the base surface to ensure that the base surface is dry, flat and clean, without obvious protrusions and depressions. Step 2: Laying of crack-resistant fabric: The prepared crack-resistant fabric is laid longitudinally between the base layer and the asphalt surface layer along the road, and the overlap width of adjacent crack-resistant fabrics is controlled at 12cm; hot asphalt is used as tack coat and is evenly applied to the base layer surface and the overlap area of ​​the crack-resistant fabric to ensure effective bonding between the crack-resistant fabric and the base layer. Then, a road roller is used for mechanical compaction and reinforcement. Step 3: Asphalt surface layer construction: Spray tack coat evenly on the surface of the crack-resistant fabric, then spread the hot-mix asphalt mixture and compact it, controlling the compaction temperature at 145℃.

[0048] Example 2 A crack-resistant fabric for road interlayer structures comprises the following raw materials by weight: 100 parts polypropylene resin, 5 parts UV-resistant masterbatch, 2 parts titanium dioxide, and 5 parts shape memory polyurethane. The polypropylene resin has a melt index of 2.8 g / 10 min (230℃, 2.16 kg). The UV-resistant masterbatch is a compound of light stabilizer, UV absorber, carrier resin, and dispersant. The shape memory polyurethane has a shape recovery rate of 95%, an elongation at break of 600%, and a glass transition temperature of -5℃.

[0049] Preparation method: Step 1: Mixing process: By weight, mix polypropylene resin, UV-resistant masterbatch, titanium dioxide and shape memory polyurethane in the corresponding weight ratio, control the mixing temperature at 140℃ and the mixing time at 18min to obtain a uniformly mixed raw material mixture, and then convey it to the extrusion system through a screw extruder. Step 2: Melt spinning process: The raw material mixture is melt-extruded at 225℃. The temperature fluctuation of the spinning box is controlled within ±1℃. After being metered by the spinning box, it is conveyed to the spinneret (0.35mm orifice, with the spinneret orifices evenly distributed in a regular hexagonal shape), and multiple monofilaments are formed by spinning. Step 3: Cooling and drawing process: The monofilament is cooled by side blowing air with a wind speed of 1.0 m / s, a temperature of 22℃, and a cooling time of 5s to form nascent fibers. At the same time, high-speed drawing is performed at a fiber speed of 4500 m / min with a drawing ratio of 4.5 times to obtain drawn fibers. Step 4: Web Forming and Needling Process: The drawn fibers are adsorbed onto the forming mesh curtain, which runs at a speed of 2.5 m / min to form a fiber web. A mixed oil agent (composed of silane coupling agent, oleate, butyl stearate, and mineral oil in a mass ratio of 1:3:4:2) is prepared at 9% of the total mass of raw materials and sprayed evenly onto the fiber web using a bidirectional cross-spraying method at a spray pressure of 0.25 MPa. Subsequently, pre-needling (frequency 1200 times / min, needle depth 3.5 mm) and main needleling (frequency 1550 times / min, needle depth 5 mm) treatments are performed sequentially to make the fiber web intertwine and form a three-dimensional fabric. Step 5: Stretching and Shaping Process: The three-dimensional fabric is stretched laterally at 145℃ for 7 minutes, with a stretching ratio of 3.0 times. After stretching to the required dimensions, the edges are cut and the fabric is wound into a crack-resistant finished product.

[0050] The application method is as described in Example 1.

[0051] Example 3 A crack-resistant fabric for road interlayer structures comprises the following raw materials by weight: 95 parts polypropylene resin, 3 parts UV-resistant masterbatch, 1 part titanium dioxide, and 3 parts shape memory polyurethane. The polypropylene resin has a melt index of 1.8 g / 10 min (230℃, 2.16 kg). The UV-resistant masterbatch is a compound of light stabilizer, UV absorber, carrier resin, and dispersant. The shape memory polyurethane has a shape recovery rate of 90%, an elongation at break of 500%, and a glass transition temperature of -10℃.

[0052] Preparation method: Step 1: Mixing process: By weight, mix polypropylene resin, UV-resistant masterbatch, titanium dioxide and shape memory polyurethane in the corresponding weight ratio, control the mixing temperature at 125℃ and the mixing time at 12min to obtain a uniformly mixed raw material mixture, and then convey it to the extrusion system through a screw extruder. Step 2: Melt spinning process: The raw material mixture is melt-extruded at 205℃. The temperature fluctuation of the spinning box is controlled within ±2℃. After being metered by the spinning box, it is conveyed to the spinneret (0.25mm orifice, with the spinneret orifices evenly distributed in a regular hexagonal shape), and multiple monofilaments are formed by spinning. Step 3: Cooling and drawing process: The monofilament is cooled by side blowing air with a wind speed of 0.6 m / s, a temperature of 18℃, and a cooling time of 3 seconds to form nascent fibers. At the same time, high-speed drawing is performed at a fiber speed of 4500 m / min with a drawing ratio of 3.5 times to obtain drawn fibers. Step 4: Web Forming and Needling Process: The drawn fibers are adsorbed onto the forming mesh curtain, which runs at a speed of 1.5 m / min to form a fiber web; a mixed oil agent (composed of silane coupling agent, mineral oil, and oleic acid ester in a mass ratio of 3:4:3) is prepared at 6% of the total mass of raw materials and sprayed evenly onto the fiber web using a bidirectional cross-spraying method at a spray pressure of 0.15 MPa; then, pre-needling (frequency 1050 times / min, needle depth 2.5 mm) and main needleling (frequency 1350 times / min, needle depth 4.5 mm) are performed sequentially to make the fiber web intertwine and form a three-dimensional fabric; Step 5: Stretching and Shaping Process: The three-dimensional fabric is stretched laterally at 125℃ for 5 minutes, with a stretching ratio of 2.6 times. After stretching to the required dimensions, the edges are cut and the fabric is wound into a crack-resistant finished product.

[0053] The application method is as described in Example 1.

[0054] Comparative Example 1 A crack-resistant fabric for road interlayer structures comprises the following raw materials by weight: 100 parts polypropylene resin, 5 parts UV-resistant masterbatch, and 2 parts titanium dioxide. The polypropylene resin has a melt index of 2.8 g / 10 min (230℃, 2.16 kg). The UV-resistant masterbatch is a compound of light stabilizer, UV absorber, carrier resin, and dispersant.

[0055] Preparation method: Step 1: Mixing process: By weight, mix polypropylene resin, UV-resistant masterbatch, and titanium dioxide in the corresponding weight ratio, control the mixing temperature at 140℃ and the mixing time at 18min to obtain a uniformly mixed raw material mixture, and then convey it to the extrusion system through a screw extruder. Step 2: Melt spinning process: The raw material mixture is melt-extruded at 225℃. The temperature fluctuation of the spinning box is controlled within ±1℃. After being metered by the spinning box, it is conveyed to the spinneret (0.35mm orifice, with the spinneret orifices evenly distributed in a regular hexagonal shape), and multiple monofilaments are formed by spinning. Step 3: Cooling and drawing process: The monofilament is cooled by side blowing air with a wind speed of 1.0 m / s, a temperature of 22℃, and a cooling time of 5s to form nascent fibers. At the same time, high-speed drawing is performed at a fiber speed of 4500 m / min with a drawing ratio of 4.5 times to obtain drawn fibers. Step 4: Web Forming and Needling Process: The drawn fibers are adsorbed onto the forming mesh curtain, which runs at a speed of 2.5 m / min to form a fiber web. A mixed oil agent (composed of silane coupling agent, oleate, butyl stearate, and mineral oil in a mass ratio of 1:3:4:2) is prepared at 9% of the total mass of raw materials and sprayed evenly onto the fiber web using a bidirectional cross-spraying method at a spray pressure of 0.25 MPa. Subsequently, pre-needling (frequency 1200 times / min, needle depth 3.5 mm) and main needleling (frequency 1550 times / min, needle depth 5 mm) treatments are performed sequentially to make the fiber web intertwine and form a three-dimensional fabric. Step 5: Stretching and Shaping Process: The three-dimensional fabric is stretched laterally at 145℃ for 7 minutes, with a stretching ratio of 3.0 times. After stretching to the required dimensions, the edges are cut and the fabric is wound into a crack-resistant finished product.

[0056] The application method is as described in Example 1.

[0057] As can be seen, the only difference between Comparative Example 1 and Example 2 is that shape memory polyurethane was not added.

[0058] Comparative Example 2 A crack-resistant fabric for road interlayer structures comprises the following raw materials by weight: 100 parts polypropylene resin, 5 parts UV-resistant masterbatch, 2 parts titanium dioxide, and 8 parts shape memory polyurethane. The polypropylene resin has a melt index of 2.8 g / 10 min (230℃, 2.16 kg). The UV-resistant masterbatch is a compound of light stabilizer, UV absorber, carrier resin, and dispersant. The shape memory polyurethane exhibits a shape recovery rate of 95%, an elongation at break of 600%, and a glass transition temperature of -5℃.

[0059] Preparation method: Step 1: Mixing process: By weight, mix polypropylene resin, UV-resistant masterbatch, titanium dioxide and shape memory polyurethane in the corresponding weight ratio, control the mixing temperature at 140℃ and the mixing time at 18min to obtain a uniformly mixed raw material mixture, and then convey it to the extrusion system through a screw extruder. Step 2: Melt spinning process: The raw material mixture is melt-extruded at 225℃. The temperature fluctuation of the spinning box is controlled within ±1℃. After being metered by the spinning box, it is conveyed to the spinneret (0.35mm orifice, with the spinneret orifices evenly distributed in a regular hexagonal shape), and multiple monofilaments are formed by spinning. Step 3: Cooling and drawing process: The monofilament is cooled by side blowing air with a wind speed of 1.0 m / s, a temperature of 22℃, and a cooling time of 5s to form nascent fibers. At the same time, high-speed drawing is performed at a fiber speed of 4500 m / min with a drawing ratio of 4.5 times to obtain drawn fibers. Step 4: Web Forming and Needling Process: The drawn fibers are adsorbed onto the forming mesh curtain, which runs at a speed of 2.5 m / min to form a fiber web. A mixed oil agent (composed of silane coupling agent, oleate, butyl stearate, and mineral oil in a mass ratio of 1:3:4:2) is prepared at 9% of the total mass of raw materials and sprayed evenly onto the fiber web using a bidirectional cross-spraying method at a spray pressure of 0.25 MPa. Subsequently, pre-needling (frequency 1200 times / min, needle depth 3.5 mm) and main needleling (frequency 1550 times / min, needle depth 5 mm) treatments are performed sequentially to make the fiber web intertwine and form a three-dimensional fabric. Step 5: Stretching and Shaping Process: The three-dimensional fabric is stretched laterally at 145℃ for 7 minutes, with a stretching ratio of 3.0 times. After stretching to the required dimensions, the edges are cut and the fabric is wound into a crack-resistant finished product.

[0060] The application method is as described in Example 1.

[0061] As can be seen, the only difference compared to Example 2 is that the amount of shape memory polyurethane added to the raw materials in Comparative Example 2 is 8 parts.

[0062] Comparative Example 3 A crack-resistant fabric for road interlayer structures comprises the following raw materials by weight: 100 parts polypropylene resin, 5 parts UV-resistant masterbatch, 2 parts titanium dioxide, and 5 parts shape memory polyurethane. The polypropylene resin has a melt index of 2.8 g / 10 min (230℃, 2.16 kg). The UV-resistant masterbatch is a compound of light stabilizer, UV absorber, carrier resin, and dispersant. The shape memory polyurethane has a shape recovery rate of 95%, an elongation at break of 600%, and a glass transition temperature of -5℃.

[0063] Preparation method: Step 1: Mixing process: By weight, mix polypropylene resin, UV-resistant masterbatch, titanium dioxide and shape memory polyurethane in the corresponding weight ratio, control the mixing temperature at 140℃ and the mixing time at 18min to obtain a uniformly mixed raw material mixture, and then convey it to the extrusion system through a screw extruder. Step 2: Melt spinning process: The raw material mixture is melt-extruded at 225℃. The temperature fluctuation of the spinning box is controlled within ±1℃. After being metered by the spinning box, it is conveyed to the spinneret (0.35mm orifice, with the spinneret orifices evenly distributed in a regular hexagonal shape), and multiple monofilaments are formed by spinning. Step 3: Cooling and drawing process: The monofilament is cooled by side blowing air with a wind speed of 1.0 m / s, a temperature of 22℃, and a cooling time of 5s to form nascent fibers. At the same time, high-speed drawing is performed at a fiber speed of 4500 m / min with a drawing ratio of 4.5 times to obtain drawn fibers. Step 4: Web Forming and Needling Process: The drawn fibers are adsorbed onto the forming mesh curtain, which runs at a speed of 2.5 m / min to form a fiber web. Silane coupling agent is sprayed evenly onto the fiber web at a spraying pressure of 0.25 MPa using a bidirectional cross-spraying method, accounting for 9% of the total mass of the raw materials. Subsequently, pre-needling (frequency 1200 times / min, needle depth 3.5 mm) and main needleling (frequency 1550 times / min, needle depth 5 mm) are performed sequentially to interweave and entangle the fiber web, forming a three-dimensional fabric. Step 5: Stretching and Shaping Process: The three-dimensional fabric is stretched laterally at 145℃ for 7 minutes, with a stretching ratio of 3.0 times. After stretching to the required dimensions, the edges are cut and the fabric is wound into a crack-resistant finished product.

[0064] The application method is as described in Example 1.

[0065] As can be seen, the only difference compared to Example 2 is that in Comparative Example 3, only a silane coupling agent was added to the mixed oil.

[0066] Comparative Example 4 A crack-resistant fabric for road interlayer structures comprises the following raw materials by weight: 100 parts polypropylene resin, 5 parts UV-resistant masterbatch, 2 parts titanium dioxide, and 5 parts shape memory polyurethane. The polypropylene resin has a melt index of 2.8 g / 10 min (230℃, 2.16 kg). The UV-resistant masterbatch is a compound of light stabilizer, UV absorber, carrier resin, and dispersant. The shape memory polyurethane has a shape recovery rate of 95%, an elongation at break of 600%, and a glass transition temperature of -5℃.

[0067] Preparation method: Step 1: Mixing process: By weight, mix polypropylene resin, UV-resistant masterbatch, titanium dioxide and shape memory polyurethane in the corresponding weight ratio, control the mixing temperature at 140℃ and the mixing time at 18min to obtain a uniformly mixed raw material mixture, and then convey it to the extrusion system through a screw extruder. Step 2: Melt spinning process: The raw material mixture is melt-extruded at 225℃. The temperature fluctuation of the spinning box is controlled within ±1℃. After being metered by the spinning box, it is conveyed to the spinneret (0.35mm orifice, with the spinneret orifices evenly distributed in a regular hexagonal shape), and multiple monofilaments are formed by spinning. Step 3: Cooling and drawing process: The monofilament is cooled by side blowing air with a wind speed of 1.0 m / s, a temperature of 22℃, and a cooling time of 5s to form nascent fibers. At the same time, high-speed drawing is performed at a fiber speed of 4500 m / min with a drawing ratio of 4.5 times to obtain drawn fibers. Step 4: Web Forming and Needling Process: The drawn fibers are adsorbed onto the forming mesh curtain, which runs at a speed of 2.5 m / min to form a fiber web. A mixed oil agent (composed of silane coupling agent, oleate, butyl stearate, and mineral oil in a mass ratio of 1:3:4:2) is prepared at 9% of the total mass of raw materials and sprayed evenly onto the fiber web using a bidirectional cross-spraying method at a spray pressure of 0.25 MPa. Subsequently, pre-needling (frequency 900 times / min, needle depth 3.5 mm) and main needleling (frequency 1800 times / min, needle depth 5 mm) treatments are performed sequentially to make the fiber web intertwine and form a three-dimensional fabric. Step 5: Stretching and Shaping Process: The three-dimensional fabric is stretched laterally at 145℃ for 7 minutes, with a stretching ratio of 3.0 times. After stretching to the required dimensions, the edges are cut and the fabric is wound into a crack-resistant finished product.

[0068] The application method is as described in Example 1.

[0069] As can be seen, compared with Example 2, the only difference is that in step four of the preparation method of Comparative Example 4, the pre-needle puncture frequency is 900 times / min and the main needle puncture frequency is 1800 times / min.

[0070] Comparative Example 5 A crack-resistant fabric for road interlayer structures comprises the following raw materials by weight: 100 parts polypropylene resin, 5 parts UV-resistant masterbatch, 2 parts titanium dioxide, and 5 parts shape memory polyurethane. The polypropylene resin has a melt index of 2.8 g / 10 min (230℃, 2.16 kg). The UV-resistant masterbatch is a compound of light stabilizer, UV absorber, carrier resin, and dispersant. The shape memory polyurethane has a shape recovery rate of 95%, an elongation at break of 600%, and a glass transition temperature of -5℃.

[0071] Preparation method: Step 1: Mixing process: By weight, mix polypropylene resin, UV-resistant masterbatch, titanium dioxide and shape memory polyurethane in the corresponding weight ratio, control the mixing temperature at 140℃ and the mixing time at 18min to obtain a uniformly mixed raw material mixture, and then convey it to the extrusion system through a screw extruder. Step 2: Melt spinning process: The raw material mixture is melt-extruded at 225℃. The temperature fluctuation of the spinning box is controlled within ±1℃. After being metered by the spinning box, it is conveyed to the spinneret (0.35mm orifice, with the spinneret orifices evenly distributed in a regular hexagonal shape), and multiple monofilaments are formed by spinning. Step 3: Cooling and drawing process: The monofilament is cooled by side blowing air with a wind speed of 1.0 m / s, a temperature of 22℃, and a cooling time of 5s to form nascent fibers. At the same time, high-speed drawing is performed at a fiber speed of 4500 m / min with a drawing ratio of 4.5 times to obtain drawn fibers. Step 4: Web Forming and Needling Process: The drawn fibers are adsorbed onto the forming mesh curtain, which runs at a speed of 2.5 m / min to form a fiber web. A mixed oil agent (composed of silane coupling agent, oleate, butyl stearate, and mineral oil in a mass ratio of 1:3:4:2) is prepared at 9% of the total mass of raw materials and sprayed evenly onto the fiber web using a bidirectional cross-spraying method at a spray pressure of 0.25 MPa. Subsequently, pre-needling (frequency 1200 times / min, needle depth 3.5 mm) and main needleling (frequency 1550 times / min, needle depth 5 mm) treatments are performed sequentially to make the fiber web intertwine and form a three-dimensional fabric. Step 5: Stretching and Shaping Process: The three-dimensional fabric is stretched laterally at 145℃ for 7 minutes, with a stretching ratio of 5.0 times. After stretching to the required dimensions, the edges are cut and the fabric is wound into a crack-resistant finished product.

[0072] The application method is as described in Example 1.

[0073] As can be seen, the only difference between Comparative Example 5 and Example 2 is that the transverse stretching ratio in step five of the preparation method is 5 times.

[0074] The properties of the crack-resistant fabrics prepared in Examples 1-3 and Comparative Examples 1-5 are shown in Table 1: Table 1 Comparison of the crack-resistant fabric properties prepared in Examples 1-3 and Comparative Examples 1-5

[0075] The crack-resistant fabrics prepared in Examples 1-3 exhibit a tensile strength ≥15kN / m and an elongation at break ≥30%, ensuring that the fabrics do not break under load and shear stress, thus guaranteeing the continued effectiveness of their crack-resistant and shear-resistant functions. Simultaneously, they impart good flexibility to the fabrics, and combined with the recovery properties of shape memory polyurethane, further enhance their adaptability to road surface deformation, strengthen long-term crack resistance, and prevent core performance failure due to brittle fracture of the fabric. Furthermore, the permeability coefficient of the crack-resistant fabrics is ≤1×10⁻⁶. -9 The speed of cm / s ensures the reliability of the waterproof function. This indicator shows that the fabric has extremely strong water impermeability. Its three-dimensional structure, together with the asphalt, forms a dense waterproof barrier, effectively blocking water penetration and preventing the base layer from softening and losing strength due to water immersion. This reduces water damage-induced cracks, subsidence, and other defects at the source. Combined with crack resistance and shear resistance, it comprehensively improves the stability between road layers. In Examples 1-3, the tensile strength retention rate after 1000 hours of UV aging is ≥85%, ensuring that the crack-resistant fabric resists environmental erosion such as UV radiation, high and low temperature cycles, and rain and snow erosion, delaying the decline of the fabric's mechanical properties. In Examples 1-3, the interlayer adhesive pull-out strength of the fabric is ≥0.8MPa, ensuring that the crack-resistant fabric and the interlayer structure form a strong whole. This adhesive strength effectively prevents interlayer slippage and peeling under repeated vehicle loads, ensuring efficient stress transfer between layers.

[0076] Compared with Example 2, the fabric in Comparative Example 1, which did not contain shape memory polyurethane, showed a significant decrease in elongation at break and shear strength, as well as a significant weakening of interlayer adhesion and waterproof performance, making it impossible to achieve long-term crack resistance.

[0077] The addition of excessive shape memory polyurethane in Comparative Example 2 resulted in decreased compatibility with the substrate, poorer shear strength and interlayer adhesion, and increased costs.

[0078] Comparative Example 3 oil only added silane coupling agent and lacked the synergistic effect of components such as oleate and mineral oil. Insufficient fiber lubrication led to poor needle punching effect, decreased structural density, and significantly insufficient waterproof and bonding performance.

[0079] In Comparative Example 4, deviations in the needle punching frequency can easily lead to fiber breakage, resulting in a decrease in shear strength and elongation at break.

[0080] In Comparative Example 5, the increased transverse stretching ratio led to excessive fiber stretching, resulting in increased brittleness and deterioration of elongation at break, weather resistance, and interlayer adhesion.

[0081] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any modifications or equivalent changes made based on the technical essence of the present invention shall still fall within the scope of protection claimed by the present invention.

Claims

1. A crack-resistant fabric for road interlayer structures, characterized in that, By weight, it contains the following raw materials: 95-100 parts polypropylene resin, 3-5 parts UV-resistant masterbatch, 1-2 parts titanium dioxide, and 3-5 parts shape memory polyurethane. The crack-resistant fabric is prepared by melt spinning to form a three-dimensional needle-punched structure. Its physical properties meet the following requirements: single filament fineness 4~13 dtex, breaking strength ≥15kN / m, breaking elongation ≥30%, and permeability coefficient ≤1×10⁻⁶. -9 cm / s.

2. The anti-crack fabric according to claim 1, characterized in that, The shape memory polyurethane has a shape recovery rate of ≥90%, an elongation at break of ≥500%, and contains active epoxy groups at the ends of the molecular chains.

3. The anti-crack fabric according to claim 1, characterized in that, The formation of the three-dimensional needle-punched structure includes: the monofilaments obtained by the melt spinning method are processed into a fiber web by web forming, the fiber web is sprayed with a mixed oil agent, and then the fiber web is intertwined and entangled by pre-needling and main needle-punching processes in sequence. The amount of mixed oil agent added is 5 to 10% of the total mass of the raw materials.

4. The anti-crack fabric according to claim 3, characterized in that, The mixed oil is a mixture of at least two of the following: silane coupling agent, oleate, butyl stearate, and mineral oil.

5. The anti-crack fabric according to claim 3, characterized in that, The pre-needling frequency of the three-dimensional acupuncture structure is 1000~1200 times / min, the main acupuncture frequency is 1300~1600 times / min, and the acupuncture depth is 2~5mm.

6. The anti-crack fabric according to claim 1, characterized in that, The UV-resistant masterbatch is composed of light stabilizers, UV absorbers, carrier resins, and dispersants.

7. A method for preparing the anti-crack fabric according to any one of claims 1 to 6, characterized in that, Includes the following steps: Step 1: Mixing process: Polypropylene resin, UV-resistant masterbatch, titanium dioxide and shape memory polyurethane are mixed in the corresponding mass ratio, the mixing temperature is 120~150℃, the mixing time is 10~20min, and a uniformly mixed raw material mixture is obtained, which is then conveyed to the extrusion system through a screw extruder. Step 2: Melt spinning process: The raw material mixture is melted and extruded at 200℃~230℃, and after being metered by the spinning box, it is conveyed to the spinneret, where it is spun into multiple monofilaments. Step 3: Cooling and drawing process: The monofilament is cooled by side blowing air to form nascent fibers, and at the same time, the nascent fibers are drawn at high speed to obtain drawn fibers; Step 4: Web forming and needle punching process: The drawn fibers are adsorbed onto the forming mesh curtain to form a fiber web. A mixed oil agent is sprayed onto the fiber web at the same time, and then the web is subjected to pre-needling and main needle punching processes in sequence to make the fiber web intertwine and entangle to form a three-dimensional fabric. Step 5: Stretching and Shaping Process: The three-dimensional fabric is stretched laterally and then cut and wound into a crack-resistant fabric.

8. The preparation method according to claim 7, characterized in that, The spraying pressure of the mixed oil agent in step four is 0.1~0.3MPa, and the spraying method is bidirectional cross spraying.

9. The preparation method according to claim 7, characterized in that, The stretching ratio of the transverse stretching in step five is controlled between 2.5 and 3.0 times.

10. The application of the crack-resistant fabric according to any one of claims 1 to 6 in road interlayer structures, characterized in that, Application scenarios include the interlayer between the base course and asphalt surface course of newly built roads, the interlayer reinforcement area for the maintenance of existing roads, the crack treatment area for the reconstruction of old roads, the interlayer between highways and bridges, the interlayer between tunnels and roadbeds, and other road interlayer structures that require improved interlayer crack resistance.

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