Construction method of layered asphalt pavement and layered asphalt pavement

Abstract

The invention discloses a construction method of a layered asphalt pavement and the layered asphalt pavement. The construction method of the layered asphalt pavement comprises the following steps: S1, constructing a base layer; s2, construction of a lower surface layer; s3, middle surface layer construction; s4, constructing an upper surface layer; wherein in the paving and compacting processes of the steps S2, S3 and S4, the temperature field distribution of a paving surface is continuously monitored by adopting infrared thermal imaging equipment, and the compacting operation is dynamically guided according to real-time temperature feedback information. A layered asphalt pavement construction scheme integrating long service life, high performance, greenness and economy is constructed, the traditional technical problems of rut resistance and crack resistance of the asphalt pavement are solved, the situation that the overall performance of the pavement is excessive, the interlayer treatment effect is excellent, interlayer slippage, shear failure and peeling cannot be caused is avoided, the overall strength of the pavement is improved, and the service life of the pavement is prolonged. And a solution is provided for sustainable development of traffic infrastructure.

Description

Technical Field

[0001] This invention relates to the field of road construction technology, and in particular to a construction method for layered asphalt pavement and a layered asphalt pavement. Background Technology

[0002] In existing technologies, asphalt pavement refers to a road surface paved primarily with asphalt. Asphalt pavement is mainly composed of asphalt mixtures, which typically include asphalt binder and aggregates. Compared to concrete pavement, asphalt pavement has a faster construction speed and is relatively easy to maintain, allowing for localized repairs and overlays. However, due to the viscoelasticity of asphalt materials, asphalt pavement is prone to rutting in channelized traffic areas due to high temperatures. This not only poses traffic safety hazards but also causes serious economic losses and social impacts. Therefore, solving the problem of rutting in asphalt pavement is particularly important. Currently, composite grouting technology for asphalt pavement typically involves injecting cement-based grout into an open-graded asphalt mixture matrix pavement, thereby forming a composite pavement that combines the characteristics of both cement concrete and asphalt concrete pavements. This composite pavement exhibits better rutting resistance and effectively improves rutting conditions in asphalt pavement.

[0003] However, cement-based grouting materials are generally composed of cement, fine sand, fillers, and modified additives. After being poured and molded, they have the characteristics of a rigid slab. Especially when used on road sections with high traffic volume and / or heavy vehicles, they are prone to mud pumping, misalignment, and edge chipping at the joints. At the same time, the use of materials with similar performance in each structural layer of the road surface, i.e., integrated design, leads to an over-performance of the overall road surface or an inability to resist specific damage. For example, the middle and lower layers have insufficient resistance to rutting, and the upper layer has limited anti-skid and noise reduction functions, forming a performance weakness.

[0004] Chinese invention patent application number 202110189589.4 discloses a construction method for asphalt pavement, including paving a base asphalt pavement with a porous structure, preparing a grout, and injecting the grout into the base asphalt pavement. The preparation of the grout includes: using polyetheretherketone (PEEK) modified fly ash hollow microspheres; heating to 170°C... After mixing ABS modified asphalt at 185℃ with modified fly ash hollow microspheres, the mixture was then heated to 260℃. Extrusion and cooling granulation at 280°C; at 80°C Add sand particles at 100℃ and mix; at 40℃ The grout is prepared by mixing silicate cement, additives, and water at a temperature of 60℃. However, this construction method for asphalt pavement uses materials with similar properties in each structural layer, resulting in an overemphasis on the overall pavement performance. Furthermore, the use of high-performance materials requires higher construction temperatures and stricter process control, which can easily lead to problems such as asphalt aging and compaction difficulties during construction. The interlayer treatment effect is also poor, which can easily cause interlayer slippage, shear failure, and spalling, affecting the overall strength of the pavement. Summary of the Invention

[0005] The purpose of this invention is to provide a construction method for layered asphalt pavement and a layered asphalt pavement.

[0006] To achieve the above objectives, the technical solution proposed by this invention is as follows: A construction method for layered asphalt pavement includes the following steps: S1. Base course construction: Samples of old road milling material are taken and laboratory mix design is carried out to determine the ratio of recycled binder to water. On-site cold recycling equipment is used to mix, spread and compact the old road milling material, recycled binder and water on site according to the design ratio to form a recycled base course. S2. Construction of the lower layer: The lower layer asphalt mixture is spread and compacted on the recycled base course. The lower layer asphalt mixture is plant-mixed hot recycled asphalt mixture, wherein the mass ratio of recycled asphalt mixture RAP is 30%-50%. Warm mixing technology is used in the construction, and the compaction temperature range is controlled between 135℃ and 150℃. S3. Construction of intermediate layer: The intermediate layer asphalt mixture is laid and compacted on the lower layer. The intermediate layer asphalt mixture is a high modulus asphalt mixture with a dynamic modulus of not less than 14,000 MPa. Warm mix technology is used in construction, and the compaction temperature range is controlled between 130℃ and 145℃. S4. Construction of the top layer: The top layer asphalt mixture is laid and compacted on the intermediate layer. The top layer asphalt mixture is SMA asphalt mastic macadam mixture with high viscoelasticity modified asphalt or OGFC open-graded anti-skid wear layer mixture. Warm mix technology is used in the construction, and the compaction temperature range is controlled between 130℃ and 140℃. In the paving and compaction process of steps S2, S3, and S4, infrared thermal imaging equipment is used to continuously monitor the temperature field distribution of the paved surface and dynamically guide the compaction operation based on real-time temperature feedback information.

[0007] In step S1, the recycled binder is cement or foamed asphalt. When cement is used, its addition amount is 1.5%-3.0% of the dry mass of the old road milling material, and the addition amount of water is 5%-7% of the total mass of the mixture.

[0008] In step S2, the plant-mixed hot recycled asphalt mixture contains asphalt recycling agent accounting for 2%-5% of the mass of aged asphalt during mixing.

[0009] In step S3, the high-modulus asphalt mixture is made by adding high-modulus additives or by using hard asphalt with a penetration grade of 20-30.

[0010] In step S4, when the upper layer asphalt mixture is asphalt mastic aggregate SMA, lignin fiber or polyester fiber accounting for 0.3%-0.5% of the total mass of the mixture is added.

[0011] "Dynamically guiding compaction operations based on real-time temperature feedback information" specifically includes: When infrared thermal imaging shows that there are areas on the paved surface with local temperatures more than 10°C below the set threshold, the compaction equipment will immediately compact those areas first. Based on the overall temperature drop rate of the paved surface, the compaction sequence and number of passes of the compaction equipment are dynamically adjusted to complete effective compaction before the temperature drops to the lower limit of compaction.

[0012] During the compaction process, the amount of water sprayed onto the steel roller is dynamically adjusted or the water spraying start / stop strategy is adjusted based on the cooling effect caused by the steel roller as monitored by infrared thermal imaging.

[0013] In step S3, when compacting the intermediate layer, a double-drum vibratory roller with a tonnage of not less than 13 tons is used, and high-frequency low-amplitude mode is adopted for compaction, and the number of vibration compaction passes is not less than 6.

[0014] Before construction in step S2, a tack coat is sprayed onto the surface of the recycled base layer; Before construction in step S3, a first tack coat is sprayed onto the surface of the lower layer; Before construction in step S4, a second tack coat is sprayed onto the surface of the intermediate layer; The tack coat is a high-performance modified emulsified asphalt.

[0015] A layered asphalt pavement constructed using the above method comprises, from bottom to top: The recycled base layer is composed of in-situ cold recycled mixture; The lower layer consists of warm-mix plant-mixed hot recycled asphalt mixture with a RAP mass ratio of 30%-50%. The intermediate layer consists of warm-mix high-modulus asphalt mixture with a dynamic modulus of not less than 14,000 MPa; The top layer consists of warm-mix asphalt mastic aggregate (SMA) or warm-mix open-graded anti-skid wear layer aggregate (OGFC) made with high viscoelastic modified asphalt.

[0016] The beneficial effects of this invention are: By combining layered customized materials with a continuous low-carbon, high-performance process, a layered asphalt pavement construction solution integrating longevity, high performance, greenness, and economy is constructed. This solves the traditional technical problems of asphalt pavement resistance to rutting and cracking, avoids excessive overall pavement performance, and has excellent interlayer treatment effect, without causing interlayer slippage, shear failure, and spalling. It improves the overall strength of the pavement and provides a fully validated complete solution for the green, high-quality, and sustainable development of transportation infrastructure. Attached Figure Description

[0017] Figure 1 This is a flowchart of the construction method according to Embodiment 1 of the present invention. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings. Example 1: A construction method for layered asphalt pavement includes the following steps: S1. Base course construction: Samples of old road milling material are taken and laboratory mix design is carried out to determine the ratio of recycled binder to water. On-site cold recycling equipment is used to mix, spread and compact the old road milling material, recycled binder and water on site according to the design ratio to form a recycled base course. S2. Construction of the lower layer: The lower layer asphalt mixture is laid and compacted on the recycled base course. The lower layer asphalt mixture is plant-mixed hot recycled asphalt mixture, in which the mass ratio of recycled asphalt mixture RAP is 30%-50%. Warm mix technology is used in construction, and its compaction temperature range is controlled between 135℃ and 150℃. S3. Construction of intermediate layer: The intermediate layer asphalt mixture is laid and compacted on the lower layer. The intermediate layer asphalt mixture is a high modulus asphalt mixture with a dynamic modulus of not less than 14000MPa. Warm mix technology is used in construction, and the compaction temperature range is controlled between 130℃ and 145℃. S4. Construction of the top layer: The top layer asphalt mixture is laid and compacted on the middle layer. The top layer asphalt mixture is SMA asphalt mastic macadam mixture with high viscoelasticity modified asphalt or OGFC open-graded anti-skid wear layer mixture. Warm mix technology is used in construction, and its compaction temperature range is controlled between 130℃ and 140℃. In the paving and compaction process of steps S2, S3, and S4, infrared thermal imaging equipment is used to continuously monitor the temperature field distribution of the paved surface and dynamically guide the compaction operation based on real-time temperature feedback information.

[0019] The construction method flowchart of this invention is as follows: Figure 1 As shown In step S1, the recycled binder is cement or foamed asphalt. When cement is used, its addition amount is 1.5%-3.0% of the dry mass of the old road milling material, and the addition amount of water is 5%-7% of the total mass of the mixture.

[0020] In step S2, the plant-mixed hot recycled asphalt mixture contains asphalt recycling agent accounting for 2%-5% of the mass of aged asphalt during mixing.

[0021] In step S3, the high-modulus asphalt mixture is made by adding high-modulus additives or by using hard asphalt with a penetration grade of 20-30.

[0022] In step S4, when the upper layer asphalt mixture is asphalt mastic aggregate (SMA), lignin fiber or polyester fiber accounting for 0.3%-0.5% of the total mass of the mixture is added.

[0023] "Dynamically guiding compaction operations based on real-time temperature feedback information" specifically includes: When infrared thermal imaging shows that there are areas on the paved surface with local temperatures more than 10°C below the set threshold, the compaction equipment will immediately compact those areas first. Based on the overall temperature drop rate of the paved surface, the compaction sequence and number of passes of the compaction equipment are dynamically adjusted to complete effective compaction before the temperature drops to the lower limit of compaction.

[0024] During the compaction process, the amount of water sprayed onto the steel roller is dynamically adjusted or the water spraying start / stop strategy is adjusted based on the cooling effect caused by the steel roller as monitored by infrared thermal imaging.

[0025] In step S3, when compacting the intermediate layer, a double-drum vibratory roller with a tonnage of not less than 13 tons is used, and high-frequency low-amplitude mode is adopted for compaction, and the number of vibration compaction passes is not less than 6.

[0026] Before step S2, spray a tack coat onto the surface of the recycled base layer; Before construction in step S3, spray the first tack coat onto the surface of the lower layer; Before step S4, spray the second tack coat onto the surface of the intermediate layer; The tack coat is a high-performance modified emulsified asphalt.

[0027] The proportion of materials in the in-situ cold recycled base layer is not a fixed value, but is determined by mix design based on detailed laboratory analysis of old road milling material, i.e., RAP.

[0028] The design process is as follows: Step 1: Evaluation of old materials.

[0029] A full set of tests were conducted on the milled RAP material, including sieving, moisture content, asphalt content, aged asphalt properties, and sand equivalent, to clarify its gradation composition and engineering characteristics.

[0030] Step 2: Determine the type and initial proportion of stabilizer.

[0031] Stabilizer types: The most commonly used are cement, such as PO 32.5, with a dosage of 1.5%-3.0% of the dry weight of aggregates, or foamed asphalt, with a dosage of 2.0%-3.5% of the dry weight of aggregates. Sometimes lime, emulsified asphalt, or composite stabilizers are also used. Objective: Cement primarily provides hydraulic strength, while foamed asphalt primarily provides flexible bonding and has better resistance to drying shrinkage cracks.

[0032] Step 3: Compaction and strength test.

[0033] RAP material is mixed with different doses of stabilizer and different total moisture contents, usually 4%-8% of the total mass of the mixture. Heavy compaction tests are then conducted to determine the maximum dry density and optimum moisture content.

[0034] Step 4: Performance verification.

[0035] Specimens were molded according to the optimum moisture content and the selected stabilizer dosage, and unconfined compressive strength, drying shrinkage, and compressive resilience modulus were tested to verify whether they met the design specifications, such as 7-day unconfined compressive strength ≥ 1.5-2.0 MPa.

[0036] Taking cement stabilization as an example, the old road milling material RAP accounts for approximately 95% - 98% of the total mass of the mixture. This is the matrix, and the remainder consists of added new materials or stabilizers. The stabilizer is cement, which accounts for 1.5% - 3.0% of the dry aggregate mass of RAP. Water is added until the mixture reaches the optimal moisture content, usually 5% - 7% of the total mass, and the moisture content of the RAP material itself needs to be deducted.

[0037] A dynamic compaction process adjustment method based on infrared thermal imaging temperature feedback: Among them, the key areas and targets for temperature detection are: Temperature uniformity of paved surface: Monitor for "strip-like" or "block-like" low-temperature zones, i.e., temperature segregation or high-temperature zones.

[0038] Temperature gradient in the compaction zone: monitoring the uniformity of temperature on the surface and below the surface of the area being compacted.

[0039] Temperature decay in uncompacted areas: tracking the rate of temperature drop of the mixture from paving to the start of compaction.

[0040] If localized low-temperature zones appear on the paved surface, it indicates temperature segregation during transportation or material buildup in the paver hopper. The paving process needs to be adjusted: instruct the paver operator to slow down the paving speed to allow more hot material to mix, or manually remove and replace the localized cold material; adjust the compaction strategy: mark the area, and have the roller compact the area in advance when the temperature is still acceptable, and add one or two more compaction passes.

[0041] If the overall temperature of the paved surface is lower than the lower limit of the target compaction temperature, it indicates that the ambient temperature is low, the wind is strong, or the temperature of the mixture leaving the factory is insufficient. The compaction process needs to be adjusted: immediately start all road rollers and use the "close following, high frequency, low amplitude" mode for strong vibration compaction, cancel or significantly shorten the static compaction stage, and consider adding 1-2 road rollers to complete the initial and secondary compaction as quickly as possible.

[0042] If the temperature at the roller tracks is significantly lower than that on both sides, it indicates that the water spray volume of the steel wheel roller is too large or the temperature of the steel wheel itself is too low. The equipment parameters need to be adjusted: immediately reduce or turn off the water spray of the roller's steel wheel, switch to a spraying system with better atomization, and preheat the steel wheel with hot water before construction.

[0043] If, at the end of the compaction, the temperature of a certain area of ​​the road surface is still significantly higher than that of the surrounding area, it indicates that the number of compaction passes in that area is insufficient or the initial temperature is too high. The compaction process needs to be adjusted: instruct the road roller to perform supplementary compaction on that area until its surface temperature is similar to that of the surrounding qualified areas.

[0044] If the temperature difference between different points in the lateral direction is greater than 15℃, it indicates that the screed of the paver is not heated evenly, or that the material is segregating during unloading from the trolley. The paving parameters need to be adjusted: check and adjust the screed heating system; optimize the material unloading and hopper collection operations; and adjust the compaction sequence: adopt a zoned compaction strategy of "compacting the high-temperature zone first and focusing on compacting the low-temperature zone".

[0045] Example 2: A layered asphalt pavement constructed using the above method comprises, from bottom to top: The recycled base layer is composed of on-site cold recycled mixture, in which the recycled base layer serves as the main load-bearing and structural support layer.

[0046] The lower layer consists of warm-mixed hot recycled asphalt mixture with a RAP mass ratio of 30%-50%. The lower layer is a leveling and load-bearing layer, which can provide space for the large-scale use of recycled materials and solve the problem of material waste in the lower layer.

[0047] The intermediate layer is composed of warm-mix high-modulus asphalt mixture with a dynamic modulus of not less than 14,000 MPa. The intermediate layer is a load-bearing layer that can bear the main load and solve the problem of rutting.

[0048] The top layer is composed of warm-mix asphalt mastic aggregate (SMA) or warm-mix open-graded anti-skid wear course aggregate (OGFC) using high viscoelastic modified asphalt. The top layer is a wear course, which can play the functions of anti-skid, noise reduction, wear resistance and crack resistance, and can solve the problems of insufficient anti-skid, high noise and easy scattering of traditional asphalt pavement.

[0049] The layered asphalt pavement in this technical solution can effectively and fully utilize the material performance of each layer of the pavement, achieving synergistic efficiency and overall performance far exceeding the sum of the performance of each layer.

[0050] Example 3: A construction method for layered asphalt pavement includes the following steps: a. Base course construction: First, samples of the milled material from the old concrete pavement were taken. Laboratory analysis showed that it had good gradation and a sand equivalent of 65. Through mix design, foamed asphalt was selected as the recycled binder, with a designed admixture amount of 2.8% of the dry aggregate mass of the milled material and a designed optimum moisture content of 6.2%. During construction, a Wirtgen WR250 in-situ cold recycling machine was used. As the equipment moved, the front rotor milled and crushed the old road. At the same time, through a precise control system, pre-prepared foamed asphalt and water were sprayed into the mixing chamber in the design ratio and thoroughly mixed with the milled material. The uniformly mixed recycled mixture was initially leveled by a paver, then compacted four times with a 22-ton single-drum vibratory roller, and six times with a 25-ton pneumatic tire roller. Finally, a double-drum roller was used for static compaction to form a dense foamed asphalt cold recycled base course. After three days of curing, a tack coat was sprayed. The tack coat used was PC-2 type emulsified asphalt, with a dosage of 1.2 L / m².

[0051] b. Construction of the lower layer: AC-25 type gradation is adopted, and the target mix ratio is: 55% new aggregate, 40% RAP material, and 2.1% new asphalt, i.e. No. 70 road petroleum asphalt. Before mixing, RA-1 type recycling agent accounting for 3% of the mass of aged asphalt is added to the milled material. The mixture adopts warm mixing technology, and the discharge temperature is 142℃. After being transported to the site, the paver spread the paving material at a uniform speed of 3 m / min. During the paving process, a FLIR A655sc infrared thermal imager was set up to continuously scan the paved surface. Initial compaction was achieved by a 13-ton double-drum roller with static compaction once, followed by four passes each from two 30-ton pneumatic tire rollers. The infrared thermal imager showed a weak low-temperature zone in the middle of the paved surface, approximately 135°C. Based on the prompts on the monitoring screen, the roller operator immediately directed one pneumatic tire roller to add an extra pass of compaction to this zone. The final compaction was achieved by two passes of static compaction with a double-drum roller to eliminate wheel tracks.

[0052] c. Construction of intermediate layer: HMAC-20 high modulus asphalt mixture is used. The material composition is: basalt aggregate, 2% PR high modulus additive, and 4.5% No. 30 hard asphalt. The surfactant-based warm mix technology is used, the discharge temperature is 138℃, and the dynamic modulus is 15200 MPa as tested in the laboratory. Before paving, SBS modified emulsified asphalt tack coat oil was sprayed onto the lower surface at a rate of 0.5 L / m². During paving, the infrared thermal imager showed that the temperature of the entire working surface was uniform at 137±3℃. The compaction adopted a "strong vibration following" strategy: a 13-ton double-drum roller followed the paver in a high-frequency, low-amplitude mode and vibrated and compacted three times for initial compaction. Then, a 15-ton double-drum roller vibrated and compacted three times in the same mode for secondary compaction. Finally, two static compactions were performed, for a total of six vibration compactions, ensuring the density of the high-modulus mixture.

[0053] d. Top layer construction: SMA-13 ​​mixture is used, with SBS high viscosity modified asphalt at a dosage of 5.8%, and 0.4% polyester fiber is added. Organic viscosity-reducing warm mix admixture is used, and the discharge temperature is controlled at 135℃. Before paving, tack coat was sprayed. After paving, infrared thermal imaging showed that the mixture cooled down gradually. Compaction strictly followed the principle of "close following, slow compaction, and static compaction as the main method": the double-drum roller was turned off and statically compacted twice in close proximity to the paver. During the process, the thermal imager found that one roller sprayed too much water on its steel wheel, resulting in a cooling strip behind it. The commander immediately notified the roller to turn off the water spray and used a subsequent roller to add static compaction to the strip to ensure surface uniformity.

[0054] This results in a composite pavement consisting of "foamed asphalt cold recycled base course + high-dosage warm-mix recycled lower course + warm-mix high-modulus intermediate course + warm-mix high-functionality upper course," achieving efficient utilization of milled material. The base course and lower course combined utilize over 80% of the material, and the entire process of warm mixing reduces energy consumption by approximately 25%. The measured dynamic stability of the pavement exceeds 8000 cycles / mm, and its expected service life is more than 50% longer than that of traditional pavements.

[0055] Example 4: A construction method for layered asphalt pavement includes the following steps: A. Base layer construction: After analyzing the milled material from the old asphalt pavement, it was decided to use cement as a stabilizer. The mix design determined that the cement content was 2.2% of the mass of the RAP dry aggregate, and the optimum moisture content was 5.8%. The construction process utilizes a combination of cement slurry conveyor trucks and cold recycling machines to precisely control the amount of cement slurry sprayed. After compaction, a cement-stabilized cold recycled base layer is formed.

[0056] B. Construction of the lower layer: The RAP content was adjusted to 35%, using No. 90 asphalt with greater penetration and adding 2.5% recycling agent. Asphalt foaming warm mix technology was adopted, with a discharge temperature of 148℃ and a compaction temperature range of 140-150℃.

[0057] C. Construction of intermediate layer: High-modulus mixtures were prepared directly using hard asphalt with a penetration of 25 without the use of external admixtures. The measured dynamic modulus was 14,500 MPa. Chemical viscosity-reducing warm mixing technology was adopted, and the discharge temperature was 142℃.

[0058] D. Construction of the upper layer: OGFC-13 was selected as the top layer, using high-viscosity modified asphalt with a designed porosity of 18%. During the compaction process, the temperature was closely monitored by an infrared thermal imager, and the number of compaction passes was strictly controlled. Only three static compaction passes with steel wheels were used to ensure that the target porosity was achieved and maintained, thus realizing excellent drainage and noise reduction functions.

[0059] The asphalt pavement structure obtained through the construction method of this embodiment proves that even with changes in binder type, material parameters, and pavement function, a layered asphalt pavement can still be formed.

[0060] Example 5: A construction method for layered asphalt pavement includes the following steps: 1) Base course construction: Instead of using in-situ cold recycling, graded crushed stone is laid as a conventional base course, but tack coat is still sprayed.

[0061] 2) Construction of the lower layer: Plant-mixed hot recycled AC-25 mixture with 30% RAP content was used, and a warm mix agent was added to control the discharge temperature at 150℃. The compaction process was conventional, but a handheld infrared thermometer was used to conduct spot checks on the paving edges and joints, and the temperature measurement results guided the priority compaction of these easily cooled areas.

[0062] 3) Construction of intermediate and top layers: During the two-layer construction, a single portable infrared thermal imager system is used. After the intermediate layer is laid and compacted, it is moved to the upper layer construction area for use. The system still provides a full-width temperature map to determine temperature segregation and guide compaction, but it is not yet linked with the road roller for data. Instead, it is directed by a person based on the information displayed on the screen.

[0063] The asphalt pavement structure obtained through the construction method of this embodiment proves that even without automated equipment, a layered asphalt pavement can still be formed using the material system in this technical solution, namely, the high-recyclable lower layer, the high-modulus middle layer, and the functional upper layer, by adopting the full-process warm mix technology and the compaction method based on infrared temperature monitoring.

[0064] Working principle: The asphalt pavement adopts a layered, customized design with reinforced interlayer bonding. It features a layered gradient design incorporating recycling, strengthening the base, and enhancing functionality, ensuring a perfect match between the mechanical properties and functional requirements of each layer. This achieves synergistic effects on the overall structure, avoiding the performance limitations of traditional homogeneous pavements. Load stress is effectively distributed and borne by each functional layer, extending the overall fatigue life of the pavement by 30%-50%. Warm-mix technology is applied throughout the process, achieving low-carbon construction and providing process assurance for high-performance materials. The lower layers utilize a high proportion of RAP material, directly using milling waste to address the environmental issue of waste accumulation. The base layer employs in-situ cold recycling technology to maximize resource utilization. Real-time temperature field monitoring and dynamic compaction control based on infrared thermal imaging completely eliminate quality blind spots, ensuring standardized and traceable construction quality control.

[0065] The beneficial effects of this invention are that by combining layered customized materials with a through-process low-carbon high-performance technology, a layered asphalt pavement construction solution that integrates longevity, high performance, greenness, and economy is constructed. This solves the traditional technical problems of asphalt pavement resistance to rutting and cracking, avoids excessive overall pavement performance, has excellent interlayer treatment effect, and will not cause interlayer slippage, shear failure, and spalling, thereby improving the overall strength of the pavement. It provides a fully proven and complete solution for the green, high-quality, and sustainable development of transportation infrastructure.

[0066] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A construction method for layered asphalt pavement, characterized in that, Includes the following steps: S1. Base course construction: Samples of old road milling material are taken and laboratory mix design is carried out to determine the ratio of recycled binder to water. On-site cold recycling equipment is used to mix, spread and compact the old road milling material, recycled binder and water on site according to the design ratio to form a recycled base course. S2. Construction of the lower layer: The lower layer asphalt mixture is spread and compacted on the recycled base course. The lower layer asphalt mixture is plant-mixed hot recycled asphalt mixture, wherein the mass ratio of recycled asphalt mixture RAP is 30%-50%. Warm mixing technology is used in the construction, and the compaction temperature range is controlled between 135℃ and 150℃. S3. Construction of intermediate layer: The intermediate layer asphalt mixture is laid and compacted on the lower layer. The intermediate layer asphalt mixture is a high modulus asphalt mixture with a dynamic modulus of not less than 14,000 MPa. Warm mix technology is used in construction, and the compaction temperature range is controlled between 130℃ and 145℃. S4. Construction of the top layer: The top layer asphalt mixture is laid and compacted on the intermediate layer. The top layer asphalt mixture is SMA asphalt mastic macadam mixture with high viscoelasticity modified asphalt or OGFC open-graded anti-skid wear layer mixture. Warm mix technology is used in the construction, and the compaction temperature range is controlled between 130℃ and 140℃. In the paving and compaction process of steps S2, S3, and S4, infrared thermal imaging equipment is used to continuously monitor the temperature field distribution of the paved surface and dynamically guide the compaction operation based on real-time temperature feedback information.

2. The construction method for a layered asphalt pavement as described in claim 1, characterized in that, In step S1, the recycled binder is cement or foamed asphalt. When cement is used, its addition amount is 1.5%-3.0% of the dry mass of the old road milling material, and the addition amount of water is 5%-7% of the total mass of the mixture.

3. The construction method for a layered asphalt pavement as described in claim 1, characterized in that, In step S2, the plant-mixed hot recycled asphalt mixture contains asphalt recycling agent accounting for 2%-5% of the mass of aged asphalt during mixing.

4. The construction method for a layered asphalt pavement as described in claim 1, characterized in that, In step S3, the high-modulus asphalt mixture is made by adding high-modulus additives or by using hard asphalt with a penetration grade of 20-30.

5. The construction method for a layered asphalt pavement as described in claim 1, characterized in that, In step S4, when the upper layer asphalt mixture is asphalt mastic aggregate SMA, lignin fiber or polyester fiber accounting for 0.3%-0.5% of the total mass of the mixture is added.

6. The construction method for a layered asphalt pavement as described in claim 1, characterized in that, "Dynamically guiding compaction operations based on real-time temperature feedback information" specifically includes: When infrared thermal imaging shows that there are areas on the paved surface with local temperatures more than 10°C below the set threshold, the compaction equipment will immediately compact those areas first. Based on the overall temperature drop rate of the paved surface, the compaction sequence and number of passes of the compaction equipment are dynamically adjusted to complete effective compaction before the temperature drops to the lower limit of compaction.

7. The construction method for a layered asphalt pavement as described in claim 6, characterized in that, During the compaction process, the amount of water sprayed onto the steel roller is dynamically adjusted or the water spraying start / stop strategy is adjusted based on the cooling effect caused by the steel roller as monitored by infrared thermal imaging.

8. The construction method for a layered asphalt pavement as described in claim 1, characterized in that, In step S3, when compacting the intermediate layer, a double-drum vibratory roller with a tonnage of not less than 13 tons is used, and high-frequency low-amplitude mode is adopted for compaction, and the number of vibration compaction passes is not less than 6.

9. The construction method for a layered asphalt pavement as described in claim 1, characterized in that, Before construction in step S2, a tack coat is sprayed onto the surface of the recycled base layer; Before construction in step S3, a first tack coat is sprayed onto the surface of the lower layer; Before construction in step S4, a second tack coat is sprayed onto the surface of the intermediate layer; The tack coat is a high-performance modified emulsified asphalt.

10. A layered asphalt pavement constructed by the method described in any one of claims 1-9, characterized in that, From bottom to top, including: The recycled base layer is composed of in-situ cold recycled mixture; The lower layer consists of warm-mix plant-mixed hot recycled asphalt mixture with a RAP mass ratio of 30%-50%. The intermediate layer consists of warm-mix high-modulus asphalt mixture with a dynamic modulus of not less than 14,000 MPa; The top layer consists of warm-mix asphalt mastic aggregate (SMA) with high viscoelasticity modified asphalt or warm-mix open-graded anti-skid wear layer aggregate (OGFC).

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