Foamed asphalt cold recycling filling type composite pavement process
By using foamed asphalt cold recycling and injection composite pavement technology, a large-void matrix is formed by milling old asphalt pavement material and then injecting cement-based grout, which solves the problems of pavement distress and high energy consumption under heavy traffic and improves high stability and rapid traffic capacity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHEJIANG SHILU ENG TECH CO LTD
- Filing Date
- 2026-03-25
- Publication Date
- 2026-06-09
AI Technical Summary
Existing roads are prone to rutting, shoving, bulging, potholes and local structural instability under heavy traffic conditions. Traditional pavement structures are insufficient in terms of rutting resistance, durability and rapid traffic capacity, and hot-mix asphalt construction has problems of high energy consumption and long road closure time.
The foamed asphalt cold recycling grouting composite pavement process is adopted. Through milling, screening, gradation design, cold recycling mixing, paving and compaction, and cement-based grouting of the old asphalt pavement, a large-void foamed asphalt cold recycled pavement matrix is formed, and cement-based grouting material is injected to form a composite load-bearing structure.
It improves the structural stability and high-temperature deformation resistance of the road surface, reduces construction energy consumption, shortens road closure time, and enables rapid traffic reopening under normal temperature conditions. It is suitable for heavy traffic sections and scenarios with high rutting resistance requirements.
Smart Images
Figure CN122169409A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of composite pavement technology, specifically a foamed asphalt cold recycling injection composite pavement process. Background Technology
[0002] Existing municipal roads, heavy-load highway sections, bus stops, intersections, uphill sections, and ramps are prone to rutting, shoving, bulging, potholes, and local structural instability under long-term repeated loads. To improve these problems, existing projects typically use ordinary asphalt pavement, SBS modified asphalt pavement, or SMA asphalt pavement for repair and overlay. However, when facing continuously increasing traffic flow and high axle load conditions, traditional pavement structures still have shortcomings in terms of rutting resistance, durability, and rapid traffic capacity. At the same time, conventional hot-mix asphalt construction also has problems such as high construction temperature, long road closure time, high energy consumption, and insufficient recycling rate. Summary of the Invention
[0003] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a foamed asphalt cold recycling injection composite pavement process.
[0004] The objective of this invention can be achieved through the following technical solutions: A foamed asphalt cold recycling injection composite pavement process includes the following steps: The damaged old asphalt pavement is milled and the original pavement is cleaned. Emulsified asphalt tack coat is then sprayed onto the cleaned original pavement. The old asphalt milled material obtained by milling is pre-treated by screening to obtain milled material components with different particle size ranges. Based on the screening of the milled material components, the mix design is carried out to form a gradation structure that meets the requirements of large-void asphalt mixture. The milled material components after the mix design are cold recycled and mixed with foamed asphalt and cement binder to obtain foamed asphalt cold recycled mixture. The foamed asphalt cold recycled mixture is transported to the construction site for paving and compaction to form a large-void foamed asphalt cold recycled pavement base. After sealing material is applied around the road surface substrate, cement-based grouting material is prepared and injected into the interconnected voids of the road surface substrate until the grout no longer seeps or bubbles and the voids are filled. After the grouting is completed, the surface is scraped with grout and then cured before traffic is opened, thus forming a foamed asphalt cold recycled grouting composite pavement.
[0005] Furthermore, the milling of the damaged old asphalt pavement includes: Milling equipment is used to mill the original damaged asphalt pavement in layers or in one go to remove the damaged parts in the surface or structural layers. The milled material is then transported to the back site for subsequent screening and pretreatment. After milling, the loose particles, dust and debris remaining on the original pavement surface are cleaned up, and then emulsified asphalt tack coat is sprayed to improve the bonding performance between the subsequent paving layers and the original pavement.
[0006] Furthermore, the milled material undergoes a screening pretreatment, including: The recycled old asphalt milled material is screened into 0-5mm, 5-11mm and 11-31.5mm particle size components using screening equipment. The 0-5mm and 11-31.5mm particle size components are used as the main grading materials for large-void foamed asphalt cold recycled mixtures in subsequent mix design.
[0007] Furthermore, the mix design includes: The 0-5mm particle size component and the 11-31.5mm particle size component are screened and blended to obtain a large-void foamed asphalt cold recycled mixture with a total void ratio controlled at 19%-28% and a connected void ratio controlled at 17%-26%. The asphalt used is 70# ordinary base asphalt and the cement used is P.O42.5 ordinary Portland cement.
[0008] Furthermore, the foamed asphalt cold recycled mixture is mixed using a plant-mixed cold recycling equipment. During the mixing process, the sieved milled material components, foamed asphalt, and cement binder are added according to the designed mix proportion to form a foamed asphalt cold recycled mixture with a large void skeleton structure under normal temperature conditions.
[0009] Furthermore, the paving and compaction include transporting the mixed foamed asphalt cold recycled mixture to the construction site for paving. During paving, the loose paving coefficient is controlled at 1.1-1.2, and a 12t steel wheel roller is used for static compaction to make the foamed asphalt cold recycled mixture form a large-void pavement matrix that meets the grouting requirements.
[0010] Furthermore, during the compaction process, a slow and uniform static compaction is performed, with 5 passes. The smoothness of the compacted large-void foamed asphalt cold recycled pavement substrate is tested, and the maximum smoothness value is controlled to be no greater than 8 mm and the average value is no greater than 5 mm. For areas where the smoothness does not meet the requirements, a road roller is used to perform static compaction again until the requirements are met.
[0011] Furthermore, before grouting, the perimeter of the large-void foamed asphalt cold recycled pavement substrate is covered and sealed with sealing material to prevent grout from flowing out during the grouting process and causing pollution to adjacent pavement or curb stones, and to provide boundary constraints for subsequent grouting and finishing construction.
[0012] Furthermore, the cement-based grouting material is prepared using on-site grouting equipment. Its dry material is semi-flexible early-strength pavement grout, and the mixing water is water source that meets general drinking water standards. The prepared cement grout is pumped to the surface of the large-void foamed asphalt cold recycled pavement substrate and, under the action of gravity, self-levels and penetrates into the connected voids until the grout stops seeping and bubbling and the voids are filled.
[0013] Furthermore, after the grouting is completed, a grouting surface treatment is carried out to remove the cement grout remaining on the surface, so as to expose the uneven structure of the base asphalt mixture surface. During the curing period, traffic is strictly closed to prevent the passage of personnel and vehicles and rainwater erosion. After the grout has finally set, water curing is carried out, and the curing time is controlled according to the construction temperature so that the road surface is ready for traffic within 1-2 hours after grouting.
[0014] Compared with the prior art, this application has the following advantages: The foamed asphalt cold recycling and infill composite pavement process provided by this invention uses milled material from damaged old asphalt pavement as the base raw material. Through steps such as screening, gradation design, foamed asphalt cold recycling mixing, paving and compaction, edge sealing grouting, and maintenance and opening to traffic, a composite pavement structure with both flexible skeleton and rigid filling is formed. This process is not simply a replacement for the traditional cold recycling process, but rather introduces cement-based grouting material on top of the large-pore foamed asphalt cold recycling matrix, so that a composite load-bearing system is formed inside the pavement, thereby significantly improving the structural stability and high-temperature deformation resistance of the pavement.
[0015] The technological features of this invention also include the ability to complete the mixing and paving of foamed asphalt cold recycled mixture under normal temperature conditions, and to reuse old asphalt milled material for resource recovery, thereby reducing construction energy consumption and shortening road closure time. Compared with traditional hot-mix pavement, this invention avoids the problem of waiting for cooling and grouting after high-temperature construction of large-void asphalt mixture, allowing the grouting process to be carried out more continuously. At the same time, combined with semi-flexible pavement early-strength grouting material, traffic can be opened in a shorter time. It is suitable for scenarios with high requirements for rutting resistance, such as port areas with heavy traffic, intersections, bus stops and ramps.
[0016] Furthermore, this invention systematically controls the particle size distribution, total porosity, interconnected porosity, compaction smoothness, and grouting termination state of the milled material. This ensures that the large-void matrix possesses both a good interconnected porosity structure and sufficient grout penetration and filling, ultimately forming a composite pavement with high grouting rate, high strength, and high durability. Based on the data you provided, the pavement produced by this invention exhibits good performance in terms of dynamic stability at 70℃, Marshall stability, splitting tensile strength, and water damage resistance, demonstrating significant engineering application value. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of foamed asphalt production; Figure 2 This is a schematic diagram of the production of foamed asphalt matrix mixtures; Figure 3 It is a microscopic diagram of the microstructure of the mixture; Figure 4 This is a schematic diagram of grouting for foamed asphalt cold recycled mixture; Figure 5 This is a schematic diagram of a core sample of a foamed asphalt cold-recycled composite pavement. Figure 6 This is a schematic diagram of the open traffic surface state of a foamed asphalt cold recycling pavement. Detailed Implementation
[0018] This invention provides a foamed asphalt cold recycling and grouting composite pavement process. The overall concept involves first using milled old asphalt pavement material to form a large-void foamed asphalt cold recycled pavement matrix with interconnected voids. Then, cement-based grouting material is injected into these interconnected voids, allowing the asphalt skeleton and grout filling to jointly form a composite load-bearing structure. The core of this process lies in simultaneously achieving the reuse of old materials, ambient temperature construction, large-void formation, sufficient grout injection, and rapid opening to traffic. like Figure 1-6 As shown, a foamed asphalt cold recycling injection composite pavement process includes the following steps: Step 1: Mill the damaged old asphalt pavement and clean the original pavement, and spray emulsified asphalt tack coat on the cleaned original pavement. The milling of the damaged old asphalt pavement includes: Milling equipment is used to mill the original damaged asphalt pavement in layers or in one go to remove the damaged parts in the surface or structural layers. The milled material is then transported to the back site for subsequent screening and pretreatment. After milling, the loose particles, dust and debris remaining on the original pavement surface are cleaned up, and then emulsified asphalt tack coat is sprayed to improve the bonding performance between the subsequent paving layers and the original pavement.
[0019] First, the damaged old asphalt pavement is milled. A milling machine is used to remove the original asphalt layer with ruts, bumps, or local damage. The resulting milled material is then transported to the back site for further screening. After milling, the original pavement surface is thoroughly cleaned to remove loose particles, dust, and debris. Subsequently, emulsified asphalt tack coat is evenly sprayed onto the cleaned original pavement surface to enhance the adhesion between the subsequent paving layer and the original pavement.
[0020] In this embodiment, the construction section is a heavy-load traffic area in the port area, and the road surface has obvious ruts and local wear. Before construction, the milling boundary is marked and the milling depth is controlled to cover the damaged layer area. After cleaning, emulsified asphalt tack coat is continuously sprayed along the construction section using spraying equipment. After a uniform bonding layer is formed on the surface, the subsequent paving process is carried out. It can also be applied to road intersections, bus stops, uphill sections, ramps, etc.
[0021] The milled material undergoes screening pretreatment, including: The recycled old asphalt milled material is screened into 0-5mm, 5-11mm and 11-31.5mm particle size components using screening equipment. The 0-5mm and 11-31.5mm particle size components are used as the main grading materials for large-void foamed asphalt cold recycled mixtures in subsequent mix design.
[0022] The recycled old asphalt milled material is pre-treated by screening using a screening machine to obtain milled material components with three particle size ranges: 0-5mm, 5-11mm, and 11-31.5mm. Through this grading process, the problem of disordered particle size distribution in the original old material can be transformed into a controllable gradation problem, providing conditions for the subsequent construction of large-void foamed asphalt cold recycled mixture.
[0023] In this embodiment, the recycled milled material is initially removed and then sent to a screening device to obtain fine material, intermediate material and coarse material stockpiles. During construction, 0-5mm particle size components and 11-31.5mm particle size components are selected for subsequent gradation design to form a road matrix material system with a skeleton void structure.
[0024] Step 2: The old asphalt milled material obtained by milling is pre-treated by screening to obtain milled material components with different particle size ranges. Based on the screening of the milled material components, the mix design is carried out to form a gradation structure that meets the requirements of large-void asphalt mixture.
[0025] The mix design includes: The 0-5mm particle size component and the 11-31.5mm particle size component are screened and blended to obtain a large-void foamed asphalt cold recycled mixture with a total void ratio controlled at 19%-28% and a connected void ratio controlled at 17%-26%. The asphalt used is 70# ordinary base asphalt and the cement used is P.O42.5 ordinary Portland cement.
[0026] Before construction, a targeted mix design is carried out, and the 0-5mm particle size component and the 11-31.5mm particle size component are screened and blended to ensure that the resulting mixture gradation meets the requirements of large-void asphalt mixture. The total void ratio of the large-void foamed asphalt cold recycled asphalt mixture is controlled at 19%-28%, and the interconnected void ratio is controlled at 17%-26%. The asphalt used is 70# ordinary base asphalt, and the cement used is P.O42.5 ordinary Portland cement. Through the above parameter settings, the pavement substrate can have both the necessary void connectivity and sufficient skeleton stability.
[0027] In this embodiment, the ratio of fine to coarse materials is adjusted by trial mixing before construction, and the void structure of the sample is tested. When the total void ratio of the sample is within the target range and the connected voids form a continuous seepage channel, it is determined as the final construction gradation. Subsequently, continuous on-site production is organized according to this gradation.
[0028] Step 3: Mix the milled material components with foamed asphalt and cement binder after the mix design to obtain foamed asphalt cold recycled mixture.
[0029] The foamed asphalt cold recycling mixture is mixed using a plant-mixed cold recycling equipment. During the mixing process, the sieved milling material components, foamed asphalt, and cement binder are added according to the designed mix proportion to form a foamed asphalt cold recycling mixture with a large void skeleton structure under normal temperature conditions.
[0030] The 0-5mm particle size component and the 11-31.5mm particle size component after screening are mixed in the determined mix design ratio using a plant-mixed cold recycling equipment. Foamed asphalt and cement binder are added during the mixing process to form a foamed asphalt cold recycled mixture with a large void skeleton structure. The plant-mixed cold recycling equipment is a Wirtgen KMA plant-mixed cold recycling machine.
[0031] In this embodiment, each milled material is fed into the cold recycling mixing equipment by the conveying system. The equipment adds foamed asphalt and cement binder in a preset ratio to make the materials quickly and evenly mixed under normal temperature conditions. After discharge, the state of the mixture should be observed. It should show a uniform coating and maintain a clear skeleton void to facilitate subsequent paving and grouting penetration.
[0032] In this process, foamed asphalt is produced by introducing hot asphalt into the conical cavity of the foaming chamber, followed by the introduction of cold water and compressed air, which are then sprayed into the hot asphalt stream under high pressure. The cold water vaporizes instantly upon encountering the high-temperature asphalt, forming numerous tiny bubbles. The compressed air further disperses and expands these bubbles, causing the asphalt volume to increase dramatically and its viscosity to decrease. The asphalt completes the process of bubble nucleation, growth, and stabilization within the foaming chamber. Figure 1 As shown, where Figure 1 The foamed asphalt in the text refers to this foamed asphalt.
[0033] Figure 2 In this context, cold aggregate refers to the milling material component after the mix design.
[0034] Figure 3 In this context, new aggregates are newly added high-quality aggregates, while recycled materials are the milling material components.
[0035] Step 4: Transport the foamed asphalt cold recycled mixture to the construction site for paving and compaction to form a large-void foamed asphalt cold recycled pavement base.
[0036] The paving and compaction process includes transporting the mixed foamed asphalt cold recycled mixture to the construction site for paving. During paving, the loose paving coefficient is controlled at 1.1-1.2, and a 12t steel wheel roller is used for static compaction to make the foamed asphalt cold recycled mixture form a large-void pavement matrix that meets the grouting requirements.
[0037] During the compaction process, a slow and uniform static compaction is performed, with 5 passes. The smoothness of the compacted large-void foamed asphalt cold recycled pavement substrate is tested, and the maximum smoothness value is controlled to be no more than 8 mm and the average value is no more than 5 mm. For areas where the smoothness does not meet the requirements, a road roller is used to perform static compaction again until the requirements are met.
[0038] In this embodiment, a paver is used for continuous paving on site to control the paving thickness to be consistent. Then, a steel wheel roller is used for the first pass of compaction and subsequent static compaction. For areas with local unevenness, the paver is repaired by a combination of material replenishment and re-compaction. Finally, a large-void pavement base with continuous and connected voids, a smooth surface, and a stable structure is obtained.
[0039] Step 5: After setting the sealing material around the road surface substrate, prepare cement-based grouting material and pour it into the connecting voids of the road surface substrate until the grout no longer seeps or bubbles and the voids are filled.
[0040] Before grouting, the perimeter of the large-void foamed asphalt cold recycled pavement substrate is covered and sealed with edge sealing material to prevent the grout from flowing out during the grouting process and causing pollution to adjacent pavement or curb stones, and to provide boundary constraints for subsequent grouting and finishing construction.
[0041] Before grouting, the perimeter of the large-void foamed asphalt cold recycled pavement substrate is covered and sealed with edge sealing material to prevent subsequent grout overflow from contaminating adjacent pavements or curbs, while also providing boundary constraints for grouting and finishing. This step can reduce grout loss and help ensure the edge forming quality of the grouting area.
[0042] In this embodiment, sealing strips are laid along the edge of the construction section, and auxiliary shielding components are used to seal the manhole cover, side stones and joints, so that the grout mainly penetrates into the interior along the vertical direction and the void channels during injection, instead of flowing out disorderly.
[0043] The cement-based grouting material is prepared using on-site grouting equipment. Its dry material is semi-flexible early-strength grouting material for road surfaces. The mixing water is sourced from water sources that meet general drinking water standards. The prepared cement grout is pumped to the surface of the large-void foamed asphalt cold recycled road surface substrate and, under the action of gravity, self-levels and penetrates into the interconnected voids until the grout stops seeping and bubbling and the voids are filled.
[0044] Grouting is carried out using on-site grouting equipment. The dry material of the cement-based grouting material used is semi-flexible pavement early-strength grouting material. The water used for mixing is water source that meets the general drinking water standards. On-site grouting can shorten the time interval between grout preparation and grouting, and improve grout fluidity and construction continuity.
[0045] In this embodiment, an independent slurry preparation area is set up at the construction site. Water and dry materials are continuously added according to the equipment setting ratio to produce a cement slurry with stable fluidity. After the slurry is formed, it is immediately transported to the grouting operation surface to reduce fluidity decay caused by standing.
[0046] In this embodiment, the construction workers advance the grouting operation sequentially along the paving width direction; for areas with faster local grout absorption, the number of grouting operations is appropriately increased to ensure that the internal voids are fully filled; for areas where the infiltration rate tends to stabilize and the surface grout layer no longer drops significantly, grouting is stopped and the work proceeds to the next section.
[0047] Step 6: After the grouting is completed, the surface is scraped and cured before traffic is opened, thus forming a foamed asphalt cold recycled grouting composite pavement.
[0048] After the grouting is completed, a grouting surface treatment is carried out to remove the cement grout remaining on the surface, so as to expose the uneven structure of the base asphalt mixture surface. During the curing period, traffic is strictly closed to prevent the passage of people and vehicles and rainwater erosion. After the grout has finally set, water curing is carried out, and the curing time is controlled according to the construction temperature so that the road surface is ready for traffic within 1-2 hours after grouting.
[0049] After the grouting is completed, the road surface should be scraped immediately to remove the excess cement grout remaining on the surface, so as to expose the uneven structure of the base asphalt mixture surface. This is to prevent the grout from forming a continuous hard shell on the surface, which would affect the surface texture depth and skid resistance of the road.
[0050] In this embodiment, a combination of rubber scraper and manual trimming is used for surface treatment, focusing on cleaning up local slurry accumulation areas and residual slurry at the edges and corners, so that the surface after molding is both fully grouted and retains the necessary rough texture.
[0051] After grouting is completed, the curing stage begins. During the curing period, traffic is strictly closed, and personnel and vehicles are prohibited from passing through. Attention should be paid to preventing rainwater erosion. Water curing is carried out after the grout has set. The time for opening traffic is adjusted according to the construction temperature, and traffic can usually be opened 1-2 hours after grouting. By using early-strength grouting materials, the curing time can be effectively shortened and the construction efficiency can be improved.
[0052] The following table compares the properties of this application with those of existing materials: project unit Foamed asphalt cold recycling injection composite pavement AC-16 Ordinary Asphalt Pavement AC-16 SBS modified asphalt pavement SMA asphalt pavement 70℃ dynamic stability times / mm 23000 1800 3200 5200 Marshall stability kN 14.51 8.3 9.2 9.3 Stream value mm 2.1 3.6 3.3 4.2 Infusion rate % 93 - - - Water immersion residual stability % 88 81 83 85 Dry splitting strength MPa 2.3 1.1 1.2 0.92 Dry-wet splitting strength ratio % 87 81 84 86 Freeze-thaw splitting strength ratio % 86 80 82 86 Construction temperature ℃ normal temperature 130 150 150 The test results above show that: Based on performance comparison data, the foamed asphalt cold-recycled infill composite pavement formed by this invention achieves a dynamic stability of 23,000 cycles / mm at 70℃, while AC-16 ordinary asphalt pavement, AC-16 SBS modified asphalt pavement, and SMA asphalt pavement achieve 1,800 cycles / mm, 3,200 cycles / mm, and 5,200 cycles / mm, respectively. In terms of Marshall stability, the pavement of this invention achieves 14.51 kN, which is higher than the aforementioned comparative pavements. Regarding construction temperature, this invention can be constructed at room temperature, while the construction temperatures for the comparative pavements are 130℃, 150℃, and 150℃, respectively. Therefore, this invention simultaneously possesses strong rutting resistance, high construction efficiency, and good resource recycling value.
[0053] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.
Claims
1. A foamed asphalt cold recycling injection composite pavement process, characterized in that, Includes the following steps: The damaged old asphalt pavement is milled and the original pavement is cleaned. Emulsified asphalt tack coat is then sprayed onto the cleaned original pavement. The old asphalt milled material obtained by milling is pre-treated by screening to obtain milled material components with different particle size ranges. Based on the screening of the milled material components, the mix design is carried out to form a gradation structure that meets the requirements of large-void asphalt mixture. The milled material components after the mix design are cold recycled and mixed with foamed asphalt and cement binder to obtain foamed asphalt cold recycled mixture. The foamed asphalt cold recycled mixture is transported to the construction site for paving and compaction to form a large-void foamed asphalt cold recycled pavement base. After sealing material is applied around the road surface substrate, cement-based grouting material is prepared and injected into the interconnected voids of the road surface substrate until the grout no longer seeps or bubbles and the voids are filled. After the grouting is completed, the surface is scraped with grout and then cured before traffic is opened, thus forming a foamed asphalt cold recycled grouting composite pavement.
2. The foamed asphalt cold recycling injection composite pavement process according to claim 1, characterized in that, The milling of the damaged old asphalt pavement includes: Milling equipment is used to mill the original damaged asphalt pavement in layers or in one go to remove the damaged parts in the surface or structural layers. The milled material is then transported to the back site for subsequent screening and pretreatment. After milling, the loose particles, dust and debris remaining on the original pavement surface are cleaned up, and then emulsified asphalt tack coat is sprayed to improve the bonding performance between the subsequent paving layers and the original pavement.
3. The foamed asphalt cold recycling injection composite pavement process according to claim 2, characterized in that, The milled material undergoes screening pretreatment, including: The recycled old asphalt milled material is screened into 0-5mm, 5-11mm and 11-31.5mm particle size components using screening equipment. The 0-5mm and 11-31.5mm particle size components are used as the main grading materials for large-void foamed asphalt cold recycled mixtures in subsequent mix design.
4. The foamed asphalt cold recycling injection composite pavement process according to claim 3, characterized in that, The mix design includes: The 0-5mm particle size component and the 11-31.5mm particle size component are screened and blended to obtain a large-void foamed asphalt cold recycled mixture with a total void ratio controlled at 19%-28% and a connected void ratio controlled at 17%-26%. The asphalt used is 70# ordinary base asphalt and the cement used is P.O42.5 ordinary Portland cement.
5. The foamed asphalt cold recycling injection composite pavement process according to claim 1, characterized in that, The foamed asphalt cold recycling mixture is mixed using a plant-mixed cold recycling equipment. During the mixing process, the sieved milling material components, foamed asphalt, and cement binder are added according to the designed mix proportion to form a foamed asphalt cold recycling mixture with a large void skeleton structure under normal temperature conditions.
6. The foamed asphalt cold recycling injection composite pavement process according to claim 1, characterized in that, The paving and compaction process includes transporting the mixed foamed asphalt cold recycled mixture to the construction site for paving. During paving, the loose paving coefficient is controlled at 1.1-1.2, and a 12t steel wheel roller is used for static compaction to make the foamed asphalt cold recycled mixture form a large-void pavement matrix that meets the grouting requirements.
7. The foamed asphalt cold recycling injection composite pavement process according to claim 6, characterized in that, During the compaction process, a slow and uniform static compaction is performed, with 5 passes. The smoothness of the compacted large-void foamed asphalt cold recycled pavement substrate is tested, and the maximum smoothness value is controlled to be no more than 8 mm and the average value is no more than 5 mm. For areas where the smoothness does not meet the requirements, a road roller is used to perform static compaction again until the requirements are met.
8. The foamed asphalt cold recycling injection composite pavement process according to claim 1, characterized in that, Before grouting, the perimeter of the large-void foamed asphalt cold recycled pavement substrate is covered and sealed with edge sealing material to prevent the grout from flowing out during the grouting process and causing pollution to adjacent pavement or curb stones, and to provide boundary constraints for subsequent grouting and finishing construction.
9. The foamed asphalt cold recycling injection composite pavement process according to claim 8, characterized in that, The cement-based grouting material is prepared using on-site grouting equipment. Its dry material is semi-flexible early-strength grouting material for road surfaces. The mixing water is sourced from water sources that meet general drinking water standards. The prepared cement grout is pumped to the surface of the large-void foamed asphalt cold recycled road surface substrate and, under the action of gravity, self-levels and penetrates into the interconnected voids until the grout stops seeping and bubbling and the voids are filled.
10. The foamed asphalt cold recycling injection composite pavement process according to claim 1, characterized in that, After the grouting is completed, a grouting surface treatment is carried out to remove the cement grout remaining on the surface, so as to expose the uneven structure of the base asphalt mixture surface. During the curing period, traffic is strictly closed to prevent the passage of people and vehicles and rainwater erosion. After the grout has finally set, water curing is carried out, and the curing time is controlled according to the construction temperature so that the road surface is ready for traffic within 1-2 hours after grouting.