A method of laying a composite pavement structure

Abstract

The application discloses a paving method of a composite pavement structure, and further discloses a repairing method of a damaged pavement structure.

Description

Technical Field

[0001] This invention belongs to the field of road maintenance and paving technology, specifically, it relates to a method for paving a composite pavement structure and a method for repairing damaged pavement structures. The damaged pavement structure refers to a damaged semi-rigid asphalt pavement structure. Background Technology

[0002] Semi-rigid pavement refers to a base course constructed using soil or crushed stone treated with inorganic binders such as cement and lime, or industrial waste containing hydraulic binders. It exhibits the mechanical properties of a flexible pavement in its early stages, with a significant increase in strength and stiffness over time, although its final strength and stiffness are still far less than that of cement concrete. Because the rigidity of this material lies between that of flexible and rigid pavements, this base course and the asphalt surface layer laid upon it are collectively referred to as semi-rigid pavement.

[0003] Semi-rigid asphalt pavement possesses excellent mechanical properties and driving comfort, making it suitable for various vehicle types. It also exhibits good anti-skid, impermeability, and fatigue resistance, thus gaining widespread use. However, due to the drying and temperature shrinkage characteristics of semi-rigid materials, under the influence of vehicle loads and environmental factors, early damage to asphalt pavement, such as base layer cracking, reflective cracking, longitudinal cracking, and localized depressions and cracks, frequently occurs, severely impacting the normal use of highways.

[0004] At level crossings and heavy traffic sections, semi-rigid asphalt pavements bear significant vehicle loads, making the asphalt pavement of the driving lanes prone to rutting. The semi-rigid base layer is also prone to transverse cracks, which are reflected onto the asphalt surface layer, shortening the pavement's lifespan and posing safety hazards to vehicles.

[0005] Therefore, a technology is needed to promptly repair existing semi-rigid asphalt pavements when problems occur. Ideally, the damaged semi-rigid asphalt pavement should be replaced by laying a new pavement structure to eliminate safety hazards and achieve optimal driving performance. Summary of the Invention

[0006] In order to overcome the defects in the existing technology, the present invention provides a method for laying composite pavement structure and a method for repairing damaged pavement structure.

[0007] According to one aspect of the present invention, a method for laying a composite pavement structure is provided, the method comprising:

[0008] Step S101, laying of crushed stone subbase;

[0009] Step S102: Laying of lean concrete base course;

[0010] Step S103: Lay the isolation sliding layer;

[0011] Step S104, laying the precast prestressed concrete lower layer; further, this step includes:

[0012] Step S104-1: Prefabricate the side panels and middle panels;

[0013] Step S104-2: Install the side plates, several middle plates, and side plates in sequence from beginning to end; leave a gap of 18cm-22cm between adjacent longitudinal plates for setting self-stressing joints; leave a gap of 2cm-3cm between the edges and the semi-rigid asphalt pavement on both sides.

[0014] Step S104-3: Treat the self-stressing joint;

[0015] Step S105: Inject the leveling layer;

[0016] Step S106, Asphalt mortar joint treatment;

[0017] Step S107, laying the adhesive layer;

[0018] Step S108: Laying the high-modulus asphalt concrete surface layer.

[0019] According to a specific embodiment of the present invention, step S103 further includes:

[0020] Step S103-1: Spray emulsified asphalt onto the lean concrete base layer;

[0021] Step S103-2: Lay a layer of geotextile on the emulsified asphalt;

[0022] Step S103-3: Lay a double layer of plastic sheeting on the geotextile;

[0023] Step S103-4: Apply lubricant between the two layers of plastic sheeting.

[0024] According to another specific embodiment of the present invention, the width of the side plate and the middle plate is 4cm-6cm narrower than that of a lane, the thickness is 16cm-24cm, and the length is 6m-9m; the design strength is 35MPa-45MPa; the steel strands are evenly distributed 1cm below the center of the plate;

[0025] Two layers of self-stressing joint connecting bars are provided at both ends of the middle plate in a one-to-one correspondence and evenly distributed manner.

[0026] A self-stressing tensioning device and high-expansion concrete are provided at the outer end of the side plate, and a double-layer self-stressing joint connecting bar corresponding to the middle plate is provided at the inner end.

[0027] According to another specific embodiment of the present invention, step S104-3 is further comprising:

[0028] Seal the gaps between the side plates, middle plates, and isolation sliding layer, as well as the semi-rigid asphalt pavement, in the self-stressing joint with construction adhesive;

[0029] Weld the self-stressing joint connecting bars one-to-one and tie the self-stressing joint stirrups;

[0030] High-expansion concrete is poured, wherein the expansion amount of the high-expansion concrete is 8%-12%.

[0031] According to another specific embodiment of the present invention, step S105 further includes:

[0032] Mixing emulsified asphalt mortar;

[0033] The asphalt mortar is discharged into the storage funnel. After the storage funnel reaches 80% of its capacity, the valve is opened and the asphalt mortar is injected into the bottom of the slab through the injection hole.

[0034] After the grouting is completed, the grouting hole is sealed with high-grade mortar.

[0035] According to another specific embodiment of the present invention, step S108 further includes:

[0036] Step S108-1: Lay a 3cm-5cm thick high-modulus asphalt concrete layer on the adhesive layer and compact it;

[0037] Step S108-2: Set lane markings.

[0038] According to another specific embodiment of the present invention, the dosage of the high modulus agent in the high modulus asphalt concrete is 0.5%-0.6%.

[0039] According to another aspect of the present invention, a method for repairing damaged semi-rigid asphalt pavement structures is provided, the method comprising:

[0040] Cut and chisel away the damaged semi-rigid asphalt pavement;

[0041] Laying composite pavement structures;

[0042] The composite pavement structure is laid using the paving method provided by any of the above technical solutions.

[0043] According to a specific embodiment of the present invention, the cutting and chiseling of the damaged semi-rigid asphalt pavement further includes:

[0044] The cutting dimensions are determined based on the degree of damage to the semi-rigid asphalt pavement.

[0045] Based on the cutting dimensions, the milling dimensions are determined, and the semi-rigid asphalt pavement is milled using a milling machine;

[0046] The semi-rigid asphalt pavement is cut in one go according to the cutting dimensions;

[0047] The semi-rigid asphalt pavement, which was cut in one go, is then cut into several small pieces;

[0048] Remove the semi-rigid asphalt pavement.

[0049] According to another specific embodiment of the present invention,

[0050] The cutting dimensions are:

[0051] The length of the cut is the damaged length of the semi-rigid asphalt pavement, the width is the width of one lane, and the depth is the thickness of the asphalt precast prestressed concrete composite pavement used to replace the semi-rigid asphalt pavement.

[0052] The milling dimensions are:

[0053] The milling length is the damaged length of the semi-rigid asphalt pavement, the width is 20cm-30cm wider on each side than the original lane, and the depth is 3cm-5cm.

[0054] This invention utilizes cement-emulsified asphalt mortar to form a leveling layer, solving the problem of stress concentration caused by the difficulty in bonding prestressed pavement slabs and base layers. The base and subbase layers do not require large machinery for installation, minimizing impact on traffic at intersections. The top layer is composed of high-modulus asphalt concrete, exhibiting strong deformation resistance. The bottom layer consists of precast prestressed concrete pavement slabs; due to the presence of prestress and self-stress, the entire bottom layer works seamlessly and isolates reflective cracks from the base layer, effectively reducing the frequency of surface layer maintenance. Compared to semi-rigid asphalt pavement structures, the composite pavement structure laid using the method described in this invention has a longer service life, higher economic efficiency, and eliminates traffic safety hazards caused by rutting and transverse cracks at their source. Attached Figure Description

[0055] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0056] Figure 1 The diagram shown is a flowchart illustrating a specific embodiment of a method for laying a composite pavement structure according to the present invention.

[0057] Figure 2 The image shown is a front sectional view of the composite pavement structure in this invention;

[0058] Figure 3 The image shown is a front sectional view of a specific embodiment of the precast prestressed concrete lower layer in this invention.

[0059] Figure 4 As shown Figure 3 The top view of the precast prestressed concrete lower layer shown;

[0060] Figure 5 The figure shown is a three-dimensional schematic diagram of a specific embodiment of the self-stressed tensioning device of the present invention;

[0061] Figure 6 The figure shown is a top view of a specific embodiment of the height adjustment device for the middle plate and side plates in this invention;

[0062] Figure 7 As shown Figure 6 The front view of the height adjustment device for the middle plate and side plates is shown.

[0063] Figure 8 The diagram shown is a connection schematic of a specific embodiment of the mortar injection equipment of the present invention.

[0064] The same or similar reference numerals in the accompanying drawings represent the same or similar parts.

[0065] The reference numerals in the attached figures are as follows:

[0066] 1. Semi-rigid asphalt pavement; 2. High-modulus asphalt concrete surface layer; 3. Tack coat; 4. Precast prestressed concrete bottom layer; 5. Leveling layer; 6. Isolation and sliding layer; 7. Lean concrete base course; 8. Crushed stone subbase; 9. Subgrade; 10. Asphalt sand; 11. Cutting line; 12. Intermediate slab; 13. Side slab; 14. Ordinary concrete; 15. High-expansion concrete; 16. Steel strand; 17. Self-stressing steel reinforcement; 18. Self-stressing tension plate; 19. Self-stressing joint connecting bar; 20. Self-stressing joint stirrup; 21. Self-stressing joint; 22. Side slab end stress compensation boundary line; 23. Self-stressing steel reinforcement stirrup; 24. Grouting hole; 25. Steel pad; 26. Square head bolt; 27. Embedded steel plate; 28. Anchor bar; 29. ​​Leveling horizontal steel plate; 30. Flat-mouth concrete mixer; 31. Storage funnel; 32. Grouting hose; 33. Mixer discharge port; 34. Feeding valve; 35. Feeding hose; 36. Cable tie and buckle; 37. Horizontal reinforcing bar; 38. Lane marking center line; 39. Milling line; 40. Geotextile; 41. Double-layer plastic sheet. Detailed Implementation

[0067] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, components and arrangements of specific examples are described below. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. It should be noted that the components illustrated in the drawings are not necessarily drawn to scale. Descriptions of well-known components, processing techniques, and processes are omitted to avoid unnecessarily limiting the invention.

[0068] See Figure 1 This invention provides a method for laying a composite pavement structure, the method comprising:

[0069] Step S101: Laying of the crushed stone subbase 8.

[0070] Further, to lay the crushed stone subbase 8, the original paving location must first be cleared, such as removing residual waste from the semi-rigid asphalt pavement on the roadbed 9, and cleaning and leveling the underlying layer of the crushed stone subbase 8. Next, the main paving process is carried out, requiring the laying of a 15cm-20cm crushed stone subbase 8. After laying, leveling is performed to ensure a smoother road surface structure. After leveling, compaction is required, with a compaction degree of not less than 95%. It is preferable to use a small vibratory compaction device for compaction, which not only saves costs but also minimizes the impact on the surrounding environment. Finally, a 2cm-3cm mortar layer is laid on the crushed stone subbase 8 and allowed to stand for 2-3 days. The laying of the crushed stone subbase 8 is then completed through these operations.

[0071] Continue with step S102, laying the lean concrete base layer 7.

[0072] First, sprinkle water on the mortar layer to fully moisten it; then, pour lean concrete on the mortar layer, vibrate it to compact it, and level it; finally, cover it with moisturizing cotton for 3-5 days to complete the laying of the lean concrete base layer 7.

[0073] Step S103: Lay the isolation sliding layer 6. The isolation sliding layer 6 consists of a layer of geotextile 40 and two layers of plastic sheeting 41.

[0074] The laying steps include:

[0075] Step S103-1: Spray emulsified asphalt onto the lean concrete base layer 7;

[0076] Step S103-2: Lay a layer of geotextile 40 on the emulsified asphalt;

[0077] Step S103-3: Lay a double layer of plastic sheet 41 on the geotextile 40;

[0078] Step S103-4: Apply lubricant between the double-layer plastic sheet 41.

[0079] Step S104, laying the precast prestressed concrete lower layer; further, this step includes:

[0080] Step S104-1: Prefabricate the side panels and middle panels.

[0081] The middle plate 12 and the side plate 13 are both precast using the pre-tensioning method. After the steel strands 16 in the pre-tensioned precast plate are cut and released, the steel strands 16 transmit stress through friction with the surrounding concrete. Therefore, the stress at the end of the plate has a transmission length. Within the transmission length, the stress does not reach the design value and stress compensation is required.

[0082] The specific operations for prefabricating the middle slab 12 and the side slab 13 are as follows:

[0083] Construct a tensioning table with the same width as the side plate 13 and the middle plate 12;

[0084] Fix the end templates and side templates of the side plate 13 and the middle plate 12;

[0085] At the end of the middle plate 12, double rows of self-stressing joint connecting bars 19 are provided with the steel strand 16 as the symmetrical point. The outer end of the side plate 13 is provided with a self-stressing tensioning device, in which four self-stressing steel bars 17 are arranged in a square and welded to the self-stressing tensioning plate 18. The steel strand 16 is located at the center point of the square. At the other end, double rows of self-stressing joint connecting bars 19 are provided with the steel strand 16 as the symmetrical point.

[0086] 16 tensioned steel strands.

[0087] The transverse reinforcing bars 37 are tied and the self-stressing joint connecting bars 19 are fixed. The transverse reinforcing bars 37 are set at the lower part of the longitudinal steel strands 16.

[0088] Emulsified asphalt mortar injection holes 24 are reserved in the middle plate 12 and the side plate 13. The diameter of the injection hole 24 is 8cm-10cm, for example: 8cm, 9cm or 10cm. Embedded steel plates 27 for height adjustment devices are fixed at the ends of the middle plate 12 and the side plate 13. Anchor bars 28 that serve to anchor the steel plates are welded on the embedded steel plates 27.

[0089] Further, the middle slab 12 and the edge slab 13 are poured. The middle slab 12 is poured with ordinary concrete 14 in one go from one end to the other; the edge slab 13 is poured in two stages. First, the ordinary concrete 14 within the stress compensation boundary line 22 at the end of the edge slab is poured, and part of the self-stressing steel bars 17 of the self-stressing tensioning device extends into the ordinary concrete 14 with an extension length of 40cm-50cm, for example: 40cm, 45cm or 50cm; after the strength reaches 80% of the design strength, high-expansion concrete 15 is poured outside the stress compensation boundary line 22 at its end, with the amount of high-expansion agent being 8%-12%, for example: 8%, 10% or 12%.

[0090] The poured middle plate 12 and side plate 13 are kept moist for 5 to 7 days.

[0091] The expansion of the high-expansion concrete 15 at the outer end of the edge plate 13 generates compressive stress on the self-stressed tension plate 18, and the self-stressed tension plate 18 generates reverse stress on the middle plate 12 and the ends of the edge plate 13, thereby providing stress compensation at the outer end of the edge plate 13.

[0092] The width of the side panels 13 and the center panel 12 is 4cm-6cm narrower than that of a lane, for example: 4cm, 5cm or 6cm; the thickness is 16cm-24cm, for example: 16cm, 20cm or 24cm; the length is 6m-9m, for example: 6m, 7m or 9m. The design strength is 35MPa-45MPa, for example: 35MPa, 40MPa or 45MPa.

[0093] The steel strands 16 are evenly distributed 1 cm below the center of the slab. After the steel strands are released, the top and bottom concrete of the pre-tensioned slab have a certain compressive stress, and the compressive stress of the bottom concrete is slightly greater than that of the top concrete, which matches the actual stress on the pavement slab. Therefore, this effectively solves the problem of excessive tensile stress in the top and bottom concrete of the pre-tensioned slab causing concrete cracking.

[0094] Preferably, the steel strand 16 has a strength grade of 1860MPa and a diameter of 12.7mm.

[0095] Double-layer self-stressing joint connecting bars 19 are provided at both ends of the joint in the middle plate 12, and are evenly distributed. The self-stressing joint connecting bars 19 are grade II steel bars with a diameter of 16mm-18mm, for example, 16mm, 17mm or 18mm. The anchorage length at the end of the middle plate 12 and on the inner side of the side plate 13 is 70cm-80cm, for example, 70cm, 75cm or 80cm; the exposed length is 16cm-18cm, for example, 16cm, 17cm or 18cm.

[0096] A self-stressing tensioning device and high-expansion concrete 15 are provided at the outer end of the side plate 13, and a double-layer self-stressing joint connecting bar 19 corresponding to the middle plate 12 is provided at the inner end.

[0097] The self-stressing tensioning device consists of a self-stressing tensioning plate 18, self-stressing reinforcing bars 17, and self-stressing reinforcing bar stirrups 23. The self-stressing reinforcing bars 17 are arranged in groups of four, distributed at the vertices of a square centered on the steel strand 16, and welded to the self-stressing tensioning plate 18. The self-stressing tensioning plate 18 has a height of 20cm-24cm, for example, 20cm, 22cm, or 24cm; a width of 15cm-20cm, for example, 15cm, 18cm, or 20cm; and a thickness of 0.4cm-0.6cm, for example, 0.4cm, 0.5cm, or 0.6cm. The self-stressing reinforcing bars 17 have a diameter of 20mm-22mm, for example, 20mm, 21mm, or 22mm; and a length of 1.2m-1.4m, for example, 1.2m, 1.3m, or 1.4m.

[0098] Step S104-2: Install the side plates 13, several middle plates 12, and the side plates 13 sequentially from beginning to end. Due to the size limitations of the middle plates 12 and side plates 13, multiple plates need to be laid for each layer during road paving. Preferably, a gap of 18cm-22cm is reserved between longitudinally adjacent plates for setting self-stressing joints 21. At the edges, a gap of 2cm-3cm is reserved between the edge and the semi-rigid asphalt pavement on both sides.

[0099] The specific installation process is as follows: Weld the leveling steel plate 29, which is part of the height adjustment device, to the ends of the side plate 13 and the middle plate 12. (See also...) Figure 6 , Figure 7 The leveling steel plate 29 has a length of 6cm-8cm, for example: 6cm, 7cm, or 8cm; a width of 4cm-5cm, for example: 4cm, 4.5cm, or 5cm; and a thickness of 6mm-8mm, for example: 6mm, 7mm, or 8mm; with a pre-drilled threading hole in the middle with a diameter of 20mm-22mm. After the leveling steel plate 29 is transported to the site, it is installed in the order of side plate 13, several middle plates 12, and side plate 13. Square head screws 26 are screwed into the leveling steel plate 29. Preferably, the diameter of the square head screws 26 is 20mm-22mm, for example: 20mm, 21mm, or 22mm. Place a steel pad 25 under the square head screw 26. Use a T-shaped inner four-corner socket wrench to rotate the square head screw 26 and adjust the elevation of the middle plate 12 and the side plate 13 up and down until the distance between the bottom of the plate and the isolation sliding layer 6 is 4cm-5cm, for example: 4cm, 4.5cm or 5cm; and the flatness between the tops of two adjacent plates is no more than 3mm.

[0100] See Figure 3 and Figure 4 Step S104-3, treat the self-stressing joint 21.

[0101] Furthermore, the gaps between the side plate 13, the middle plate 12, the isolation sliding layer 6, and the semi-rigid asphalt pavement in the self-stressing joint 21 are sealed with construction adhesive;

[0102] Weld the self-stressing joint connecting bars 19 one by one, with a welding length of not less than 10 times the diameter of the steel bar, and tie the self-stressing joint stirrups 20.

[0103] Thoroughly moisten the concrete at the end of the side plate of self-stressing joint 21 with clean water;

[0104] Pour high-expansion concrete 15, preferably with an expansion dose of 8%-12%, for example: 8%, 10% or 12%, and then cover it with moisturizing cotton for 5 days;

[0105] The high-expansion concrete 15 in the self-stressing joint 21 expands and applies stress to the ends of the middle plate 12 and the side plate 13, thus completing the stress compensation at the ends of the pre-tensioned precast slab. The side plates 13, multiple middle plates 12, and side plates 13 are arranged to form the precast prestressed concrete lower layer 4 connected by the self-stressing joint 21.

[0106] After the self-stressing joint 21 has fully set, step S105 can be performed, including pouring the leveling layer 5. See below. Figure 8 Step S105 further includes:

[0107] Mixing emulsified asphalt mortar; preferably, a 30mm flat-mouth concrete mixer can be used to mix emulsified asphalt mortar;

[0108] After thorough mixing, the discharge valve 34 is opened, and the emulsified asphalt mortar is discharged into the storage funnel 31 through the mixer discharge port 33 and the discharge hose 35. The storage funnel 31 has a capacity of not less than 1 cubic meter and is connected to an injection hose 32, which is equipped with a cable tie buckle 36. When the storage funnel 31 reaches 80% of its capacity, the valve (i.e., the cable tie buckle 36 of the injection hose 32) is opened, and the asphalt mortar is injected into the bottom of the slab through the injection hole 24.

[0109] The grouting sequence should proceed gradually from one end of the slab to the other, until the grout gushes out from both sides of the slab and exceeds the bottom of the slab by 1-2 cm. If the grout exceeds the bottom of the slab, it indicates that the lower part has been completely grouted; exceeding it too much will waste grout and affect subsequent process steps, so 1-2 cm is recommended. The entire leveling layer 5 must be grouted in one continuous operation without interruption.

[0110] After the grouting is completed, the grouting hole 24 is sealed with high-grade mortar.

[0111] Next, proceed to step S106 to treat the asphalt mortar joints. Clean the gaps between the precast prestressed concrete pavement slab and other pavement connected to it; fill the gaps with asphalt sand 10; and compact the filled asphalt sand 10.

[0112] Then proceed to step S107, where the adhesive layer 3 is laid.

[0113] First, roughen the precast prestressed concrete lower layer 4 using a roughening machine; then, clean the precast prestressed concrete lower layer 4 and allow it to dry completely; finally, apply a modified emulsified asphalt tack coat 3 onto the precast prestressed concrete lower layer 4.

[0114] Finally, step S108 is performed, where the high-modulus asphalt concrete surface layer 2 is laid. Further, step S108 includes:

[0115] Step S108-1: Lay 3cm-5cm of high-modulus asphalt concrete on the tack coat 3 and compact it. Preferably, the dosage of high-modulus agent in the high-modulus asphalt concrete is 0.5%-0.6%, for example: 0.5%, 0.55% or 0.6%.

[0116] Step S108-2: Set lane markings.

[0117] The composite pavement structure can be laid through steps S101 to S108. This composite pavement structure is durable, has a long service life, and is highly safe.

[0118] Accordingly, the present invention also provides a method for repairing damaged semi-rigid asphalt pavement structures, the method comprising: cutting and chiseling away the damaged semi-rigid asphalt pavement 1; and laying a composite pavement structure. It is worth noting that the composite pavement structure needs to be laid using the aforementioned composite pavement structure laying method.

[0119] Preferably, the cutting and chiseling of the damaged semi-rigid asphalt pavement 1 further includes:

[0120] Based on the degree of damage to the semi-rigid asphalt pavement 1, the cutting dimensions are determined, and cutting lines 11 are marked. More preferably, the cutting dimensions are: the cutting length is the damaged length of the semi-rigid asphalt pavement 1, the width is the width of one lane, and the depth is the thickness of the asphalt precast prestressed concrete composite pavement structure used to replace the semi-rigid asphalt pavement 1. Further, based on the cutting dimensions, the milling dimensions are determined, milling lines 39 are marked, and the semi-rigid asphalt pavement is milled using a milling machine. Preferably, the milling dimensions are: the milling length is the damaged length of the semi-rigid asphalt pavement 1, the width is S segments wider outward from each side of the center lines 38 of the two original lane markings, preferably 20cm-30cm, for example: 20cm, 25cm, or 30cm; and the depth is 3cm-5cm, for example: 3cm, 4cm, or 5cm.

[0121] According to the cutting dimensions, the semi-rigid asphalt pavement 1 is cut in one go; then, the semi-rigid asphalt pavement cut in one go is cut into several small pieces; finally, the semi-rigid asphalt pavement 1 is removed.

[0122] This invention has the following advantages: The construction of the base course and subbase does not require large machinery, minimizing the impact on traffic at intersections; the leveling layer uses cement emulsified asphalt mortar, solving the problem of stress concentration in the lower layer of precast prestressed concrete caused by the difficulty in bonding the prestressed pavement slab and base course; the upper layer is composed of high-modulus asphalt concrete, exhibiting strong resistance to deformation; the precast prestressed concrete lower layer is constructed by arranging edge slabs, several middle slabs, and edge slabs connected by self-stressing joints. Both the edge and middle slabs are pre-tensioned precast slabs with end stress compensation, and the edge and middle slabs reinforce the ends of the pre-tensioned precast slabs through self-stressing tensioning devices and self-stressing joints. Due to the presence of prestress and self-stress, the entire lower layer works seamlessly; it also isolates reflective cracks in the base course, reducing the frequency of surface layer maintenance, resulting in a longer lifespan than semi-rigid asphalt pavement structures, and fundamentally eliminating traffic safety hazards caused by rutting and transverse cracks.

[0123] While exemplary embodiments and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications can be made to these embodiments without departing from the spirit of the invention and the scope of protection defined by the appended claims. For other examples, those skilled in the art should readily understand that the order of process steps can be varied while remaining within the scope of the invention.

[0124] Furthermore, the scope of this invention is not limited to the processes, mechanisms, manufacturing methods, material compositions, means, methods, and steps of the specific embodiments described in the specification. From the disclosure of this invention, those skilled in the art will readily understand that any existing or future processes, mechanisms, manufacturing methods, material compositions, means, methods, or steps that perform substantially the same function or obtain substantially the same results as the corresponding embodiments described in this invention can be applied according to this invention. Therefore, the appended claims are intended to include these processes, mechanisms, manufacturing methods, material compositions, means, methods, or steps within their scope of protection.

Claims

1. A method for laying a composite pavement structure, characterized in that, The laying method includes: Step S101, laying of crushed stone subbase; Step S102: Laying of lean concrete base course; Step S103: Lay the isolation sliding layer; Step S104, laying the precast prestressed concrete lower layer; further, this step includes: Step S104-1: Prefabricate the side panels and middle panels; Pre-drilling holes (24) are reserved in the middle plate (12) and the side plate (13); Two layers of self-stressing joint connecting bars are provided at both ends of the middle plate in a one-to-one correspondence and evenly distributed manner. A self-stressing tensioning device and high-expansion concrete are provided at the outer end of the side plate, and a double-layer self-stressing connecting bar corresponding to the middle plate is provided at the inner end. The self-stressing tensioning device consists of a self-stressing tensioning plate (18), a self-stressing steel bar (17), and a self-stressing steel bar stirrup (23); The concrete of the side plate (13) is poured in two stages. First, ordinary concrete (14) within the end of the side plate's stress compensation boundary line (22) is poured. Some of the self-stressing steel bars (17) of the self-stressing tensioning device are inserted into the ordinary concrete (14). After the strength reaches 80% of the design strength, high-expansion concrete (15) is poured outside the end of the stress compensation boundary line (22). The poured middle plate (12) and side plate (13) are moisturized for 5 to 7 days. Step S104-2: Install the side plates, several middle plates, and side plates in sequence from beginning to end; leave a gap of 18cm-22cm between adjacent longitudinal plates for setting self-stressing joints; leave a gap of 2cm-3cm between the edges and the semi-rigid asphalt pavement on both sides. Fix height adjustment devices at the ends of the middle plate (12) and the side plate (13), and adjust the elevation of the middle plate (12) and the side plate (13) up and down until the distance between the bottom of the plate and the isolation sliding layer (6) is 4cm-5cm and the flatness between the tops of two adjacent plates is no more than 3mm. Step S104-3: Treat the self-stressing joint; Step S105: Inject the leveling layer; Step S106, Asphalt mortar joint treatment; Step S107, laying the adhesive layer; Step S108: Laying the high-modulus asphalt concrete surface layer; Step S105 further includes: Mixing emulsified asphalt mortar; The asphalt mortar is discharged into the storage funnel. After the storage funnel reaches 80% of its capacity, the valve is opened and the asphalt mortar is injected into the bottom of the slab through the injection hole. After the grouting is completed, the grouting hole is sealed with high-grade mortar.

2. The method for laying composite pavement structure according to claim 1, characterized in that, Step S103 further includes: Step S103-1: Spray emulsified asphalt onto the lean concrete base layer; Step S103-2: Lay a layer of geotextile on the emulsified asphalt; Step S103-3: Lay a double layer of plastic sheeting on the geotextile; Step S103-4: Apply lubricant between the two layers of plastic sheeting.

3. The method for laying composite pavement structures according to claim 1, characterized in that, The width of the side plates and the middle plates is 4cm-6cm narrower than that of a lane, the thickness is 16cm-24cm, and the length is 6m-9m; the design strength is 35MPa-45MPa; the steel strands are evenly distributed 1cm below the center of the plate.

4. The method for laying composite pavement structures according to claim 1, characterized in that, Step S104-3 further comprises: Seal the gaps between the side plates, middle plates, and isolation sliding layer, as well as the semi-rigid asphalt pavement, in the self-stressing joint with construction adhesive; Weld the self-stressing joint connecting bars one-to-one and tie the self-stressing joint stirrups; High-expansion concrete is poured, wherein the expansion amount of the high-expansion concrete is 8%-12%.

5. The method for laying composite pavement structure according to claim 1, characterized in that, Step S108 further includes: Step S108-1: Lay a 3cm-5cm thick high-modulus asphalt concrete layer on the adhesive layer and compact it; Step S108-2: Set lane markings.

6. The method for laying composite pavement structures according to claim 5, characterized in that, The dosage of high modulus agent in the high modulus asphalt concrete is 0.5%-0.6%.

7. A method for repairing damaged semi-rigid asphalt pavement structures, the method comprising: Cut and chisel away the damaged semi-rigid asphalt pavement; Laying composite pavement structures; The feature is that the composite pavement structure is laid using the paving method of any one of claims 1 to 6.

8. The repair method for damaged semi-rigid asphalt pavement structures according to claim 7, characterized in that, The cutting and chiseling of the damaged semi-rigid asphalt pavement further includes: The cutting dimensions are determined based on the degree of damage to the semi-rigid asphalt pavement. Based on the cutting dimensions, the milling dimensions are determined, and the semi-rigid asphalt pavement is milled using a milling machine; The semi-rigid asphalt pavement is cut in one go according to the cutting dimensions; The semi-rigid asphalt pavement, which was cut in one go, is then cut into several small pieces; Remove the semi-rigid asphalt pavement.

9. The repair method for damaged semi-rigid asphalt pavement structures according to claim 8, characterized in that, The cutting dimensions are: The length of the cut is the damaged length of the semi-rigid asphalt pavement, the width is the width of one lane, and the depth is the thickness of the asphalt precast prestressed concrete composite pavement used to replace the semi-rigid asphalt pavement. The milling dimensions are: The milling length is the damaged length of the semi-rigid asphalt pavement, the width is 20cm-30cm wider on each side than the original lane, and the depth is 3cm-5cm.

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