Municipal road engineering rigid and flexible pavement lap joint expansion structure and construction method

Abstract

The invention belongs to the technical field of pavement reconstruction and expansion, and relates to a municipal road engineering rigid-flexible pavement lap joint expansion structure and a construction method.The municipal road engineering rigid-flexible pavement lap joint expansion structure comprises a subbase layer, an old concrete pavement and steel bar pull rods, an existing base layer is laid on the subbase layer, and the old concrete pavement is laid on the existing base layer; the old concrete pavement is connected with one side of the step-type concrete transition plate through the rebar pull rod, the other side of the step-type concrete transition plate abuts against the base layer, and the asphalt pavement is laid on the top face of the step-type concrete transition plate and the top face of the base layer. The newly-poured stepped concrete transition plate is used for balancing the base performance of the new and old roads, and the rebar pull rod is implanted to eliminate slab staggering between the new and old concrete, so that the settlement between the new and old roads is smoothly transited; and meanwhile, the structural thickness of the asphalt surface layer is ensured, the defects that the asphalt thickness is insufficient when a connecting overlay sequential connecting process is not arranged and a penetrating road surface stress concentration area is formed when a strip-shaped connecting process is arranged are overcome, and the structural durability and driving comfort of the lap joint part of the rigid and flexible road surfaces are ensured.

Description

Technical Field

[0001] The invention relates to the technical field of road reconstruction and expansion, and in particular to a rigid-flexible road surface overlap expansion structure and a construction method for a municipal road engineering project. Background Art

[0002] In recent years, municipal road reconstruction and expansion projects have become the mainstream projects in infrastructure projects. Due to the limitations of construction technology and cost, most low-grade roads such as branch roads and factory roads used concrete rigid pavement ten years ago. With the development of social transportation, it is necessary to widen and reconstruct the original roads, generally changing from existing concrete rigid roads to asphalt concrete flexible roads. In the process of reconstruction and expansion, how to better overlap the rigid and flexible pavement is the focus of current research.

[0003] In the reconstruction and expansion of old municipal roads, the overlay smooth connection technology is often used to treat the overlap of rigid and flexible pavements. According to historical statistical data, the overlay smooth connection treatment of the overlap of rigid and flexible pavements often causes quality problems such as cracks, damage, misalignment, and poor driving comfort. By analyzing the causes of various quality problems, the commonly used overlay smooth connection construction technology has been improved to solve common quality problems such as cracks and misalignment in the overlap. Summary of the invention

[0004] In order to solve the above existing technical problems, the present invention provides a municipal road engineering rigid-flexible pavement structure and a splicing method.

[0005] The technical solution of the present invention is realized by the following solution: a rigid-flexible pavement overlap extension structure for a municipal road project, comprising a subbase, an old concrete pavement and a steel bar tie rod, an existing base is laid on the subbase, the old concrete pavement is laid on the existing base, the old concrete pavement is connected to one side of a stepped concrete transition plate through a steel bar tie rod, the other side of the stepped concrete transition plate abuts against the base, and asphalt pavement is laid on the top surface of the stepped concrete transition plate and the top surface of the base; A steel cage is arranged in the stepped concrete transition plate, and the portion of the steel tie rod in the stepped concrete transition plate serves as the longitudinal steel bars of the steel cage.

[0006] Through the above technical scheme, the newly cast stepped concrete transition plate is used to balance the performance of the new and old road bases, and steel tie rods are implanted to eliminate the misalignment between the new and old concrete, so that the settlement between the new and old roads can transition smoothly; at the same time, the newly cast concrete step structure is used to ensure the thickness of the asphalt surface layer structure, to solve the defects of insufficient asphalt thickness without the joint cover process and the formation of concentrated stress areas through the road surface by the strip joint process, to ensure the structural durability and driving comfort of the overlap parts of the rigid and flexible pavements.

[0007] Preferably, the base layer is laid on an existing base layer, and the asphalt pavement is at the same level as the old concrete pavement. A construction method for a rigid-flexible pavement overlap extension structure of a municipal road project, comprising the following steps: S1, prepare detailed construction plan and required material plan based on design documents and drawings; S2: Before construction, remove the topsoil, silt and garbage from the existing base in the area to be expanded, and level and compact it; S3, base construction and reserve transition area; S4, old concrete pavement structure with steel tie rods implanted; S5, at this time, the exposed section of the steel bar is used as the longitudinal steel bar for casting the steel cage of the stepped concrete transition plate, and the steel cage is set up, and the formwork is supported to cast the stepped concrete transition plate; S6, leveling and curing of stepped concrete transition slab; S7, laying fiberglass grid; S8, construction of penetrating oil and lower sealing layer; S9, asphalt surface structure construction.

[0008] Preferably, in step S2, the compaction degree should not be less than 95% (determined according to the design road grade), and the unfavorable geology is strengthened by replacement filling, piling, etc., and the soil base surface is set with a cross slope according to the design requirements.

[0009] Preferably, the specific construction steps of the base layer in step S3 include: S301, measuring and reserving a transition area; S302, paving and pressing of graded crushed stone; S303, laying and pressing of water-stabilizing layer; S304, simultaneous laying of gravel seal and permeable layer.

[0010] Preferably, in step S302, a reference line is set up 30 cm outside the edge of the graded layer and checked, a paver is used for paving, and a double steel wheel roller is used for full compaction; In step S303, a reference line is set up 30 cm outside the edge of the graded layer and checked, a paver is used for paving, a 12t double steel wheel roller is used for compaction first, and then a 20t single steel wheel roller is used for subsequent compaction.

[0011] Preferably, in step S4, the diameter of the steel bar pull rod is φ25 mm, the spacing between the embedded bars is 40 cm, a drill is used to drill holes, a hair dryer is used to remove dust in the holes, and the embedded bar adhesive is Class A adhesive. After the embedded bars are completed, a pull-out test should be carried out. The steel bar pull rod is cut mechanically, and oxygen cutting is not allowed.

[0012] Preferably, the specific construction steps of step S5 include: S501, install the force transmission rod; S502, notch template acceptance; S503, apply water-soluble release agent and isolation agent on the template surface; S504, after the board surface is dry, install the notch template; S505, using the exposed section of the steel bar tie rod as the longitudinal steel bar for casting the steel cage of the stepped concrete transition slab, and setting up the steel cage; S506, pouring the stepped concrete transition slab.

[0013] Preferably, the specific construction steps of step S8 include: S801, inspect the base layer and clean the dust and other debris on the top surface of the base layer; S802, sprinkle water on the surface of the base layer, and then pour the penetration asphalt after the surface layer is dried in the shade; S803, lower seal layer paving; S804: After the construction of the lower sealing layer is completed, the closed curing shall be carried out for ≥ 24 hours. Preferably, in step S9, the asphalt surface layer is paved by two pavers in echelon, 10 to 13 m apart, with the paving machine screeds overlapping by 10 cm, and the paving is controlled by double-sided wires, with one wire for every 10 m, and the paving speed is 1 to 1.5 m / min; Finally, a double steel wheel roller is used for compaction.

[0014] In summary, the present invention has the following beneficial effects: 1. The present invention utilizes a newly cast stepped concrete transition plate to balance the performance of the new and old road bases, and implants steel bar tie rods to eliminate the misalignment between the new and old concretes, so that the settlement between the new and old roads can transition smoothly; at the same time, the newly cast concrete step structure is utilized to ensure the thickness of the asphalt surface layer structure, so as to solve the defects of insufficient asphalt thickness when no joint cover smooth connection process is set and the formation of a stress concentration area through the road surface when a strip joint process is set, so as to ensure the structural durability and driving comfort of the overlapped parts of the rigid and flexible pavements.

[0015] 2. At the junction of new and old concrete, cracking or damage is prone to occur due to the small tensile strength value in the mechanical properties of concrete materials. The steel tie rod serves as the connecting section between the new and old concrete, and its exposed section serves as the longitudinal steel bar, which improves the efficiency of steel cage erection, saves costs, and significantly improves the tensile strength of this area, thereby preventing damage and misalignment caused by insufficient tensile resistance.

[0016] 3. Due to the different structural forms and construction times of the overlapping parts of the new and old pavements, there is uneven settlement. By setting up a stepped concrete transition plate, the settlement difference between the new and old pavements can be smoothly transitioned, effectively balancing the performance differences of the new and old road bases, and avoiding road damage and cracks caused by inconsistent base performance.

[0017] 4. By setting up a stepped concrete transition plate to reserve the thickness of the pavement surface structure, the durability of the surface layer at the joint position and driving comfort are ensured.

[0018] 5. Compared with the cover surface smooth connection method with strip joints, this type of construction can effectively avoid the formation of stress concentration areas running through the road surface, ensure the construction quality of the joint position, and improve the construction quality of the joint position, making the road smoother, more durable and comfortable overall.

[0019] 6. The technical solution of the present invention can not only prevent cracking or settlement in the transition zone between rigid and flexible pavement, but also avoid stratification in the transition zone (for example, by using a pressure plate). BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overlapping construction process of the present invention; Figure 2 It is a schematic diagram of the pavement structure of the present invention.

[0021] Explanation of the accompanying reference numerals: 1. Old concrete pavement; 2. Steel bar tie rod; 3. Stepped concrete transition plate; 4. Asphalt pavement; 5. Existing base layer; 6. Subbase layer; 7. Base layer. DETAILED DESCRIPTION

[0022] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described below with reference to the accompanying drawings and embodiments.

[0023] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments of the following disclosure. The present invention is further described in detail below in conjunction with the accompanying drawings.

[0024] Embodiment 1: A rigid-flexible pavement overlap extension structure for a municipal road project, such as Figure 1As shown, it includes a subbase layer 6, an old concrete pavement 1 and a steel bar tie rod 2. An existing base layer 5 is laid on the subbase layer 6. The old concrete pavement 1 is laid on the existing base layer 5. The old concrete pavement 1 is connected to one side of a stepped concrete transition plate 3 through the steel bar tie rod 2. The other side of the stepped concrete transition plate 3 abuts against the base layer 7. Asphalt pavement 4 is laid on the top surface of the stepped concrete transition plate 3 and the top surface of the base layer 7. The base layer 7 is laid on the existing base layer 5. The asphalt pavement 4 is at the same level as the old concrete pavement 1. By setting the stepped concrete transition plate 3, the problem of sudden settlement change is solved. A steel cage is arranged in the stepped concrete transition plate 3, and the part of the steel bar tie rod 2 in the stepped concrete transition plate 3 serves as the longitudinal steel bar of the steel cage. The steel bar tie rod 2 not only connects the new and old concrete, but also reduces the erection cost.

[0025] The total length of the stepped concrete transition plate 3 is 300cm. A transition area is reserved at the joint position of the old road reconstruction to install the stepped concrete transition plate 3, which solves the problems of insufficient asphalt thickness in the overlay surface connection method, cracks, damage, and misaligned joints at the joint position, ensures the durability of the surface layer at the joint position and driving comfort, optimizes the overlay surface connection method with strip joints, avoids the formation of a concentrated stress area running through the road surface, and ensures the construction quality of the joint position.

[0026] Embodiment 2: A construction method for a municipal road project rigid-flexible pavement overlap extension structure, such as Figure 1-2 As shown, the following steps are included: S1, prepare detailed construction plan and required material plan based on design documents and drawings; According to the construction organization design, prepare the material consumption plan required for the project as the basis for material preparation, supply, determining the warehouse and yard area and organizing transportation. Organize the materials to enter the site as planned and ensure their safekeeping. According to the construction methods determined in the construction organization, the construction machinery and equipment requirements, quantity and construction schedule, arrange the construction machinery and equipment demand plan. According to the construction schedule, organize construction teams to continue to enter the site, and conduct on-the-job training for construction personnel in technical trades, and implement the policy of holding certificates before taking up their posts. In order to ensure the quality and construction period of the project, the project organizes experienced teams to enter the site for construction. Before construction, various technical information is collected, and construction personnel are organized to familiarize themselves with the design documents, drawings, and information. Detailed construction plans and technical briefings are prepared according to construction needs, and detailed technical briefings are given to construction management personnel and operators to ensure that personnel are familiar with the construction process.

[0027] S2, before construction, remove the soil, silt and garbage on the surface of the existing base 5 in the area to be expanded, and level and compact it; In step S2, the compaction degree should not be less than 95% (based on the designed road grade). For areas with poor geology, replacement filling, piling and other methods are used for reinforcement. The soil base surface is set with a cross slope according to the design requirements, and the existing base layer 5 in the area to be expanded is compacted to facilitate subsequent construction.

[0028] S3, construction of base layer 7 and reservation of transition zone; S301, measuring and reserving a transition area; The transition zone in this project is 300 cm, which is subject to the specific project and is reserved through manual measurement to leave a casting position for the stepped concrete transition plate 3.

[0029] S302, paving and pressing of graded crushed stone; In step S302, a reference line is set up 30 cm outside the edge of the graded layer and checked. A paver is used for paving and a double-steel-wheel roller is used for compaction throughout the process. The double-steel-wheel roller is preferably an HD138 double-steel-wheel roller. First, static compaction is performed once, followed by weak vibration once, strong vibration three times, and finally static compaction once for a total of six times. The compaction thickness of the graded gravel is 15 cm.

[0030] S303, laying and pressing of water-stabilizing layer; In step S303, a reference line is set up 30 cm outside the edge of the graded layer and checked. A paver is used for paving. A 12t double steel wheel roller is used for compaction first, and then a 20t single steel wheel roller is used for subsequent compaction. The 12t double steel wheel roller is used for static compaction once, and then a 20t single steel wheel roller is used for strong vibration three times and weak vibration two times, for a total of six times.

[0031] The water-stabilizing layer is laid in two layers. The first water-stabilizing layer is 4% cement stabilized gravel, and the second water-temperature layer is 5% cement stabilized gravel. The single-layer water-stabilizing layer has a loose thickness of 26cm and a compacted thickness of 20cm. The compaction coefficient is 1.3.

[0032] S304, simultaneous laying of chip seal and permeable layer; The total thickness of the synchronous chip seal layer and the permeable layer is 1 cm, forming an intermediate layer, which enhances the bonding force between the base layer 7 and the asphalt surface layer, and also improves the stability and durability of the entire road structure.

[0033] S4, the old concrete pavement 1 structure is implanted with steel bar 2; In step S4, the diameter of the steel bar tie rod 2 is φ25mm, and the steel bar tie rod 2 is partially implanted, and the rest is an exposed section to meet the requirements of structural strength. The spacing between implanted bars is 40cm to ensure that the steel bar tie rod 2 is evenly distributed in the concrete. A drilling rig is used to drill holes, and a hair dryer is used to remove dust and debris in the hole to ensure that the hole wall is clean and smooth, and to ensure that the implant glue can be fully bonded to the hole wall to improve the firmness of the implanted bars. The implanted bar bonding glue uses Class A glue, and a pull-out test should be carried out after the implantation is completed. The steel bar tie rod 2 is mechanically cut, and oxygen cutting is not allowed to avoid damage to the steel bar tie rod 2 and concrete caused by the high temperature generated by thermal cutting. The implantation should be carried out before the construction of the connection part to avoid long-term exposure and corrosion of the implanted steel bar tie rod 2. Otherwise, anti-rust measures should be taken, such as applying anti-rust paint or wrapping with anti-rust materials.

[0034] S5, at this time, the exposed section of the steel bar 2 is used as the longitudinal steel bar for casting the steel cage of the stepped concrete transition plate 3, and the steel cage is set up, and the formwork is supported to cast the stepped concrete transition plate 3; S501, install the force transmission rod; S502, notch template acceptance; S503, apply water-soluble release agent and isolation agent on the template surface; S504, after the board surface is dry, install the notch template; S505, using the exposed section of the steel bar tie rod 2 as the longitudinal steel bar for casting the steel cage of the stepped concrete transition plate 3, and setting up the steel cage; S506, pouring the stepped concrete transition plate 3.

[0035] According to the requirements of the design drawings, holes are drilled at predetermined positions and force transfer rods are installed. The force transfer rods are used to connect and transfer the load between concrete slabs to ensure the integrity and stability of the structure. The notched formwork uses bamboo plywood. Before use, check whether the geometric dimensions of the formwork are correct, whether the joints of the formwork are tight, and whether the formwork is misaligned. It can only be used after acceptance to prevent leakage during concrete pouring.

[0036] Before erecting the formwork, the formwork surface must be carefully cleaned and applied with a water-soluble release agent. Organic or inorganic types can be selected. It should be applied twice. Avoid applying too thick an agent each time to prevent flowing. Apply the second application after the first application is dry. Apply evenly without any omissions, flow or tears. After applying the release agent, cover it with plastic sheeting to protect it from contamination. Remove the plastic sheeting after drying. The release agent and release agent facilitate the removal of the formwork after concrete pouring, while protecting the formwork surface from being bonded by concrete.

[0037] Then start to install the vertical formwork. According to the requirements of the design drawings, install the notched formwork to ensure that the formwork is accurately positioned and firmly fixed. Check whether the joints of the formwork are tight to prevent leakage, provide support for pouring the stepped concrete transition plate 3, pour and vibrate the concrete, and use the exposed section of the steel tie rod 2 as the longitudinal steel bar for pouring the stepped concrete transition plate 3 steel cage, which is directly poured inside to eliminate the misalignment between the new and old concrete. At the junction of the new and old concrete, due to the small tensile strength value in the mechanical properties of the concrete material, cracking or damage is prone to occur, and the steel tie rod 2 can significantly improve the tensile strength of this area, thereby preventing damage and misalignment caused by insufficient tensile resistance. The steel tie rod 2 can effectively connect the new and old concrete to form a whole, which not only enhances the stability of the concrete structure, but also limits the deformation of the concrete during the force process, especially vertical displacement and shear deformation, thereby reducing the possibility of misalignment between the new and old concrete.

[0038] S6, leveling and curing of stepped concrete transition plate 3; After the concrete is vibrated, promptly trim and smooth the exposed surface of the concrete, apply a second coat and press it after the slurry is set. After the concrete has initially set, promptly cover it with plastic film and sprinkle water for maintenance. Maintain it continuously to avoid the formation of dry-wet cycles. The maintenance time should be no less than 14 days.

[0039] S7, laying fiberglass grid; Fiberglass grating can be used in two types: with self-adhesive glue and without self-adhesive glue; the one with self-adhesive glue can be laid directly; the one without self-adhesive glue can be laid by nailing and iron sheet fixing method; when laying by nailing and iron sheet fixing method, first fix one end with iron sheet and nail on the lower layer of asphalt with adhesive layer asphalt, then tighten the grating longitudinally and fix it in sections, each section is 2 to 5m long; the longitudinal joint overlap length shall not be less than 20cm, and the transverse overlap length shall not be less than 15cm.

[0040] S8, construction of penetrating oil and lower sealing layer; S801, inspect the base layer 7 and clean the dust and other debris on the top surface of the base layer 7; S802, sprinkle water on the surface of the base layer 7, and after the surface layer is dried in the shade, pour the penetration layer of asphalt; S803, lower seal layer paving; S804: After the construction of the lower sealing layer is completed, the closed curing shall be carried out for ≥ 24 hours.

[0041] If the base layer 7 is completed and the surface is relatively dry after a long time, first clean up all kinds of dust, scum, etc. on the base layer 7. If necessary, use a wire brush with a high-pressure blower, a water gun, etc. to process it manually, and sprinkle a small amount of water on the surface of the base layer 7. After the surface is dried in the shade, sprinkle a penetration layer of asphalt.

[0042] Before paving the lower seal layer, the paver should fully stir the mixture to be paved. If lumps or sediments are found, they should be dealt with or discarded in time. The paver starts paving along the walking line, tracks and checks the thickness of the seal layer, and adjusts it until the paving thickness reaches the design thickness. In order to ensure the uniformity of the paving thickness and the flatness of the surface, after the seal layer construction is completed, it must be closed and cured for at least 24 hours. The lower seal layer is 7cm thick AC-25C coarse-grained asphalt concrete.

[0043] S9, asphalt surface structure construction.

[0044] In step S9, the asphalt surface layer is paved by two pavers in echelon, 10 to 13 m apart, one paving machine is 6 m wide and the other is 5.5 m wide, the paving machine screeds overlap by 10 cm, double-sided wires are used to control paving, one wire is 10 m long, the paving speed is 1 to 1.5 m / min, the first paver before the start of paving is 3 loads of material, and the first paver is 2 loads of material, the starting speed is gradually increased to 1 m / min, and the thickness and slope control of the sensors on both sides are adjusted according to the measurement results within 5 to 10 m; Finally, a double steel wheel roller is used for compaction, preferably HD138 double steel wheel roller. The compaction process is to first perform static compaction once, then perform weak vibration once, then perform strong vibration three times, and finally perform static compaction once for smooth surface.

[0045] When pressing, one return is considered as one pass. The asphalt pavement 4 is paved in two layers. When paving, the emulsified asphalt tack coat oil PC-3 is sprinkled on the lower sealing layer, and then a 5 cm thick AC-16C medium-grained asphalt concrete is spread. After pressing, the emulsified asphalt tack coat oil PC-3 is sprinkled thereon, and then a 4 cm thick AC-13C fine-grained asphalt concrete is laid as the final surface layer. The emulsified asphalt tack coat oil PC-3 is used for bonding between asphalt layers to enhance the bonding strength between layers, prevent moisture penetration, and improve the durability and stability of the pavement.

[0046] The above description is only a preferred embodiment of the present invention and does not limit the present invention in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes for application in other fields. However, any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A rigid-flexible pavement overlap extension structure for municipal road engineering, characterized by: It comprises a subbase (6), an old concrete pavement (1) and a steel bar tie rod (2), wherein an existing base (5) is laid on the subbase (6), the old concrete pavement (1) is laid on the existing base (5), the old concrete pavement (1) is connected to one side of a stepped concrete transition plate (3) through the steel bar tie rod (2), the other side of the stepped concrete transition plate (3) abuts against a base (7), and an asphalt pavement (4) is laid on the top surface of the stepped concrete transition plate (3) and the top surface of the base (7); A steel cage is arranged in the stepped concrete transition plate (3), and the portion of the steel tie rod (2) in the stepped concrete transition plate (3) serves as the longitudinal steel bars of the steel cage.

2. According to claim 1, a municipal road engineering rigid-flexible pavement overlap extension structure is characterized by: The base layer (7) is laid on the existing base layer (5), and the asphalt pavement (4) is at the same level as the old concrete pavement (1).

3. A construction method for a rigid-flexible pavement overlap extension structure for a municipal road project, characterized in that: The construction of the rigid-flexible pavement overlap extension structure of the municipal road project described in claim 2 comprises the following steps: S1, prepare detailed construction plan and required material plan based on design documents and drawings; S2: Before construction, remove the topsoil, silt and garbage on the surface of the existing base layer (5) in the area to be expanded, and level and compact it; S3, base layer (7) construction and reservation of transition zone; S4, old concrete pavement (1) with steel tie rods (2) embedded in the structure; S5, at this time, the exposed section of the steel bar tie rod (2) is used as the longitudinal steel bar for casting the steel cage of the stepped concrete transition plate (3), and the steel cage is set up, and the stepped concrete transition plate (3) is cast in a formwork; S6, leveling and curing of the stepped concrete transition plate (3); S7, laying fiberglass grid; S8, construction of penetrating oil and lower sealing layer; S9, asphalt surface structure construction.

4. According to claim 3, a construction method for a rigid-flexible pavement overlap extension structure for a municipal road project is characterized by: In step S2, the compaction degree should not be less than 95% (based on the designed road grade). For areas with poor geology, reinforcement treatment is carried out by replacement filling, piling, etc., and the soil base surface is set with a cross slope according to the design requirements.

5. According to claim 3, a construction method for a rigid-flexible pavement overlap extension structure for a municipal road project is characterized by: The specific construction steps of the base layer (7) in step S3 include: S301, measuring and reserving a transition area; S302, paving and pressing of graded crushed stone; S303, laying and pressing of water-stabilizing layer; S304, simultaneous laying of gravel seal and permeable layer.

6. The construction method of a rigid-flexible pavement overlap extension structure for a municipal road project according to claim 5, characterized in that: In step S302, a reference line is set up 30 cm outside the edge of the graded layer and checked, a paver is used for paving, and a double steel wheel roller is used for full compaction; In step S303, a reference line is set up 30 cm outside the edge of the graded layer and checked, a paver is used for paving, a 12t double steel wheel roller is used for compaction first, and then a 20t single steel wheel roller is used for subsequent compaction.

7. The construction method of a municipal road engineering rigid-flexible pavement overlap extension structure according to claim 3, characterized in that: In step S4, the diameter of the steel bar tie rod (2) is φ25 mm, the spacing between the embedded bars is 40 cm, a drilling rig is used to drill holes, a blower is used to remove dust and residue in the holes, and the embedded bar adhesive is grade A adhesive. After the embedded bars are completed, a pull-out test should be carried out. The steel bar tie rod (2) is cut mechanically, and oxygen cutting is not allowed.

8. The construction method of a municipal road engineering rigid-flexible pavement overlap extension structure according to claim 3, characterized in that: The specific construction steps of step S5 include: S501, install the force transmission rod; S502, notch template acceptance; S503, apply water-soluble release agent and isolation agent on the template surface; S504, after the board surface is dry, install the notch template; S505, using the exposed section of the steel bar tie rod (2) as the longitudinal steel bar for casting the steel cage of the stepped concrete transition plate (3), and setting up the steel cage; S506, pouring the stepped concrete transition plate (3).

9. The construction method of a municipal road engineering rigid-flexible pavement overlap extension structure according to claim 3, characterized in that: The specific construction steps of step S8 include: S801, inspect the base layer (7), and clean the dust and other debris on the top surface of the base layer (7); S802, sprinkle water on the surface of the base layer (7), and after the surface layer is dried in the shade, pour a penetration layer of asphalt; S803, lower seal layer paving; S804: After the construction of the lower sealing layer is completed, the closed curing shall be carried out for ≥ 24 hours.

10. The construction method of a rigid-flexible pavement overlap extension structure for a municipal road project according to claim 3, characterized in that: In step S9, the asphalt surface layer is paved by two pavers in echelon, 10 to 13 m apart, with the paving machine screeds overlapping by 10 cm, and the paving is controlled by double-sided wires, with one wire for every 10 m, and the paving speed is 1 to 1.5 m / min; Finally, a double steel wheel roller is used for compaction.

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