Prestressed concrete pavement repair structure and construction method

Abstract

The application discloses a prestressed concrete pavement maintenance structure and a construction method, which are suitable for the design and construction of damaged prestressed concrete pavements. The structure is composed of a road pre-tensioned slab, a cast-in-place slab and a structural joint. The structural joint comprises a self-stress joint and a pre-cut joint. The self-stress joint, the road pre-tensioned slab, the cast-in-place slab and the pre-cut joint are combined to form a new partial prestressed concrete pavement maintenance structure, which not only meets the requirements of high bearing capacity and high durability of heavy-load traffic, but also takes into account the safety and economy of driving.

Description

Technical Field

[0001] This invention relates to the field of highway engineering technology, and in particular to a prestressed concrete pavement maintenance structure and construction method. Background Technology

[0002] With the sustained and rapid development of my country's economy and the rapid increase in heavy-duty traffic, the mileage of prestressed concrete pavements suitable for heavy-duty traffic is also increasing. However, there is a problem that damaged prestressed concrete pavements are difficult to repair. Currently, there is an urgent need in highway maintenance for a high-quality, fast, economical, and durable repair structure and construction method. Traditional methods use ordinary reinforced concrete structures for repair, which have drawbacks such as low stiffness, easy cracking, and short service life.

[0003] This invention discloses a prestressed concrete pavement maintenance structure and construction method. It combines four structural elements—self-stressing joints, pre-tensioned road slabs, cast-in-place slabs, and pre-cut joints—to form a novel, high-quality, fast-developing, economical, and durable partially prestressed concrete pavement maintenance structure. The specific layout is as follows: High-rigidity, high-load-bearing pre-tensioned road slabs are installed in the driving lane and overtaking lane. Two pre-tensioned road slabs are connected by a self-stressing longitudinal joint, which works seamlessly, facilitating safe lane changes between the two lanes. At the curb, The hard shoulder section uses a conventional reinforced concrete structure, which meets traffic requirements while being relatively economical. Self-stressing transverse joints connect the driving lanes and overtaking lanes to pre-tensioned slabs, ensuring that the rigidity of the two lanes meets the requirements of prestressed pavement while also guaranteeing driving safety and comfort. These same self-stressing transverse joints longitudinally connect the curb strip and the cast-in-place slab of the hard shoulder to the concrete pavement. The self-stress of these joints provides longitudinal compressive stress to the cast-in-place slab, preventing transverse cracks and ensuring its durability and safety. Therefore, this invention not only meets the requirements of heavy traffic for high load-bearing capacity and durability but also balances driving safety and economy.

[0004] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0005] 1) The present invention uses pre-tensioned road slabs with high rigidity and strong load-bearing capacity for the driving lane and overtaking lane. The pre-tensioned road slabs are connected longitudinally by self-stressing joints and prestressed concrete pavement. The repaired highway has good integrity, strong load-bearing capacity and high durability.

[0006] 2) Road slabs are prefabricated in factories, with standardized production, green and environmentally friendly, and guaranteed in quality.

[0007] The curb and hard shoulder sections use ordinary concrete structures, and with the addition of self-stressing joints at the top and bottom, cracks are avoided compared to ordinary reinforced concrete structures. Partial prestressed concrete pavement maintenance structures are also included. Summary of the Invention

[0008] The technical problem solved by this invention is the difficulty in repairing damaged prestressed concrete pavements. Traditional methods use ordinary reinforced concrete structures for repair, which have defects such as low stiffness, easy cracking, and short service life.

[0009] To address the aforementioned problems, this invention provides a prestressed concrete pavement repair structure and construction method. The repaired highway exhibits good overall integrity, strong load-bearing capacity, and high durability, making it more economical, safer, more comfortable, and more durable than reinforced concrete structures.

[0010] A maintenance structure for prestressed concrete pavement, characterized in that the structure consists of three parts: a pre-tensioned road slab, a cast-in-place slab, and a structural joint.

[0011] The road prestressing slab includes a road prestressing slab for the overtaking lane and a road prestressing slab for the driving lane;

[0012] The cast-in-place slabs include hard shoulder cast-in-place slabs and curb strip cast-in-place slabs;

[0013] The structural joint consists of an upper self-stressing transverse joint, a lower self-stressing transverse joint, a self-stressing longitudinal joint, and a pre-cut joint.

[0014] The prestressed concrete pavement maintenance structure further includes an upper self-stressing transverse joint, a parallel structural slab, and a lower self-stressing transverse joint; wherein the parallel structural slab is located between the upper self-stressing transverse joint and the lower self-stressing transverse joint.

[0015] The parallel structural slabs are arranged from left to right as follows: cast-in-place slab for curb strip, pre-tensioned slab for overtaking lane, self-stressing longitudinal joint, pre-tensioned slab for driving lane, and cast-in-place slab for pre-cut joint and hard shoulder.

[0016] According to a preferred embodiment of the present invention, the upper self-stressing transverse joint and the lower self-stressing transverse joint are both perpendicular to the longitudinal centerline of the road surface, and the self-stressing longitudinal joint, the pre-cut joint and the longitudinal centerline of the road surface are parallel and perpendicular to the upper self-stressing transverse joint and the lower self-stressing transverse joint.

[0017] According to another preferred embodiment of the present invention, the positions of the curb strip cast-in-place slab, the overtaking lane pre-tensioned slab, the driving lane pre-tensioned slab, and the hard shoulder cast-in-place slab correspond one-to-one with the curb strip, overtaking lane, driving lane, and hard shoulder portions of the road surface, respectively.

[0018] According to another preferred embodiment of the present invention, the road prestressed slab is composed of concrete, longitudinally arranged steel strands, and transversely arranged double rows of transverse reinforcing bars.

[0019] According to another preferred embodiment of the present invention, the dimensions of the pre-tensioned slab for road use are: length 5m-9m, width 3.50m-3.70m, height 20cm-24cm, concrete grade 40MPa-45MPa, the position of the steel strands is set 2cm-3cm below the centerline of the slab's cross-section, and the longitudinal spacing of the upper and lower double rows of transverse steel bars is 60cm-80cm.

[0020] According to another preferred embodiment of the present invention, the curb strip cast-in-place slab and the hard shoulder cast-in-place slab are composed of concrete, a single row of longitudinally arranged longitudinal steel bars and a single row of transversely arranged transverse steel bars.

[0021] According to another preferred embodiment of the present invention, the dimensions of the cast-in-place curb slab structure are: 5m-9m in length, 0.5m in width, 20cm-24cm in height, with a concrete grade of 40MPa-45MPa, longitudinal reinforcement bars are placed 2cm-3cm on the central axis of the slab's cross-section, and transverse reinforcement bars are spaced 60cm-80cm apart longitudinally and placed below the longitudinal reinforcement bars.

[0022] According to another preferred embodiment of the present invention, the dimensions of the cast-in-place slab structure with hard shoulder are: length 5m-9m, width 2.5m-3.0m, height 20cm-24cm, longitudinal reinforcement is arranged on the central axis of the slab cross section at 2cm-3cm, and transverse reinforcement is arranged with a longitudinal spacing of 60cm-80cm and below the longitudinal reinforcement.

[0023] According to another preferred embodiment of the present invention, the upper self-stressing transverse joint and the lower self-stressing transverse joint are composed of longitudinal self-stressing tendons, transverse self-stressing tendons and high-expansion concrete;

[0024] The self-stressing longitudinal joint is composed of transverse self-stressing tendons, longitudinal self-stressing tendons, and expansive concrete;

[0025] The pre-cut joint is a dummy joint pre-cut between the pre-tensioned slab of the driving lane and the cast-in-place slab of the hard shoulder.

[0026] According to another preferred embodiment of the present invention, the dimensions of the upper self-stressing transverse joint and the lower self-stressing transverse joint are: width 22cm-25cm, height 20cm-24cm, transverse length 10.5m-11.0m, the longitudinal self-stressing tendons are arranged as double rows of steel bars with a longitudinal spacing of 15cm-20cm, the transverse self-stressing tendons are double rows of double steel bars, the high expansion concrete grade is 40MPa-45MPa, and the longitudinal self-stress value of the 90-day self-stressing joint is 2.5MPa-4.0MPa;

[0027] The dimensions of the self-stressing longitudinal joint are: 10cm wide, 20cm-24cm high, and 5.0m-9.0m long. It is arranged with double rows of double transverse self-stressing tendons with a longitudinal spacing of 60cm-80cm. The longitudinal self-stressing tendons are single steel bars in double rows. The expansive concrete grade is 40MPa-45MPa. The transverse self-stress value of the 90-day self-stressing longitudinal joint is 1.5MPa-2.5MPa.

[0028] According to another preferred embodiment of the present invention, the dimensions of the pre-cut joint are: 4mm-6mm wide and 7.0cm-8.0cm deep, and the filling material in the joint is hot asphalt.

[0029] According to another aspect of the present invention, a prestressed concrete pavement maintenance structure and construction method are provided, characterized in that the method includes the following steps:

[0030] 1) Precast road slabs: Tensile the steel strands on the tensioning table, tie the transverse reinforcement of the precast slab, support the precast slab steel mold, pour concrete, vibrate thoroughly, polish with a grinder and finish manually, cure for 7 days, release the steel strands, and move the precast slab to the beam storage yard.

[0031] 2) Remove the damaged prestressed concrete pavement: Depending on the size of the damaged area, use a concrete cutter to cut a rectangular concrete pavement with a length of 5.44m-9.44m and a width of 11m along the outer edge of the upper and lower self-stressing transverse joints. The damaged old pavement is removed manually in conjunction with the machinery.

[0032] 3) Self-stressing transverse joint reinforcement: On the upper and lower transverse surfaces formed after cutting and damaging the prestressed pavement, longitudinal self-stressing anchor bars are inserted at the positions of the longitudinal self-stressing tendons arranged at the upper and lower self-stressing transverse joints.

[0033] 4) Install the road prestressed slab: Install the overtaking road prestressed slab and the driving road prestressed slab at the positions corresponding to the overtaking lane and the driving lane. The distance between the road prestressed slab and the upper and lower prestressed pavement is 20cm-25cm, and the distance between the two slabs is 10cm.

[0034] 5) Casting the cast-in-place slab and self-stressing longitudinal joint: Tie the longitudinal and transverse steel bars of the cast-in-place slab of the curb strip and the cast-in-place slab of the hard shoulder, weld the transverse self-stressing tendons of the longitudinal joint, tie the longitudinal self-stressing tendons of the longitudinal joint, support the formwork of the cast-in-place slab and the self-stressing longitudinal joint respectively, pour ordinary concrete into the cast-in-place slab, pour the expansive concrete into the self-stressing longitudinal joint, cover with curing cloth, and cure for 5 days;

[0035] 6) Casting the upper and lower self-stressing transverse joints: Weld the longitudinal reinforcement of the upper and lower self-stressing transverse joints, tie the transverse reinforcement of the upper and lower self-stressing transverse joints, erect the self-stressing transverse joint formwork, pour high-expansion concrete into the joints, cover with curing cloth, and water-cur for 7 days.

[0036] 7) Construction of pre-cut joint: Use a concrete cutter to cut the pre-cut joint along the joint between the precast slab of the driving lane and the cast-in-place slab of the hard shoulder. The dimensions are 4mm-6mm wide and 7cm-8cm deep. Use a blower to clean and dry the pre-cut joint, and then fill the joint with hot asphalt. Attached Figure Description

[0037] Figure 1 This is a plan view of the present invention;

[0038] Figure 2 This is a cross-sectional view (I-I) of the present invention;

[0039] Figure 3 This is a cross-sectional view (II-II) of the present invention;

[0040] Figure 4 This is a cross-sectional view (III-III) of the present invention.

[0041] The relevant labels in the figure are as follows:

[0042] 1. Pre-stressed slab for overtaking lanes; 2. Pre-stressed slab for driving lanes; 3. Cast-in-place slab for hard shoulder; 4. Cast-in-place slab for curb strip; 5. Upper self-stressing transverse joint; 6. Lower self-stressing transverse joint; 7. Self-stressing longitudinal joint; 8. Pre-cut joint; 9. Overtaking lane; 10. Driving lane; 11. Curb strip; 12. Hard shoulder; 13. Prestressed concrete pavement; 14. Longitudinal anchorage bars for transverse joints; 15. Longitudinal pre-reserved bars for road pre-stressed slabs; 16. Transverse self-stressing 17. Longitudinal reinforcement of cast-in-place slab for hard shoulder; 18. Longitudinal reserved reinforcement of cast-in-place slab; 19. High expansion concrete; 20. Transverse reinforcement of pre-tensioned slab for road use; 21. Transverse reinforcement of cast-in-place slab for hard shoulder; 22. Transverse self-stressing reinforcement of longitudinal joint; 23. Longitudinal self-stressing reinforcement of longitudinal joint; 24. Expansion concrete of longitudinal joint; 25. Transverse reinforcement of cast-in-place slab for curb; 26. Longitudinal reinforcement of cast-in-place slab for curb; 27. Longitudinal self-stressing reinforcement; 28. Steel strand. Detailed Implementation

[0043] With the sustained and rapid development of my country's economy and the rapid increase in heavy-duty traffic, the mileage of prestressed concrete pavements suitable for heavy-duty traffic is also increasing. However, there is a problem that damaged prestressed concrete pavements are difficult to repair, urgently requiring a high-quality, fast, economical, and durable repair structure and construction method. This invention provides a partially prestressed concrete pavement repair structure. The designed driving lane and overtaking lane sections use pre-tensioned road slabs, which are prefabricated in a factory, resulting in uniform prestressing, high stiffness, and strong load-bearing capacity. The pre-tensioned road slabs are longitudinally connected to the prestressed concrete pavement via transverse self-stressing joints. The high-expansion concrete within the self-stressing joints expands, generating self-stress, ensuring uniform stress at the joint and high longitudinal flatness. This satisfies both the stiffness and strength requirements of the repaired pavement and the safety and comfort requirements for driving.

[0044] The following is a reference to the appendix. Figure 1-4 This invention provides a detailed description and explanation of a prestressed concrete pavement repair structure and construction method for which protection is claimed.

[0045] like Figure 1 The diagram shows a plan view of a partially prestressed concrete pavement repair structure, which is applicable to the design and construction of damaged prestressed concrete pavements. The structure is characterized by consisting of three parts: a pre-tensioned slab (1, 2), a cast-in-place slab (3, 4), and a structural joint (5, 6, 7, 8).

[0046] The pre-tensioned slab for road use includes the pre-tensioned slab 1 for the overtaking lane 9 and the pre-tensioned slab 2 for the driving lane 10;

[0047] Cast-in-place slabs include hard shoulder cast-in-place slabs 3 and curb strip cast-in-place slabs 4;

[0048] The structural joint consists of an upper self-stressing transverse joint 5, a lower self-stressing transverse joint 6, a self-stressing longitudinal joint 7, and a pre-cut joint 8.

[0049] The prestressed concrete pavement maintenance structure further includes an upper self-stressing transverse joint 5, a parallel structural plate, and a lower self-stressing transverse joint 6; wherein the parallel structural plate is located between the upper self-stressing transverse joint and the lower self-stressing transverse joint.

[0050] The parallel structural slabs are arranged from left to right as follows: 4. Curb strip cast-in-place slab, 1. Overtaking lane pre-tensioned slab, 7. Self-stressing longitudinal joint, 2. Driving lane pre-tensioned slab, 8. Pre-cut joint, and 3. Hard shoulder cast-in-place slab.

[0051] The upper self-stressing transverse joint 5 and the lower self-stressing transverse joint 6 are both perpendicular to the longitudinal centerline of the road surface. The self-stressing longitudinal joint 7 and the pre-cut joint 8 are parallel to the longitudinal centerline of the road surface and perpendicular to the upper self-stressing transverse joint 5 and the lower self-stressing transverse joint 6.

[0052] The positions of the curb strip cast-in-place slab 4, the overtaking lane pre-stressed slab 1, the driving lane pre-stressed slab 2, and the hard shoulder cast-in-place slab 3 correspond one-to-one with the curb strip 11, the overtaking lane 9, the driving lane 10, and the hard shoulder 12 of the road surface.

[0053] Because there are many vehicles and heavy loads in the driving lane 10 and overtaking lane 9, pre-tensioned road slabs (1, 2) with high rigidity, strong load-bearing capacity and good durability are installed.

[0054] like Figure 2 As shown, the pre-tensioned slabs (1, 2) for road use are composed of concrete, longitudinally arranged steel strands 28, and transversely arranged double rows of transverse reinforcing bars 20.

[0055] The dimensions of the pre-stressed slabs (1, 2) for road use are as follows: the length can be selected from 5m to 9m and the height from 20cm to 24cm, depending on the area of ​​road damage. The preferred height is 20cm or 24cm. The width can be selected from 3.50m or 3.70m depending on the width of the lane. The concrete grade is 40MPa to 45MPa, with the preferred strength being 40MPa or 45MPa. The position of the steel strands (28) is set 2cm to 3cm below the centerline of the slab cross section. The preferred diameter of the steel strands is 12.7mm. The longitudinal spacing of the upper and lower double-row transverse steel bars (20) is 60cm to 80cm, with the preferred spacing being 60cm or 70cm. The transverse steel bars (20) are grade II steel bars with a diameter of 16m to 18mm, with the preferred diameter being 16m or 18mm.

[0056] like Figure 2 , 3 As shown, in the structural parts of the curb strip 11 and hard shoulder 12, because there are few vehicles, ordinary reinforced concrete slab structures with low stiffness and low load-bearing capacity are adopted. The curb strip cast-in-place slab 4 and the hard shoulder cast-in-place slab 3 are composed of concrete, a single row of longitudinally arranged longitudinal steel bars (17, 26) and a single row of transversely arranged transverse steel bars (21, 25).

[0057] The dimensions of the cast-in-place curb slab 4 are as follows: 5m-9m in length, 0.5m in width, and 20cm-24cm in height, depending on the area of ​​road damage. The pre-selected heights are 20cm and 24cm. The concrete grade is 40MPa-45MPa, with preferred strengths of 40MPa and 45MPa. The longitudinal reinforcement 26 of the cast-in-place curb slab is made of grade II steel with a diameter of 22mm-25mm, preferably 22mm and 25mm, and is placed 2cm-3cm above the centerline of the slab's cross-section. The transverse reinforcement 25 of the cast-in-place curb slab is grade II steel with a diameter of 16mm-18mm, preferably 16mm and 18mm, with a longitudinal spacing of 60cm-80cm, preferably 16mm and 18mm, and is placed below the longitudinal reinforcement 26.

[0058] like Figure 2As shown in Figure 3, the structural dimensions of the cast-in-place slab 3 for the hard shoulder are as follows: The length can be selected as 5m-9m, the width as 2.5m-3.0m (preferred width 2.5m or 3.0m), and the height as 20cm-24cm (preferred height 20cm or 24cm). The concrete grade is 40MPa-45MPa (preferred strength 40MPa or 45MPa). The longitudinal reinforcement 17 of the cast-in-place slab for the hard shoulder is made of grade II steel bars with a diameter of 22mm-25mm (preferred diameter 22mm or 25mm), and is placed 2cm-3cm above the centerline of the slab's cross-section. The transverse reinforcement 21 of the cast-in-place slab for the hard shoulder is grade II steel bar with a diameter of 16mm-18mm (preferred diameter 16mm or 18mm), with a longitudinal spacing of 60cm-80cm (preferred diameter 16mm or 18mm), and is placed below the longitudinal reinforcement 17.

[0059] The connection between the pre-tensioned slabs (1, 2), cast-in-place slabs (3, 4) and the prestressed concrete pavement 13 is the key to the maintenance quality. The upper and lower self-stressing transverse joints (5, 6) are used for connection to ensure that the rigidity and durability of the overtaking lane 9 and the driving lane 10 meet the requirements of the prestressed pavement 13 after connection. The upper and lower self-stressing transverse joints (5, 6) are composed of longitudinally arranged longitudinal self-stressing tendons 27, transverse self-stressing tendons 16 and high-expansion concrete 19.

[0060] The dimensions of the upper and lower self-stressing transverse joints (5, 6) are: width 22cm-25cm, preferably 22cm or 25cm; height 20cm-24cm, preferably 20cm or 24cm; transverse length 10.5m-11.0m depending on the road surface; longitudinal self-stressing tendons 27 are arranged as double-row steel bars with a diameter of 16mm-18mm, grade II steel bars, preferably 16mm or 18mm; longitudinal spacing 15cm-20cm, preferably 15cm or 20cm; transverse self-stressing tendons 16 are double-row double-strand steel bars; high-expansion concrete 19 grade is 40MPa-45MPa, preferably 40MPa or 45MPa; 90-day self-stressing joints (5, 6) longitudinal self-stress value is 2.5MPa-4.0MPa, preferably 3.0MPa or 4.0MPa.

[0061] like Figure 4 As shown, the two pre-tensioned slabs (1, 2) are connected by a self-stressing longitudinal joint 7. The self-stressing longitudinal joint 7 works seamlessly, which facilitates vehicles to safely change lanes between the two lanes (9, 10).

[0062] The self-stressing longitudinal joint 7 is composed of transverse self-stressing tendons 22 and longitudinal self-stressing tendons 23 arranged transversely, and expansive concrete 24. Its specific dimensions are: width 10cm, height 20cm-24cm, preferably 20cm or 24cm, length 5.0m-9.0m selected according to the damaged area. The transverse self-stressing tendons 22 are arranged in double rows with double roots, using grade II steel bars with a diameter of 16mm-18mm, preferably 16mm or 18mm, and longitudinal spacing of 60cm-80cm. The longitudinal self-stressing tendons 23 are single steel bars in double rows. The design grade of the expansive concrete 24 is 40MPa-45MPa, preferably 40MPa or 45MPa. The 90-day transverse self-stress value of the self-stressing longitudinal joint is 1.5MPa-2.5MPa, preferably 1.0MPa or 2.0MPa.

[0063] The pre-cut joint 8 is a dummy joint pre-cut between the pre-tensioned slab 2 and the cast-in-place slab 3 of the hard shoulder along the roadway. The dimensions of the pre-cut joint 8 are: width 4mm-6mm, preferably 5mm, depth 7.0cm-8.0cm, preferably 7.5cm, and the filling material in the joint is hot asphalt.

[0064] It should be noted that the specific data and parameters mentioned above are the optimal parameters selected by the inventors through numerous experiments and on-site construction results. They are not subjective conjectures, but rather obtained through numerous comparisons, references, and continuous modifications. These parameters are indispensable for the technical contribution to this invention and the optimization of the product's specific performance.

[0065] like Figure 1 , 2 As shown in Figures 3 and 4, a construction method for a prestressed concrete pavement damage repair structure is characterized by the following steps:

[0066] 1) Precast road prestressed slabs (1, 2): Tensile 28 steel strands on the tensioning table, tie 20 transverse steel bars of the prestressed slab, support the precast slab steel mold, pour concrete, vibrate thoroughly, polish with a grinder and finish manually, cure for 7 days, release 28 steel strands, and move the precast slab to the beam storage yard.

[0067] 2) Remove damaged prestressed concrete pavement: Depending on the size of the damaged area, use a concrete cutter to cut a rectangular piece of the damaged concrete pavement, 5.44m long and 5.44m wide, along the outer edge of the upper and lower self-stressing joints (5, 6). The damaged old pavement is removed by combining mechanical and manual labor.

[0068] 3) Rebar installation in self-stressing transverse joints (5, 6): After cutting and damaging the prestressed pavement, longitudinal self-stressing anchor bars 14 are installed at the positions of the longitudinal self-stressing tendons 27 arranged in the self-stressing transverse joints on the upper and lower transverse surfaces.

[0069] 4) Install road prestressed slabs (1, 2): Install prestressed slab 1 for overtaking lane 9 and prestressed slab 2 for driving lane at the positions corresponding to the overtaking lane 9 and driving lane 10. The distance between the road prestressed slabs (1, 2) and the upper and lower prestressed concrete pavement 13 is 20cm-25cm, and the distance between the two slabs (1, 2) is 10cm.

[0070] 5) Casting the cast-in-place slabs (3, 4) and the self-stressing longitudinal joint 7: Tie the longitudinal and transverse reinforcement (17, 21, 25, 26) of the curb strip cast-in-place slab 4 and the hard shoulder cast-in-place slab 3, weld the transverse self-stressing tendons 22 of the longitudinal joint, tie the longitudinal self-stressing tendons 23 of the longitudinal joint, support the formwork of the cast-in-place slab and the self-stressing longitudinal joint 7 respectively, pour ordinary concrete in the cast-in-place slab, pour expansive concrete 24 in the self-stressing longitudinal joint 7, cover with curing cloth, and cure for 5 days;

[0071] 6) Pour the upper and lower self-stressing transverse joints (5, 6): Weld the longitudinal steel bars 27 of the upper and lower self-stressing transverse joints (5, 6), tie the transverse steel bars 16 of the upper and lower self-stressing transverse joints, reinforce the formwork of the upper and lower self-stressing transverse joints (5, 6), pour high-expansion concrete 19 into the joints, cover with curing cloth, and water-cur for 7 days.

[0072] 7) Construction of pre-cut joint 8: Use a concrete cutter to cut pre-cut joint 8 along the joint between the precast slab 2 of the driving lane and the cast-in-place slab 3 of the hard shoulder. The dimensions are 4mm-6mm wide and 7cm-8cm deep. Use a blower to clean the cut joint and inject hot asphalt into the joint.

[0073] 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.

[0074] 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 prestressed concrete pavement maintenance structure, characterized in that, The structure consists of three parts: a pre-tensioned road slab, a cast-in-place slab, and structural joints. The road prestressing slab includes a road prestressing slab for the overtaking lane and a road prestressing slab for the driving lane; The cast-in-place slabs include hard shoulder cast-in-place slabs and curb strip cast-in-place slabs; The structural joint consists of an upper self-stressing transverse joint, a lower self-stressing transverse joint, a self-stressing longitudinal joint, and a pre-cut joint. The prestressed concrete pavement maintenance structure further includes an upper self-stressing transverse joint, a parallel structural slab, and a lower self-stressing transverse joint; wherein the parallel structural slab is located between the upper self-stressing transverse joint and the lower self-stressing transverse joint. The parallel structural slabs are arranged from left to right as follows: cast-in-place slab for curb strip, pre-tensioned slab for overtaking lane, self-stressing longitudinal joint, pre-tensioned slab for driving lane, and cast-in-place slab for pre-cut joint and hard shoulder; The aforementioned upper and lower self-stressing transverse joints are composed of longitudinal self-stressing tendons, transverse self-stressing tendons, and high-expansion concrete. The self-stressing longitudinal joint is composed of transverse self-stressing tendons, longitudinal self-stressing tendons, and expansive concrete; The pre-cut joint is a dummy joint pre-cut between the pre-tensioned slab of the carriageway and the cast-in-place slab of the hard shoulder; The dimensions of the upper and lower self-stressing transverse joints are: width 22cm-25cm, height 20cm-24cm, transverse length 10.5m-11.0m, longitudinal self-stressing tendons are arranged in double rows of steel bars with a longitudinal spacing of 15cm-20cm, transverse self-stressing tendons are double rows of double steel bars, the high expansion concrete grade is 40mpa-45mpa, and the longitudinal self-stress value of the 90-day self-stressing joint is 2.5mpa-4.0mpa; The dimensions of the self-stressing longitudinal joint are: 10cm wide, 20cm-24cm high, and 5.0m-9.0m long. It is arranged with double rows of double transverse self-stressing tendons with a longitudinal spacing of 60cm-80cm. The longitudinal self-stressing tendons are single steel bars in double rows. The expansive concrete grade is 40MPa-45MPa. The transverse self-stress value of the 90-day self-stressing longitudinal joint is 1.5MPa-2.5MPa.

2. The prestressed concrete pavement maintenance structure according to claim 1, characterized in that, The upper self-stressing transverse joint and the lower self-stressing transverse joint are both perpendicular to the longitudinal centerline of the road surface. The self-stressing longitudinal joint and the pre-cut joint are parallel to the longitudinal centerline of the road surface and perpendicular to the upper self-stressing transverse joint and the lower self-stressing transverse joint.

3. The prestressed concrete pavement maintenance structure according to claim 1, characterized in that, The positions of the cast-in-place slabs for the curb, the pre-tensioned slabs for the overtaking lane, the pre-tensioned slabs for the driving lane, and the cast-in-place slabs for the hard shoulder correspond one-to-one with the curb, overtaking lane, driving lane, and hard shoulder sections of the road surface.

4. The prestressed concrete pavement maintenance structure according to claim 1, characterized in that, The aforementioned pre-tensioned slab for road use is composed of concrete, longitudinally arranged steel strands, and transversely arranged double rows of horizontal reinforcing bars.

5. The prestressed concrete pavement maintenance structure according to claim 4, characterized in that, The dimensions of the pre-tensioned slab for road use are: length 5m-9m, width 3.50m-3.70m, height 20cm-24cm, concrete grade 40MPa-45MPa, the position of the steel strands is set 2cm-3cm below the centerline of the slab cross-section, and the longitudinal spacing of the upper and lower double rows of transverse steel bars is 60cm-80cm.

6. The prestressed concrete pavement maintenance structure according to claim 1, characterized in that, The aforementioned curb strip cast-in-place slab and hard shoulder cast-in-place slab are composed of concrete, a single row of longitudinally arranged longitudinal steel bars, and a single row of transversely arranged transverse steel bars.

7. The prestressed concrete pavement maintenance structure according to claim 6, characterized in that, The dimensions of the cast-in-place curb slab structure are: 5m-9m in length, 0.5m in width, and 20cm-24cm in height. The concrete grade is 40mpa-45mpa. The longitudinal reinforcement is placed 2cm-3cm on the centerline of the slab's cross-section, and the transverse reinforcement is spaced 60cm-80cm apart and placed below the longitudinal reinforcement.

8. The prestressed concrete pavement maintenance structure according to claim 6, characterized in that, The dimensions of the cast-in-place slab with hard shoulder are: length 5m-9m, width 2.5m-3.0m, height 20cm-24cm, longitudinal reinforcement is placed on the central axis of the slab cross-section at 2cm-3cm, and transverse reinforcement is placed at a longitudinal spacing of 60cm-80cm below the longitudinal reinforcement.

9. The prestressed concrete pavement maintenance structure according to claim 1, characterized in that, The dimensions of the pre-cut joint are: 4mm-6mm wide and 7.0cm-8.0cm deep, and the filling material inside the joint is hot asphalt.

10. A construction method for a prestressed concrete pavement repair structure as described in any one of claims 1-9, characterized in that, The method includes the following steps: 1) Precast pre-tensioned slabs for road use: tension the steel strands on the tensioning table, tie the transverse reinforcement of the pre-tensioned slabs, support the precast slab steel mold, pour concrete, vibrate thoroughly, polish with a grinder and finish manually, cure for 7 days, release the steel strands, and move the precast slabs to the beam storage yard. 2) Remove the damaged prestressed concrete pavement: Depending on the size of the damaged area, use a concrete cutter to cut a rectangular concrete pavement with a length of 5.44m-9.44m and a width of 11m along the outer edge of the upper and lower self-stressing transverse joints. The damaged old pavement is removed manually in conjunction with the machinery. 3) Self-stressing transverse joint reinforcement: On the upper and lower transverse surfaces formed after cutting and damaging the prestressed pavement, longitudinal self-stressing anchor bars are inserted at the positions of the longitudinal self-stressing tendons arranged in the upper and lower self-stressing transverse joints. 4) Install the road prestressed slab: Install the overtaking road prestressed slab and the driving road prestressed slab at the positions corresponding to the overtaking lane and the driving lane. The distance between the road prestressed slab and the upper and lower prestressed pavement is 20cm-25cm, and the distance between the two slabs is 10cm. 5) Casting the cast-in-place slab and self-stressing longitudinal joint: Tie the longitudinal and transverse steel bars of the cast-in-place slab of the curb strip and the cast-in-place slab of the hard shoulder, weld the transverse self-stressing tendons of the longitudinal joint, tie the longitudinal self-stressing tendons of the longitudinal joint, support the formwork of the cast-in-place slab and the self-stressing longitudinal joint respectively, pour ordinary concrete into the cast-in-place slab, pour the expansive concrete into the self-stressing longitudinal joint, cover with curing cloth, and cure for 5 days; 6) Casting the upper and lower self-stressing transverse joints: Weld the longitudinal reinforcement of the upper and lower self-stressing transverse joints, tie the transverse reinforcement of the upper and lower self-stressing transverse joints, erect the self-stressing transverse joint formwork, pour high-expansion concrete into the joints, cover with curing cloth, and water-cur for 7 days. 7) Construction of pre-cut joint: Use a concrete cutter to cut the pre-cut joint along the joint between the precast slab of the driving lane and the cast-in-place slab of the hard shoulder. The dimensions are 4mm-6mm wide and 7cm-8cm deep. Use a blower to clean and dry the pre-cut joint, and then fill the joint with hot asphalt.

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