A construction method for replaceable concrete pavement for large aircraft tests

Abstract

The invention discloses a construction method of a replaceable concrete test pavement for large aircraft tests, comprising the following steps: S1: cutting the steel bar heads on the side of the groove of the bearing platform (1) and grinding and leveling the uneven places of the concrete, chiseling the top surface of the groove concrete and treating the mesh cracks; S2: measuring and setting out, checking and verifying the position and elevation of the groove, and pouring a leveling layer of fine aggregate concrete; S3: laying rubber sheets; S4: installing side formworks, tying steel bars, then installing end formworks, and then carrying out concrete pouring, surface hairing of the concrete, curing, and removing the end formworks; S5: grooving at the time when the concrete strength reaches 25%-30%; S6: hoisting out the precast concrete test pavement slabs and installing angle steels at the longitudinal four corners; S7: installing longitudinal expansion joint boards, precast concrete test pavement slabs, and transverse joint boards; S8: filling the longitudinal joints with joint fillers. It has the advantages of short construction period and high precision.

Description

Technical Field

[0001] The present invention relates to the technical field of pavement construction, and particularly relates to a construction method for a replaceable concrete pavement for large aircraft tests. Background Art

[0002] The large aircraft ground dynamics test platform is the world's leading and the only one in China after the NASA test base in the United States. It is used to test the high-speed dynamic characteristics of various aircraft tires, wheel brakes, and landing gear systems under different pavements and the dynamic characteristics at large sideslip angles under real runways, collect basic data, break the foreign monopoly on the basic data of key technologies, and fill the domestic gap.

[0003] This test platform uses a test trolley to simulate the dynamics test of large aircraft on different pavement structures. Therefore, a pavement structure that can be replaced at any time according to test requirements is required. The existing precast pavement construction not only has a long construction period, but also cannot meet the accuracy requirements of this test platform after installation. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a construction method for a replaceable concrete pavement for large aircraft tests with a shortened construction period and high precision.

[0005] To solve the above technical problem, the present invention adopts the following technical solutions:

[0006] A construction method for a replaceable concrete pavement for large aircraft tests, the replaceable concrete pavement is laid in a groove of a bearing platform, the replaceable concrete pavement includes a plurality of precast slabs, the precast slabs are precast in a skip-joint manner in the groove of the bearing platform, and the construction method includes the following steps:

[0007] S1: Cut the steel bar heads on the side of the groove of the bearing platform and grind and level the uneven places of the concrete, chisel the top surface of the groove concrete and deal with the mesh cracks;

[0008] S2: Measure and set out, review the position and elevation of the groove, and pour a leveling layer of fine aggregate concrete;

[0009] S3: Lay a rubber sheet;

[0010] S4: Install the side formwork, tie the steel bars, then install the end formwork, and then carry out concrete pouring, surface roughening of the concrete, curing, and removal of the end formwork;

[0011] S5: Grooving when the concrete strength reaches 25%-30%;

[0012] S6: Lift out the precast slab 2 and install angle steel at the four longitudinal corners;

[0013] S7: Install the longitudinal expansion joint board, precast slab, and transverse joint board;

[0014] S8: Filling longitudinal joints with joint filler.

[0015] As a further improvement of the above technical solution:

[0016] In step S1, for cracks with a width less than 0.15 mm, directly roughen the surface; for cracks with a width greater than 0.15 mm, chisel them open to a width of 50 mm. After cleaning the mortar and weak layer with a large vacuum cleaner and high-pressure water until clean, simultaneously pour and seal with leveling course concrete.

[0017] In step S2, the designed grade of the fine aggregate concrete is C30. Pour it to the elevation position, level the surface after vibrating it densely, and cover it with permeable geotextile and sprinkle water for curing.

[0018] In step S3, the rubber sheet is an industrial hard rubber sheet, and a plastic film is laid on the surface of the hard rubber sheet and a release agent is brushed.

[0019] In step S4, the side formwork is made of rigid polyurethane foam board. A plastic film is laid on the surface of the rigid foam board and a release agent is brushed. The end formwork is a plastic toughened formwork. When constructing by the alternate bay method, the transverse formwork uses a high-strength rubber sheet as the formwork, and a plastic film is laid on the surface and a release agent is brushed.

[0020] After the construction of the side formwork is completed, it serves as the longitudinal expansion joint board and is reused. When constructing by the alternate bay method, the transverse formwork serves as the transverse joint board and is reused.

[0021] In step S4, when tying the steel bars, there is a layer of corner bars, and lifting rings for hoisting the precast slab are embedded and tied at the four corners of the precast slab.

[0022] In step S4, the designed grade of the concrete is C40. The concrete is poured in two layers, and each layer of concrete is vibrated densely with a vibrating rod after pouring.

[0023] In step S4, when vibrating, the vibrating rod is inserted quickly and pulled out slowly, the vibrating time is controlled within 15 - 20 seconds, and the moving distance of the vibrating rod in the concrete is not greater than 50 cm.

[0024] In step S4, the concrete is finished in two times. After finishing, it is roughened, cured, and the end formwork is removed.

[0025] After removing the end formwork, install high-strength rubber pads.

[0026] In step S5, the groove is a trapezoidal groove with an inverted shape.

[0027] In step S8, the top of the longitudinal joint is filled with high-polyurethane and silicone joint fillers.

[0028] Compared with the prior art, the advantages of the present invention are as follows:

[0029] For the construction method of the concrete replaceable pavement for large aircraft tests of the present invention, the precast slabs of this method are precast in situ by the casting bay method, which not only ensures the fit between the precast slabs and the bearing platform, avoids the problem of misalignment between the precast slabs, but also shortens the construction period. The flatness of the precast slabs is ensured by pouring the leveling layer. By installing angle steel at the four corners of the precast slabs, the precast slabs are protected during the installation and replacement process, avoiding chipping and ensuring the integrity of the precast slabs. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the replaceable pavement structure.

[0031] Figure 2 It is the construction flow chart of the present invention.

[0032] Each label in the figure represents:

[0033] 1; bearing platform, 2; precast slab. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The present invention will be further described in detail below with reference to the drawings in the specification and specific embodiments.

[0035] As Figure 1 and Figure 2 shown, for the construction method of the concrete replaceable pavement for large aircraft tests of this embodiment, the concrete replaceable pavement is laid in the groove of the bearing platform 1. The concrete replaceable pavement includes multiple precast slabs 2. The precast slabs 2 are precast in the groove of the bearing platform 1 by the casting bay method. The construction method includes the following steps:

[0036] S1: Cut the steel bar heads on the side of the groove of the bearing platform 1 and grind and level the uneven places of the concrete. Chisel the top surface of the groove concrete and deal with the mesh cracks;

[0037] S2: Measure and set out the lines, review the position and elevation of the groove, and pour the fine aggregate concrete leveling layer;

[0038] S3: Lay the rubber sheet;

[0039] S4: Install the side formwork, tie the steel bars, then install the end formwork, and then carry out concrete pouring, surface roughening, curing, and removal of the end formwork;

[0040] S5: Groove at the moment when the concrete strength reaches 25%-30%;

[0041] S6: Lift out the precast slab 2 and install angle steel at the four longitudinal corners;

[0042] S7: Install the longitudinal expansion joint board, precast slab 2, and transverse joint board;

[0043] S8: Pouring longitudinal joint filler.

[0044] For the precast slab 2 of this method, the skip-joint method is used for in-situ precasting, which not only ensures the fit between the precast slab 2 and the bearing platform 1, avoids the problem of offset between precast slabs 2, but also shortens the construction period. The flatness of the precast slab 2 is ensured by pouring the leveling layer. By installing corner angle steel at the four corners of the precast slab 2, the precast slab 2 is protected during the installation and replacement process, avoiding chipping and ensuring the integrity of the precast slab 2.

[0045] In this embodiment, in step S1, for cracks with a width less than 0.15 mm, directly roughen the surface; for cracks with a width greater than 0.15 mm, chisel them open with a width of 50 mm. After cleaning the mortar and weak layer with a large vacuum cleaner and high-pressure water until clean, simultaneously pour and seal with leveling layer concrete. After treating the cracks and roughening the concrete surface, the concrete on the surface of the bearing platform combines well with the newly poured concrete.

[0046] In this embodiment, in step S2, the designed grade of the fine aggregate concrete is C30. Pour it to the elevation position, level it by vibrating thoroughly and then scrape and finish it, and cover it with permeable geotextile and sprinkle water for curing. Ensure the flatness of the leveling layer, prevent it from cracking, and avoid the precast slab 2 from cracking due to the unevenness of the leveling layer.

[0047] In this embodiment, in step S3, the rubber sheet uses industrial hard rubber sheet, and a plastic film is laid on the surface of the hard rubber sheet and a release agent is brushed. The rubber sheet has a buffering and shock-absorbing effect, and laying the rubber sheet improves the stability of the pavement structure.

[0048] In this embodiment, in step S4, the side formwork uses polyurethane rigid foam board, a plastic film is laid on the surface of the rigid foam board and a release agent is brushed. The end formwork is set as plastic toughened template. When constructing by the skip-joint method, the transverse formwork uses high-strength rubber sheet as the formwork, and a plastic film is laid on the surface and a release agent is brushed. Using polyurethane rigid foam board as the side formwork eliminates the need for formwork removal, and it can serve as the expansion joint board for the longitudinal joint subsequently, reducing processes, improving efficiency, and saving costs. The end formwork is set as plastic toughened template, which has high strength and is not easily deformed.

[0049] In this embodiment, after the construction of the side formwork is completed, it is used as the longitudinal expansion joint board for reuse. When constructing by the skip-joint method, the transverse formwork is used as the transverse joint board for reuse. Using the longitudinal and transverse joint boards as formwork saves costs.

[0050] In this embodiment, in step S4, when tying the steel bars, there is a layer of corner reinforcement, and lifting rings for hoisting the precast slab 2 are pre-buried and tied at the four corners of the precast slab 2. Setting the lifting rings facilitates hoisting and makes the installation and replacement convenient.

[0051] In this embodiment, in step S4, the designed grade of the concrete is C40. The concrete is poured in two layers, and after each layer of concrete is poured, a vibrating rod is used to vibrate it until it is dense. Pouring in layers avoids the formation of cold joints in the concrete structure and maintains the structural integrity.

[0052] In this embodiment, in step S4, when vibrating, the vibrating rod is inserted quickly and pulled out slowly. The vibrating time is controlled within 15 - 20 seconds, and the moving spacing of the vibrating rod in the concrete is not greater than 50 cm. This avoids leaving voids in the concrete, reduces air bubbles, and makes the concrete dense.

[0053] In this embodiment, in step S4, the concrete is finished in two times. After finishing, it is roughened, cured, and the end formwork is removed. The concrete finishing is carried out in two times. The first time, a square hollow aluminum alloy plate combined with an iron float is used to finish according to the elevation of the formwork top and the center line elevation strip. The second time, a polishing machine is used to finish before the concrete reaches final set. When checking the flatness during finishing, a wire is hung along the diagonal of each slab for inspection. After finishing with the polishing machine, a 3m straightedge is used for inspection to ensure that the flatness is not greater than 3 mm, and the elevation difference between slabs is not greater than 3 mm. After finishing, a roughening tool is used for roughening, and the texture depth is not less than 1 mm to ensure the flatness and accuracy requirements.

[0054] In this embodiment, in step S4, after removing the end formwork, high-strength rubber pads are installed.

[0055] In this embodiment, in step S5, the groove is set as an inverted trapezoidal groove. The inverted trapezoidal groove avoids the formation of a water film on the replaceable concrete pavement surface and enhances the anti-skid performance at the same time.

[0056] In this embodiment, in step S8, the top of the longitudinal joint is filled with a high-polyurethane or silicone sealant. Before filling the joint, the stuffing and other sundries in the joint are cleaned up. After cleaning, it is washed clean with a large vacuum cleaner to keep the joint groove in a clean and dry state. Then, a high-polyurethane or silicone sealant is used for filling, which has good waterproof effect.

[0057] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes, without departing from the scope of the technical solution of the present invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A construction method for a replaceable concrete pavement for large aircraft tests, characterized in that: The replaceable concrete pavement is laid in a groove of a cap (1), the replaceable concrete pavement comprises a plurality of prefabricated panels (2), the prefabricated panels (2) are prefabricated in the groove of the cap (1), and the construction method comprises the following steps: S1: Cut the steel bar heads on the side of the groove of the cap (1), grind and level the uneven areas of the concrete, and roughen the top surface of the groove concrete and treat the mesh cracks; S2: Measure and set out, check the groove position and elevation, and pour the fine stone concrete leveling layer; S3: Laying rubber sheets; S4: Install the side formwork, tie the steel bars, install the end formwork, then pour concrete, roughen the concrete surface, maintain, and remove the end formwork; S5: Groove when the concrete strength reaches 25%-30%; the groove is set as an inverted trapezoidal groove; S6: Lift out the prefabricated panel 2 and install the edge angle steels at the four longitudinal corners; S7: Install the longitudinal expansion joint plate, the prefabricated plate (2), and the transverse joint plate; S8: Fill the longitudinal joints with filler.

2. The construction method for a replaceable concrete pavement for large aircraft tests according to claim 1, characterized in that: In step S1, cracks with a width less than 0.15 mm are directly roughened, and cracks with a width greater than 0.15 mm are chiseled open to a width of 50 mm. A large vacuum cleaner and high-pressure water are used to clean the mortar and loose layers, and then the leveling layer concrete is poured and sealed simultaneously.

3. The construction method for a replaceable concrete pavement for large aircraft tests according to claim 1, characterized in that: In step S2, the fine stone concrete is designed as C30, poured to the elevation, vibrated and compacted, then scraped and leveled, and covered with a permeable geotextile and watered for curing.

4. The construction method for a replaceable concrete pavement for large aircraft tests according to claim 1, characterized in that: In step S3, the rubber sheet is an industrial hard rubber sheet, a plastic film is laid on the surface of the hard rubber sheet and a mold release agent is applied.

5. The construction method for a replaceable concrete pavement for large aircraft tests according to claim 1, characterized in that: In step S4, the side formwork uses a polyurethane rigid foam board, a plastic film is laid on the surface of the rigid foam board and a release agent is applied, the end formwork is set as a plastic tempered formwork, and during the skip-bin method construction, the transverse formwork uses a high-strength rubber board as the formwork, a plastic film is laid on the surface and a release agent is applied.

6. The construction method for a replaceable concrete pavement for large aircraft tests according to claim 5, characterized in that: After the side template is constructed, it is reused as a longitudinal expansion joint plate, and during the skip-bin method construction, the transverse template is reused as a transverse joint plate.

7. The construction method for a replaceable concrete pavement for large aircraft tests according to claim 6, characterized in that: In step S4, when tying the steel bars, a layer of corner steel bars is provided, and the four corners of the precast panel (2) are pre-embedded with lifting rings for lifting the precast panel (2).

8. The construction method for a replaceable concrete pavement for large aircraft tests according to claim 7, characterized in that: In step S4, the concrete design number is C40, and the concrete is poured in two layers. After each layer of concrete is poured, it is vibrated and compacted using a vibrating rod.

9. The construction method for a replaceable concrete pavement for large aircraft tests according to claim 8, characterized in that: In step S4, during vibration, the vibrating rod is inserted quickly and pulled out slowly, the vibration time is controlled within 15-20 seconds, and the moving distance of the vibrating rod in the concrete is not greater than 50 cm.

10. The construction method for a replaceable concrete pavement for large aircraft tests according to claim 9, characterized in that: In step S4, the concrete is finished in two steps, and after finishing, it is roughened, cured, and the end formwork is removed.

11. The construction method for a replaceable concrete pavement for large aircraft tests according to claim 10, characterized in that: In step S4, after removing the end template, a high-strength rubber pad is installed.

12. The construction method for a replaceable concrete pavement for large aircraft tests according to claim 1, characterized in that: In step S8, the top of the longitudinal seam is filled with high polyurethane or silicone fillers.

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