Pavement structure with asphalt-based isolating layer and construction method of pavement structure

Abstract

The invention relates to the technical field of pavement construction, in particular to a pavement structure with an asphalt-based isolating layer, which comprises a soil base layer, a composite layer structure is laid above the soil base layer, drainage systems are arranged on two sides of the soil base layer, and drainage wells are connected to outlets of the drainage systems; the composite layer structure comprises a water-stable broken stone hardcore, an asphalt layer and a pavement layer which are laid from bottom to top, a geogrid is arranged on the upper surface of the soil base layer, the water-stable broken stone hardcore is embedded in the geogrid, and the upper end of the geogrid is embedded in the lower end face of the asphalt layer. The composite layer structure is arranged on the soil base layer, so that the stability and the deformation resistance strength of the pavement structure are enhanced, drainage can be effectively promoted through the asphalt layer in the composite layer structure, and the situation that the pavement structure is damaged due to long-time water accumulation is avoided. The technical problem that in the high-strength and high-frequency heavy load process, an existing pavement structure is difficult to effectively disperse and buffer the taking-off and landing load of an airplane, and consequently the pavement is subjected to fatigue depression is solved.

Description

Technical Field

[0001] This invention relates to the field of road construction technology, and in particular to a road structure with an asphalt-based isolation layer and its construction method. Background Technology

[0002] Airports are an important type of infrastructure, one of their primary uses being to provide a suitable landing site for aircraft. Aircraft typically taxi on airport runways during takeoff and landing, subjecting the runways to frequent loads. Over the years, these loads can easily cause runways to crack, and the infiltration of surface water often further damages these cracks.

[0003] In airport construction, traditional airport pavement structures often employ a combination of cement concrete pavement layers and various base layers. While this structure has served its purpose for a long time and supported air traffic, its defects have become increasingly apparent over time. Taking some domestic airports as examples, some airports built at the end of the last century or the beginning of this century have experienced numerous defects in their runway and apron cement concrete pavements after years of frequent use. Cement concrete pavements are highly susceptible to cracking under the repeated, enormous loads generated by aircraft takeoffs and landings. Once cracks appear, surface water can seep into the base layer. For example, common cement-stabilized crushed stone base layers, composed of a specific ratio of cement, water, and coarse aggregate, suffer severe damage to their internal structural stability under long-term erosion by surface water, especially when groundwater is also involved, easily leading to longitudinal through cracks. In airports in Northeast China, due to the cold winters and the freeze-thaw cycle affecting the pavement, this cracking problem in the base layer is even more pronounced. The formation of these cracks not only causes groundwater to carry soil to the surface of the cement concrete layer, resulting in phenomena such as frost heave and mud accumulation, interfering with aircraft takeoff and landing, but also greatly increases the cost and difficulty of pavement maintenance.

[0004] A search revealed Chinese patent application number 202311371438.6, which discloses a pavement structure with an asphalt-based isolation layer. The airport pavement structure includes a composite pavement and drainage ditches on both sides of the composite pavement. The composite pavement comprises, from bottom to top, a water-stabilized crushed stone layer, an asphalt-based isolation layer, a geotextile layer, and a cement concrete layer. The asphalt-based isolation layer is constructed from asphalt mixture, with a designed porosity of 13-17%. The drainage ditches are used to drain water seeping from both sides of the asphalt-based isolation layer. The asphalt-based isolation layer and geotextile layer of this application together reduce the probability of frost heave and mud accumulation on the pavement surface, helping to reduce the interference of frost heave and mud accumulation on aircraft takeoff and landing.

[0005] The existing airport pavement structures described above are unable to effectively disperse and buffer aircraft take-off and landing loads under high-intensity and high-frequency heavy loads, leading to fatigue depression damage on the pavement, which greatly shortens the service life of the pavement. Furthermore, the airport pavement surface cannot achieve timely automatic drainage, which allows rainwater to seep into the pavement structure, softening the cement concrete layer, reducing the load-bearing capacity of the cement concrete layer, and causing problems such as pavement subsidence and cracking. Summary of the Invention

[0006] The existing technologies address the following technical problems: airport pavement structures are unable to effectively distribute and buffer aircraft take-off and landing loads under high-intensity and high-frequency heavy loads, leading to fatigue depression damage and significantly shortening the service life of the pavement; airport pavement surfaces cannot achieve timely automatic drainage, which allows rainwater to seep into the pavement structure, softening the cement concrete layer, reducing the load-bearing capacity of the cement concrete layer, and ultimately causing pavement subsidence and cracking.

[0007] Technical concept: This application provides a pavement structure with an asphalt-based isolation layer. By setting a composite layer structure on the soil base, the stability and deformation resistance of the pavement structure are enhanced. The trapezoidal asphalt layer in the composite layer structure has two advantages. First, the thickened asphalt layer in the middle can improve the impact resistance and stress distribution, thus providing a buffer and preventing the pavement structure from being damaged and sunken due to long-term pressure. Second, the trapezoidal slope structure can effectively promote drainage and prevent the pavement structure from being damaged by water accumulation over a long period of time.

[0008] To achieve the above technical concept, the technical solution adopted by this invention is as follows: This application provides a pavement structure with an asphalt-based isolation layer, including a soil base course, a composite layer structure laid on top of the soil base course, and drainage systems provided on both sides of the soil base course, with drainage wells connected to the outlets of the drainage systems; the composite layer structure includes a water-stabilized crushed stone cushion layer, an asphalt layer, and a pavement layer laid from bottom to top, a geogrid provided on the upper surface of the soil base course, the water-stabilized crushed stone cushion layer embedded in the geogrid, and the upper end of the geogrid embedded in the lower end face of the asphalt layer.

[0009] Furthermore, the geogrid is composed of a grid array of squares of a certain height, and anchor rods are provided at the top of the connection points between some of the squares.

[0010] It should be noted that water-stabilized crushed stone is filled into the geogrid so that the water-stabilized crushed stone is flush with the geogrid to form a water-stabilized crushed stone cushion layer.

[0011] Specifically, the asphalt layer has an isosceles trapezoidal structure. The asphalt layer possesses waterproof, corrosion-resistant, and crack-resistant properties. On one hand, the thickened asphalt layer in the middle enhances impact resistance and acts as a buffer to disperse stress. When the road surface is subjected to aircraft pressure, the force is transmitted to the central area of ​​the asphalt layer, causing the thickened central area to disperse the force to both sides, thereby stabilizing and dispersing the pressure on the road surface, and thus improving runway stability and deformation resistance.

[0012] On the other hand, the isosceles trapezoidal slope structure of the asphalt layer allows water seeping into the pavement layer to be discharged into the drainage system on both sides in a timely manner, thereby preventing structural damage to the pavement structure due to prolonged water immersion.

[0013] Furthermore, the drainage system includes drainage channels and connecting blocks located on both sides of the soil base, with drainage grooves provided on the connecting blocks; multiple drainage holes are provided at the top of the drainage channels, and the drainage grooves and drainage channels are connected through the drainage holes.

[0014] In detail, the drainage channel has a segmented structure, and each segment is arranged continuously. The drainage channel corresponds to a drainage well, so that the water in the drainage channel is discharged into the drainage well.

[0015] More specifically, the connecting block has an "L" shaped structure, with its inner side connected to the drainage channel and its outer side and bottom end connected to the soil base.

[0016] Furthermore, the drainage channel is provided with an exhaust trough and a drainage trough from bottom to top on the outer side near the asphalt layer and the pavement layer; an exhaust hole is provided through the side of the drainage channel at the position corresponding to the exhaust trough, and a drainage hole is provided through the side of the drainage channel at the position corresponding to the drainage trough; a self-floating component is rotatably connected to the inner side of the drainage channel, and the self-floating component cooperates with the exhaust hole and the drainage hole respectively.

[0017] Furthermore, the self-floating component includes a connecting rod rotatably connected to the inner side of the drainage channel. One end of the connecting rod is fixedly connected to a float, and the other end is fixedly connected to a baffle. The baffle cooperates with the vent hole and the drainage hole, respectively.

[0018] It should be noted that the connecting rod is connected to the inner side of the drainage channel via a rotating shaft, and the baffle has a disc structure.

[0019] This application provides a construction method for a pavement structure with an asphalt-based isolation layer, including the following steps: (1) Lay geogrid on the pre-set soil base and fill water-stabilized crushed stone into the geogrid to form a water-stabilized crushed stone cushion layer. (2) Asphalt is laid on the entire surface of the water-stabilized crushed stone subbase using a paver to form an asphalt layer; (3) Install drainage systems on both sides of the soil base, and backfill and compact after installation; (4) Pour and spread cement concrete on the asphalt layer to form a road surface layer, and then repair and smooth the road surface layer.

[0020] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention enhances the stability and deformation resistance of the pavement structure by setting a composite layer structure on the subgrade. Furthermore, the drainage system set on both sides of the subgrade allows water and gas in the composite layer structure to be discharged in a timely manner, preventing damage and deformation of the composite layer structure due to long-term water or gas accumulation, which would otherwise shorten the service life of the pavement structure.

[0021] 2. The present invention achieves the technical effect of enhancing the stability of the pavement structure and its resistance to deformation by setting a geogrid on the soil base and filling the geogrid with water-stabilized crushed stone to form a water-stabilized crushed stone cushion layer.

[0022] 3. This invention, by setting an isosceles trapezoidal asphalt layer, on the one hand, enhances impact resistance and acts as a buffer by dispersing stress through the thickened asphalt layer structure in the middle. When the pavement is subjected to aircraft pressure, the force is transmitted to the central area of ​​the asphalt layer, causing the thickened central area to disperse the force to both sides, thereby stabilizing and dispersing the pressure on the pavement, and thus improving runway stability and deformation resistance. On the other hand, the isosceles trapezoidal slope structure of the asphalt layer allows water seeping from the pavement to be promptly discharged into the drainage systems on both sides, thus preventing structural damage to the pavement due to prolonged water immersion.

[0023] 4. This invention utilizes a drainage system installed on both sides of the subgrade. Rainwater from the pavement surface flows through drainage channels into the drainage system, causing a float to rise due to buoyancy. This opens the drainage holes, allowing water that has seeped into the asphalt layer to drain through the drainage channels and holes into the drainage system. This ensures timely rainwater removal and prevents damage to the pavement structure caused by water accumulation. In the absence of water accumulation, the float descends, opening the vent holes and closing the drainage holes. This allows moisture to escape through the vent holes during pressure stress on the composite layer structure, preventing expansion and deformation of the pavement structure. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a perspective view of the overall structure of the present invention; Figure 2 For the present invention Figure 1 The main view; Figure 3 For the present invention Figure 2 A magnified view of a portion of the image; Figure 4 This is a diagram showing the connection relationship between the soil base layer and the geogrid in this invention; Figure 5 For the present invention Figure 4 A magnified view of a portion of the image; Figure 6 This is a schematic diagram of the drainage channel of the present invention; Figure 7 For the present invention Figure 6 A cross-sectional view along the AA direction; Figure 8 For the present invention Figure 6 A three-dimensional structural diagram; Figure 9 For the present invention Figure 8 A sectional view; Figure 10 This is a three-dimensional structural view of the self-buoyancy component of the present invention; Figure 11 This is a three-dimensional view of the connecting block of the present invention; Figure 12 For the present invention Figure 11 A magnified view of a portion of the image; Figure 13 This is a three-dimensional view of the drainage channel of the present invention; Figure 14 For the present invention Figure 13 A magnified view of a portion of the image; In the diagram: 1. Subbase; 2. Composite layer structure; 21. Water-stabilized crushed stone subbase; 22. Asphalt layer; 23. Pavement layer; 24. Geogrid; 3. Drainage system; 31. Drainage channel; 32. Connecting block; 33. Drainage trough; 34. Drainage hole; 35. Vent trough; 36. Drainage trough; 37. Vent hole; 38. Drainage hole; 39. Self-floating component; 391. Connecting rod; 392. Float; 393. Baffle. Detailed Implementation

[0026] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0027] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "front end", "rear end", "inner side", "outer side", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0028] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0029] During actual construction, the inventors discovered that existing airport runway asphalt pavement structures, due to the fact that asphalt-based structural layers are inherently flexible, suffer from repeated compaction caused by aircraft passing back and forth. Furthermore, the weight of the aircraft causes the structure in the center of the pavement to expand outwards at an accelerated rate, resulting in localized cracking along the edges of the pavement.

[0030] Based on the above findings, this application provides a pavement structure with an asphalt-based isolation layer, including a soil base 1, a composite layer structure 2 laid on top of the soil base 1, and drainage systems 3 provided on both sides of the soil base 1, with drainage wells connected to the outlets of the drainage systems 3; the composite layer structure 2 includes a water-stabilized crushed stone cushion layer 21, an asphalt layer 22, and a pavement layer 23 laid from bottom to top, a geogrid 24 provided on the upper surface of the soil base 1, the water-stabilized crushed stone cushion layer 21 embedded in the geogrid 24, and the upper end of the geogrid 24 embedded in the lower end face of the asphalt layer 22. Example 1

[0031] Reference Figure 1-14 As shown, this application provides a pavement structure with an asphalt-based isolation layer, including a soil base 1, a composite layer structure 2 laid on top of the soil base 1, and drainage systems 3 provided on both sides of the soil base 1, with drainage wells connected to the outlets of the drainage systems 3.

[0032] Further, the composite layer structure 2 includes a water-stabilized crushed stone cushion layer 21, an asphalt layer 22, and a pavement layer 23 laid from bottom to top. A geogrid 24 is provided on the upper surface of the subgrade 1, and the water-stabilized crushed stone is embedded in the geogrid 24 to form the water-stabilized crushed stone cushion layer 21. Through the interaction between the geogrid 24 and the water-stabilized crushed stone cushion layer 21, the stability and deformation resistance of the pavement structure are improved. Multiple anchor rods are provided at the upper end of the geogrid 24, and the anchor rods are embedded in the lower end face of the asphalt layer 22, thus making the connection between the water-stabilized crushed stone cushion layer 21 and the asphalt layer 22 more stable.

[0033] As an example, the asphalt layer 22 has an isosceles trapezoidal structure. On the one hand, the thickened asphalt layer 22 in the middle enhances impact resistance and acts as a buffer to disperse stress. When the pavement layer 23 is subjected to aircraft pressure, the force is transmitted to the middle area of ​​the asphalt layer 22, causing the thickened area in the middle of the asphalt layer 22 to disperse the force to both sides, thereby stabilizing and dispersing the pressure on the pavement layer 23, and thus improving the runway's stability and deformation resistance. On the other hand, the isosceles trapezoidal slope structure of the asphalt layer 22 allows water seeping from the pavement layer 23 to be discharged into the drainage systems 3 on both sides in a timely manner, thus preventing structural damage to the pavement structure due to prolonged water immersion.

[0034] Further, the drainage system 3 includes drainage channels 31 and connecting blocks 32 disposed on both sides of the subgrade 1. Drainage troughs 33 are provided on the connecting blocks 32. Multiple drainage holes 34 are provided at the top of the drainage channels 31, and the drainage troughs 33 and drainage channels 31 are connected through the drainage holes 34. Rainwater from the pavement layer 23 flows to both sides into the drainage troughs 33 and then into the drainage channels 31 through the drainage holes 34.

[0035] As an example, the drainage channel 31 has a segmented structure, and each segment is arranged continuously. A drainage well is provided at the corresponding drainage channel 31 so that the water accumulated in the drainage channel 31 can be discharged into the drainage well.

[0036] Furthermore, the drainage channel 31 is provided with an exhaust trough 35 and a drainage trough 36 from bottom to top on the outer side near the asphalt layer 22 and the road surface layer 23; an exhaust hole 37 is provided through the side of the drainage channel 31 at the position corresponding to the exhaust trough 35, and a drainage hole 38 is provided through the side of the drainage channel 31 at the position corresponding to the drainage trough 36; a self-floating component 39 is rotatably connected to the inner side of the drainage channel 31, and the self-floating component 39 cooperates with the exhaust hole 37 and the drainage hole 38 respectively.

[0037] Specifically, the self-floating component 39 includes a connecting rod 391 rotatably connected to the inner side of the drainage channel 31. One end of the connecting rod 391 is fixedly connected to a float 392, and the other end is fixedly connected to a baffle 393. The baffle 393 cooperates with the exhaust hole 37 and the drainage hole 38 respectively.

[0038] In the specific process, rainwater on the surface of the pavement layer 23 enters the drainage channel 31 through the drainage channel 33. This causes the float 392 to move and rise under the buoyancy of the water, opening the drainage hole 38. Water that has penetrated the pavement layer 23 and reached the asphalt layer 22 enters the drainage channel 31 through the drainage channel 36 and drainage hole 38, achieving the technical effect of timely rainwater drainage and preventing damage to the pavement structure caused by water accumulation. When there is no water accumulation, the float 392 descends, opening the vent hole 37 and closing the drainage hole 38. This allows water vapor to escape through the vent hole 37 during the pressure process of the composite layer structure, thus preventing the pavement structure from expanding and deforming. Example 2

[0039] Based on Example 1, this application provides a construction method for a pavement structure with an asphalt-based isolation layer, comprising the following steps: (1) A geogrid 24 is laid on the pre-set soil base 1, and water-stabilized crushed stone is filled into the geogrid 24 to form a water-stabilized crushed stone cushion layer 21. (2) Asphalt layer 22 is formed by paving the entire surface of the water-stabilized crushed stone subbase 21 with a paver; (3) Install drainage systems 3 on both sides of the soil base 1, and backfill and compact them after installation; (4) Pour cement concrete on the asphalt layer 22 to form the road surface layer 23, and repair and smooth the road surface layer 23.

[0040] Specific application examples The following describes the specific application process of a pavement structure with an asphalt-based isolation layer in the construction of an airport runway, in conjunction with Embodiment 1 and Embodiment 2.

[0041] Before construction, the location, length and width of the airport runway are determined, and geological surveys and measurements are conducted. Construction plans and drawings are prepared, and construction materials and equipment are acquired.

[0042] Foundation treatment: Clear the site, demolish existing buildings and obstacles, and carry out earthwork excavation and filling to ensure the flatness and stability of the foundation.

[0043] Construction of subgrade 1: Lay a layer of sand and gravel on the foundation and compact it to form a uniform and solid subgrade 1.

[0044] A geogrid 24 is laid on the pre-set soil base 1, and water-stabilized crushed stone is filled into the geogrid 24 to form a water-stabilized crushed stone cushion layer 21. Asphalt layer 22 is formed by paving the entire surface of the water-stabilized crushed stone subbase 21 with a paver. Drainage systems 3 are installed on both sides of the soil base 1. After installation, the soil is backfilled and compacted. Cement concrete is poured and laid on the asphalt layer 22 to form the road surface layer 23, and the road surface layer 23 is repaired and leveled.

[0045] After the airport runway pavement structure is completed, aircraft can taxi, take off, and land on the pavement layer 23. During the taxiing process, the thickened asphalt layer 22 in the middle enhances the impact resistance and disperses stress, thus playing a buffering role. When the pavement layer 23 is subjected to aircraft pressure, the force is transmitted to the middle area of ​​the asphalt layer 22, causing the thickened area in the middle of the asphalt layer 22 to disperse the force to both sides, thereby stabilizing and dispersing the pressure on the pavement layer 23, and thus improving the runway stability and deformation resistance.

[0046] The isosceles trapezoidal slope structure of the asphalt layer 22 ensures that water seeping from the pavement layer 23 is promptly discharged into the drainage systems 3 on both sides. Rainwater on the surface of the pavement layer 23 enters the drainage channel 31 through the drainage channel 33, causing the float 392 to rise under the buoyancy of the water. This opens the drainage hole 38, and water that has seeped into the pavement layer 23 and reached the asphalt layer 22 enters the drainage channel 31 through the drainage channel 36 and drainage hole 38. This achieves the technical effect of timely rainwater discharge, preventing damage to the pavement structure caused by water accumulation. When there is no water accumulation, the float 392 descends, opening the vent hole 37 and closing the drainage hole 38. This allows water vapor to escape through the vent hole 37 during the pressure process of the composite layer structure, thus preventing the pavement structure from expanding and deforming.

[0047] It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of this invention, and these should also be considered within the scope of protection of this invention. These modifications and improvements will not affect the effectiveness of the invention or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A pavement structure with bituminous-based separating layer, comprising a subbase layer (1), characterised in that: The composite layer structure (2) is arranged above the soil foundation layer (1), and the drainage system (3) is arranged on both sides of the soil foundation layer (1), and the outlet of the drainage system (3) is connected with a drainage well; The composite layer structure (2) comprises, from bottom to top, a water-stable macadam cushion layer (21), an asphalt layer (22) and a pavement layer (23), the soil foundation layer (1) is provided with a geogrid (24) on the upper surface, the water-stable macadam cushion layer (21) is embedded in the geogrid (24), and the upper end of the geogrid (24) is embedded in the lower end surface of the asphalt layer (22).

2. A pavement structure having a bituminous based separating layer according to claim 1, characterised in that: The drainage system (3) comprises drainage channels (31) and connecting blocks (32) arranged on both sides of the soil foundation layer (1), and the connecting block (32) is provided with a drainage groove (33); The top of the drainage channel (31) is provided with a plurality of drainage holes (34), and the drainage groove (33) and the drainage channel (31) are communicated through the drainage holes (34).

3. A pavement structure having a bituminous based separating layer according to claim 2, characterised in that: The drainage channel (31) is provided with an air exhaust channel (35) and a drainage channel (36) from bottom to top near the outer side of the asphalt layer (22) and the pavement layer (23); The side surface of the drainage channel (31) is provided with an air exhaust hole (37) corresponding to the air exhaust channel (35) and a drainage hole (38) corresponding to the drainage channel (36); The inner side of the drainage channel (31) is rotatably connected with a self-floating lowering component (39), and the self-floating lowering component (39) is matched with the air exhaust hole (37) and the drainage hole (38) respectively.

4. A pavement structure having a bituminous based separating layer according to claim 3, characterised in that: The self-floating lowering component (39) comprises a connecting rod (391) rotatably connected to the inner side of the drainage channel (31), one end of the connecting rod (391) is fixedly connected with a floating ball (392), and the other end is fixedly connected with a baffle (393), and the baffle (393) is matched with the air exhaust hole (37) and the drainage hole (38) respectively.

5. A pavement structure having a bituminous based separating layer according to claim 1 or 4, characterised in that: The asphalt layer (22) is in the shape of an isosceles trapezoid.

6. A pavement structure having a bituminous based separating layer according to claim 5, characterised in that: The drainage channel (31) is in a segmented structure, and each segment is arranged continuously.

7. The method of constructing a pavement structure having a bituminous based separating layer according to claim 1, wherein, The method comprises the following steps: (1) laying the geogrid (24) on the predetermined soil foundation layer (1), and filling the water-stable macadam into the geogrid (24) to form the water-stable macadam cushion layer (21); (2) using a paver to pave the asphalt on the water-stable macadam cushion layer (21) to form the asphalt layer (22); (3) installing the drainage system (3) on both sides of the soil foundation layer (1), and backfilling and tamping after installation; (4) pouring and paving the cement concrete on the asphalt layer (22) to form the pavement layer (23), and performing finishing and scraping treatment on the pavement layer (23).

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