Renovation Road Surface Structure of Rural Waste Cement Concrete Road and Its Filling Method

Abstract

The present invention discloses a pavement structure for renovating and reconstructing rural waste cement concrete roads and its filling method. The pavement structure includes an asphalt surface layer, a graded gravel layer, and a recycled gravel layer arranged from top to bottom above the subgrade; V-shaped recycled gravel drainage ditches are opened on both sides of the recycled gravel layer, and the ditches are filled with recycled gravel; road shoulders are provided on both sides of the pavement structure extending from the asphalt surface layer to the recycled gravel drainage ditches; the graded gravel layer is surrounded by plant fiber grids. The present invention makes full use of the pavement materials of rural waste cement concrete roads to form a recycled gravel layer and recycled gravel drainage ditches, which not only reduces environmental pollution and makes full use of waste materials, but also can further accelerate road drainage. The application of plant fiber grids effectively enhances the structural strength of the road surface, reduces the generation of various cracks, improves the quality of the asphalt pavement, thereby extending the service life of the asphalt pavement, reducing road maintenance costs, optimizing the comprehensive benefits of road operation, and is of great significance to promoting rural economic development.

Description

Technical Field

[0001] The invention belongs to the field of highway pavement structures, and relates to a method for repairing highway pavement structures, specifically a pavement structure for renovating and reconstructing rural waste cement concrete roads and its filling method. Background Art

[0002] Due to the advantages of high strength, mature road construction technology, and low investment of cement concrete pavements, since the 1970s and 1980s, cement concrete has been widely used to pave roads in rural areas of China. However, with the increasing traffic demand in rural areas, a large number of cement concrete pavements have suffered from diseases such as slab cracking, pumping, and potholes, and can no longer meet the requirements of rapidity, safety, and comfort of highways for economic development. Therefore, it is urgent to renovate and reconstruct these waste cement concrete roads.

[0003] There are usually two methods for renovating and reconstructing cement concrete roads, namely:

[0004] (1) Milling and excavating the entire original road surface, directly transporting the waste materials out of the renovation area, and then constructing a new base course and paving a new road surface. This renovation method increases the transportation and raw material purchase costs. If the milled waste materials are not properly treated, they will become construction waste and cause environmental pollution.

[0005] (2) Directly paving an asphalt mixture surface layer on the original cement concrete road surface. However, over time, reflection cracks of the original cement road surface will appear on the newly paved road surface. The generation of reflection cracks will cause the road surface to seep water, resulting in a large number of diseases on the renovated road surface, shortening the service life of the renovated road surface and affecting traffic. Summary of the Invention

[0006] Technical Problem to be Solved: In order to overcome the deficiencies of the prior art and obtain a method that can effectively improve the overall structural stability of the roadbed, increase the bearing capacity of the roadbed, reduce the possibility of reflection cracks in the asphalt pavement, and extend the service life of the renovated road surface, the invention provides a pavement structure for renovating and reconstructing rural waste cement concrete roads and its filling method.

[0007] Technical Solution: A pavement structure for renovating and reconstructing rural waste cement concrete roads, the pavement structure includes an asphalt surface layer, a graded crushed stone layer, and a recycled crushed stone layer arranged from top to bottom above the subgrade; V-shaped recycled crushed stone drainage ditches are opened on both sides of the recycled crushed stone layer, and the ditches are filled with recycled crushed stone; shoulders are provided on both sides of the pavement structure extending from the asphalt surface layer to the recycled crushed stone drainage ditches; and a plant fiber grid surrounds the graded crushed stone layer.

[0008] Preferably, the maximum particle size of the recycled crushed stones in the recycled crushed stone layer is 40 mm, among which the crushed stones with a particle size less than 5 mm account for 25%-30%, the crushed stones with a particle size of 5 mm-10 mm account for 25%-30%, the crushed stones with a particle size of 10 mm-20 mm account for 25%-35%, the crushed stones with a particle size of 20 mm-30 mm account for 10%-20%, and the crushed stones with a particle size of 30 mm-40 mm account for 5%-10%.

[0009] Preferably, the recycled crushed stone drainage ditch is filled with recycled crushed stones, the top of the ditch is flush with the top surface of the recycled crushed stone layer, and the elevation of the bottom of the ditch is lower than the elevation of the bottom surface of the recycled crushed stone layer.

[0010] Preferably, the particle size of the recycled crushed stones filled in the recycled crushed stone drainage ditch is 20-40 mm.

[0011] Preferably, the plant fiber grid is divided into an upper grid, a side grid and a lower grid, and the three are connected in sequence; among them, the upper grid is located between the asphalt surface layer and the graded crushed stone layer, the lower grid is located between the graded crushed stone layer and the recycled crushed stone layer, and the side grid is located between the road shoulder and the graded crushed stone layer.

[0012] Preferably, the side length of the mesh holes of the plant fiber grid is 20 mm-40 mm.

[0013] Preferably, the material of the plant fiber grid is straw fiber, coconut shell fiber or hemp plant fiber.

[0014] Preferably, turf is laid on the road shoulder.

[0015] For the filling method of the renovated pavement structure of the rural waste cement concrete road described in any one of the above, the method includes the following steps: S1 Milling and crushing the waste cement concrete pavement; S2 Cleaning, leveling and compacting the original soil subgrade; S3 Laying the recycled crushed stone layer; S4 Laying the lower grid; S5 Laying the graded crushed stone layer; S6 Laying the upper grid and the side grid; S7 Laying the asphalt surface layer; S8 Filling the recycled crushed stone drainage ditch; S9 Laying the road shoulder.

[0016] The principle of the pavement structure design for the renovation of rural waste cement concrete roads in the present invention lies in that when the pavement load is transmitted to the graded crushed stone layer through the asphalt surface layer, the interlocking and biting effect and frictional effect generated between the unique mesh structure of the plant fiber grille and the aggregates can effectively reduce or delay the number of reflective cracks, resist the rutting of the asphalt pavement, slow down the fatigue cracking, and improve the stability of the pavement structure. At the same time, the side plant fiber grille is buried in the shoulder soil body. Due to the frictional effect generated between the mesh structure and the soil body, it can enhance the strength and stability of the soil body and improve the anti-scouring ability of the road shoulder. In the structure, the graded crushed stone layer, the recycled crushed stone layer, and the recycled crushed stone drainage ditch form a drainage system, enabling the downward seepage water of the pavement layer to quickly infiltrate and flow, effectively avoiding the adverse effects caused by the seepage water on the subgrade and the pavement layer, and preventing phenomena such as frost heaving, thaw settlement, and mud pumping on the pavement.

[0017] Beneficial effects: (1) The raw material of the plant fiber grille comes from local crop straws. While reducing the environmental pollution caused by straw burning, the crop straw resources are comprehensively utilized, which is of great significance for promoting farmers' income increase, environmental protection, resource conservation, and the sustainable development of the agricultural economy. The plant fiber grille layer in the present invention includes an upper grille placed between the asphalt surface layer and the graded crushed stone layer, a lower grille placed between the recycled crushed stone layer and the graded crushed stone layer, and a side grille. The three parts of the grille are connected into one body through a weaving process, which can effectively improve the overall structural stability of the subgrade, enhance the bearing capacity of the subgrade, reduce the possibility of reflective cracks in the asphalt pavement at the same time, and improve the service life of the renovated pavement. The side grille can play a role in fixing the soil and turf, and improve the anti-rainwater scouring ability of the road shoulder slope.

[0018] (2) The raw materials of the recycled crushed stone layer and the recycled crushed stone drainage ditch are the crushed stones obtained by crushing the original waste cement concrete road. The crushed stones are mixed according to the corresponding particle size and gradation requirements to meet the bearing capacity requirements. The remaining strength and remaining value of the old cement pavement are fully utilized, saving raw materials. Compared with the overall excavation and abandonment of the road, the investment is greatly reduced, and the construction waste is reduced, which is of great significance for environmental protection.

[0019] (3) The drainage ditch is filled with recycled crushed stones to form a recycled crushed stone drainage ditch, avoiding the disadvantages such as blockage, siltation, odor, and mosquito breeding of the open drainage ditch, and having the advantages of beauty and greater safety.

[0020] (4) By setting the graded crushed stone layer, the recycled crushed stone layer, and the recycled crushed stone drainage ditch, the downward seepage water of the pavement layer can quickly infiltrate and flow, thereby realizing the rapid drainage of the subgrade water, effectively avoiding the adverse effects caused by the seepage water on the subgrade and the pavement layer, and preventing phenomena such as frost heaving, thaw settlement, and mud pumping on the pavement. Description of the Drawings

[0021] Figure 1Schematic diagram of the road structure renovated and transformed according to the present invention;

[0022] Figure 2 Schematic diagram of the plant fiber grid of the present invention;

[0023] Wherein: 1 - asphalt surface layer, 2 - plant fiber grid, 3 - graded crushed stone layer, 4 - recycled crushed stone layer, 5 - road shoulder, 6 - recycled crushed stone drainage ditch. Specific embodiments

[0024] The following embodiments further illustrate the content of the present invention, but should not be construed as limiting the present invention. Without departing from the spirit and essence of the present invention, modifications and substitutions made to the methods, steps or conditions of the present invention all fall within the scope of the present invention. If not specifically specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0025] Embodiment 1

[0026] Renovation and transformation pavement structure of rural waste cement concrete road, the pavement structure includes an asphalt surface layer 1, a graded crushed stone layer 3 and a recycled crushed stone layer 4 arranged from top to bottom above the subgrade; V-shaped recycled crushed stone drainage ditches 6 are opened on both sides of the recycled crushed stone layer 4, and the ditches are filled with recycled crushed stone; road shoulders 5 are provided on both sides of the pavement structure extending from the asphalt surface layer 1 to the recycled crushed stone drainage ditch 6; the graded crushed stone layer 3 is surrounded by a plant fiber grid 2.

[0027] The maximum particle size of the recycled crushed stone in the recycled crushed stone layer 4 is 40 mm, wherein the crushed stone with a particle size less than 5 mm accounts for 25% - 30%, the crushed stone with a particle size of 5 mm - 10 mm accounts for 25% - 30%, the crushed stone with a particle size of 10 mm - 20 mm accounts for 25% - 35%, the crushed stone with a particle size of 20 mm - 30 mm accounts for 10% - 20%, and the crushed stone with a particle size of 30 mm - 40 mm accounts for 5% - 10%.

[0028] The recycled crushed stone filled in the recycled crushed stone drainage ditch 6 has a particle size of 20 - 40 mm.

[0029] The plant fiber grid 2 is divided into an upper grid, a side grid and a lower grid, and the three are connected in sequence into one body; wherein the upper grid is located between the asphalt surface layer 1 and the graded crushed stone layer 3, the lower grid is located between the graded crushed stone layer 3 and the recycled crushed stone layer 4, and the side grid is located between the road shoulder 5 and the graded crushed stone layer 3.

[0030] The mesh side length of the plant fiber grid 2 is 20 mm - 40 mm.

[0031] The material of the plant fiber grid 2 is straw fiber, coconut shell fiber or hemp plant fiber. And it has been subjected to anti-corrosion treatment.

[0032] The filling method of the renovated pavement structure of the rural waste cement concrete road is characterized in that the method comprises the following processes:

[0033] S1 Milling and crushing the waste cement concrete pavement. It can be crushed multiple times by a crusher so that the maximum particle size of the recycled crushed stones obtained after crushing is 40 mm, and the recycled crushed stones are screened nearby;

[0034] S2 Cleaning, leveling and compacting the original soil subgrade. Debris on the surface of the original soil subgrade should be removed, and the pits caused by milling and crushing the original concrete pavement should be filled, and then compacted by a roller.

[0035] S3 Laying the recycled crushed stone layer 4; mixing the recycled crushed stones according to the gradation, then mechanically spreading and compacting them densely. During the compaction process, by controlling the optimum moisture content, ensure that the recycled crushed stone layer 4 reaches the maximum dry density after compaction.

[0036] S4 Laying the lower layer grille; the width of the lower layer grille of the plant fiber grille 2 should be 10 cm - 20 cm wider than the recycled crushed stone layer 4, so that both sides of it extend 5 cm - 10 cm out of the recycled crushed stone layer 4. During the laying process, it should be tightened as much as possible and fixed on the recycled crushed stone layer 4 with "U" - shaped nails. When laying longitudinally, it can be connected by knitting technology or nylon rope binding.

[0037] S5 Laying the graded crushed stone layer 3; select appropriate crushed stone raw materials, determine the optimum moisture content and maximum dry density of the crushed stones before laying, ensure that the graded crushed stone layer 3 is compacted and flat, and at the same time avoid disturbing the lower - layer plant fiber grille.

[0038] S6 Laying the upper layer grille and the side grille; the width of the upper - layer plant grille should be 10 cm - 20 cm wider than the graded crushed stone layer 4, so that both sides of it extend 5 cm - 10 cm out of the graded crushed stone layer 4. During the laying process, it should be tightened as much as possible and fixed on the recycled crushed stone layer 4 with "U" - shaped nails. When laying longitudinally, it can be connected by knitting technology or nylon rope binding. After the upper - layer plant grille is laid, connect the side grille to the upper - layer grille and the lower - layer grille through knitting technology.

[0039] S7 Laying the asphalt surface layer 1; after the upper - layer grille is laid, sprinkle the emulsified asphalt penetration oil, spread stone chips after demulsification, and then lay the asphalt surface layer 1 as soon as possible.

[0040] S8 Filling the recycled crushed stone drainage ditch 6; excavate drainage ditches on both sides of the recycled crushed stone layer, the elevation of the ditch bottom is lower than the bottom elevation of the recycled crushed stone layer 4, and then fill it with recycled crushed stones, and make it flush with the top surface of the recycled crushed stone layer 4 after filling. The construction of the recycled crushed stone drainage ditch 6 can be carried out synchronously with S5 laying the graded crushed stone layer 3.

[0041] S9 Laying the road shoulder 5; after the S1 - S8 processes are completed, lay the road shoulder 5 and lay turf on the road shoulder 5.

[0042] In summary, the present invention fully recycles the materials milled from rural waste cement concrete roads, and has huge economic, environmental and social benefits. The application of the plant fiber grille effectively enhances the structural strength of the road surface, reduces the generation of various cracks, improves the quality of the asphalt pavement, thereby extending the service life of the asphalt pavement, reducing the maintenance cost of the road, and optimizing the comprehensive benefits of road operation. The combination of the graded crushed stone layer, the recycled crushed stone layer and the recycled crushed stone drainage ditch in the road surface structure of the present invention enables the downward seepage of the road surface layer to quickly infiltrate and flow, thereby realizing the rapid drainage of the subgrade water, effectively avoiding the adverse effects caused by the seepage on the subgrade and the road surface layer, and preventing phenomena such as frost heave, thaw settlement and pumping on the road surface.

Claims

1. Refurbishment and reconstruction pavement structure of rural waste cement concrete road, Characterized in that, The pavement structure includes an asphalt surface layer (1), a graded crushed stone layer (3) and a recycled crushed stone layer (4) arranged from top to bottom above the soil subgrade; V-shaped recycled crushed stone drainage ditches (6) are opened on both sides of the recycled crushed stone layer (4), and the ditches are filled with recycled crushed stones; shoulders (5) are provided on both sides of the pavement structure extending from the asphalt surface layer (1) to the recycled crushed stone drainage ditches (6); the graded crushed stone layer (3) is surrounded by a plant fiber grid (2) around; The maximum particle size of the recycled crushed stones in the recycled crushed stone layer (4) is 40 mm, of which the crushed stones with a particle size less than 5 mm account for 25%-30%, the crushed stones with a particle size of 5 mm-10 mm account for 25%-30%, the crushed stones with a particle size of 10 mm-20 mm account for 25%-35%, the crushed stones with a particle size of 20 mm-30 mm account for 10%-20%, and the crushed stones of 30 mm-40 mm account for 5%-10%; The recycled crushed stone drainage ditch (6) is filled with recycled crushed stones, the top of the ditch is flush with the top surface of the recycled crushed stone layer (4), and the bottom elevation of the ditch is lower than the bottom elevation of the recycled crushed stone layer (4); The plant fiber grid (2) is divided into an upper grid, a side grid and a lower grid, and the three are connected in sequence; among them, the upper grid is located between the asphalt surface layer (1) and the graded crushed stone layer (3), the lower grid is located between the graded crushed stone layer (3) and the recycled crushed stone layer (4), and the side grid is located between the shoulder (5) and the graded crushed stone layer (3).

2. The refurbishment and reconstruction pavement structure of rural waste cement concrete road according to claim 1, Characterized in that, The recycled crushed stones filled in the recycled crushed stone drainage ditch (6) have a particle size of 20-40 mm.

3. The refurbishment and reconstruction pavement structure of rural waste cement concrete road according to claim 1, Characterized in that, The mesh side length of the plant fiber grid (2) is 20 mm-40 mm.

4. The refurbishment and reconstruction pavement structure of rural waste cement concrete road according to claim 1, Characterized in that, The material of the plant fiber grid (2) is straw fiber, coconut shell fiber or hemp plant fiber.

5. The refurbishment and reconstruction pavement structure of rural waste cement concrete road according to claim 1, Characterized in that, The shoulder (5) is paved with turf.

6. The filling method of the refurbishment and reconstruction pavement structure of rural waste cement concrete road according to any one of claims 1-5, Characterized in that, The method includes the following steps: S1 Milling and crushing the waste cement concrete pavement; S2 Cleaning, leveling and compacting the original soil subgrade; S3 Laying the recycled crushed stone layer (4); S4 Laying the lower grid of the plant fiber grid (2); S5 Laying the graded crushed stone layer (3); S6 Laying the upper grid and the side grid of the plant fiber grid (2); S7 Laying the asphalt surface layer (1); S8 Filling the recycled crushed stone drainage ditch (6); S9 Laying the shoulder (5).

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