Lightweight asphalt pavement structure

Abstract

The utility model relates to the technical field of road engineering, and discloses a lightweight asphalt pavement structure which sequentially comprises an anti-crack anti-skid ultrathin wearing layer, an anti-rut composite modified middle surface layer, an anti-crack porous anti-fatigue leveling layer, a high-viscosity asphalt synchronous gravel sealing layer, a cement stabilized gravel base layer and a graded gravel hardcore from top to bottom, the thickness of the anti-crack and anti-skid ultrathin wearing layer is 1.5-3.0 cm, and the structural depth of the surface of the anti-crack and anti-skid ultrathin wearing layer is not less than 0.8 mm; the thickness of the anti-rutting composite modified middle surface layer is 2.5 to 4.5 cm; the thickness of the anti-crack porous anti-fatigue leveling layer is 3.0 to 5.0 cm; the thickness of the high-viscosity asphalt synchronous gravel sealing layer is 1.0 cm; the thickness of the cement stabilized macadam base layer is 36.0 to 40.0 cm; and the thickness of the graded broken stone hardcore layer is 15.0 to 20.0 cm. Under the condition that the thickness of the total pavement structure is reduced, the overall anti-cracking performance of the pavement structure is maintained, the anti-sliding durability of the pavement structure is improved, light weight is achieved while the overall service life of the pavement is not affected, and the lightweight pavement structure is suitable for application scenes such as viaducts and bridges.

Description

TECHNICAL FIELD

[0001] The utility model relates to road engineering technical field especially relates to a light weight asphalt pavement structure. BACKGROUND

[0002] The semi -rigid base asphalt pavement becomes the mainstream structure form of our country high -grade road because of possessing the characteristics of strong integrity, high bearing capacity, however, the biggest problem of this pavement structure is easy to crack, especially the dry shrinkage and temperature shrinkage crack of semi -rigid material itself, the asphalt pavement reflection crack has become one of the most common diseases, seriously influence pavement performance and service life.

[0003] In order to slow down the expansion of reflection crack, usually increase the thickness of asphalt surface layer in the construction process. However, due to the performance limitation of asphalt material and the lack of targeted anti -crack design, the anti -reflection crack effect of this mode is not ideal, and the cracking problem still exists. At the same time, the increase of surface layer thickness means more resource consumption, such as asphalt and gravel, which leads to the rise of construction cost and also causes greater pressure on the environment. At the same time, the increase of surface layer thickness also leads to the increase of the overall weight of the road, which is not conducive to the application of pavement structure in elevated or bridge and other scenes. SUMMARY

[0004] In view of the above -mentioned defects, the purpose of the utility model is to provide a light weight asphalt pavement structure, solve the problem that the pavement structure with long service life is thick, not applicable to the application scene needing support such as elevated, bridge and the like.

[0005] To achieve this purpose, the utility model adopts the following technical scheme:

[0006] A light weight asphalt pavement structure, from top to bottom in turn is anti -crack anti -slip ultra -thin wearing layer, anti -rut composite modified middle surface layer, anti -crack porous anti -fatigue leveling layer, high -viscosity asphalt synchronous gravel seal coat, cement stabilized gravel base and graded gravel cushion layer;

[0007] The thickness of the anti -crack anti -slip ultra -thin wearing layer is 1.5~3.0cm, and the structure depth of the surface of the anti -crack anti -slip ultra -thin wearing layer is not less than 0.8mm;

[0008] The thickness of the anti -rut composite modified middle surface layer is 2.5~4.5cm;

[0009] The thickness of the anti -crack porous anti -fatigue leveling layer is 3.0~5.0cm;

[0010] The thickness of the high -viscosity asphalt synchronous gravel seal coat is 1.0cm;

[0011] The thickness of the cement stabilized gravel base is 36.0~40.0cm;

[0012] The thickness of the graded crushed stone cushion layer is 15.0 to 20.0 cm.

[0013] Preferably, the anti-cracking and anti-skid ultra-thin wear layer is a dense-graded asphalt pavement structure, and the anti-cracking and anti-skid ultra-thin wear layer is an asphalt mixture layer prepared using a first high-viscosity and high-elasticity modified asphalt, and the first high-viscosity and high-elasticity modified asphalt has a dynamic viscosity at 60°C greater than 580,000 Pa·s and a complex shear modulus at 60°C greater than 12 kPa.

[0014] Preferably, the nominal diameter of the maximum particle size of the anti-cracking and anti-slip ultra-thin wear layer is 10 mm.

[0015] Preferably, the anti-rutting composite modified middle surface layer is a dense-graded asphalt pavement structure, and the anti-rutting composite modified middle surface layer is an asphalt mixture layer prepared using a first high-viscosity and high-elasticity modified asphalt. The first high-viscosity and high-elasticity modified asphalt has a dynamic viscosity at 60°C greater than 580,000 Pa·s and a complex shear modulus at 60°C greater than 12 kPa. The nominal diameter of the maximum particle size of the anti-rutting composite modified middle surface layer is 15 mm.

[0016] Preferably, the crack-resistant porous anti-fatigue leveling layer is an open-graded asphalt pavement structure, and the crack-resistant porous anti-fatigue leveling layer is an asphalt mixture layer prepared using a first high-viscosity and high-elasticity modified asphalt. The first high-viscosity and high-elasticity modified asphalt has a dynamic viscosity at 60°C greater than 580,000 Pa·s and a complex shear modulus at 60°C greater than 12 kPa. The nominal diameter of the maximum particle size of the crack-resistant porous anti-fatigue leveling layer is 10 mm.

[0017] Preferably, the high-viscosity asphalt synchronous chip seal layer is an asphalt mixture layer prepared using a second high-viscosity and high-elasticity modified asphalt, the second high-viscosity and high-elasticity modified asphalt having a 60°C dynamic viscosity greater than 150,000 Pa·s and a 60°C complex shear modulus greater than 10 kPa, and the nominal diameter of the maximum particle size of the high-viscosity asphalt synchronous chip seal layer is 10 mm.

[0018] Preferably, the maximum particle size of the cement-stabilized crushed stone base layer has a nominal diameter of 26.5 mm.

[0019] Preferably, the nominal diameter of the maximum particle size of the graded crushed stone cushion layer is 31.5 mm.

[0020] The technical solution provided by the utility model may have the following beneficial effects:

[0021] In the case of total structure thickness thinning, the anti-cracking performance of the overall pavement structure is maintained, the anti-sliding durability of the pavement structure is improved, the overall stability of the pavement is enhanced, the overall service life of the pavement is ensured, and the lightweight is realized, the thickness of the asphalt composite surface layer in the pavement structure is thinned from the conventional 18cm to 7-12.5cm, the weight of each square meter of the pavement is reduced by 137.5-275kg per cubic meter according to the density of the asphalt mixture 2500kg per cubic meter, and the lightweight pavement structure is suitable for application scenarios such as viaducts and bridges. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The structure schematic view of one embodiment of the utility model.

[0023] Among them: anti-cracking and anti-sliding ultra-thin wearing layer 1, anti-rutting composite modified middle surface layer 2, anti-cracking porous anti-fatigue leveling layer 3, high-viscosity asphalt synchronous macadam seal coat 4, cement stabilized macadam base 5, graded macadam cushion 6. DETAILED DESCRIPTION

[0024] In order to facilitate the understanding of the utility model, the utility model is described more comprehensively below. The utility model can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the utility model more thorough and comprehensive.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the utility model belongs. The terms used in the specification of the utility model herein are only for the purpose of describing specific embodiments and are not intended to limit the utility model. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0026] As Figure 1 shown, a lightweight asphalt pavement structure, from top to bottom, is anti-cracking and anti-sliding ultra-thin wearing layer 1, anti-rutting composite modified middle surface layer 2, anti-cracking porous anti-fatigue leveling layer 3, high-viscosity asphalt synchronous macadam seal coat 4, cement stabilized macadam base 5 and graded macadam cushion 6.

[0027] The thickness of the anti-cracking and anti-sliding ultra-thin wearing layer 1 is 1.5-3.0cm, and the structure depth of the surface of the anti-cracking and anti-sliding ultra-thin wearing layer 1 is not less than 0.8mm;

[0028] The thickness of the anti-rutting composite modified middle surface layer 2 is 2.5-4.5cm;

[0029] The thickness of the anti-cracking porous anti-fatigue leveling layer 3 is 3.0-5.0cm;

[0030] The thickness of the high-viscosity asphalt synchronous chip seal 4 is 1.0 cm;

[0031] The thickness of the cement stabilized macadam base 5 is 36.0-40.0 cm;

[0032] The thickness of the graded macadam cushion layer 6 is 15.0-20.0 cm.

[0033] The service life of the pavement structure is closely related to the rutting deformation, cracking and other diseases in the service period. Once the rutting deformation, cracking and other diseases with serious consequences occur, the asphalt pavement is milled and repaved, and the industry believes that this is the terminal service life of the structure layer position that is milled.

[0034] When the anti-skid performance of the asphalt pavement cannot meet the use requirements and is milled and repaved, the industry also believes that the terminal service life of this layer position has been reached, that is, the anti-skid service life reaches the end.

[0035] The layer structure combination and thickness limitation of the present scheme can maintain the overall anti-cracking performance of the pavement structure under the condition of reducing the total structure thickness, the structural depth of the anti-cracking and anti-skid ultra-thin wearing layer 1 is not less than 0.8 mm, and the anti-skid durability of the pavement structure is improved. While not affecting the overall service life of the pavement, lightweight pavement structure is suitable for high-speed rail, bridge and other application scenarios.

[0036] Preferably, the anti-cracking and anti-skid ultra-thin wearing layer 1 is a dense graded asphalt pavement structure, the anti-cracking and anti-skid ultra-thin wearing layer 1 is an asphalt mixture layer prepared by using first high-viscosity and high-elasticity modified asphalt, the 60℃ dynamic viscosity of the first high-viscosity and high-elasticity modified asphalt is greater than 580,000 Pa·s, and the 60℃ complex shear modulus is greater than 12 kPa.

[0037] The anti-cracking and anti-skid ultra-thin wearing layer 1 is the upper layer structure layer position as the uppermost layer, which will be in direct contact with the tire load, so it needs to have good anti-cracking, anti-deformation and anti-skid performance at the same time.

[0038] The first high-viscosity and high-elasticity modified asphalt with a 60℃ dynamic viscosity greater than 580,000 Pa·s and a 60℃ complex shear modulus greater than 12 kPa is prepared by using the existing asphalt preparation method. The asphalt mixture layer prepared by using the first high-viscosity and high-elasticity modified asphalt can improve the toughness of the layer structure and has good stress dispersion effect under repeated load, thereby improving the anti-cracking and anti-deformation performance of the anti-cracking and anti-skid ultra-thin wearing layer 1.

[0039] Preferably, the nominal diameter of the maximum particle size of the anti-cracking and anti-skid ultra-thin wearing layer 1 is 10 mm.

[0040] Preferably, the anti-rutting composite modified middle surface layer 2 is a dense-graded asphalt pavement structure, and the anti-rutting composite modified middle surface layer 2 is an asphalt mixture layer prepared using a first high-viscosity and high-elasticity modified asphalt. The first high-viscosity and high-elasticity modified asphalt has a dynamic viscosity at 60°C greater than 580,000 Pa·s and a complex shear modulus at 60°C greater than 12 kPa. The nominal diameter of the maximum particle size of the anti-rutting composite modified middle surface layer 2 is 15 mm.

[0041] Mechanical response analysis of typical asphalt pavement structures shows that the area 3 to 7 cm from the road surface is a high-stress area in the entire asphalt pavement structure, where shear stress is concentrated. This causes the asphalt middle surface layer to be a high-frequency layer for rutting and shear failure. Therefore, the anti-rutting composite modified middle surface layer 2 must have good deformation resistance and durable stability.

[0042] The primary function of the mid-surface layer is rutting resistance, placing higher technical demands on rutting dynamic stability and uniaxial penetration anti-sliding strength. The anti-rutting composite modified mid-surface layer 2, prepared using the first high-viscosity, high-elasticity modified asphalt, achieves rutting resistance performance exceeding or equivalent to that of conventional mid-surface layers while maintaining a reduced thickness.

[0043] Preferably, the crack-resistant porous anti-fatigue leveling layer 3 is an open-graded asphalt pavement structure, and the crack-resistant porous anti-fatigue leveling layer 3 is an asphalt mixture layer prepared using a first high-viscosity and high-elasticity modified asphalt. The first high-viscosity and high-elasticity modified asphalt has a dynamic viscosity at 60°C greater than 580,000 Pa·s and a complex shear modulus at 60°C greater than 12 kPa. The nominal diameter of the maximum particle size of the crack-resistant porous anti-fatigue leveling layer 3 is 10 mm.

[0044] The lower layer is the lowest structural layer in the asphalt surface structure. Under the action of tire load, its bottom bending tensile stress is the largest. In addition, the lower layer is connected to the cement-stabilized gravel base layer 5 through a high-viscosity synchronous gravel seal layer. It also needs to directly withstand the concentrated stress after cracks appear in the base layer. Therefore, this layer is most prone to fatigue damage and reflective cracking.

[0045] The crack-resistant porous anti-fatigue leveling layer 3 serves as the lower layer, adopts a skeleton void type open gradation design, and uses the asphalt mixture layer prepared with the first high-viscosity and high-elasticity modified asphalt to dissipate the stress at the crack tip through the void structure, inhibit the transmission of reflected cracks, and thus improve the material's resistance to reflective cracking and fatigue cracking.

[0046] Preferably, the high-viscosity asphalt synchronous chip seal layer 4 is an asphalt mixture layer prepared using a second high-viscosity and high-elasticity modified asphalt, the second high-viscosity and high-elasticity modified asphalt having a 60°C dynamic viscosity greater than 150,000 Pa·s and a 60°C complex shear modulus greater than 10 kPa, and the nominal diameter of the maximum particle size of the high-viscosity asphalt synchronous chip seal layer 4 is 10 mm.

[0047] By utilizing the existing asphalt preparation method, a second high-viscosity and high-elasticity modified asphalt with a 60°C dynamic viscosity greater than 150,000 Pa·s and a 60°C complex shear modulus greater than 10 kPa is prepared. The high-viscosity asphalt synchronous chip seal 4 utilizes the second high-viscosity and high-elasticity modified asphalt in combination with crushed stones with a maximum nominal diameter of 10 mm, which can achieve a stronger connection between the asphalt surface layer and the cement-stabilized chip seal 5. When cracks occur in the pavement base layer, the high-viscosity asphalt synchronous chip seal 4 can disperse and absorb stress, delaying the reflection and extension of cracks in the cement-stabilized chip seal 5 to the asphalt surface layer.

[0048] Preferably, the nominal diameter of the maximum particle size of the cement-stabilized crushed stone base layer 5 is 26 mm.

[0049] Cement-stabilized crushed stone base layers offer excellent fatigue and crack resistance. Through their rigidity, they provide a stable support layer for the pavement, effectively distributing and evenly transferring vertical loads from vehicles to the underlying structure. This reduces stress concentration in the underlying materials and prevents localized settlement or structural damage. This structure resists fatigue damage caused by repeated vehicle loads and prevents fatigue cracking in the base layer over long-term use. Furthermore, the high strength and rigidity of the cement-stabilized crushed stone base layer provide a solid foundation for the asphalt composite layer, further enhancing the overall structural stability of the pavement and reducing the occurrence of uneven settlement and cracking.

[0050] Preferably, the nominal diameter of the maximum particle size of the graded crushed stone cushion layer 6 is 31 mm.

[0051] The graded crushed stone cushion layer 6 forms a high-bearing structure that effectively disperses and evenly transfers vehicle loads, alleviating stress concentration in the underlying subsoil and reducing the risk of localized settlement. Its high strength and stability also help improve the fatigue resistance of the asphalt composite layer, reducing the formation of cracks in the asphalt composite layer over long-term use, thereby enhancing the overall stability of the pavement and extending its service life.

[0052] Example 1

[0053] A lightweight pavement structure, the components of which are as follows:

[0054] The first high-viscosity and high-elasticity modified asphalt uses a modified asphalt with a dynamic viscosity of >580,000 Pa·s at 60℃ and a complex shear modulus of 15.2kPa at 60℃. The second high-viscosity and high-elasticity modified asphalt uses a high-viscosity and high-elasticity modified asphalt with a dynamic viscosity of 186,000 Pa·s at 60℃ and a complex shear modulus of 10.5kPa at 60℃.

[0055] The parameters of the asphalt mixture in the anti-cracking and anti-skid ultra-thin wear layer 1 are: oil-stone ratio of 7.5%, void ratio of 4.5%, asphalt saturation of 80.5%, surface structural depth of 1.05mm, and four-point bending fatigue life (15℃, 1000με) of 486550 times.

[0056] The parameters of the asphalt mixture in the anti-rutting composite modified middle surface layer 2 are: oil-stone ratio of 6.6%, void ratio of 4.2%, asphalt saturation of 76.4%, rutting dynamic stability at 60℃ of 12550 times / mm, rutting dynamic stability at 70℃ of 7540 times / mm, and uniaxial penetration shear strength of 1.5 MPa.

[0057] The parameters of the asphalt mixture in the crack-resistant porous anti-fatigue leveling layer 3 are: oil-stone ratio is 6.3%, porosity is 20.3%, four-point bending fatigue life (15℃, 1000με) is 155680 times, rutting dynamic stability at 60℃ is 7626 times / mm, and uniaxial penetration shear strength is 1.05MPa.

[0058] The pavement structure from top to bottom is as follows:

[0059] The anti-crack and anti-slip ultra-thin wear layer 1 has a thickness of 2.0 cm;

[0060] Anti-rutting composite modified middle surface layer 2, having a thickness of 3.0 cm;

[0061] The crack-resistant porous anti-fatigue leveling layer 3 has a thickness of 4.0 cm;

[0062] High-viscosity asphalt synchronous chip seal 4, with a thickness of 1.0 cm;

[0063] Cement stabilized gravel base 5, with a thickness of 36 cm;

[0064] Graded crushed stone cushion layer 6, with a thickness of 18 cm;

[0065] Soil foundation.

[0066] Example 2

[0067] A lightweight pavement structure, wherein the asphalt mixture parameters of the crack-resistant and anti-skid ultra-thin wear layer 1, the anti-rutting composite modified middle surface layer 2, the crack-resistant porous anti-fatigue leveling layer 3, and the high-viscosity asphalt synchronous chip seal 4 are the same as those in Example 1. The pavement structure from top to bottom is as follows:

[0068] The anti-crack and anti-slip ultra-thin wear layer 1 has a thickness of 1.5 cm;

[0069] Anti-rutting composite modified middle surface layer 2, with a thickness of 3.5 cm;

[0070] The crack-resistant porous anti-fatigue leveling layer 3 has a thickness of 4.0 cm;

[0071] High-viscosity asphalt synchronous chip seal 4, with a thickness of 1.0 cm;

[0072] Cement stabilized gravel base 5, with a thickness of 36.0 cm;

[0073] Graded crushed stone cushion layer 6, with a thickness of 18.0 cm;

[0074] Soil foundation.

[0075] Example 3

[0076] A lightweight pavement structure, wherein the asphalt mixture parameters of the crack-resistant and anti-skid ultra-thin wear layer 1, the anti-rutting composite modified middle surface layer 2, the crack-resistant porous anti-fatigue leveling layer 3, and the high-viscosity asphalt synchronous chip seal 4 are the same as those in Example 1. The pavement structure from top to bottom is as follows:

[0077] The anti-crack and anti-slip ultra-thin wear layer 1 has a thickness of 2.0 cm;

[0078] Anti-rutting composite modified middle surface layer 2, having a thickness of 4.0 cm;

[0079] The crack-resistant porous anti-fatigue leveling layer 3 has a thickness of 3.0 cm;

[0080] High-viscosity asphalt synchronous chip seal 4, with a thickness of 1.0 cm;

[0081] Cement stabilized gravel base 5, with a thickness of 36.0 cm;

[0082] Graded crushed stone cushion layer 6, with a thickness of 18.0 cm;

[0083] Soil foundation.

[0084] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0085] The above-described embodiments merely represent several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present utility model patent shall be determined by the appended claims.

Claims

1. A lightweight asphalt pavement structure, characterized by: From top to bottom, they are anti-cracking and anti-skid ultra-thin wear layer, anti-rutting composite modified middle surface layer, anti-cracking porous anti-fatigue leveling layer, high-viscosity asphalt synchronous gravel seal layer, cement-stabilized gravel base layer and graded gravel cushion layer; The thickness of the anti-crack and anti-slip ultra-thin wear layer is 1.5 to 3.0 cm, and the surface structure depth of the anti-crack and anti-slip ultra-thin wear layer is not less than 0.8 mm; The thickness of the anti-rutting composite modified middle surface layer is 2.5 to 4.5 cm; The thickness of the crack-resistant porous anti-fatigue leveling layer is 3.0 to 5.0 cm; The thickness of the high-viscosity asphalt synchronous chip seal is 1.0 cm; The thickness of the cement-stabilized crushed stone base is 36.0 to 40.0 cm; The thickness of the graded crushed stone cushion layer is 15.0 to 20.0 cm.

2. A lightweight asphalt pavement structure according to claim 1, characterized in that: The anti-cracking and anti-skid ultra-thin wear layer is a dense-graded asphalt pavement structure, and the anti-cracking and anti-skid ultra-thin wear layer is an asphalt mixture layer prepared using a first high-viscosity and high-elasticity modified asphalt. The first high-viscosity and high-elasticity modified asphalt has a dynamic viscosity at 60°C greater than 580,000 Pa·s and a complex shear modulus at 60°C greater than 12 kPa.

3. The lightweight asphalt pavement structure according to claim 2, characterized in that: The nominal diameter of the maximum particle size of the anti-cracking and anti-slip ultra-thin wear layer is 10 mm.

4. The lightweight asphalt pavement structure according to claim 1, characterized in that: The anti-rutting composite modified middle surface layer is a dense-graded asphalt pavement structure. The anti-rutting composite modified middle surface layer is an asphalt mixture layer prepared using a first high-viscosity and high-elasticity modified asphalt. The first high-viscosity and high-elasticity modified asphalt has a dynamic viscosity at 60°C greater than 580,000 Pa·s and a complex shear modulus at 60°C greater than 12 kPa. The nominal diameter of the maximum particle size of the anti-rutting composite modified middle surface layer is 15 mm.

5. The lightweight asphalt pavement structure according to claim 1, characterized in that: The crack-resistant, porous, and fatigue-resistant leveling layer is an open-graded asphalt pavement structure. The crack-resistant, porous, and fatigue-resistant leveling layer is an asphalt mixture layer prepared using a first high-viscosity and high-elasticity modified asphalt. The first high-viscosity and high-elasticity modified asphalt has a dynamic viscosity at 60°C greater than 580,000 Pa·s and a complex shear modulus at 60°C greater than 12 kPa. The nominal diameter of the maximum particle size of the crack-resistant, porous, and fatigue-resistant leveling layer is 10 mm.

6. The lightweight asphalt pavement structure according to claim 1, characterized in that: The high-viscosity asphalt synchronous chip seal layer is an asphalt mixture layer prepared using a second high-viscosity and high-elasticity modified asphalt. The second high-viscosity and high-elasticity modified asphalt has a dynamic viscosity at 60°C greater than 150,000 Pa·s and a complex shear modulus at 60°C greater than 10 kPa. The nominal diameter of the maximum particle size of the high-viscosity asphalt synchronous chip seal layer is 10 mm.

7. The lightweight asphalt pavement structure according to claim 1, characterized in that: The nominal diameter of the maximum particle size of the cement-stabilized crushed stone base is 26.5 mm.

8. The lightweight asphalt pavement structure according to claim 1, characterized in that: The nominal diameter of the maximum particle size of the graded crushed stone cushion layer is 31.5 mm.

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