Noise reduction asphalt pavement structure

Abstract

The invention belongs to the field of asphalt pavements, and particularly relates to a noise reduction asphalt pavement structure which comprises a semi-open graded modified asphalt mixture upper surface layer with the void ratio of 7%-10%. And SMA-10 is arranged on the upper layer of the semi-open graded modified asphalt mixture. In the pavement structure provided by the invention, the upper surface layer is the SMA-10 semi-open graded modified asphalt mixture with the porosity of 7-10%, certain open pores are reserved on the surface of the surface layer, and most closed pores are formed in the surface layer. Compared with a porous asphalt pavement with the void ratio of about 20%, dust and other impurities of a surface layer adopting 7-10% of the semi-open graded modified asphalt mixture are not prone to entering the asphalt mixture, pores of the asphalt mixture are not prone to being blocked, the noise reduction effect is lasting compared with a conventional porous asphalt pavement structure, and the structural performance is stable.

Description

Technical Field

[0001] The invention belongs to the technical field of asphalt pavement, and in particular relates to a noise-reducing asphalt pavement structure. Background Art

[0002] Road vehicles generate noise when in motion. The methods for controlling traffic noise generally start from three aspects: the noise source, the sound channel and the receiving end. For the friction noise (tire noise) generated by the contact between the tire and the road surface, if we start from the road surface, we can use noise reduction pavement to reduce tire noise. Existing noise reduction pavements usually include: (1) porous asphalt pavement; (2) fine aggregate asphalt pavement; (3) rubber asphalt pavement.

[0003] The surface layer of porous asphalt pavement is mostly fine-grained drainage asphalt concrete (such as PAC-13) and open-graded anti-skid surface layer (such as OGFC-13), with a void ratio of up to 15% to 20%, or even more than 20%. Due to the large void ratio, the noise generated by the tire and the road surface during driving can be reduced. However, due to the large porosity, rainwater and the soil it carries can penetrate into the road surface, which is prone to blockage during long-term service and difficult to handle, resulting in general noise reduction durability; and due to the large void ratio, the density of asphalt and aggregate is lower than that of dense-graded asphalt pavement, and the durability is poor.

[0004] Therefore, there is an urgent need for a new pavement structure to solve the problem that existing porous asphalt pavements are prone to clogging. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a noise-reducing asphalt pavement structure, aiming to solve the problem that the existing porous asphalt pavement is prone to clogging, while improving the durability of the noise reduction effect of the pavement structure.

[0006] In order to achieve the above object, the present invention provides the following technical solutions: A noise reduction asphalt pavement structure comprises a semi-open graded modified asphalt mixture upper layer, wherein the void ratio of the semi-open graded modified asphalt mixture upper layer is 7% to 10%; the gradation of the semi-open graded modified asphalt mixture upper layer is SMA-10, and the raw materials thereof comprise the following components in parts by mass: 5.8%~6.0% asphalt, 90%~91.2% mineral material, 2%~3% mineral powder, 0.3%~0.5% lignin fiber, the total mass of raw materials meets 100%.

[0007] Furthermore, the noise reduction asphalt pavement structure includes, from top to bottom, the semi-open graded modified asphalt mixture upper layer, the first modified emulsified asphalt tack coat, the dense graded modified asphalt mixture middle layer, the second modified emulsified asphalt tack coat, the dense graded asphalt mixture lower layer, the synchronous crushed stone seal coat, the cement stabilized crushed stone base layer and the cement stabilized crushed stone subbase layer.

[0008] Furthermore, the first modified emulsified asphalt adhesive layer and the second modified emulsified asphalt adhesive layer have the same composition, and the first modified emulsified asphalt adhesive layer is SBS modified emulsified asphalt.

[0009] Furthermore, the surface layer gradation of the dense-graded modified asphalt mixture is AC-20C, and its raw materials include the following components in parts by mass: 3.9%~4.1% asphalt, 94.5%~95.5% mineral material, 0.8%~1% mineral powder, the total mass of raw materials meets 100%.

[0010] Furthermore, the lower layer of the dense-graded asphalt mixture is graded as AC-25C, and its raw materials include the following components in parts by mass: 3.5%~3.7% asphalt, 95.5%~96.5% mineral material, 0.5%~0.8% mineral powder, the total mass of raw materials meets 100%.

[0011] Furthermore, the synchronous chip seal is an SBS modified asphalt synchronous chip seal, and the amount of SBS modified asphalt is 2.0-2.4 kg / m 2 , spread 60~70% of the gravel, the amount of gravel spread is 9~11m per 1000 square meters 3 The particle size of the gravel is 13.2~19mm.

[0012] Furthermore, the cement-stabilized crushed stone base layer adopts skeleton-dense cement-stabilized crushed stone, and its raw material composition is cement, crushed stone and water, cement mass / crushed stone mass=5%, and the strength is 5.0~7.0Mpa.

[0013] Furthermore, the cement-stabilized crushed stone subbase layer adopts skeleton-dense cement-stabilized crushed stone, and its raw material composition is cement, crushed stone and water, cement mass / crushed stone mass=4%, and the strength is 3.0~5.0Mpa.

[0014] Furthermore, the thickness of the upper layer of the semi-open graded modified asphalt mixture is 2-3 cm, and the dosage of the first modified emulsified asphalt adhesive layer and the second modified emulsified asphalt adhesive layer is 0.4-0.6 L / m 2The thickness of the surface layer of dense-graded modified asphalt mixture is 6~8cm, the thickness of the lower layer of dense-graded asphalt mixture is 8~10cm, the thickness of the synchronous crushed stone seal layer is 0.5~1cm, the thickness of the cement-stabilized crushed stone base layer is 36~40cm and the thickness of the cement-stabilized crushed stone subbase layer is 20~25cm.

[0015] Furthermore, the thickness of the upper layer of the semi-open graded modified asphalt mixture is 3 cm, and the dosage of the first modified emulsified asphalt adhesive layer and the second modified emulsified asphalt adhesive layer is 0.5 L / m 2 The thickness of the surface layer of dense-graded modified asphalt mixture is 6 cm, the thickness of the lower layer of dense-graded modified asphalt mixture is 8 cm, the thickness of the synchronous crushed stone seal layer is 1 cm, the thickness of the cement-stabilized crushed stone base layer is 36 cm and the thickness of the cement-stabilized crushed stone subbase layer is 20 cm.

[0016] The noise reduction function of asphalt pavement has not received widespread attention before. PAC (permeable asphalt concrete) or OGFC (open graded anti-skid surface) asphalt pavement has drainage and noise reduction function, but its main purpose is to solve the problem of road surface drainage and improve the anti-skid ability of the pavement. Noise reduction performance is its subsidiary function. In recent years, with the increase in the number of cars and the emphasis on the quality of urban life, the noise reduction function of pavement has received widespread attention. PAC or OGFC pavements with a void ratio of 15-20% will indeed have a good noise reduction effect in the short term, but their easy clogging problem makes their noise reduction effect not lasting, and their road performance will also be reduced. With the pavement structure proposed in this application, the void ratio of the upper layer is appropriately reduced, making the noise reduction effect more lasting, and relative to the pavement with a void ratio of 15-20%, the pavement structure proposed in this application has a better density, and is also superior to it in terms of road performance.

[0017] The beneficial effects of the present invention are: In the pavement structure proposed in this application, the upper layer is a SMA-10 semi-open graded modified asphalt mixture with a porosity of 7~10%. The surface of the pavement structure layer retains a certain amount of open pores, and the interior is mostly closed pores. The open pores consume part of the energy of the sound. After the sound waves pass through the open pores and enter the closed pores, the sound energy is repeatedly refracted and consumed in the closed pores, thereby achieving a better noise reduction effect. Compared with porous asphalt pavements with a porosity of about 20%, dust and other debris are not easy to enter the asphalt mixture with a 7~10% SMA-10 semi-open graded modified asphalt mixture surface layer, and the pores of the asphalt mixture are not easy to be blocked. The noise reduction effect is more lasting than that of conventional porous asphalt pavement structures, and the structural performance is stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them: Figure 1 Schematic diagram of the pavement structure according to an embodiment of the present invention.

[0019] In the figure: semi-open graded modified asphalt mixture upper layer - 1, modified emulsified asphalt tack coat - 2, dense graded modified asphalt mixture middle layer - 3, second modified emulsified asphalt tack coat - 4, dense graded asphalt mixture lower layer - 5, synchronous crushed stone seal layer - 6, cement stabilized crushed stone base layer - 7, cement stabilized crushed stone subbase layer - 8. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0021] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0022] like Figure 1 As shown, a noise reduction asphalt pavement structure includes, from top to bottom, the semi-open-graded modified asphalt mixture upper layer 1, the first modified emulsified asphalt adhesive layer 2, the dense-graded modified asphalt mixture middle layer 3, the second modified emulsified asphalt adhesive layer 4, the dense-graded asphalt mixture lower layer 5, the synchronous crushed stone seal layer 6, the cement stabilized crushed stone base layer 7 and the cement stabilized crushed stone subbase layer 8; The void ratio of the upper layer 1 of the semi-open graded modified asphalt mixture is 7% to 10%; the gradation of the upper layer 1 of the semi-open graded modified asphalt mixture is SMA-10, and its raw materials include the following components in parts by mass: 5.8%~6.0% asphalt, 90%~91.2% mineral material, 2%~3% mineral powder, 0.3%~0.5% lignin fiber, the total mass of raw materials meets 100%.

[0023] The first modified emulsified asphalt adhesive layer 2 and the second modified emulsified asphalt adhesive layer 4 have the same composition, and the first modified emulsified asphalt adhesive layer 2 is SBS modified emulsified asphalt. SBS modified emulsified asphalt is a mature commercial product, and its performance meets JC / T975-2005 "Waterproof Coating for Roads and Bridges" and JC / T408-2005 "Water-emulsified Asphalt Waterproof Coating".

[0024] The grading of the surface layer 3 of the dense-graded modified asphalt mixture is AC-20C, and its raw materials include the following components in mass fractions: 3.9%~4.1% asphalt, 94.5%~95.5% mineral material, 0.8%~1% mineral powder, and the total mass of the raw materials meets 100%.

[0025] The lower layer 5 of the dense-graded asphalt mixture is graded AC-25C, and its raw materials include the following components in mass fractions: 3.5%~3.7% asphalt, 95.5%~96.5% mineral material, 0.5%~0.8% mineral powder, and the total mass of the raw materials meets 100%.

[0026] The synchronous chip seal 6 is a SBS modified asphalt synchronous chip seal 6, and the amount of SBS modified asphalt is 2.0-2.4 kg / m 2 , spread 60~70% of the gravel, the amount of gravel spread is 9~11m per 1000 square meters 3 The particle size of the gravel is 13.2~19mm.

[0027] The cement content of the cement stabilized crushed stone base 7 is 5% (cement mass / crushed stone mass); the maximum aggregate particle size should not exceed 31.5mm, and the mass percentage of components ≥5mm should not be less than 60%; when the fine-grained soil below 0.5mm in the aggregate has a plasticity index, the content of particles smaller than 0.075mm should not exceed 3.5%, and when the fine-grained soil below 0.5mm in the aggregate has no plasticity index, the content of particles smaller than 0.075mm should not exceed 5%. The raw materials of the cement stabilized crushed stone base 7 are used to make test specimens by vibration molding, and the representative strength value of the test specimens is 5.0~7.0Mpa.

[0028] The cement content of the cement stabilized crushed stone subbase 8 is 4% (cement mass / crushed stone mass); the maximum aggregate particle size should not exceed 31.5mm, and the mass percentage of components ≥5mm should not be less than 50%; when the fine-grained soil below 0.5mm in the aggregate has a plasticity index, the content of particles smaller than 0.075m should not exceed 5%, and when the fine-grained soil below 0.5mm in the aggregate has no plasticity index, the content of particles smaller than 0.075m should not exceed 7%. The raw materials of the cement stabilized crushed stone base 7 are used to make test specimens by vibration molding method, and the representative strength value of the test specimens is 3.0~5.0Mpa. The gradation of cement stabilized crushed stone base 7 and subbase aggregate is shown in Table 1.

[0029] Table 1 Aggregate gradation of cement stabilized crushed stone

[0030] The biggest difference between the pavement structure proposed in this application and the traditional pavement structure lies in the upper layer. By setting the void ratio to 7% to 10%, the problem of easy blockage of the existing porous asphalt pavement is solved on the basis of ensuring the noise reduction effect, and the durability of the noise reduction effect is improved; at the same time, the joint action of each surface layer and the base enhances the pavement performance and service life, among which: The first modified emulsified asphalt adhesive layer 2 and the second modified emulsified asphalt adhesive layer 4 enhance the interlayer bonding force, ensure the close combination of the upper layer, the middle layer and the lower layer, and form a continuous and stable structural system; at the same time, based on the waterproof performance of asphalt, it can prevent the water infiltrating from the upper layer from continuing to infiltrate and causing damage to the lower pavement layer; The surface layer 3 of the dense-graded modified asphalt mixture is responsible for bearing vehicle loads, transferring stress, and dispersing pressure. Its dense-graded design helps to reduce road deformation and improve road durability and smoothness. The lower layer 5 of dense graded asphalt mixture further enhances the bearing capacity and stability of the road surface, and at the same time, as a transition layer between the base layer and the base layer, it helps to disperse the load borne by the base layer and reduce the deformation of the base layer; The synchronous crushed stone seal layer 6 has the functions of bonding and waterproofing, which can effectively improve the road service performance and extend the service life of the road; the synchronous crushed stone seal layer 6 makes the dense graded asphalt mixture lower layer 5 and the cement stabilized crushed stone base layer 7 closely combined, ensuring the stability and durability of the entire road surface structure and preventing road surface damage caused by uneven foundation settlement; The cement stabilized crushed stone base layer 7 and the cement stabilized crushed stone subbase layer 8 provide a solid foundation for the entire road surface structure, have high strength and good water stability, can ensure the stability of the road surface under various climatic conditions, and prevent road surface settlement and uneven deformation.

[0031] Furthermore, the thickness of the upper layer 1 of the semi-open graded modified asphalt mixture is 2-3 cm, the thickness of the middle layer 3 of the dense graded modified asphalt mixture is 6-8 cm, the thickness of the lower layer 5 of the dense graded asphalt mixture is 8-10 cm, the thickness of the synchronous crushed stone seal layer 6 is 0.5-1 cm, the thickness of the cement stabilized crushed stone base layer 7 is 36-40 cm and the thickness of the cement stabilized crushed stone subbase layer 8 is 20-25 cm.

[0032] In a preferred embodiment, the thickness of the upper layer 1 of the semi-open graded modified asphalt mixture is 3 cm, the thickness of the middle layer 3 of the dense graded modified asphalt mixture is 6 cm, the thickness of the lower layer 5 of the dense graded asphalt mixture is 8 cm, the thickness of the synchronous crushed stone seal layer 6 is 1 cm, the thickness of the cement stabilized crushed stone base layer 7 is 36 cm and the thickness of the cement stabilized crushed stone subbase layer 8 is 20 cm.

[0033] According to the layer thickness of the preferred embodiment, a test road was paved and tested according to conventional construction methods. The test road paved by the invention is recorded as Example 1, and Comparative Examples 1 and 2 are obtained by changing the upper layer.

[0034] In Example 1, the raw material composition is 5.9% asphalt, 91.6% mineral material, 2% mineral powder, 0.5% lignin fiber, and the total mass of the raw materials is 100%; the porosity is 8.2%, and the thickness is 3 cm; the asphalt used in the raw material is high-viscosity asphalt, which must meet the requirements of the National Standard of the People's Republic of China GB / T 30516-2014 "High-viscosity and High-elastic Road Asphalt", among which the most important indicators must meet: dynamic viscosity (60°C) greater than 20000Pa·s, elastic recovery (25°C) greater than 85%. The mineral raw material used is basalt, and the mineral material is the mineral powder obtained by grinding limestone.

[0035] The upper layer of Comparative Example 1 is a PAC-13 drainage asphalt mixture, whose raw material composition is 4.2% SBS modified asphalt, 93.8% mineral material, 2% mineral powder, and the total mass of the raw materials is 100%; the void ratio is 20.7%, and the thickness is 3 cm. Comparative Example 1 represents a traditional PAC-13 drainage asphalt pavement.

[0036] The upper layer of Comparative Example 2 is SMA-13 ​​asphalt mastic crushed stone mixture, and its raw material composition is 5.7% SBS modified asphalt, 91.9% mineral material, 2% mineral powder, 0.4% lignin fiber, and the total mass of the raw materials is 100%; the void ratio is 3.6%, and the thickness is 3 cm. Comparative Example 2 represents a common SMA-13 ​​asphalt pavement.

[0037] After the test road was paved, the sound pressure level of Example 1, Comparative Example 1 and Comparative Example 2 was tested by the trailer method (CPX method) for three consecutive years. The test speed was 70 km / h. The test results are as follows: Table 2 Noise test results

[0038] It can be seen from Table 2 that Example 1 can maintain almost the same noise reduction effect as that of Comparative Example 1, but the noise reduction effect of Comparative Example 1 is not long-lasting. In the third year, the sound pressure level increases, that is, the noise between the road surface and the tire increases, and the noise reduction effect is significantly reduced; while the noise reduction effect of Example 1 can still maintain the noise reduction effect after 2 years, indicating that its noise reduction effect is more durable than that of the conventional porous asphalt pavement structure.

[0039] According to the Highway Technical Condition Assessment Standard (JTG 5210-2018), the rutting index, damage index and structural strength index of Example 1, Comparative Example 1 and Comparative Example 2 were evaluated in the past three years. For these three indicators, the larger the value, the better the performance of the road section. From the test results in Table 3, it can be seen that from the perspective of road performance, the road performance of Example 1 is close to that of Comparative Example 2, while the rutting index, damage index and structural strength index of Comparative Example 1 decay significantly in the third year. It shows that the road performance of Example 1 and Comparative Example 2 is relatively stable, and the road performance of Example 1 of the present invention can basically reach the level of Comparative Example 2.

[0040] Table 3 Road performance test results

[0041] A comprehensive analysis of the noise reduction effects and road performance of Example 1, Comparative Example 1 and Comparative Example 2 shows that, from the perspective of noise reduction effect, the initial noise reduction effect of Example 1 is close to that of Comparative Example 1 (traditional PAC-13 drainage asphalt pavement), and its noise reduction effect is better and more stable over time; from the perspective of road performance, the road performance of Example 1 is close to that of Comparative Example 2 (common SMA-13 ​​asphalt pavement), and compared with Comparative Example 1 (traditional PAC-13 drainage asphalt pavement), the road performance is also more stable.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. A noise reduction asphalt pavement structure, characterized by: The invention comprises a semi-open graded modified asphalt mixture upper layer (1), wherein the void ratio of the semi-open graded modified asphalt mixture upper layer (1) is 7% to 10%; the thickness of the semi-open graded modified asphalt mixture upper layer (1) is 2 to 3 cm; the grade of the semi-open graded modified asphalt mixture upper layer (1) is SMA-10, and its raw materials include the following components in parts by weight: 5.8%~6.0% asphalt, 90%~91.2% mineral material, 2%~3% mineral powder, 0.3%~0.5% lignin fiber, the total mass of raw materials meets 100%.

2. The noise reduction asphalt pavement structure according to claim 1 is characterized in that: The invention comprises, from top to bottom, the semi-open-graded modified asphalt mixture upper layer (1), the first modified emulsified asphalt tack layer (2), the dense-graded modified asphalt mixture middle layer (3), the second modified emulsified asphalt tack layer (4), the dense-graded asphalt mixture lower layer (5), the synchronous crushed stone seal layer (6), the cement-stabilized crushed stone base layer (7) and the cement-stabilized crushed stone subbase layer (8).

3. The noise reduction asphalt pavement structure according to claim 2 is characterized in that: The first modified emulsified asphalt adhesive layer (2) and the second modified emulsified asphalt adhesive layer (4) have the same composition, and the first modified emulsified asphalt adhesive layer (2) is SBS modified emulsified asphalt.

4. The noise reduction asphalt pavement structure according to claim 2, characterized in that: The dense-graded modified asphalt mixture middle surface layer (3) is graded AC-20C, and its raw materials include the following components in parts by weight: 3.9%~4.1% asphalt, 94.5%~95.5% mineral material, 0.8%~1% mineral powder, the total mass of raw materials meets 100%.

5. The noise reduction asphalt pavement structure according to claim 2 is characterized in that: The lower layer (5) of the dense-graded asphalt mixture has a grading of AC-25C, and its raw materials include the following components in parts by weight: 3.5%~3.7% asphalt, 95.5%~96.5% mineral material, 0.5%~0.8% mineral powder, the total mass of raw materials meets 100%.

6. The noise reduction asphalt pavement structure according to claim 2, characterized in that: The synchronous chip seal (6) is a SBS modified asphalt synchronous chip seal (6), and the amount of SBS modified asphalt is 2.0-2.4 kg / m 2 , spread 60~70% of the gravel, the amount of gravel spread is 9~11m per 1000 square meters 3 The particle size of the gravel is 13.2~19mm.

7. The noise reduction asphalt pavement structure according to claim 2, characterized in that: The cement-stabilized crushed stone base (7) uses a skeleton-dense cement-stabilized crushed stone, the raw materials of which are cement, crushed stone and water, the cement mass / crushed stone mass = 5%, and the strength is 5.0-7.0 MPa.

8. The noise reduction asphalt pavement structure according to claim 2, characterized in that: The cement-stabilized crushed stone subbase (8) uses skeleton-dense cement-stabilized crushed stone, whose raw material composition is cement, crushed stone and water, cement mass / crushed stone mass=4%, and strength is 3.0~5.0Mpa.

9. The noise reduction asphalt pavement structure according to claim 2, characterized in that: The dosage of the first modified emulsified asphalt adhesive layer (2) and the second modified emulsified asphalt adhesive layer (4) is 0.4-0.6 L / m 2 The thickness of the surface layer (3) of the dense-graded modified asphalt mixture is 6 to 8 cm, the thickness of the lower layer (5) of the dense-graded asphalt mixture is 8 to 10 cm, the thickness of the synchronous crushed stone seal layer (6) is 0.5 to 1 cm, the thickness of the cement-stabilized crushed stone base layer (7) is 36 to 40 cm, and the thickness of the cement-stabilized crushed stone subbase layer (8) is 20 to 25 cm.

10. The noise reduction asphalt pavement structure according to claim 2, characterized in that: The thickness of the upper layer (1) of the semi-open graded modified asphalt mixture is 3 cm, and the dosage of the first modified emulsified asphalt adhesive layer (2) and the second modified emulsified asphalt adhesive layer (4) is 0.5 L / m 2 The thickness of the dense-graded modified asphalt mixture surface layer (3) is 6 cm, the thickness of the dense-graded asphalt mixture lower layer (5) is 8 cm, the thickness of the synchronous crushed stone seal layer (6) is 1 cm, the thickness of the cement-stabilized crushed stone base layer (7) is 36 cm, and the thickness of the cement-stabilized crushed stone subbase layer (8) is 20 cm.

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