CN108643037B - A kind of bridge asphalt pavement structure and method of construction - Google Patents

Abstract

The invention discloses a bridge asphalt pavement structure and a construction method. The structure includes a roadbed and an upper layer laid on the roadbed. The upper layer has expansion joints in the longitudinal direction, and the upper layer includes an asphalt concrete layer and an asphalt mixture layer in the lower layer. The asphalt mixture layer includes densely graded asphalt mixture and open grade asphalt mixture, and the thickness of the asphalt mixture layer is 1.8-2.3cm. During construction, part of the upper layer shall be removed first, and then densely graded asphalt mixture and open-graded asphalt mixture shall be laid. This construction method only needs to remove about half of the thickness of the upper layer of the road surface, which is more energy-saving and environmentally friendly; after the thickness of the removal becomes smaller, the construction time is relatively shortened, construction noise and dust pollution will also be reduced, and the interference to existing traffic and surrounding residents will be reduced. Small; the combination of open-graded asphalt mixture and dense-graded asphalt mixture is conducive to drainage and noise absorption, making the road safer. The invention is used in the field of road construction.

Description

Bridge asphalt pavement structure and construction method

technical field

The invention relates to the field of road surface construction, in particular to a bridge asphalt pavement structure and a construction method.

Background technique

The asphalt material has high compressibility and can buffer the vertical vibration of vehicles; it does not need to be grooved on the surface of the road surface in order to increase the anti-skid performance like cement pavement; it is convenient to construct, and the construction process has little interference with the traffic arteries. Based on the above advantages, the existing bridge pavement structure is dominated by asphalt concrete pavement.

The traditional asphalt pavement surface layer is generally divided into two or three layers according to the pavement grade. The two layers are the upper layer and the lower layer, and the three layers are the upper layer, the middle layer and the lower layer. Generally, densely graded asphalt concrete is used. For the choice of particle size, the upper layer of the three-layer structure is AC-13 or SMA13, the middle layer is AC-20 or SMA20, and the lower layer is AC-25; the upper layer of the two-layer structure is AC-13 or SMA13, the lower layer is AC-20. The particle size selection of the surface layer generally follows the principle of fine top and coarse bottom, and is continuous. For example, the upper layer is AC-13, and the middle surface layer is AC-20, instead of AC-25 across AC-20. The thickness of each layer of asphalt surface layer is generally 2.5 to 3 times the nominal maximum particle size of the aggregate. According to this principle, the thickness of the upper layer is 4 to 6 cm, generally 4 cm. During the construction of the bridge pavement structure, if the pavement structure is within the design period, and the integrity of the surface layer is shown to be good by core pulling, only the upper layer needs to be constructed. The construction method is to remove the entire 4cm upper layer, and then add the same level Asphalt mixture with matching, particle size and thickness.

Each kind of asphalt mixture has its own advantages and disadvantages. If densely graded asphalt mixture is laid on the upper layer, although it has a good waterproof effect, it will be accompanied by problems such as rapid attenuation of anti-skid performance, loud noise and water drift; if using It is an open-graded asphalt mixture. Although it has good anti-skid performance and noise absorption function, it is necessary to reserve gaps and drainage paths inside the structure of the open-graded asphalt mixture. The gaps are easy to mix with debris on the road surface and damage its original effect. If open-graded asphalt mixture is used on the bridge pavement, there will be two main problems. The first problem is the above-mentioned drainage problem. In view of the defects of open-graded asphalt mixture, this scheme is used for commonly used open-graded asphalt mixture. After reflection, it is believed that the layer thickness of this gradation is the main cause of drainage defects; the second problem is that if all the graded asphalt mixture is spread out, the water inside the pavement structure will flow longitudinally at this time, causing damage to the expansion joints. Negative Effects.

The traditional solution is that the entire upper layer is an asphalt concrete structure, the thickness is too large, and various fillers are easily mixed inside the upper layer. After the upper layer is dense, its various functions are greatly reduced.

Contents of the invention

The object of the present invention is to provide a bridge asphalt pavement structure and construction method, which has the advantages of good drainage effect and low construction cost.

The technical scheme that the present invention takes is:

A bridge asphalt pavement structure, comprising a roadbed and an upper layer laid on the roadbed, side stones are arranged on both lateral sides of the upper layer, expansion joints are provided in the longitudinal direction of the upper layer, and the upper layer includes an asphalt concrete layer on the lower side and a The asphalt mixture layer on the upper side, the asphalt mixture layer includes densely graded asphalt mixture near the left and right sides of the expansion joint and open grade asphalt mixture far away from the expansion joint, the thickness of the asphalt mixture layer is 1.8-2.3cm.

As an improvement of the above scheme, the open-graded asphalt mixture contains high-viscosity asphalt.

As an improvement of the above scheme, the width of the two densely graded asphalt mixtures located on both sides of the expansion joint is 4-6m.

As an improvement of the above scheme, the thickness of the asphalt mixture layer is 2 cm, the width of the densely graded asphalt mixture is 5 m, and the maximum particle size of the open graded asphalt mixture is less than 10 mm.

A construction method for constructing the bridge asphalt pavement structure as above, comprising the following steps:

a. Cut off part of the thickness of the upper layer to expose the asphalt concrete layer, and then remove the floating dust and debris on the road surface;

b. Laying open-graded asphalt mixture and dense-graded asphalt mixture;

c. Open traffic after the temperature of the upper layer is lower than the acceptance standard.

As an improvement of the above scheme, half of the pavement is closed before the upper layer is removed, and the construction is carried out in a side-by-side manner.

As an improvement of the above scheme, in step b, the open-graded asphalt mixture on both sides is laid first, and then the dense-graded asphalt mixture in the middle is laid.

Beneficial effects of the present invention: this construction method only needs to remove about half of the thickness of the upper layer of the road surface. Compared with the traditional method of removing the entire upper layer, there are fewer waste materials and fewer materials for overlaying, which is more energy-saving and environmentally friendly; Similarly, after the removal thickness becomes smaller, the construction time is relatively shortened, the construction noise and dust pollution will also be reduced, and the interference to existing traffic and surrounding residents will be reduced; the combination of open-graded asphalt mixture and dense-graded asphalt mixture, It is conducive to drainage and noise absorption, making the road safer.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing:

Figure 1 is a cross-sectional view of the pavement structure;

Fig. 2 is a top view of the pavement structure.

Detailed ways

In terms of the drainage path inside the structure, it can be divided into two types according to the situation: when it rains, the pavement is drained vertically; when it is sunny, it is drained through evaporation. Side stones 3 are arranged on the left and right side edges of the road paved with asphalt for supporting, and the top surface of the side stones 3 will be higher than the elevation of the road surface, so the side stones 3 block the lateral drainage of moisture inside the road surface. Based on the direction in Figure 2, the longitudinal direction of the road surface refers to the left and right directions, that is, the extending direction of the road surface; the horizontal direction of the road surface refers to the up and down direction, that is, the width direction of the road surface. During the rainy period, the water retained by the pavement structure has two flow directions, vertical and horizontal. When the water flows in the horizontal direction, it will be blocked by the side stones 3, and then the water will rush to the surface of the pavement, and then flow away in the vertical direction.

With reference to Fig. 1, Fig. 2, the present invention is a kind of bridge asphalt pavement structure, comprises subgrade 1 and the upper layer 2 that is laid on the subgrade 1, side stone 3 is arranged on the transverse both sides of upper layer 2, the longitudinal direction of upper layer 2 With expansion joints 4 , the upper layer 2 comprises an asphalt concrete layer 21 on the lower side and an asphalt mixture layer 22 on the upper side. The asphalt mixture layer 22 includes densely graded asphalt mixture 222 close to the left and right sides of the expansion joint 4 and openly graded asphalt mixture 221 far away from the expansion joint 4. The thickness of the asphalt mixture layer 22 is 1.8-2.3 cm.

The study found that the thickness of the open-graded asphalt mixture 221 can be skillfully controlled to reduce the amount of water retained inside the road surface, correspondingly reduce the amount of water gushing up on both sides of the road surface, and reduce the interference of gushing water on the road surface. At the same time, the thinner open-graded asphalt mixture 221 helps to increase the evaporation rate of water after the weather is fine. After the thickness is reduced, the residual moisture in the upper layer 2 can easily flow out of the upper layer 2 under the action of the dynamic load of the vehicle and the traction of the water itself; for bridge structures, the longitudinal flow of water in the upper layer 2 will affect the life of the expansion joint 4, so The pavement near the expansion joint 4 should avoid moisture accumulation, so the densely graded asphalt mixture 222 is used here.

As a preferred embodiment, the open-graded asphalt mixture 221 contains high-viscosity asphalt, because the open-graded asphalt mixture 221 has relatively large voids, and if it contains high-viscosity asphalt, it can be more effectively combined into a whole.

As a preferred embodiment, the width of the two densely graded asphalt mixtures 222 located on both sides of the expansion joint 4 is 4-6 m.

The preferred size is that the thickness of the asphalt mixture layer 22 is 2 cm, that is, the thickness of the open-graded asphalt mixture 221 and the dense-graded asphalt mixture 222 are both 2 cm; the width of the dense-graded asphalt mixture 222 is 5 m; The maximum particle size of the asphalt mixture 221 is less than 10mm.

A construction method for constructing the bridge asphalt pavement structure as above, comprising the following steps:

a. Close half of the pavement in turn, and use the pavement side-by-side method for construction, usually at night;

b. Excavate part of the thickness of the upper layer 2 to expose the asphalt concrete layer, and then remove the floating dust and sundries on the road surface;

c. Lay open-graded asphalt mixture 221 and densely-graded asphalt mixture 222, first lay open-graded asphalt mixture 221 on both sides, and then lay dense-graded asphalt mixture 222 in the middle;

d. Open traffic after the temperature of the upper layer 2 is lower than 50°C;

e. Next, construct the road on the other side.

This construction method only needs to remove about half of the thickness of the upper layer 2 of the pavement. Compared with the traditional method of removing the upper layer 2, there are fewer waste materials and less materials for overlaying, which is more energy-saving and environmentally friendly; After the thickness becomes smaller, the construction time is relatively shortened, construction noise and dust pollution will also be reduced, and the interference to existing traffic and surrounding residents will be reduced; the combination of open-graded asphalt mixture 221 and dense-graded asphalt mixture 222 is beneficial Water drainage and noise absorption make the road safer.

Of course, the present design creation is not limited to the above-mentioned embodiments, and the combination of different features of the above-mentioned embodiments can also achieve good effects. Those skilled in the art can also make equivalent modifications or replacements without departing from the spirit of the present invention, and these equivalent modifications or replacements are all included within the scope defined by the claims of the present application.

Claims (7)

1. a kind of bridge asphalt pavement structure, it is characterised in that: including roadbed (1) and be laid on roadbed (1) layer the upper surface of above (2), the both lateral sides of the upper layer (2) are equipped with kerbstone (3), and the longitudinal direction of the upper layer (2) has expansion joint (4), The upper layer (2) includes the asphalt concrete layer (21) in downside and asphalt layer (22) in upside, described Asphalt layer (22) includes the dense bitumen mixture (222) and separate expansion joint at left and right sides of expansion joint (4) (4) open gradation asphalt (221), the asphalt layer (22) with a thickness of 1.8~2.3cm.

2. bridge asphalt pavement structure according to claim 1, it is characterised in that: the open gradation asphalt (221) contain high-viscosity asphalt.

3. bridge asphalt pavement structure according to claim 2, it is characterised in that: be located at two of expansion joint (4) two sides The width of the dense bitumen mixture (222) is 4~6m.

4. bridge asphalt pavement structure according to claim 1 or 2 or 3, it is characterised in that: the asphalt layer (22) with a thickness of 2cm, the width of the dense bitumen mixture (222) is 5m, the open gradation asphalt (221) Maximum particle diameter be less than 10mm.

5. a kind of method of construction, special for bridge asphalt pavement structure as described in any one of claims 1 to 4 of constructing Sign be the following steps are included:

A, the segment thickness of upper layer (2) is excluded to asphalt concrete layer (21) are exposed, and the floating dust for then removing road surface is miscellaneous Object；

B, open gradation asphalt (221) and dense bitumen mixture (222) are laid with；

C, the open to traffic after the temperature of upper layer (2) is lower than acceptance criteria.

6. method of construction according to claim 5, it is characterised in that: first close half range road before excluding upper layer (2) Face is constructed using a point side mode.

7. method of construction according to claim 6, it is characterised in that: in the step b, be first laid with the open gradation drip of two sides Green mixture (221) re-lays intermediate dense bitumen mixture (222).