Noise-reducing and flame-retardant pavement structure for tunnel

Abstract

The utility model relates to a tunnel noise-reducing and flame-retardant pavement structure, which aims to solve the problems of high noise and poor flame-retardant property of the conventional tunnel pavement. The tunnel noise-reduction and flame-retardant pavement structure sequentially comprises an upper surface layer, a middle surface layer, a lower surface layer, a base layer, a subbase layer, a stress absorption layer and a tunnel inverted arch from top to bottom, thermal spraying type modified asphalt is adopted between the upper surface layer and the middle surface layer to serve as a first bonding layer, and thermal spraying type modified asphalt is adopted between the middle surface layer and the lower surface layer to serve as a second bonding layer. A broken stone sealing layer is adopted between the lower surface layer and the base layer as a third bonding layer; wherein the upper surface layer is made of a macroporous asphalt mixture doped with a flame retardant, the middle surface layer is made of an asphalt mixture of SBS modified asphalt, and the lower surface layer is made of a rubber asphalt mixture. According to the tunnel noise-reducing and flame-retardant pavement structure, the fire retardant is doped in the surface layer, the ignition point of the pavement is improved, and the pavement surface layer adopts the macroporous asphalt mixture, so that the driving noise of the pavement is reduced, and the influence on driving and pedestrians is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of high-performance tunnel noise reduction, flame-retardant pavement structure. BACKGROUND

[0002] With the continuous construction of urban tunnel and the increase of tunnel traffic, the frequency of various tunnel disasters is increasing. Urban tunnel traffic presents characteristics such as frequent and periodic traffic congestion, which makes the probability of fire in urban tunnel higher and the difficulty of fire rescue and evacuation greater. Due to the narrow and closed space structure of the tunnel, once a fire occurs, the asphalt pavement laid in the tunnel is easy to become a fire source and release a large amount of toxic smoke, affecting personnel evacuation and rescue operations. At the same time, the noise of driving in the narrow space of the tunnel is very high, which is 3-7 db higher than that of conventional roads. In addition, as an important node of urban infrastructure, urban tunnel is an important guarantee for smooth operation of urban traffic. Therefore, the pavement structure in the tunnel not only needs to have higher fire resistance, but also needs to have low noise and high durability. SUMMARY

[0003] The utility model aims at solving the problems of high noise and poor flame-retardant performance of current tunnel pavement, and provides a tunnel noise reduction and flame-retardant pavement structure.

[0004] The tunnel noise reduction and flame-retardant pavement structure comprises an upper layer, a middle layer, a lower layer, a base layer, a bottom base layer, a stress absorption layer and a tunnel invert. The pavement structure comprises, from top to bottom, the upper layer, the middle layer, the lower layer, the base layer, the bottom base layer, the stress absorption layer and the tunnel invert. Hot spray modified asphalt is used as the first bonding layer between the upper layer and the middle layer, hot spray modified asphalt is used as the second bonding layer between the middle layer and the lower layer, and crushed stone seal coat (hot asphalt and crushed stone) is used as the third bonding layer between the lower layer and the base layer.

[0005] The upper layer uses macroporous asphalt mixture with added flame retardant, the middle layer uses SBS modified asphalt mixture, and the lower layer uses rubber asphalt mixture.

[0006] The tunnel noise reduction and flame-retardant pavement structure can enhance the flame-retardant performance of asphalt pavement, reduce pavement noise, improve the interlayer adhesion and crack resistance of each layer of pavement based on the existing tunnel pavement structure, and reduce the influence of expansion joints of tunnel invert (cement concrete pavement) and temperature and dry shrinkage cracks of semi-rigid base layer on reflective cracks.

[0007] The tunnel noise reduction and flame-retardant pavement structure has the following beneficial effects:

[0008] (1) The inorganic salt flame retardant is added to the surface layer of the tunnel pavement to improve the ignition point of the pavement and reduce the risk of pavement fire accidents.

[0009] (2) The road surface layer adopts large-pore asphalt mixture, reduces road driving noise, reduces the influence on driving and pedestrians, and achieves green environmental protection.

[0010] (3) The lower layer adopts rubber modified asphalt mixture, has excellent fatigue resistance and anti-reflection cracking ability, the upper part of the inverted arch adopts stress absorbing layer, reduces the risk of upward cracking of the inverted arch cement concrete expansion joint. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 It is the whole structure schematic view of the tunnel noise reduction and flame-retardant pavement structure. DETAILED DESCRIPTION

[0012] Specific implementation one: the tunnel noise reduction and flame-retardant pavement structure of the embodiment comprises an upper layer 1, a middle layer 2, a lower layer 3, a base layer 4, a bottom base layer 5, a stress absorbing layer 6 and a tunnel inverted arch 7, the pavement structure is sequentially the upper layer 1, the middle layer 2, the lower layer 3, the base layer 4, the bottom base layer 5, the stress absorbing layer 6 and the tunnel inverted arch 7 from top to bottom, hot spraying type modified asphalt is used as the first bonding layer 10 between the upper layer 1 and the middle layer 2, hot spraying type modified asphalt is used as the second bonding layer 9 between the middle layer 2 and the lower layer 3, and macadam seal coat (hot asphalt and macadam) is used as the third bonding layer 8 between the lower layer 3 and the base layer 4.

[0013] The upper layer 1 adopts large-pore asphalt mixture mixed with flame retardant, the middle layer 2 adopts SBS modified asphalt mixture, and the lower layer 3 adopts rubber asphalt mixture.

[0014] The high-performance tunnel noise reduction and flame-retardant pavement structure form of the embodiment improves the flame-retardant performance of the tunnel pavement, reduces the driving noise of the tunnel pavement, enhances the interlayer bonding and anti-reflection cracking ability, and prolongs the service life of the tunnel pavement.

[0015] Specific implementation two: different from the specific implementation one, the thickness of the upper layer 1 is 4-5 cm, and the void ratio of the large-pore asphalt mixture is 18%-25%.

[0016] Specific implementation three: different from the specific implementation one or two, the thickness of the middle layer 2 is 5-7 cm.

[0017] Specific implementation four: different from any one of the specific implementation one to three, the thickness of the lower layer 3 is 8-10 cm.

[0018] Specific implementation five: different from any one of the specific implementation one to four, the thickness of the base layer 4 is 20-25 cm.

[0019] The base layer of the embodiment uses semi-rigid base layer with cement dosage of 4.5% to 5.5%.

[0020] Specific embodiment six: the thickness of the bottom base layer 5 is 16 to 20 cm.

[0021] The base layer of the embodiment uses semi-rigid base layer with cement dosage of 3.5% to 4.5%.

[0022] The tunnel noise reduction and flame-retardant pavement structure comprises an upper surface layer 1, a middle surface layer 2, a lower surface layer 3, a base layer 4, a bottom base layer 5, a stress absorption layer 6 and a tunnel invert 7, and the pavement structure is sequentially arranged from top to bottom as the upper surface layer 1, the middle surface layer 2, the lower surface layer 3, the base layer 4, the bottom base layer 5, the stress absorption layer 6 and the tunnel invert 7, the hot spraying modified asphalt is used as the first bonding layer 10 between the upper surface layer 1 and the middle surface layer 2, the hot spraying modified asphalt is used as the second bonding layer 9 between the middle surface layer 2 and the lower surface layer 3, and the broken stone seal coat (hot asphalt and broken stone) is used as the third bonding layer 8 between the lower surface layer 3 and the base layer 4.

[0023] The thickness of the upper surface layer 1 is 4 cm, the macroporous asphalt mixture with added flame retardant is used to achieve the effects of noise reduction and flame retardation, the thickness of the middle surface layer 2 is 6 cm, the AC-20 asphalt mixture of SBS modified asphalt is used, the thickness of the lower surface layer 3 is 9 cm, the rubber asphalt mixture is used, the thickness of the base layer 4 is 23 cm, the semi-rigid base layer with cement dosage of 5% is used, the thickness of the bottom base layer 5 is 18 cm, the semi-rigid base layer with cement dosage of 4% is used, and the tunnel invert is cast in situ.

[0024] The macroporous asphalt mixture with added flame retardant refers to the addition of flame retardant in the mixing process of the asphalt mixture, the macroporous asphalt mixture OGFC-13 is used, the void ratio of the mixture is 18% to 25%, the Marshall stability is not less than 3.5 kN, the leakage test is less than 0.3%, the flying loss is less than 20%, and the dynamic stability is greater than 3000 times / mm.

[0025] The macroporous asphalt mixture OGFC-13 preferably uses high-viscosity modified asphalt, the dynamic adhesion is greater than 20000 Pa.s, the coarse aggregate uses basalt aggregate, and the fine aggregate selects limestone fine aggregate.

[0026] The flame retardant preferably uses inorganic salt flame retardant, has no lump in appearance, has a decomposition temperature greater than 280℃, has a particle size greater than 1000 mesh, and has a mixing ratio of 2% of the mass of the asphalt mixture, the oxygen index of the asphalt after adding the flame retardant is greater than 27%, and the smoke density is less than 75%.

[0027] The rubber asphalt mixture adopts rubber modified asphalt, fatigue life of which at 15 DEG C, 10Hz, control strain at 400με is not less than 100 million times.

[0028] The semi-rigid base layer is a base layer structure formed by uniformly mixing cement and aggregate, adding water and rolling, wherein when the cement dosage is 5%, the 7d unconfined compressive strength is 3.5-4.5MPa; and when the cement dosage is 4%, the 7d unconfined compressive strength is 3-4MPa.

[0029] The hot spray modified asphalt bonding layer adopts SBS modified asphalt, and the spreading amount is 0.4-0.7kg / m 2 .

[0030] The macadam seal coat is composed of SBS modified asphalt and 4.75-7.3mm size macadam, the spreading amount of SBS asphalt is 1-1.2kg / m 2 , the macadam spreading mass is 8-10kg / m 2 , and the macadam coverage rate is required to be 70%-80%.

[0031] The stress absorbing layer adopts SBS+rubber composite modified asphalt (SBS 4%-6%, rubber powder 15%-20%) and basalt coarse aggregate and limestone fine aggregate.

[0032] The embodiment provides a high-performance tunnel noise reduction and flame-retardant pavement structure, improves the flame-retardant performance of a tunnel pavement, reduces driving noise of the tunnel pavement, enhances the interlayer adhesion and the anti-reflection crack capacity, and prolongs the service life of the tunnel pavement.

Claims

1. A tunnel noise reduction and fire resistant pavement structure, characterized by The tunnel noise reduction and fire resistance pavement structure comprises an upper surface layer (1), a middle surface layer (2), a lower surface layer (3), a base layer (4), a bottom base layer (5), a stress absorption layer (6) and a tunnel inverted arch (7), and the pavement structure is sequentially provided with the upper surface layer (1), the middle surface layer (2), the lower surface layer (3), the base layer (4), the bottom base layer (5), the stress absorption layer (6) and the tunnel inverted arch (7) from top to bottom, the upper surface layer (1) and the middle surface layer (2) are provided with a first bonding layer (10) of hot spraying modified asphalt, the middle surface layer (2) and the lower surface layer (3) are provided with a second bonding layer (9) of hot spraying modified asphalt, and the lower surface layer (3) and the base layer (4) are provided with a third bonding layer (8) of gravel seal coat. The upper surface layer (1) is provided with macropore asphalt mixture mixed with a fire retardant, the middle surface layer (2) is provided with SBS modified asphalt mixture, and the lower surface layer (3) is provided with rubber asphalt mixture.

2. The tunnel noise reducing and fire resistant pavement structure of claim 1, wherein The thickness of the upper surface layer (1) is 4-5 cm, and the macropore asphalt mixture has a porosity of 18-25%.

3. The tunnel noise reducing and fire resistant pavement structure of claim 1, wherein The thickness of the middle surface layer (2) is 5-7 cm.

4. The tunnel noise reducing and fire resistant pavement structure of claim 1, wherein The thickness of the lower surface layer (3) is 8-10 cm.

5. The tunnel noise reducing and fire resistant pavement structure of claim 1, wherein The thickness of the base layer (4) is 20-25 cm.

6. The tunnel noise reducing and fire resistant pavement structure of claim 1, wherein The thickness of the bottom base layer (5) is 16-20 cm.

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