A low-noise, crack-resistant asphalt chip seal and its construction process

Abstract

The present invention relates to a low-noise anti-cracking asphalt gravel seal and a construction process, wherein the low-noise anti-cracking asphalt gravel seal comprises an asphalt gravel seal, an asphalt fiber seal and a micro-surface filler from bottom to top. The effect produced by the low-noise anti-cracking asphalt gravel seal of the present invention is that the surface is dense and flat, and the driving noise can be effectively reduced. In addition, the micro-surface filler of waste tire rubber powder can also effectively reduce the noise. The present invention also discloses a construction process, which includes making an asphalt gravel seal, opening traffic / rolling with a rubber-wheel roller, making an asphalt fiber seal, filling an MS-2 type waste tire rubber powder slurry mixture, vacuum absorbing water, and curing. The present invention adopts vacuum water absorption technology, which prolongs the construction season and significantly reduces the dependence on climate factors. Construction can be carried out as long as it does not rain or freeze, and traffic can be opened after construction.

Description

Technical Field

[0001] The invention relates to the technical field of road engineering, and in particular to a low-noise, crack-resistant asphalt chip seal and a construction process. Background Art

[0002] Asphalt chip seal is a single-layer asphalt chip seal formed by spreading / scattering the bonding materials asphalt and gravel on the road surface through natural rolling. Its construction methods are divided into asynchronous asphalt chip seal and synchronous asphalt chip seal. The asphalt and gravel in asynchronous asphalt chip seal are spread / scattered separately. The asphalt is spread by an asphalt spreader, and then the gravel is spread by a gravel spreader. The asphalt and gravel in synchronous asphalt chip seal are spread / scattered by a synchronous asphalt chip sealer. It spreads asphalt first and then gravel. They are almost synchronous. At present, synchronous asphalt chip seal is mainly used in engineering practice.

[0003] Asphalt gravel seal has good anti-skid and anti-seepage properties, and can effectively cure road oil deficiency, grain loss, slight cracking, rutting, subsidence and other diseases. It is mainly used for preventive and corrective maintenance of roads, as well as to improve the anti-skid performance of high-grade roads. This new maintenance technology can be used for both highways and ordinary roads. In France and Europe, more than 95% of roads use asphalt gravel seal for road maintenance. In addition, asphalt gravel seal can also be used directly as the surface layer of low-grade roads. In France, more than 40% of roads directly use asphalt gravel seal as the road surface, and the engineering application effect is good; in my country, a large number of rural roads are suitable for the use of asphalt gravel seal as the road surface. Furthermore, asphalt gravel seal has the advantages of low cost, fast construction speed, high efficiency, and little impact on traffic. Therefore, asphalt gravel seal is also widely used in my country, and is increasing rapidly.

[0004] The disadvantages of asphalt chip seal are: the uneven surface causes the wheels to produce high-frequency, low-amplitude vibrations, resulting in loud driving noise, both inside and outside the car, which seriously affects the comfort of the ride and causes greater noise pollution to the environment; in addition, the crack resistance of asphalt chip seal needs to be further improved.

[0005] At present, there is a Cape seal, but the construction of emulsified asphalt slurry mixture is heavily dependent on hot and sunny weather. It is generally not possible to construct it when the temperature is below 15℃, it is cloudy or it is humid. Therefore, the construction of emulsified asphalt slurry mixture can only be carried out in sunny weather from May to October in a year. Summary of the invention

[0006] The problem to be solved by the present invention is to reduce the driving noise of the asphalt chip seal, improve the riding comfort, reduce the noise pollution to the environment, and improve the crack resistance of the asphalt chip seal, and reduce the serious dependence of the construction on high temperature and fine weather.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A low-noise, crack-resistant asphalt chip seal comprises an asphalt chip seal, an asphalt fiber seal and a micro-surfacing filler from bottom to top.

[0009] Furthermore, the asphalt used for the asphalt gravel seal is rubber asphalt, that is, asphalt modified with waste tire rubber powder, and its quality meets the requirements of (JT / T 798-2011) "Rubber Asphalt of Waste Tire Rubber Powder for Highway Engineering"; the model and quality of the crushed stone used meet the requirements of (JTG F40-2004) "Technical Specifications for Highway Asphalt Pavement Construction"; the amount of rubber asphalt and crushed stone meets the requirements of (JTG F40-2004) "Technical Specifications for Highway Asphalt Pavement Construction".

[0010] Furthermore, the asphalt used in the asphalt fiber seal layer is SBR modified emulsified asphalt, and the amount used is 200kg / 1000m per layer. 2 ~300kg / 1000m 2 The fiber used is a mixture of one or more of glass fiber, polyacrylic fiber, polyester fiber, lignin fiber, mineral fiber and steel fiber. The fiber length is controlled at 5cm to 10cm, and the fiber dosage is 80kg / 1000m 2 ~160kg / 1000m 2 .

[0011] Furthermore, the micro-surfacing model of the micro-surfacing filler is MS-2; the quality of the materials used meets the requirements of (JTG F40-2004) "Technical Specifications for Highway Asphalt Pavement Construction".

[0012] Furthermore, the micro-surfacing filler is a material formed by filling the gaps between gravel with an emulsified asphalt slurry mixture mixed with waste tire rubber powder (referred to as waste tire rubber powder slurry mixture) and curing. The waste tire rubber powder slurry mixture is specifically composed of substances in the following mass ratio: stone aggregate: waste tire rubber powder: emulsified asphalt: water: additive = 97.5-98.5: 1.5-2.5: 12-15: 12-17: 4-8: 0-0.5.

[0013] Furthermore, the mix ratio design method of the waste tire rubber powder slurry mixture is:

[0014] 1) According to the requirements and methods of (JTG F40-2004) "Technical Specifications for Highway Asphalt Pavement Construction", the stone aggregate mix ratio of MS-2 slurry mixture is designed to obtain the stone aggregate mix ratio;

[0015] 2) Use waste tire rubber powder and other weight to replace the fine aggregate in the stone aggregate, and use the waste tire rubber powder as part of the stone aggregate. The replacement amount is 1.5% to 2.5% of the weight of the stone aggregate, and the mix ratio of the waste tire rubber powder slurry mixture aggregate is obtained, that is, stone aggregate: waste tire rubber powder;

[0016] 3) According to the aggregate of waste tire rubber powder slurry mixture, the dosage of emulsified asphalt, water and additives is determined in accordance with the requirements and methods of (JTG F40-2004) "Technical Specifications for Highway Asphalt Pavement Construction" to obtain the mix ratio of waste tire rubber powder slurry mixture, that is, waste tire rubber powder slurry mixture aggregate: emulsified asphalt: water: additives.

[0017] A low-noise, crack-resistant asphalt chip seal construction process comprises the following steps:

[0018] The first step is to make asphalt chip seal

[0019] According to the requirements of (JTG F40-2004) "Technical Specifications for Highway Asphalt Pavement Construction", asphalt gravel seal layer is made, and asphalt and gravel are spread / spread synchronously or asynchronously;

[0020] Step 2: Open to traffic / rolling with rubber-tyred rollers

[0021] The traffic opening time is at least 24 hours; or the rubber-wheel roller is used to roll evenly and the gravel is stable; or for places that cannot be rolled by vehicles, the rubber-wheel roller is used to roll to make the gravel stable;

[0022] The third step is to make asphalt fiber seal

[0023] The asphalt fiber seal layer is composed of two layers of asphalt and one layer of fiber. The construction method is to spread the first layer of asphalt, spread the fiber, and spread the second layer of asphalt. The two layers of asphalt and fiber are spread synchronously or asynchronously.

[0024] Step 4: Filling MS-2 waste tire rubber powder slurry mixture

[0025] According to the requirements of (JTG F40-2004) "Technical Specifications for Highway Asphalt Pavement Construction", MS-2 waste tire rubber powder slurry mixture is mixed / paved on the asphalt gravel seal layer and asphalt fiber seal layer to fill the concave parts on the surface;

[0026] Step 5: Vacuum water absorption

[0027] Start the vacuum pump, the vacuum degree in the waste tire rubber powder slurry mixture gradually increases, and the water is sucked out. When the water absorption is normal, the vacuum degree is controlled at 0.08MPa. When no water can be sucked out, the vacuum degree is gradually increased to absorb water until the vacuum degree increases to 0.13MPa. When no water can be sucked out for 2 minutes, the water absorption is terminated;

[0028] Step 6: Maintenance

[0029] Maintenance means spreading the curing material. The curing material can be spread after vacuum absorption of water. Its function is to prevent the asphalt from sticking to the wheels. After that, the road can be opened to traffic.

[0030] Furthermore, the curing material is stone chips, and the amount is 1-2 m 3 / 1000m 2 .

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. If Figure 1 The surface of the asphalt chip seal is uneven, and cars driving on it will produce high-frequency, low-amplitude vibrations, which will cause a lot of noise; Figure 2 The low-noise, crack-resistant asphalt chip seal of the present invention has the effect of making the surface dense and smooth, which can effectively reduce driving noise. In addition, the waste tire rubber powder micro-surface filler can also effectively reduce noise. Studies have found that the noise inside and outside the car can be reduced by 3dB to 7dB, which is equivalent to or even lower than asphalt concrete, which can improve the comfort of riding and reduce the pollution of driving noise to the environment.

[0033] 2. Another effect brought by the present invention is that the crack resistance is significantly improved. The first reason is that waste tire rubber powder rubber asphalt is used. It is a highly viscous, highly elastic and crack-resistant binder with strong low-temperature deformation ability and elastic recovery ability. The waste tire rubber powder particles can induce a large number of silver streaks, offset and disperse tensile stress, and prevent cracks; the second reason is that the asphalt fiber layer is used, and the fiber plays a reinforcing role in the structural layer. The simultaneous use of rubber asphalt and fiber achieves a strong superposition, resulting in a significant improvement in the crack resistance of the structural layer.

[0034] 3. The construction of micro-surfacing is heavily dependent on climatic factors. It is generally required to be carried out in fine weather from May to October, and the molding time (opening traffic time) is 2h to 3h. The molding time is very long in wet weather and other months, and construction is generally not carried out. The present invention adopts vacuum water absorption technology, which extends the construction season and significantly reduces the dependence on climatic factors. As long as it is not raining or freezing, construction can be carried out, and traffic can be opened after construction.

[0035] 4. In the emulsified asphalt slurry mixture, water first forms a water film on the aggregate surface, and then the emulsified asphalt breaks, and then an asphalt film is gradually formed outside the water film, which greatly reduces the bonding force between asphalt and aggregate. Under the condition of natural volatilization, the water wrapped by the asphalt film cannot be volatilized for a long time, resulting in a shortened service life of the micro-surface. The vacuum water absorption construction technology of the present invention can absorb most of the water wrapped by the asphalt film, reducing the adverse effect of water on the bonding force between asphalt and aggregate, which is beneficial to improving the service life of the micro-surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a structural schematic diagram of an existing asphalt chip seal;

[0037] Figure 2 It is a schematic diagram of the structure of the low-noise and crack-resistant asphalt chip seal layer of the present invention;

[0038] In the figure, 1. Rubber asphalt; 2. Gravel; 3. Asphalt fiber seal layer; 4. Micro-surface filling material; 5. Lower supporting layer. DETAILED DESCRIPTION

[0039] The technical solution and effects of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

[0040] Example 1

[0041] The technical solution of the present invention is described in detail by taking a 15 mm thick low noise and crack resistant asphalt chip seal as an example.

[0042] like Figure 2 As shown, the low noise and crack resistant asphalt chip seal layer of this embodiment includes an asphalt chip seal layer, an asphalt fiber seal layer 3 and a micro-surfacing filler 4 from bottom to top. The asphalt chip seal layer is arranged on the lower bearing layer 5 and is composed of rubber asphalt 1 and crushed stone 2.

[0043] According to the requirements of (JTG F40-2004) "Technical Specifications for Highway Asphalt Pavement Construction", the amount of asphalt chip seal material selected in this embodiment is: rubber asphalt 1 is 1.5kg / m 2 、S10 gravel 2 is 14m 3 / 1000m 2 .

[0044] The asphalt fiber seal layer 3 of this embodiment is composed of two layers of SBR modified emulsified asphalt and a layer of 5cm-10cm long lignin fiber. The amount of SBR modified emulsified asphalt is 250kg / 1000m per layer. 2 , fiber dosage 120kg / 1000m 2 .

[0045] The waste tire rubber powder slurry mixture of this embodiment is specifically composed of the following materials in the following mass ratio: rice stone: stone chips: waste tire rubber powder: emulsified asphalt: water = 30:68:2:15:5, where the emulsified asphalt is SBR modified emulsified asphalt.

[0046] The mix design process is:

[0047] According to the requirements and methods of (JTG F40-2004) "Technical Specifications for Highway Asphalt Pavement Construction", the MS-2 slurry mixture stone aggregate mix ratio design is carried out. The design result is: rice stone (2.36mm ~ 4.75mm crushed stone): stone chips = 30:70;

[0048] The amount of waste tire rubber powder is 2% of the weight of stone aggregate, that is, (30kg + 70kg) × 2% = 2kg. 2kg of waste tire rubber powder is used to replace fine aggregate (stone chips), and the aggregate mix ratio of waste tire rubber powder slurry mixture is: rice stone: stone chips: waste tire rubber powder = 30:68:2;

[0049] According to the aggregate proportion of waste tire rubber powder slurry mixture, that is, rice stone: stone chips: waste tire rubber powder = 30:68:2, the amount of emulsified asphalt, water and additives is determined in accordance with the requirements and methods of (JTG F40-2004) "Technical Specifications for Highway Asphalt Pavement Construction". The design result is: aggregate of waste tire rubber powder slurry mixture: emulsified asphalt: water = 100:15:5, and no additives are required, that is, rice stone: stone chips: waste tire rubber powder: emulsified asphalt: water = 30:68:2:15:5.

[0050] The low noise and crack resistant asphalt chip seal construction process of this embodiment includes the following steps:

[0051] The first step is to make asphalt chip seal

[0052] Load hot rubber asphalt 1 and S10 gravel 2 at 170℃~190℃ into the synchronous asphalt gravel seal vehicle; spread / spread asphalt 1 and gravel 2 simultaneously; the construction technical requirements comply with (JTG F40-2004) "Technical Specifications for Highway Asphalt Pavement Construction".

[0053] Step 2: Open to traffic / rolling with rubber-tyred rollers

[0054] The traffic is open for at least 24 hours; traffic control is required to ensure that vehicles can roll evenly and the gravel 2 is stable; for places that cannot be rolled by vehicles, a 9-16t rubber-wheeled roller is used to roll 4-6 times to stabilize the gravel 2.

[0055] The third step is to make asphalt fiber seal 3

[0056] Load the emulsified asphalt and lignin fiber into the synchronous asphalt fiber sealing machine; spread the first layer of emulsified asphalt, spread the lignin fiber and spread the second layer of emulsified asphalt simultaneously. The construction technical requirements comply with (JTG F40-2004) "Technical Specifications for Highway Asphalt Pavement Construction".

[0057] Step 4: Make MS-2 micro-surfacing filler 4

[0058] 1) Mixing aggregate and charging

[0059] Prepare the waste tire rubber powder slurry mixture aggregate in the ratio of rice stone: stone chips: waste tire rubber powder = 30:68:2, and load the waste tire rubber powder slurry mixture aggregate, emulsified asphalt and water into the slurry sealing vehicle;

[0060] 2) Mixing / spreading waste tire rubber powder slurry mixture

[0061] Drive the slurry seal vehicle onto the asphalt gravel seal and the asphalt fiber seal 3 to mix / spread the waste tire rubber powder slurry mixture. The spreading amount of the waste tire rubber powder slurry mixture is based on filling the concave parts on the surface of the asphalt gravel seal and the asphalt fiber seal 3.

[0062] 3) Vacuum water absorption

[0063] The vacuum dehydration starts 15 minutes after the waste tire rubber powder slurry mixture is spread, that is, after the waste tire rubber powder slurry mixture breaks;

[0064] The vacuum water absorption process is: start the vacuum pump to gradually increase the vacuum degree in the waste tire rubber powder slurry mixture to absorb the water. When the water absorption is normal, the vacuum degree is controlled at 0.08MPa. When no water can be absorbed, the vacuum degree is gradually increased to absorb water until the vacuum degree increases to 0.13MPa. When no water can be absorbed for 2 minutes, the water absorption is terminated.

[0065] The vacuum water absorption equipment includes: vacuum water absorption filter cloth, vacuum water absorption pad, vacuum water absorption pipe and vacuum pump. The vacuum water absorption filter cloth is laid on the paved waste tire rubber powder slurry mixture, and the vacuum water absorption pad is laid on it. The vacuum water absorption pad is connected to the vacuum pump through the vacuum water absorption pipe. The vacuum pump is turned on to suck out the water generated after the emulsified asphalt is demulsified. When the vacuum water absorption pad is laid, the emulsified asphalt cement slurry with a thickness of 5mm and a width of 30mm to 50mm is filled around and between the road surface, and it is pressed and sealed; the emulsified asphalt cement slurry is made by mixing cement and emulsified asphalt, and its consistency requirement is 0.5cm to 1cm, and in this case it is 0.6cm. Among them: the size of the vacuum water-absorbing filter cloth is 3.1m×20m, the size of the vacuum water-absorbing pad is 3.2m×20.2m, the width of the paving box, vacuum water-absorbing filter cloth and vacuum water-absorbing pad are at least 10cm wide, and the length of the vacuum water-absorbing filter cloth and vacuum water-absorbing pad are at least 20cm long. Their length can be adjusted based on the principle of construction convenience.

[0066] After vacuuming is completed, remove the emulsified asphalt cement slurry.

[0067] Research shows that the molding time of the waste tire rubber powder micro-surface filling material is directly related to the water content in the paved waste tire rubber powder slurry mixture, that is, it is directly related to the speed of water consumption. The faster the water consumption rate, the shorter the time to open traffic, and vice versa. Research shows that when the total water content (the sum of the added water and the water generated after the emulsified asphalt is demulsified) in the waste tire rubber powder slurry mixture is consumed by 70% to 80%, the conditions for opening traffic are met. Through vacuum water absorption, the total water content can be absorbed by more than 90%, so traffic can be opened as soon as possible after vacuum water absorption.

[0068] 4) Maintenance

[0069] Spread the stone chips as curing material, the amount is 1.5m 3 / 1000m 2 The waste tire rubber powder slurry mixture is cured and formed into the waste tire rubber powder micro-surface filling material 4, and then it can be opened to traffic.

[0070] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A low-noise, crack-resistant asphalt chip seal construction process, characterized in that: The low-noise and crack-resistant asphalt chip seal layer comprises an asphalt chip seal layer, an asphalt fiber seal layer and a micro-surface filler from bottom to top; The asphalt gravel seal is arranged on the lower bearing layer and is composed of rubber asphalt and gravel; the rubber asphalt is 1.5kg / m 2 、S10 gravel is 14m 3 / 1000m 2 ; The asphalt fiber seal layer consists of two layers of SBR modified emulsified asphalt and a layer of 5cm-10cm long lignin fiber. The amount of SBR modified emulsified asphalt is 250kg / 1000m per layer. 2 , fiber dosage 120kg / 1000m 2 ; The micro-surfacing model of the micro-surfacing filler is MS-2. The micro-surfacing filler is an emulsified asphalt slurry mixture mixed with waste tire rubber powder. The waste tire rubber powder slurry mixture is specifically composed of the following mass ratios: rice stone: stone chips: waste tire rubber powder: emulsified asphalt: water = 30:68:2:15:5, and the emulsified asphalt is SBR modified emulsified asphalt; The construction process comprises the following steps: The first step is to make asphalt chip seal Load the hot rubber asphalt and S10 crushed stone at 170℃~190℃ into the synchronous asphalt crushed stone sealing vehicle; spread / spread asphalt and crushed stone simultaneously; Step 2: Open to traffic / rolling with rubber-tyred rollers The traffic should be open for at least 24 hours; traffic control is required to ensure that vehicles can roll evenly and the gravel is stable; for areas that cannot be rolled by vehicles, 9-16t rubber-wheeled rollers should be used to roll 4-6 times to stabilize the gravel; The third step is to make asphalt fiber seal Loading emulsified asphalt and lignin fiber into a synchronous asphalt fiber sealing machine; simultaneously spreading a first layer of emulsified asphalt, spreading lignin fiber and spreading a second layer of emulsified asphalt; Step 4: Make MS-2 micro-surfacing filler 1) Mixing aggregate and charging Prepare the waste tire rubber powder slurry mixture aggregate in the ratio of rice stone: stone chips: waste tire rubber powder = 30:68:2, and load the waste tire rubber powder slurry mixture aggregate, emulsified asphalt and water into the slurry sealing vehicle; 2) Mixing / spreading waste tire rubber powder slurry mixture Drive the slurry sealer to the asphalt gravel seal and asphalt fiber seal to mix / spread the waste tire rubber powder slurry mixture. The amount of the waste tire rubber powder slurry mixture to be spread should be enough to fill the concave parts on the surface of the asphalt gravel seal and asphalt fiber seal; 3) Vacuum water absorption The vacuum dehydration starts 15 minutes after the waste tire rubber powder slurry mixture is spread, that is, after the waste tire rubber powder slurry mixture breaks; The vacuum water absorption process is as follows: start the vacuum pump to gradually increase the vacuum degree in the waste tire rubber powder slurry mixture to absorb the water. When the water absorption is normal, the vacuum degree is controlled at 0.08MPa. When no water can be absorbed, the vacuum degree is gradually increased to absorb water until the vacuum degree increases to 0.13MPa. When no water can be absorbed for 2 minutes, the water absorption is terminated. 4) Maintenance Spread the stone chips as curing material, the amount is 1.5m 3 / 1000m 2 The waste tire rubber powder slurry mixture is formed after curing to become the waste tire rubber powder micro-surface filling material, and then it can be opened to traffic.

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