Warm-mixed rubber asphalt-based ultra-thin wearing course pavement and construction method thereof

Abstract

The application discloses a warm-mixed rubber asphalt-based ultra-thin wearing layer pavement and a construction method thereof.The warm-mixed rubber asphalt-based ultra-thin wearing layer pavement comprises, from bottom to top, a pavement crack repairing agent, a high-modulus tack coat and an ultra-thin wearing layer three-layer structure.The application makes full use of the advantages of rubber asphalt, such as good adhesion and strong water damage resistance, solves the problems of peeling, oil bleeding and insufficient anti-skid performance in rainy and snowy weather caused by the insufficient adhesion of traditional thin-layer overlay, greatly reduces the material cost compared with high-viscosity and high-elasticity ultra-thin wearing layer and NovaChip pavement, and solves the problem of insufficient compaction caused by high rubber asphalt mixing temperature by introducing the warm-mixing technology.The pavement crack repairing agent is used for repairing cracks, so that the original pavement becomes a whole, and the integrity and service life of the warm-mixed rubber asphalt-based ultra-thin wearing layer pavement are ensured.

Description

Technical Field

[0001] This invention belongs to the field of ultra-thin wearing course technology, specifically relating to a warm-mix rubber asphalt-based ultra-thin wearing course pavement and its construction method. Background Technology

[0002] Since the beginning of the 21st century, my country's highway mileage has been continuously updated. By the end of 2021, my country's transportation infrastructure construction had achieved new breakthroughs. The total length of highways open to traffic nationwide reached 5.28 million kilometers (including 169,000 kilometers of expressways). By 2035, the total scale of the national highway network will be approximately 461,000 kilometers, of which the future demand for the construction and renovation of national expressways is approximately 58,000 kilometers (including expansion and renovation of approximately 30,000 kilometers), and the planned total mileage of the ordinary national highway network is approximately 299,000 kilometers, with a future construction and renovation demand of approximately 110,000 kilometers. From a life-cycle perspective, vigorously promoting preventative maintenance measures in road surface engineering helps to save on overall maintenance costs.

[0003] Improving the long-term functionality of highway pavements is a common concern in the highway maintenance industry. Currently, anti-skid pavement gradations such as AK anti-skid surface layer, SAC (semi-aggregate asphalt concrete), SMA (semi-aggregate asphalt mastic), and OGFC (open-graded asphalt wearing course) only improve one or a few aspects of pavement functionality, failing to comprehensively enhance overall performance and thus possessing certain limitations. Ultra-thin asphalt wearing courses, on the other hand, are a pavement maintenance technology that can extend road service life (up to 3-5 years), effectively improve anti-skid performance, smoothness, reduce noise, and minimize water damage. Due to their flexible and diverse overlay options, short construction period, and minimal alteration of the original pavement elevation, they are currently the primary form of preventative maintenance and corrective maintenance for minor defects in highway asphalt pavements.

[0004] However, traditional ultra-thin wearing layers generally have poor performance and short lifespan. Especially in high summer temperatures, the viscoelasticity of the asphalt used in the wearing layer is inconsistent, causing coarse aggregate to be compacted into the middle of the old pavement by vehicles, leaving only fine aggregate and asphalt on the surface. This severely reduces the pavement's skid resistance, leading to an increased frequency of traffic accidents, particularly in rainy or snowy weather. Furthermore, the tack coat asphalt used in existing traditional thin-layer overlay technologies is ordinary latex-modified emulsified asphalt with inconsistent bond strength, making the wearing layer prone to shoving, shoving, and spalling. To address these issues, researchers have developed high-viscosity, high-elasticity ultra-thin wearing layers and NovaChip pavement. These two types of pavements offer significantly improved performance compared to traditional thin-layer overlays and also solve the problem of insufficient tack coat bonding performance. However, their raw material costs are high, and the extensive use of SBS and high-viscosity modifiers in the modified asphalt results in inconsistent asphalt adhesion and generally poor water loss resistance in the mixture, limiting their application. Summary of the Invention

[0005] To effectively overcome the shortcomings of traditional thin-layer overlays and address the issues of high cost and mediocre water resistance in high-viscosity, high-elasticity ultra-thin wearing layers and NovaChip pavements, this invention develops a warm-mix rubber asphalt-based ultra-thin wearing layer pavement and its construction method. This wearing layer fully utilizes the excellent adhesion and low cost of rubber asphalt, while the introduced warm-mix technology solves the problem of insufficient compaction during construction caused by the high mixing temperature of current rubber asphalt.

[0006] The construction method for the warm-mix rubber asphalt-based ultra-thin wearing course pavement includes the following steps: 1) Mix components A and B of the road crack repair agent at a mass ratio of 100:40-50 evenly, and then fill and repair the cracks in the road surface to be maintained. 2) Heat the high-modulus binder material to 180-210℃ to reduce its viscosity to below 0.5 Pa·s. Apply the binder material evenly to the road surface to be maintained using a binder sprayer or a synchronized crushing truck, at a rate of 0.15-0.25 kg / m². 2 ; 3) Select the SMA-5 range, choose basalt as the aggregate, determine the gradation range and the asphalt-aggregate ratio, heat the aggregate to 160℃, add the rubber asphalt used for the ultra-thin wear layer at 140℃ and the composite warm mix agent accounting for 0.5-1% of the rubber asphalt mass to the mixing drum, mix thoroughly for 90-120 seconds, and then discharge. 4) The rubber asphalt mixture obtained after discharge is evenly spread by a paver, and the final compaction thickness is 1.8-2cm. The paving temperature is not lower than 110℃ and the compaction temperature is not lower than 100℃. Steel wheels and rubber wheels are rolled alternately, and the number of rolling times is not less than 4. After rolling is completed, it becomes a warm-mix rubber asphalt-based ultra-thin wear course pavement.

[0007] The road surface crack repair agent A is prepared by uniformly mixing 60-70 parts by weight of epoxy resin E51, 10-20 parts by weight of 1,6-hexanediol diglycidyl ether, 5-10 parts by weight of ethyl acetate, 5-10 parts by weight of 400 mesh CaO, 1-5 parts by weight of KH-560, and 1-5 parts by weight of DOP. Component B of the road crack repair agent is prepared by uniformly mixing 70-80 parts by weight of 810 underwater epoxy curing agent, 10-15 parts by weight of 2,4,6-tris(dimethylaminomethyl)phenol, and 10-15 parts by weight of 651 low molecular weight polyamide.

[0008] The preparation method of the high modulus adhesive layer material includes the following steps: 1) Weigh 100 parts by weight of 70# base petroleum asphalt and add it to the reactor. Purge with nitrogen and stir at 500 rpm at 230-250℃. Add 10-20 parts by weight of coumarone-indene resin and continue stirring for 10 min. Then add 40-60 parts by weight of 30 mesh radial tire waste rubber powder in batches. After the addition is complete, stir at 1000-2000 rpm at 230-250℃ for 30 min. 2) Weigh 3% of the total mass of linear 30 / 70 SBS and 2% of the total mass of star-shaped 40 / 60 SBS and add them to the above development vessel. Maintain the reaction temperature at 230-250℃ and shear the reaction at 3000-5000 rpm for 20 min under nitrogen protection. 3) Add 0.3-0.5% of 400-mesh sulfur and 0.3-0.5% of 4,4'-dithiodimorpholine by weight of waste rubber powder, maintain the reaction vessel temperature at 230-250℃, adjust the shear rate to 3000-5000rpm, purge with nitrogen for protection, increase the reaction vessel pressure to 5MPa, and react for 30-60min. 4) Purge with nitrogen to maintain a pressure of 3-5 MPa, lower the reaction temperature to 200℃±10℃, maintain the shear rate at 3000-5000 rpm, add 2-3% POE (melt index of 2.0 g / 10 min, softening point ≥85℃) of 70# base petroleum asphalt to the reactor, and react for 10-15 min to obtain the high modulus adhesive layer material.

[0009] The preparation method of the rubber asphalt used in the ultrathin wear layer includes the following steps: 1) Weigh 100 parts by weight of 70# base petroleum asphalt and add it to the reactor. Under nitrogen protection, stir at 500 rpm at 230-250℃. Add 20-30 parts by weight of coumarone-indene resin and continue stirring for 10 min. Then add 40-60 parts by weight of 30 mesh radial tire waste rubber powder in batches. After the addition is complete, shear and stir at 3000-5000 rpm at 230-250℃ for 30-60 min. 2) Weigh 3% of the total mass of linear 30 / 70 SBS and 2% of star-shaped 40 / 60 SBS and add them to the reactor. Maintain the reaction temperature at 200-210℃ and shear and stir at 3000-5000 rpm for 20 min under nitrogen protection. 3) Add 0.3-0.5% of 4,4'-dithiodimorpholine by weight of waste rubber powder, maintain the reaction tank temperature at 200-210℃, adjust the shear speed to 1000-2000rpm, purge with nitrogen for protection, increase the reaction tank pressure to 2MPa, stir and react for 30min to obtain the rubber asphalt used for ultra-thin wear layer.

[0010] The composite warm mix agent is composed of 40-50 wt% Evotherm-3G warm mix agent, 20-30% N-(2-hydroxyethyl)dodecylamide and 20-30 wt% cocamidopropyl betaine.

[0011] The softening point of the coumarone-indene resin is 80-100℃.

[0012] The waste rubber powder needs to be preheated to 80-100℃.

[0013] The advantages of this invention are: 1. It fully leverages the advantages of rubber asphalt's excellent adhesion and strong water resistance, solving the problems of insufficient adhesion of traditional thin-layer overlays leading to peeling, bleeding, and insufficient anti-skid performance in rainy and snowy weather; 2. By using waste rubber powder, the material cost is greatly reduced compared to high-viscosity, high-elasticity ultra-thin wear-resistant layer and NovaChip pavement. At the same time, the introduction of warm mix technology also solves the problem of insufficient compaction caused by high mixing temperature of rubber asphalt. 3. The road crack repair agent used in this technology repairs cracks, making the original road surface a whole. At the same time, the water resistance of the original road surface is greatly improved after repair by the road crack repair agent, ensuring the integrity and service life of the warm-mix rubber asphalt-based ultra-thin wearing course pavement. Detailed Implementation

[0014] To better understand this invention, the following embodiments further illustrate its content; however, the invention is not limited to these embodiments. If the experiments and construction based on this invention do not involve creative improvements or labor by the construction personnel, then these embodiments also fall within the scope of protection of this invention.

[0015] All test values ​​in this embodiment are from laboratory conditions. To better compare the performance with existing ultra-thin wearing layers, high-viscosity and high-elasticity ultra-thin wearing layers, and NovaChip pavement, the indicators tested in this experiment were all based on the same aggregate gradation. A 2cm thin wearing layer was laid on top of an AC-13 aggregated SBS modified asphalt mixture rutting slab, and then the performance of different wearing layers was evaluated through rutting tests and vehicle fatigue tests. To compare the bonding strength of the bonding layer, it was applied as an adhesive to the surface of a 4cm*4cm rough cement concrete specimen. The pull-out strength of two cement concrete specimens was tested at 25℃, and the pull-out speed was selected as 5cm / min. At the same time, mixture tests were conducted on the rubber asphalt after determining the asphalt-aggregate ratio, mainly including stability (flow value at 3mm) (kN), dynamic stability at 60℃ (cycles / mm), low-temperature bending (με), residual stability after immersion Marshall test (%), freeze-thaw splitting strength ratio (%), etc. Example 1

[0016] (1) The preparation method of the road surface crack repair agent includes the following steps: ① Component A of road crack repair agent: It is prepared by mixing 70 parts epoxy resin E51, 10 parts 1,6-hexanediol diglycidyl ether, 10 parts ethyl acetate, 5 parts 400 mesh CaO, 2 parts KH-560 and 3 parts DOP evenly. ② Component B of road crack repair agent: 70 parts of 810 underwater epoxy curing agent, 15 parts of 2,4,6-tris(dimethylaminomethyl)phenol, and 15 parts of 651 low molecular weight polyamide are mixed evenly to obtain the product. (2) The preparation method of the high modulus adhesive layer material includes the following steps: ① Weigh 100 parts of 70# base petroleum asphalt and add it to the reactor. Under nitrogen protection, stir at 500 rpm at 250℃. Add 20 parts of coumarone-indene resin and continue stirring for 10 min. Then add 60 parts of 30 mesh radial tire waste rubber powder in batches. After the addition is complete, stir at 2000 rpm at 250℃ for 30 min. 2) Weigh 3% of the total mass of linear 30 / 70 type SBS and 2% of star-shaped 40 / 60 type SBS and add them to the above development vessel. Maintain the reaction temperature at 230℃ and shear the reaction at 5000 rpm for 20 min under nitrogen protection. 3) Add 0.5% of 400-mesh sulfur and 0.5% of 4,4'-dithiodimorpholine by weight of waste rubber powder, maintain the reaction vessel temperature at 230℃, adjust the shear rate to 5000rpm, purge with nitrogen for protection, increase the reaction vessel pressure to 5MPa, and react for 30min. 4) Purge with nitrogen to maintain a pressure of 5 MPa, lower the reaction temperature to 200℃±10℃, maintain the shear rate at 5000 rpm, add 3% POE (melt index of 2.0 g / 10 min, softening point ≥85℃) of the total mass of asphalt to the reactor, and react for 15 min to obtain the high modulus adhesive layer material. The preparation method of rubber asphalt used in ultra-thin wear-resistant layers includes the following steps: 1) Weigh 100 parts of 70# base petroleum asphalt and add it to the reactor. Purge with nitrogen and stir at 500 rpm at 230°C. Add 30 parts of coumarone-indene resin and continue stirring for 10 min. Then add 60 parts of 30 mesh radial tire waste rubber powder in batches. After the addition is complete, shear and stir at 5000 rpm at 230°C for 30 min. 2) Weigh 3% of the total mass of linear 30 / 70 SBS and 2% of star-shaped 40 / 60 SBS and add them to the reactor. Maintain the reaction temperature at 200℃~210℃ and shear and stir at 3000rpm for 20min under nitrogen protection. 3) Add 0.3% of 4,4'-dithiodimorpholine by weight of waste rubber powder, maintain the reaction tank temperature at 200℃~210℃, adjust the shear speed to 2000rpm, purge with nitrogen for protection, increase the reaction tank pressure to 2MPa, stir and react for 30min to obtain the rubber asphalt used for ultra-thin wear layer.

[0017] The construction method for warm-mix rubber asphalt-based ultra-thin wearing course pavement includes the following steps: 1) Mix the road crack repair agent components A and B in a ratio of 100:50, mix them evenly, and then fill and repair the cracks in the road surface to be maintained. 2) Heat the prepared high-modulus binder material to 210℃ until its viscosity drops below 0.5 Pa·s. Then, evenly spray it onto the road surface to be maintained using a binder oil spraying truck (equipped with a heating function), at a rate of 0.25 kg / m². 2 ; 3) Select the range of SMA-5, choose basalt as the aggregate, determine the gradation range and the asphalt-aggregate ratio, heat the aggregate to 160℃, add the rubber asphalt used for the ultra-thin wear layer at 140℃ and the composite warm mix agent accounting for 0.8% of the rubber asphalt mass to the mixing drum, mix thoroughly for 120 seconds, and discharge. 4) After discharge, the rubber asphalt mixture is evenly spread by a paver. The final compaction thickness is designed to be 2cm. The paving temperature is not lower than 110℃ and the compaction temperature is not lower than 100℃. Steel wheels and rubber wheels are used for alternating rolling, and the number of rolling times is not less than 4. After rolling, it becomes a warm-mix rubber asphalt-based ultra-thin wear course pavement.

[0018] The composite warm mix agent is composed of 50% Evotherm-3G warm mix agent, 30% N-(2-hydroxyethyl)dodecylamide, and 20% cocamidopropyl betaine. The softening point of the coumarone-indene resin is 80℃~100℃. Waste rubber powder needs to be preheated to 80℃~100℃.

[0019] The adhesive material was evenly applied to the surface of a 4cm*4cm rough cement concrete test block, with an application weight of 30g. Example 2

[0020] The same aggregate gradation, asphalt-aggregate ratio, and tack coat spraying amount as in Example 1 were used. Commercially available high-viscosity, high-elasticity asphalt and high-viscosity, high-elasticity wear-resistant layer adhesive were selected, and the remaining experimental procedures were the same as in Example 1. Example 3

[0021] Modified asphalt and modified emulsified asphalt specifically for Novachip were selected, and the same aggregate gradation, asphalt-aggregate ratio, and tack coat spraying amount were used as in Example 1. The remaining steps were the same as in Example 1. Example 4

[0022] The traditional 2cm ultra-thin heat-coating technique uses the same aggregate mix as in Example 1, with 5% SBS modified asphalt and ordinary tack coat material. The remaining steps are the same as in Example 1.

[0023] The performance tests are shown in the table below, and the test methods refer to relevant standards.

[0024] The performance is as follows:

Claims

1. A construction method of a warm mix rubber asphalt-based ultra-thin wearing course pavement, characterized by, The construction method includes the following steps: 1) Mix components A and B of the road crack repair agent evenly at a mass ratio of 100:50, and then fill and repair the cracks in the road surface to be maintained. 2) The high modulus binder layer material is heated to 180-210°C to reduce its viscosity to below 0.5 Pa-s and is uniformly sprayed on the pavement to be treated by a spray-on tack vehicle or a synchronous chip spreader at a rate of 0.15-0.25 kg / m 2 ; 3) Select the SMA-5 range, choose basalt as the aggregate, heat the aggregate to 160℃, add the rubber asphalt used for the ultra-thin wear layer at 140℃ and the composite warm mix agent accounting for 0.5-1% of the rubber asphalt mass to the mixing drum, mix thoroughly for 90-120 seconds, and then discharge. 4) The rubber asphalt mixture obtained after discharge is evenly spread by a paver, and the final compaction thickness is 1.8-2cm. The paving temperature is not lower than 110℃ and the compaction temperature is not lower than 100℃. Steel wheels and rubber wheels are rolled alternately, and the number of rolling times is not less than 4. After rolling is completed, it becomes a warm-mix rubber asphalt-based ultra-thin wear course pavement. Road surface crack repair agent A is prepared by uniformly mixing 70 parts by weight of epoxy resin E51, 10 parts by weight of 1,6-hexanediol diglycidyl ether, 10 parts by weight of ethyl acetate, 5 parts by weight of 400 mesh CaO, 2 parts by weight of KH-560, and 3 parts by weight of DOP. The road crack repair agent component B is prepared by uniformly mixing 70 parts by weight of 810 underwater epoxy curing agent, 15 parts by weight of 2,4,6-tris(dimethylaminomethyl)phenol, and 15 parts by weight of 651 low molecular weight polyamide. The preparation method of high modulus adhesive layer material includes the following steps: 1) Weigh 100 parts by weight of 70# base petroleum asphalt and add it to the reactor. Purge with nitrogen and stir at 500 rpm at 230-250℃. Add 20 parts by weight of coumarone-indene resin and continue stirring for 10 min. Then add 60 parts by weight of 30 mesh radial tire waste rubber powder in batches. After the addition is complete, stir at 1000-2000 rpm at 230-250℃ for 30 min. 2) Weigh 3% of the total mass of linear 30 / 70 SBS and 2% of the total mass of star-shaped 40 / 60 SBS and add them to the above reactor. Maintain the reaction temperature at 230-250℃ and shear the reaction at 3000-5000 rpm for 20 min under nitrogen protection. 3) Add 0.5% of 400-mesh sulfur and 0.5% of 4,4'-dithiodimorpholine by weight of the waste radial tire rubber powder. Maintain the reactor temperature at 230-250℃, adjust the shear rate to 3000-5000rpm, purge with nitrogen for protection, increase the reactor pressure to 5MPa, and react for 30-60min. 4) Purge with nitrogen to maintain a pressure of 3-5 MPa, reduce the reaction temperature to 200℃±10℃, maintain the shear rate at 3000-5000 rpm, add 3% POE of 70# base petroleum asphalt by mass to the reactor, and react for 10-15 minutes to obtain the high modulus adhesive layer material. The preparation method of the rubber asphalt used in the ultrathin wear layer includes the following steps: 1) Weigh 100 parts by weight of 70# base petroleum asphalt and add it to the reactor. Under nitrogen protection, stir at 500 rpm at 230-250℃. Add 30 parts by weight of coumarone-indene resin and continue stirring for 10 min. Then add 60 parts by weight of 30 mesh radial tire waste rubber powder in batches. After the addition is complete, shear and stir at 3000-5000 rpm at 230-250℃ for 30-60 min. 2) Weigh 3% of the total mass of linear 30 / 70 SBS and 2% of star-shaped 40 / 60 SBS and add them to the reactor. Maintain the reaction temperature at 200-210℃ and shear and stir at 3000-5000 rpm for 20 min under nitrogen protection. 3) Add 0.3% of 4,4'-dithiodimorpholine by weight of waste radial tire rubber powder, maintain reactor temperature at 200-210℃, adjust shear rate to 1000-2000rpm, purge with nitrogen for protection, increase reactor pressure to 2MPa, stir reaction for 30min, and the rubber asphalt used for ultra-thin wear layer can be obtained.

2. The construction method according to claim 1, characterized in that, The composite warm mix agent is composed of 50 wt% Evotherm-3G warm mix agent, 30 wt% N-(2-hydroxyethyl)dodecylamide and 20 wt% cocamidopropyl betaine.

3. The construction method according to claim 1 or 2, characterized in that, The softening point of the coumarone-indene resin is 80-100℃.

4. The construction method according to claim 1 or 2, characterized in that, The waste rubber powder from radial tires needs to be preheated to 80-100℃.

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