Ultra-thin asphalt overlay material of reaction type full RAP material and construction method of ultra-thin asphalt overlay material

Abstract

The invention provides an ultrathin asphalt overlay material of a reaction type full RAP material and a construction method of the ultrathin asphalt overlay material, and relates to the field of recycled asphalt mixtures. The asphalt comprises an RAP material, a tackifying regenerant and an interface protective agent, the tackifying regenerant comprises matrix asphalt, epoxy resin, an asphalt warm mixing agent and an asphalt regenerant, and the interface protective agent comprises hard asphalt, an asphalt modifier and a curing agent. The construction method comprises the following steps: heating the RAP material to 130-140 DEG C, adding the tackifying regenerant, and stirring; an ultra-thin cover face with the thickness of 1.5-2.5 cm is spread, and rolling forming is carried out while spreading is carried out; and when the temperature of the rolled ultrathin cover surface is reduced, an interface protective agent is uniformly sprayed to the surface, and the temperature is reduced to 40 DEG C or below. The 100% RAP material is adopted, the ultra-thin overlay with pavement performance comparable to that of a newly-mixed mixture can be produced, it is ensured that the pavement performance of the ultra-thin overlay is not lower than that of a newly-mixed asphalt mixture of the same set, and the construction cost of the ultra-thin overlay is greatly reduced.

Description

Technical Field

[0001] The present application relates to the field of recycled asphalt mixtures, and in particular to an ultra-thin asphalt overlay material of a reactive full RAP material and a construction method thereof. Background Art

[0002] At present, the use of recycled asphalt mixture is mainly concentrated in the road base and middle and lower layers. The benefits of using it in the base are low, while the benefits of using it in the middle and lower layers are higher, but the addition ratio is generally less than 30%. In order to ensure the quality, recycled asphalt mixture is rarely used in the upper layer of asphalt pavement, while the main work of current maintenance projects is on the upper layer. Using recycled asphalt mixture safely and reliably in the surface layer can save a lot of resources and meet my country's green, low-carbon and environmental protection requirements.

[0003] Ultra-thin asphalt overlay has a small thickness, saves materials, has little impact on elevation, repairs road surface diseases, seals water, resists skidding, reduces noise and is durable. It is an important technology for surface maintenance work at present. However, ultra-thin asphalt overlay has high requirements for materials. The "Technical Specifications for Highway Asphalt Pavement Maintenance (JTG5142-2019)" stipulates that the softening point of high-viscosity modified asphalt used in ultra-thin asphalt overlay is higher than 75°C, and the high-toughness ultra-thin overlay technology even requires the softening point of modified asphalt to be higher than 90°C; in terms of stone materials, it is generally required to use strong and wear-resistant stone materials. Highway asphalt pavement requires that the crushing value of coarse aggregate of expressways and first-class highways is lower than 26, while ultra-thin overlay is generally not lower than this requirement. Therefore, it is generally difficult to add recycled asphalt mixtures in ultra-thin overlay projects, which will inevitably have a negative impact on the promotion and application of ultra-thin overlay technology in the future. Summary of the invention

[0004] In order to improve the problem that recycled asphalt mixture cannot be used in the current ultra-thin asphalt overlay, the present application provides an ultra-thin asphalt overlay material of reactive full RAP material and a construction method thereof.

[0005] In the first aspect, the present application provides an ultra-thin asphalt overlay material of reactive all-RAP material, which adopts the following technical solution: A reactive all-RAP material ultra-thin asphalt overlay material, including RAP material, viscosity increasing regeneration agent and interface protective agent. The viscosity increasing regeneration agent comprises base asphalt, epoxy resin, asphalt warm mix agent and asphalt regeneration agent, and the mass ratio of the base asphalt, the epoxy resin, the asphalt warm mix agent and the asphalt regeneration agent is 16-24:2-5:1-2:6-10; The interface protective agent comprises hard asphalt, an asphalt modifier and a curing agent, and the mass ratio of the hard asphalt, the asphalt modifier and the curing agent is 100:1-2:10-20.

[0006] Optionally, the curing agent is an amine curing agent.

[0007] Optionally, the curing agent includes at least one of isophoronediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine.

[0008] Optionally, the base asphalt is 70# road petroleum asphalt or 90# road petroleum asphalt.

[0009] Optionally, the asphalt warm mix agent is the Evothem product of Ingevity, model M1.

[0010] Optionally, the asphalt regeneration agent is the Evoflex product of Ingevity.

[0011] Optionally, the epoxy resin is E51 epoxy resin.

[0012] Optionally, the asphalt modifier includes one or both of SBS and SBR.

[0013] Optionally, the hard asphalt is 50# petroleum asphalt.

[0014] Optionally, the interface protective agent also includes a diluent, and the mass ratio of the hard asphalt to the diluent is 1:1-1.5.

[0015] Optionally, the diluent is octane.

[0016] Optionally, the interface protective agent is prepared by the following preparation method: Heat the hard asphalt to 160-170°C, add the asphalt modifier, perform high-speed shearing, and then maintain the temperature and stir for 3-4 hours until the asphalt modifier is fully swollen, then reduce the temperature of the mixture to 120-140°C, add the curing agent and the diluent, stir for 15 minutes, and cool to room temperature.

[0017] Optionally, the high-speed shearing rate is 5000-6000 r / min and the time is 30 min.

[0018] In a second aspect, the present application provides a construction method of an ultra-thin asphalt overlay material, which adopts the following technical solution: A construction method of an ultra-thin asphalt overlay material comprises the following steps: Step S1: heating the RAP material to 130-140° C., adding a viscosity increasing regeneration agent, and stirring for 20-30 seconds to obtain an asphalt mixture; Step S2: Spreading the asphalt mixture into an ultra-thin overlay with a thickness of 1.5 to 2.5 cm according to the designed thickness of the ultra-thin overlay, and rolling and forming the mixture at the same time; Step S3: Wait for the temperature of the newly rolled ultra-thin cover surface to drop to 70-80°C, spray the interface protective agent evenly onto the surface, wait for the temperature to drop below 40°C, and then open to traffic.

[0019] Optionally, in step S1, the mass ratio of the RAP material to the viscosity-increasing regeneration agent is 100:0.5-1.

[0020] Optionally, in step S1, the discharge temperature of the asphalt mixture is not less than 135°C.

[0021] Optionally, in step S2, the initial rolling temperature shall not be lower than 125°C, and the final rolling temperature shall be 100-110°C.

[0022] Optionally, in step S3, the amount of the interface protective agent used is 0.2 kg / m 2 -0.3kg / m 2 .

[0023] Optionally, in step S3, when the thickness of the ultra-thin cover is 1.5 cm, the amount of the interface protective agent used is 0.2 kg / m 2 When the thickness of the ultra-thin cover is 2.5 cm, the amount of the interface protective agent used is 0.3 kg / m 2 .

[0024] In summary, the present application includes at least one of the following beneficial effects: 1. The present application adopts the combination of a thickening regeneration agent and an interface protective agent, especially the epoxy resin in the thickening regeneration agent and the curing agent in the interface protective agent, which can produce a curing and thickening reaction, greatly increasing the cohesion of asphalt concrete, improving the strength of asphalt concrete, and increasing the water resistance of asphalt concrete.

[0025] 2. This application uses 100% RAP material, which can produce ultra-thin overlays with road performance comparable to that of new asphalt mixtures, while ensuring that its road performance is not lower than that of new asphalt mixtures with the same mix, greatly reducing the construction cost of ultra-thin overlays.

[0026] 3. By adding a diluent to the interface protective agent, the present application not only allows the interface protective agent to have a certain fluidity at room temperature, making it easier to use during construction, but also promotes the rapid penetration of the interface protective agent into the asphalt concrete and promotes full contact between the curing agent and the epoxy resin; after construction, the diluent will evaporate rapidly and will not affect the performance of the final interface protective agent.

[0027] 4. This application places the epoxy resin in the asphalt mixture and the curing agent in the interface protective agent, and relies on a two-step construction method for construction. The diluent in the interface protective agent can promote its downward penetration and promote the contact between the curing agent and the epoxy resin. At the same time, the residual heat temperature just after paving is used to promote the rate of its curing reaction.

[0028] 5. This application uses SBS or SBR as an asphalt modifier to improve the performance of hard asphalt, improve the softening point, and improve the low-temperature tensile performance, and ultimately improve the wear resistance of the oil film after molding.

[0029] 6. The ultra-thin asphalt overlay material of this application is easy to construct, does not require additional time, and does not affect construction efficiency. DETAILED DESCRIPTION

[0030] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with specific implementation methods.

[0031] Unless otherwise specified, the materials used in the following examples and comparative examples of the present invention can be obtained from the market or prepared by conventional methods. The RAP material used in the following examples and comparative examples of the present application is the RAP material of the upper layer of the road surface; the base asphalt used in the following examples and comparative examples of the present application is 70# road petroleum asphalt; the epoxy resin used in the following examples and comparative examples of the present application is the epoxy resin is E51 type epoxy resin; the asphalt warm mix agent used in the following examples and comparative examples of the present application is the Evothem product of Ingevity, model M1; the asphalt regeneration agent used in the following examples and comparative examples of the present application is the Evoflex product of Ingevity; the hard asphalt used in the following examples and comparative examples of the present application is 50# petroleum asphalt; the diluent used in the following examples and comparative examples of the present application is octane.

[0032] Example 1 provides a reactive all-RAP material ultra-thin asphalt overlay material and a construction method thereof, including RAP material, a viscosity-enhancing regeneration agent and an interface protective agent.

[0033] ① The specific composition of the viscosity increasing regeneration agent can be seen in Table 1. The preparation method thereof is carried out according to the following steps: epoxy resin, base asphalt, asphalt warm mix agent and asphalt regeneration agent are mixed according to a certain proportion.

[0034] ② The specific composition of the interface protective agent can be found in Table 1. The preparation method thereof is carried out according to the following steps: heating the hard asphalt to 170°C, adding an asphalt modifier, performing high-speed shearing, and then maintaining the temperature and stirring for 3 hours until the asphalt modifier is fully swollen, then lowering the temperature of the mixture to 130°C, adding a curing agent and a diluent, stirring for 15 minutes, and cooling to room temperature to obtain the interface protective agent, wherein the curing agent is isophorone diamine and the asphalt modifier is SBS.

[0035] ③ The specific construction method of the ultra-thin asphalt overlay material of the reactive full RAP material is as follows: Step S1: heating the RAP material to 135° C., adding the prepared viscosity increasing regeneration agent, and stirring for 30 seconds to obtain an asphalt mixture, wherein the mass ratio of the RAP material to the viscosity increasing regeneration agent is 100:0.5, and the discharge temperature of the asphalt mixture is not lower than 135° C.; Step S2: Spreading the asphalt mixture into an ultra-thin overlay with a thickness of 1.5 cm according to the designed thickness of the ultra-thin overlay, and rolling and forming the mixture at the same time; Step S3: Wait for the temperature of the ultra-thin cover surface just rolled to drop to 80°C, and spray the interface protective agent evenly on the surface. The amount of the interface protective agent sprayed is 0.2kg / m 2 , wait for the temperature to drop below 40℃ before opening traffic.

[0036] Table 1 Amount of the raw materials of the viscosity increasing regeneration agent and the raw materials of the interface protection agent in each embodiment (kg)

[0037] Example 2 provides an ultra-thin asphalt overlay material of a reactive all-RAP material and a construction method thereof, which is basically the same as Example 1, except that the amounts of each raw material in the thickening regeneration agent and the interface protective agent in Example 2 are different, as shown in Table 1 for details, and the mass ratio of the RAP material to the thickening regeneration agent is 100:1.

[0038] Example 3 provides an ultra-thin asphalt overlay material of reactive full RAP material and a construction method thereof, which is basically the same as Example 1, except that the amount of each raw material in the thickening regeneration agent and the interface protective agent in Example 3 is different, as shown in Table 1; and the mass ratio of RAP material to thickening regeneration agent is 100:0.5, the paving thickness of the ultra-thin overlay is 2.5 cm, and the spreading amount of the interface protective agent is 0.3 kg / m 2 .

[0039] Example 4 provides an ultra-thin asphalt overlay material of a reactive all-RAP material and a construction method thereof, which is basically the same as Example 1, except that the curing agent in Example 4 is diethylenetriamine.

[0040] Example 5 provides an ultra-thin asphalt overlay material of a reactive all-RAP material and a construction method thereof, which is basically the same as Example 1, except that the asphalt modifier of the interface protective agent in Example 5 is SBR.

[0041] Comparative Example 1 provides an ultra-thin asphalt overlay material of reactive full RAP material and a construction method thereof, which is basically the same as Example 1, except that the paving thickness of the ultra-thin overlay in Comparative Example 1 is 1.5 cm, and the spreading amount of the interface protective agent is 0.1 kg / m 2 .

[0042] Comparative Example 2 provides an ultra-thin asphalt overlay material of a reactive all-RAP material and a construction method thereof, which is basically the same as Example 1, except that the mass ratio of the RAP material to the thickening regeneration agent in Comparative Example 2 is 100:0.2.

[0043] Comparative Example 3 provides an ultra-thin asphalt overlay material of a reactive all-RAP material and a construction method thereof, which is basically the same as Example 1, except that the viscosity increasing regeneration agent of Comparative Example 3 does not contain epoxy resin.

[0044] Comparative Example 4 provides an ultra-thin asphalt overlay material of a reactive all-RAP material and a construction method thereof, which is basically the same as Example 1, with the only difference being that the interface protective agent of Comparative Example 4 does not contain a curing agent.

[0045] According to the test method T0702-2011 in the "Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011), asphalt mixture specimens were made from the asphalt mixtures obtained in the above embodiments and comparative examples. The surface area of ​​the specimens was calculated, and the corresponding interface protective agent was applied to the surface of the specimens, which were left to cool, to simulate the on-site paving and spraying process.

[0046] The specific test items are as follows, and the specific test results are shown in Table 2.

[0047] (1) Marshall stability and water-residual Marshall stability: The standard Marshall stability test and water-residual Marshall stability test were carried out according to T0709-2011 of the Test Procedure for Asphalt and Asphalt Mixtures for Highway Engineering (JTG E20-2011). The Marshall stability and water-residual Marshall stability of the standard specimen were obtained through the test.

[0048] When measuring the Marshall stability, the present application measured the Marshall stability of the standard specimen after curing at room temperature for 2 hours and then keeping it in a constant temperature water bath at 60°C for 30 minutes.

[0049] When determining the Marshall stability after immersion, this application determines the Marshall stability of a standard specimen cured at room temperature for 7 days after being kept in a constant temperature water tank at 60℃ for 30 minutes, and the Marshall stability of a standard specimen cured at room temperature for 7 days after being kept in a constant temperature water tank at 60℃ for 48 hours, and calculates the residual Marshall stability after immersion. The residual Marshall stability after immersion is equal to the ratio of the Marshall stability after immersion (60℃) to the standard Marshall stability (60℃). Marshall stability is used to evaluate the mechanical properties of asphalt mixtures, and the residual Marshall stability after immersion is used to evaluate the water stability of asphalt mixtures.

[0050] (2) Dynamic stability: First, the prepared asphalt mixture is rolled into a plate-shaped specimen with a length of 300 mm, a width of 300 mm, and a thickness of 50 mm using a wheel roller according to T0703-2011. The corresponding interface protective agent is applied to the surface of the specimen, and it is left to cool to simulate the process of on-site paving and spraying. Then, it is placed in an insulated box for curing at 60°C for 7 days. Then, according to T0719-2011 of the "Test Procedures for Asphalt and Asphalt Mixtures for Highway Engineering" (JTG E20-2011), the plate-shaped specimen and the test mold are moved to the rutting test machine for rutting test. During the test, the recorder automatically records the specimen deformation curve and the corresponding specimen temperature. The dynamic stability is calculated according to the calculation formula in Section 4 of T0719-2011. The dynamic stability is used to determine the high-temperature rutting resistance of the asphalt mixture. It is required to be greater than 6000 times / mm.

[0051] (3) Kentburgh scattering loss: The Kentburgh scattering test of asphalt mixture is carried out according to T0733-2011 of the "Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011). The Kentburgh scattering loss is used to evaluate the degree of aggregate loss on the pavement surface due to insufficient asphalt dosage or adhesion under traffic loads. It is expressed as the percentage of the mass of the scattered material of the asphalt mixture specimen after the Marshall specimen is rotated a specified number of times in the Los Angeles test machine.

[0052] Table 2 Performance test results

[0053] It can be seen from the results in Table 2 that after the construction of the ultra-thin asphalt overlay materials provided in Examples 1-5, the epoxy resin in the viscosity-increasing regeneration agent and the curing agent in the interface protective agent undergo a curing and viscosity-increasing reaction, thereby greatly improving the strength and water resistance of the asphalt concrete.

[0054] Compared with Example 1, since the amount of interface protective agent spread in Comparative Example 1 is only half of that in Example 1, the curing agent content therein is also only half of that in Example 1. However, a large amount of curing agent in Example 1 can fully react with the epoxy resin in the viscosity increasing regeneration agent, greatly increasing the cohesion of the asphalt concrete, thereby making its mechanical properties and water resistance much higher than those of Comparative Example 1.

[0055] Compared with Example 1, since the amount of thickening regeneration agent in Comparative Example 2 is insufficient, the amount of epoxy resin that reacts with the curing agent in the interface protective agent is also small. However, the large amount of curing agent in Example 1 can fully react with the epoxy resin in the thickening regeneration agent, greatly increasing the cohesion of the asphalt concrete, thereby making its mechanical properties and water resistance much higher than those of Comparative Example 2.

[0056] Compared with Example 1, due to the lack of epoxy resin in Comparative Example 3 and the lack of curing agent in Comparative Example 4, the interface protective agent can only float on the surface of the asphalt concrete but cannot be deeply integrated with it, so its mechanical properties and water resistance are relatively poor.

[0057] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A reactive all-RAP ultra-thin asphalt overlay material, characterized in that: Including RAP material, viscosity increasing regeneration agent and interface protective agent, The viscosity increasing regeneration agent comprises base asphalt, epoxy resin, asphalt warm mix agent and asphalt regeneration agent; and the mass ratio of the base asphalt, the epoxy resin, the asphalt warm mix agent and the asphalt regeneration agent is 16-24:2-5:1-2:6-10; The interface protective agent comprises hard asphalt, an asphalt modifier and a curing agent, and the mass ratio of the hard asphalt, the asphalt modifier and the curing agent is 100:1-2:10-20.

2. The ultra-thin asphalt overlay material of reactive full RAP material according to claim 1, characterized in that: The curing agent is an amine curing agent.

3. The ultra-thin asphalt overlay material of reactive full RAP material according to claim 2, characterized in that: The curing agent includes at least one of isophoronediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine.

4. The ultra-thin asphalt overlay material of reactive full RAP material according to claim 1, characterized in that: The base asphalt is 70# road petroleum asphalt or 90# road petroleum asphalt.

5. The ultra-thin asphalt overlay material of reactive full RAP material according to claim 1, characterized in that: The asphalt modifier includes one or both of SBS and SBR.

6. The ultra-thin asphalt overlay material of reactive full RAP material according to claim 1, characterized in that: The interface protective agent also includes a diluent, and the mass ratio of the hard asphalt to the diluent is 1:1-1.

5.

7. The ultra-thin asphalt overlay material of reactive full RAP material according to claim 6, characterized in that: The interface protective agent is prepared by the following preparation method: Heat the hard asphalt to 160-170°C, add the asphalt modifier, perform high-speed shearing, and then maintain the temperature and stir for 3-4 hours until the asphalt modifier is fully swollen, then reduce the temperature of the mixture to 120-140°C, add the curing agent and the diluent, stir for 15 minutes, and cool to room temperature.

8. A construction method for an ultra-thin asphalt overlay material of a reactive full RAP material according to any one of claims 1 to 7, characterized in that: The steps include: Step S1: heating the RAP material to 130-140° C., adding a viscosity increasing regeneration agent, and stirring for 20-30 seconds to obtain an asphalt mixture; Step S2: Spreading the asphalt mixture into an ultra-thin overlay with a thickness of 1.5 to 2.5 cm according to the designed thickness of the ultra-thin overlay, and rolling and forming the mixture at the same time; Step S3: Wait for the temperature of the newly rolled ultra-thin cover surface to drop to 70-80°C, spray the interface protective agent evenly onto the surface, wait for the temperature to drop below 40°C, and then open to traffic.

9. The construction method of the ultra-thin asphalt overlay material of reactive full RAP material according to claim 8, characterized in that: In the step S1, the mass ratio of the RAP material to the viscosity increasing regeneration agent is 100:0.5-1.

10. The construction method of the ultra-thin asphalt overlay material of reactive full RAP material according to claim 8, characterized in that: In step S3, the amount of the interface protective agent used is 0.2 kg / m 2 -0.3kg / m 2 .

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