A preparation method of high-viscosity rubber-modified asphalt

Abstract

The present invention provides a method for preparing highly viscous rubber-modified asphalt. The method is as follows: Add 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate to waste rubber powder for microwave treatment to obtain vulcanized rubber powder; Add the vulcanized rubber powder to the heated base asphalt, shear to obtain a mixture of the base asphalt and the vulcanized rubber powder, then add a tackifier, shear to obtain the modified asphalt with increased viscosity, and then add a plasticizer and stir to obtain the highly viscous rubber-modified asphalt. In the present invention, 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate is used for microwave vulcanization treatment of waste rubber powder, and the vulcanized waste rubber powder, base asphalt, tackifier, and plasticizer are added and combined, achieving a balance among the high-temperature stability, construction feasibility, water damage resistance, and storage stability of the highly viscous rubber-modified asphalt.

Description

Technical Field

[0001] The present invention belongs to the technical field of modified asphalt, and particularly relates to a preparation method of high-viscosity rubber modified asphalt. Background Art

[0002] The amount of waste tires generated from scrapping will continue to grow. If waste tires are not properly disposed of, they will not only bring environmental impacts and safety hazards, but also cause waste of resources.

[0003] In view of the advantages of asphalt pavement such as easy construction and maintenance, and high flatness, it has gradually become the main pavement form of urban roads and high-grade highways. However, new requirements are put forward for the functional diversity of asphalt pavement, such as wear resistance, skid resistance, low noise, drainage performance, etc. However, the void ratio of traditional dense-graded asphalt pavement is relatively low, and surface water is mainly drained by the cross slope of the pavement. The pavement cannot achieve longitudinal drainage, resulting in easy water accumulation on the road surface. Since rainwater is between the tire and the pavement, the contact area between the vehicle tire and the pavement is reduced, and the skid resistance of the pavement is reduced, which may lead to vehicle skidding or drifting and traffic accidents, causing casualties and property losses.

[0004] Drainage asphalt pavement is considered a new type of pavement structure that takes into account both the drainage performance and other functions of asphalt pavement. The porosity of drainage asphalt pavement is 15-20%, which is much higher than the porosity of 4-6% of traditional dense-graded asphalt pavement. This makes a large number of connected pore structures exist inside the drainage pavement structure, effectively improving the longitudinal seepage speed of rainwater, increasing the drainage methods of rainwater, and significantly reducing the thickness of the water film on the road surface. High-viscosity asphalt is the key material for drainage asphalt pavement, which realizes the porous characteristics of the asphalt pavement structure and ensures that the aggregate does not fall off during drainage.

[0005] Most of the existing high-viscosity asphalt modifiers use SBS and TPS, etc., with too high costs. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a preparation method of high-viscosity rubber modified asphalt in view of the deficiencies of the above-mentioned prior art. This method uses 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate to perform microwave vulcanization treatment on waste rubber powder, and adds and mixes the vulcanized waste rubber powder, matrix asphalt, tackifier, and plasticizer, achieving a balance among the high-temperature stability, construction feasibility, water damage resistance, and storage stability of the high-viscosity rubber modified asphalt.

[0007] To solve the above technical problem, the technical solution adopted by the present invention is: a preparation method of high-viscosity rubber modified asphalt, and this method is as follows:

[0008] S1. Add 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate to waste rubber powder. After stirring, treat it under microwave conditions with a power of 800 W for 120 s, and then cool it naturally to room temperature to obtain vulcanized rubber powder;

[0009] The waste rubber powder in the present invention is derived from waste tires;

[0010] S2. Heat the matrix asphalt to 155 °C - 165 °C, add the vulcanized rubber powder obtained in S1. After mixing, raise the temperature to 170 °C - 180 °C, and continue to shear at a shear rate of 1500 r / min for 30 min - 40 min to obtain a mixture of matrix asphalt and vulcanized rubber powder;

[0011] S3. Add a tackifier to the mixture of matrix asphalt and vulcanized rubber powder obtained in S2, and continue to shear at a constant temperature in a high-speed shearer with a shear rate of 3000 r / min for 20 min - 30 min to obtain a modified asphalt with increased viscosity;

[0012] S4. Add a plasticizer to the modified asphalt with increased viscosity obtained in S3, and continue to stir at a constant temperature at a rotation speed of 1300 r / min for 10 min - 15 min to obtain a high-viscosity rubber-modified asphalt.

[0013] Preferably, the mass ratio of the waste rubber powder to 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate in S1 is 1:0.15.

[0014] Preferably, the stirring time in S1 is 2 h.

[0015] Preferably, the matrix asphalt in S2 is 70# matrix asphalt.

[0016] Preferably, the added mass of the vulcanized rubber powder in S2 is 20% - 30% of the matrix asphalt.

[0017] Preferably, the tackifier in S3 includes one or more of C5 / C9 copolymerized petroleum resin, hydrocarbon resin, epoxy vinyl resin, and rosin resin.

[0018] Preferably, the added mass of the tackifier in S3 is 1.5% - 2.0% of the matrix asphalt.

[0019] Preferably, the plasticizer in S4 includes one or more of dibutyl phthalate, dibutyl adipate, and dibutoxyethyl phthalate.

[0020] Preferably, the added mass of the plasticizer in S4 is 2% - 3% of the matrix asphalt.

[0021] Preferably, the rotational viscosity of the high-viscosity rubber modified asphalt described in S4 at 180 °C is 0.61 Pa·s to 1.23 Pa·s, the rutting factor at 64 °C is 4.25 kPa to 5.20 kPa, and the adhesion grade is 5.

[0022] The present invention has the following advantages compared with the prior art:

[0023] The present invention mixes 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate and waste rubber powder and performs microwave vulcanization treatment. Since 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate has high electrical conductivity and can better convert microwave energy into heat energy, the temperature distribution on the surface and inside of the waste rubber powder is more uniform, improving the vulcanization efficiency of the rubber powder. Through the addition and coordination of the vulcanized waste rubber powder, matrix asphalt, tackifier, and plasticizer, a balance is achieved among the high-temperature stability, construction feasibility, water damage resistance, and storage stability of the high-viscosity rubber modified asphalt. The preparation process of the high-viscosity rubber modified asphalt proposed by the present invention is simple, the preparation equipment is simple, the preparation cost is low, the product performance is excellent, and existing rubber powder modified asphalt equipment can be directly used for production without equipment transformation and upgrading.

[0024] The present invention will be further described in detail below with reference to the embodiments. Specific Embodiments

[0025] Example 1

[0026] The preparation method of the high-viscosity rubber modified asphalt in this example is as follows:

[0027] S1. Add 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate C 9 H 16 ClF 6 N 2 P] to the waste rubber powder, stir for 2 h, then treat it under microwave conditions with a power of 800 W for 120 s, and naturally cool to room temperature to obtain vulcanized rubber powder; the mass ratio of the waste rubber powder to 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate is 1:0.15;

[0028] The waste rubber powder in this example is derived from waste tires;

[0029] S2. Heat the matrix asphalt to 160 °C, add the vulcanized rubber powder obtained in S1, mix, then raise the temperature to 175 °C, and continue to shear at a shear rate of 1500 r / min for 35 min. The matrix asphalt is 70# matrix asphalt; the added mass of the vulcanized rubber powder is 20% of the matrix asphalt;

[0030] S3. Add the mixture of the base asphalt and the vulcanized rubber powder obtained in S2 to a tackifier (C5 / C9 copolymerized petroleum resin), and conduct isothermal shearing at 175 °C for 25 min in a high-speed shearing instrument with a shearing rate of 3000 r / min to obtain the modified asphalt with increased viscosity; the added mass of the tackifier is 1.5% of the base asphalt.

[0031] S4. Add a plasticizer (dibutyl phthalate) to the modified asphalt with increased viscosity obtained in S3, and conduct isothermal stirring at 175 °C for 12 min under the condition of a rotation speed of 1300 r / min to obtain the high-viscosity rubber modified asphalt; the added mass of the plasticizer is 2% of the base asphalt.

[0032] Example 2

[0033] The preparation method of the high-viscosity rubber modified asphalt in this example is as follows:

[0034] S1. Add 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate [C9H16ClF6N2P] to the waste rubber powder, stir for 2 h, then treat it under the microwave condition with a power of 800 W for 120 s, and naturally cool to room temperature to obtain the vulcanized rubber powder; the mass ratio of the waste rubber powder to 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate is 1:0.15.

[0035] The waste rubber powder in this example is sourced from waste tires.

[0036] S2. Heat the base asphalt to 155 °C, add the vulcanized rubber powder obtained in S1, after mixing, raise the temperature to 170 °C, and continue isothermal shearing at a shearing rate of 1500 r / min for 40 min to obtain a mixture of the base asphalt and the vulcanized rubber powder; the base asphalt is 70# base asphalt; the added mass of the vulcanized rubber powder is 20% of the base asphalt.

[0037] S3. Add the mixture of the base asphalt and the vulcanized rubber powder obtained in S2 to a tackifier (hydrocarbon resin), and conduct isothermal shearing at 155 °C for 30 min in a high-speed shearing instrument with a shearing rate of 3000 r / min to obtain the modified asphalt with increased viscosity; the added mass of the tackifier is 2.0% of the base asphalt.

[0038] S4. Add a plasticizer (dibutoxyethyl phthalate) to the modified asphalt with increased viscosity obtained in S3, and conduct isothermal stirring at 155 °C for 15 min under the condition of a rotation speed of 1300 r / min to obtain the high-viscosity rubber modified asphalt; the added mass of the plasticizer is 3% of the base asphalt.

[0039] Example 3

[0040] The preparation method of the high-viscosity rubber modified asphalt in this example is as follows:

[0041] S1. Add 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate [C9H16ClF6N2P] to the waste rubber powder. After stirring for 2 h, treat it under microwave conditions with a power of 800 W for 120 s, and then naturally cool it to room temperature to obtain vulcanized rubber powder. The mass ratio of the waste rubber powder to 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate is 1:0.15;

[0042] The waste rubber powder in this example is sourced from waste tires;

[0043] S2. Heat the base asphalt to 165 °C, add the vulcanized rubber powder obtained in S1. After mixing, raise the temperature to 180 °C and continue to shear at a shear rate of 1500 r / min for 30 min to obtain a mixture of base asphalt and vulcanized rubber powder. The base asphalt is 70# base asphalt; the added mass of the vulcanized rubber powder is 30% of the base asphalt;

[0044] S3. Add a tackifier (epoxy vinyl resin) to the mixture of base asphalt and vulcanized rubber powder obtained in S2, and shear it at a constant temperature of 180 °C for 20 min in a high-speed shearer with a shear rate of 3000 r / min to obtain the modified asphalt with increased viscosity. The added mass of the tackifier is 1.5% of the base asphalt;

[0045] S4. Add a plasticizer (dibutoxyethyl phthalate) to the modified asphalt with increased viscosity obtained in S3, and stir it at a constant temperature of 180 °C for 10 min under the condition of a rotation speed of 1300 r / min to obtain a high-viscosity rubber modified asphalt. The added mass of the plasticizer is 3% of the base asphalt.

[0046] Example 4

[0047] The preparation method of the high-viscosity rubber modified asphalt in this example is as follows:

[0048] S1. Add 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate [C9H16ClF6N2P] to the waste rubber powder. After stirring for 2 h, treat it under microwave conditions with a power of 800 W for 120 s, and then naturally cool it to room temperature to obtain vulcanized rubber powder. The mass ratio of the waste rubber powder to 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate is 1:0.15;

[0049] The waste rubber powder in this example is sourced from waste tires;

[0050] S2. Heat the base asphalt to 155°C, add the vulcanized rubber powder obtained in S1, and after mixing, raise the temperature to 180°C and continue to shear at a shear rate of 1500 r / min for 30 min to obtain a mixture of base asphalt and vulcanized rubber powder; the base asphalt is 70# base asphalt; the added mass of the vulcanized rubber powder is 30% of the base asphalt.

[0051] S3. Add a tackifier (rosin resin) to the mixture of base asphalt and vulcanized rubber powder obtained in S2, and shear at a constant temperature of 180°C for 30 min in a high-speed shearer with a shear rate of 3000 r / min to obtain a modified asphalt with increased viscosity; the added mass of the tackifier is 2.0% of the base asphalt.

[0052] S4. Add a plasticizer (a mixture of dibutyl phthalate, dibutyl adipate, and dibutoxyethyl phthalate with a mass ratio of 1:1:1) to the modified asphalt with increased viscosity obtained in S3, and stir at a constant temperature of 180°C for 15 min under the condition of a rotation speed of 1300 r / min to obtain a high-viscosity rubber modified asphalt; the added mass of the plasticizer is 2% of the base asphalt.

[0053] Example 5

[0054] The preparation method of the high-viscosity rubber modified asphalt in this example is as follows:

[0055] S1. Add 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate [C9H16ClF6N2P] to the waste rubber powder, stir for 2 h, then treat it under microwave conditions with a power of 800 W for 120 s, and naturally cool to room temperature to obtain vulcanized rubber powder; the mass ratio of the waste rubber powder to 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate is 1:0.15.

[0056] The waste rubber powder in this example is sourced from waste tires.

[0057] S2. Heat the base asphalt to 160°C, add the vulcanized rubber powder obtained in S1, and after mixing, raise the temperature to 175°C and continue to shear at a shear rate of 1500 r / min for 30 min to obtain a mixture of base asphalt and vulcanized rubber powder.

[0058] The base asphalt is 70# base asphalt; the added mass of the vulcanized rubber powder is 25% of the base asphalt.

[0059] S3. Add the mixture of the base asphalt and the vulcanized rubber powder obtained in S2 to a tackifier (a mixture of C5 / C9 copolymerized petroleum resin, hydrocarbon resin, epoxy vinyl resin, and rosin resin with a mass ratio of 1:1:1:1), and carry out isothermal shearing at 175 °C for 30 min in a high-speed shearing instrument with a shearing rate of 3000 r / min to obtain the modified asphalt with increased viscosity; the added mass of the tackifier is 1.8% of the base asphalt.

[0060] S4. Add a plasticizer (a mixture of dibutyl adipate and dibutoxyethyl phthalate with a mass ratio of 2:1) to the modified asphalt with increased viscosity obtained in S3, and carry out isothermal stirring at 175 °C for 15 min under the condition of a rotation speed of 1300 r / min to obtain the high-viscosity rubber modified asphalt; the added mass of the plasticizer is 2.5% of the base asphalt.

[0061] Example 6

[0062] The preparation method of the high-viscosity rubber modified asphalt in this example is as follows:

[0063] S1. Add 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate [C9H16ClF6N2P] to the waste rubber powder, stir for 2 h, then treat it under the microwave condition with a power of 800 W for 120 s, and naturally cool to room temperature to obtain the vulcanized rubber powder; the mass ratio of the waste rubber powder to 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate is 1:0.15.

[0064] The waste rubber powder in this example is derived from waste tires.

[0065] S2. Heat the base asphalt to 158 °C, add the vulcanized rubber powder obtained in S1, after mixing, raise the temperature to 178 °C, and continue isothermal shearing at a shearing rate of 1500 r / min for 32 min to obtain a mixture of the base asphalt and the vulcanized rubber powder; the base asphalt is 70# base asphalt; the added mass of the vulcanized rubber powder is 28% of the base asphalt.

[0066] S3. Add the mixture of the base asphalt and the vulcanized rubber powder obtained in S2 to a tackifier (a mixture of hydrocarbon resin and epoxy vinyl resin with a mass ratio of 4:1), and carry out isothermal shearing at 178 °C for 30 min in a high-speed shearing instrument with a shearing rate of 3000 r / min to obtain the modified asphalt with increased viscosity; the added mass of the tackifier is 1.6% of the base asphalt.

[0067] S4. Add a plasticizer (a mixture of dibutyl phthalate and dibutoxyethyl phthalate with a mass ratio of 2:1) to the tackified modified asphalt obtained in S3, and stir at 178 °C for 15 min under the condition of a rotation speed of 1300 r / min to obtain a high-viscosity rubber modified asphalt; the added mass of the plasticizer is 2.2% of the base asphalt.

[0068] Example 7

[0069] The preparation method of the high-viscosity rubber modified asphalt in this example is as follows:

[0070] S1. Add 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate [C9H16ClF6N2P] to waste rubber powder, stir for 2 h, then treat it under the condition of microwave with a power of 800 W for 120 s, and naturally cool to room temperature to obtain vulcanized rubber powder; the mass ratio of the waste rubber powder to 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate is 1:0.15;

[0071] The waste rubber powder in this example is from waste tires;

[0072] S2. Heat the base asphalt to 160 °C, add the vulcanized rubber powder obtained in S1, after mixing, raise the temperature to 170 °C, and continue to shear at a constant temperature for 30 min at a shear rate of 1500 r / min to obtain a mixture of the base asphalt and the vulcanized rubber powder; the base asphalt is 70# base asphalt; the added mass of the vulcanized rubber powder is 22% of the base asphalt;

[0073] S3. Add a tackifier (a mixture of C5 / C9 copolymerized petroleum resin and rosin resin with a mass ratio of 2:1) to the mixture of the base asphalt and the vulcanized rubber powder obtained in S2, and shear at a constant temperature of 170 °C for 30 min in a high-speed shearer with a shear rate of 3000 r / min to obtain a tackified modified asphalt; the added mass of the tackifier is 1.7% of the base asphalt;

[0074] S4. Add a plasticizer (a mixture of dibutyl adipate and dibutoxyethyl phthalate with a mass ratio of 1:3) to the tackified modified asphalt obtained in S3, and stir at 170 °C for 15 min under the condition of a rotation speed of 1300 r / min to obtain a high-viscosity rubber modified asphalt; the added mass of the plasticizer is 2.7% of the base asphalt.

[0075] The high-viscosity rubber modified asphalt prepared in Examples 1-7 was subjected to indoor performance tests, and the tests were carried out in accordance with the relevant test regulations of the "Test Regulations for Highway Asphalt and Asphalt Mixtures" (JTG E20-2011). The rotational viscosity test method refers to T0625-2011, the rutting factor test method refers to T0628-2011, the adhesion test method refers to T0616-1993, and the 48h softening point difference test method refers to T0606-2011.

[0076] The test results are shown in Table 1. The TPS modified asphalt (asphalt:TPS = 9:1) in Table 1 was used as a comparative example.

[0077] Table 1 Performance test results of high-viscosity rubber modified asphalt

[0078]

[0079]

[0080] The data in Table 1 show that the rotational viscosity, rutting factor, and adhesion performance of the high-viscosity rubber modified asphalt prepared in the present invention are better than those of the TPS modified asphalt (comparative sample). In particular, the storage stability is significantly better than that of the TPS modified asphalt, and all meet the requirement that the softening point difference is less than 2.5 °C after 48h, indicating that the 7 kinds of high-viscosity rubber modified asphalt prepared in the present invention can prevent segregation without using external mixing equipment during the actual mixing process. Through comprehensive comparison, it is found that the rotational viscosity and rutting factor of the high-viscosity rubber modified asphalt increase with the increase of the dosage of vulcanized rubber powder and tackifier. The high-viscosity rubber modified asphalt in Examples 1, 2, 3, 5, 6, and 7 all meet the requirement that the rotational viscosity at 180 °C does not exceed 1 Pa·s, which can fully meet the construction feasibility of the high-viscosity rubber modified asphalt mixture. Although the rotational viscosity (180 °C) of the No. 4 high-viscosity rubber modified asphalt reaches 1.23 Pa·s, the construction feasibility can be achieved by slightly increasing the mixing and compaction temperatures. The rutting factor is higher than that of the TPS modified asphalt under the same temperature conditions, indicating that the high-temperature stability of the 7 kinds of high-viscosity rubber modified asphalt is better than that of the TPS modified asphalt. The adhesion grade reaches the highest level (Grade 5) in the specification, which is significantly better than that of the TPS modified asphalt (Grade 4), indicating that after the aggregate coated with the high-viscosity rubber modified asphalt is soaked in water at 80 °C for 30 minutes, the asphalt film on the surface of the aggregate is completely preserved, and the percentage of the stripping area is close to 0, showing good water damage resistance.

[0081] The above is only a preferred embodiment of the present invention, and does not impose any limitation on the present invention. Any simple modification, change, and equivalent change made to the above embodiments according to the technical essence of the invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A preparation method of high-viscosity rubber modified asphalt, characterized in that, the method is as follows: S1. Add 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate to waste rubber powder. After stirring, treat it under microwave conditions with a power of 800 W for 120 s, and naturally cool to room temperature to obtain vulcanized rubber powder. The mass ratio of the waste rubber powder to 1-(chloro-1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate in S1 is 1:0.15; S2. Heat the matrix asphalt to 155°C - 165°C, add the vulcanized rubber powder obtained in S1. After mixing, raise the temperature to 170°C - 180°C, and continue to shear at a shear rate of 1500 r / min for 30 min - 40 min to obtain a mixture of matrix asphalt and vulcanized rubber powder. The matrix asphalt in S2 is 70# matrix asphalt; the added mass of the vulcanized rubber powder in S2 is 20% - 30% of the matrix asphalt; S3. Add a tackifier to the mixture of matrix asphalt and vulcanized rubber powder obtained in S2, and continue to shear at a constant temperature in a high-speed shearer with a shear rate of 3000 r / min for 20 min - 30 min to obtain the modified asphalt with increased viscosity. The tackifier in S3 includes one or more of C5 / C9 copolymerized petroleum resin, hydrocarbon resin, epoxy vinyl resin, and rosin resin; the added mass of the tackifier in S3 is 1.5% - 2.0% of the matrix asphalt; S4. Add a plasticizer to the modified asphalt with increased viscosity obtained in S3, and continue to stir at a constant temperature under the condition of a rotation speed of 1300 r / min for 10 min - 15 min to obtain high-viscosity rubber modified asphalt. The plasticizer in S4 includes one or more of dibutyl phthalate, dibutyl adipate, and dibutoxyethyl phthalate; the added mass of the plasticizer in S4 is 2% - 3% of the matrix asphalt; the rotational viscosity of the high-viscosity rubber modified asphalt in S4 at 180°C is 0.61 Pa·s - 1.23 Pa·s, the rutting factor at 64°C is 4.25 kPa - 5.20 kPa, and the adhesion grade is 5.

2. The preparation method of high-viscosity rubber modified asphalt according to claim 1, characterized in that, the stirring time in S1 is 2 h.

Images