A highly tough and recyclable epoxy plant-mixed hot recycled asphalt pavement material and its preparation method

Abstract

The present invention discloses a highly tough and recyclable epoxy plant-mixed hot recycled asphalt pavement material and its preparation method, belonging to the technical field of asphalt pavement materials. The recycled asphalt pavement material comprises the following components in parts by weight: 100 parts of asphalt mixture waste, 1.2 - 2.4 parts of epoxy regenerant, and 0.4 - 1.2 parts of matrix asphalt; the epoxy regenerant comprises modified epoxy resin, toughened flexible curing agent and compatible regenerant; the modified epoxy resin is formed by mixing epoxy resin and active diluent; the preparation method of the toughened flexible curing agent is as follows: polyetheramines with different molecular weights are respectively reacted with the modified epoxy resin, and then the obtained products are mixed to obtain the toughened flexible curing agent. The recycled asphalt pavement material of the present invention has strong high-temperature rutting resistance, low-temperature deformation resistance and water damage resistance, and its various properties are far superior to those of newly mixed SBS modified asphalt mixture; most importantly, the recycled asphalt pavement material of the present invention can be recycled multiple times, and the properties of the mixture are still excellent after multiple recycling.

Description

Technical Field

[0001] The present invention belongs to the technical field of asphalt pavement materials, and particularly relates to a highly tough and recyclable epoxy plant-mixed hot recycled asphalt pavement material and a preparation method thereof. Background Art

[0002] At present, the total mileage of expressways in China has exceeded 1.6 million kilometers, and more than 90% of them are asphalt pavements. The roads built in the early stage have successively entered the stages of renovation, expansion and maintenance. A large amount of asphalt mixture waste (RAP) will be generated during the expansion and maintenance of roads. Therefore, the recycling technology of asphalt mixture waste has become a research hotspot.

[0003] The asphalt mixture recycling technology is a technology that renovates or abandons the old asphalt pavement, which is dug, recycled, crushed and screened, and then appropriately mixed with some new aggregates and new asphalt (and recycling agent, if necessary), and remixed to obtain recycled asphalt mixture that meets the requirements of road use performance. The asphalt mixture recycling technology can be divided into plant-mixed hot recycling technology, plant-mixed cold recycling technology, in-situ hot recycling technology, and full-depth recycling technology. Different recycling methods have their own applicable situations, advantages and disadvantages. The water stability and low-temperature deformation ability of plant-mixed cold recycled mixture are poor and cannot be used as the highway surface layer; due to the low heating temperature of RAP, the RAP content in the conventional plant-mixed hot recycled mixture is only 20% - 30%. Even in the case of using warm mix agent, the RAP content in the warm mix recycled mixture can only reach 30% - 50%, and the remaining materials are newly mixed asphalt mixture; in addition, the current plant-mixed hot recycled asphalt pavement material still has insufficient low-temperature bending deformation ability.

[0004] In the prior art, there is also a plant-mixed hot recycling technology with an RAP content of more than 90%, but the recycled mixture prepared by this technology is a thermosetting material and cannot be softened by reheating. When the asphalt mixture waste is recycled again, the performance of the obtained recycled mixture decays greatly, which is not conducive to multiple recycling; in addition, the retention time of epoxy asphalt mixture is short. Once it exceeds the retention time, it cannot be paved and compacted, and the construction requirements are high. Summary of the Invention

[0005] Aiming at the above deficiencies of the prior art, one of the purposes of the present invention is to provide a highly tough and recyclable epoxy plant-mixed hot recycled asphalt pavement material. The RAP content in the recycled asphalt mixture of the present invention is as high as 97%. At the same time, the high-temperature rutting resistance, low-temperature deformation ability and water damage resistance of the recycled asphalt mixture are strong; most importantly, the asphalt mixture of the present invention can be recycled multiple times, and the performance of the mixture is still excellent after multiple recycling; it solves the problems of low RAP blending ratio, inability to recycle multiple times, and short retention time in the prior art.

[0006] To achieve the above object, the specific technical solution of the present invention is as follows:

[0007] A highly tough and recyclable epoxy plant-mixed hot recycled asphalt pavement material, characterized by comprising the following components in parts by weight: 100 parts of asphalt mixture waste, 1.2 - 2.4 parts of epoxy regenerant, and 0.4 - 1.2 parts of matrix asphalt;

[0008] The epoxy regenerant includes modified epoxy resin, toughening flexible curing agent, and compatible regenerant;

[0009] The modified epoxy resin is formed by mixing epoxy resin and active diluent;

[0010] The preparation method of the toughening flexible curing agent includes the following steps:

[0011] S1. Prepare an accelerating curing agent: Mix polyetheramine with an average molecular weight of 220 - 240 and modified epoxy resin in a mass ratio of (4 - 6):(8 - 9), and react at 60 - 80 °C for 2 - 4 h to obtain the accelerating curing agent;

[0012] S2. Prepare a toughening curing agent: Mix polyetheramine with an average molecular weight of 390 - 410 and modified epoxy resin in a mass ratio of 1:(1 - 1.5), and react at 60 - 80 °C for 4 - 6 h to obtain the toughening curing agent;

[0013] S3. Prepare a plasticizing curing agent: Mix polyetheramine with an average molecular weight of 1900 - 2100 and modified epoxy resin in a mass ratio of (19 - 21):(3 - 5), and react at 60 - 80 °C for 10 - 12 h to obtain the plasticizing curing agent;

[0014] S4. Prepare a toughening flexible curing agent: Mix the accelerating curing agent, toughening curing agent, plasticizing curing agent, and toughening agent in a mass ratio of (4 - 6):(15 - 17):(23 - 25):1 to obtain the toughening flexible curing agent.

[0015] By reacting polyetheramines with different molecular weights with modified epoxy resins, an accelerating curing agent, a toughening curing agent, and a plasticizing curing agent are respectively prepared. Then, the accelerating curing agent, the toughening curing agent, the plasticizing curing agent, and a toughening agent are mixed to obtain a toughened flexible curing agent. The toughened flexible curing agent can endow the epoxy regenerant with the characteristics of high toughness and high plasticity. After the toughened flexible curing agent is fully mixed with the compatible regenerant, an epoxy regenerant is formed. It has a strong dissolving effect on asphalt and good compatibility. The epoxy regenerant is used to fully soften and penetrate the aged asphalt on the surface of RAP, so that the epoxy resin can firmly bond to RAP. At the same time, during the mixing process, the epoxy regenerant penetrates into the matrix asphalt to form an epoxy asphalt binder, and the bonding effect is far better than that of SBS modified asphalt. Finally, an epoxy regenerant with high toughness, high plasticity, and long curing time is prepared. The present invention uses an epoxy regenerant with high toughness, high plasticity, and long curing time as a binder, which can bond RAP into a dense structure, synchronously improve the flexibility of asphalt, improve the low-temperature deformation ability of asphalt, and increase the retention time of the recycled asphalt mixture. The recycled asphalt mixture of the present invention has excellent high-temperature rutting resistance, low-temperature deformation ability, and water damage resistance. Most importantly, the recycled asphalt mixture of the present invention can be recycled multiple times, and the performance of the mixture is still excellent after multiple recyclings.

[0016] Preferably, the mass ratio of the modified epoxy resin, the toughened flexible curing agent, and the compatible regenerant is (10 - 11):(21 - 24):(5 - 9).

[0017] Preferably, the compatible regenerant is composed of 70# petroleum asphalt, resin, and rubber oil mixed in a mass ratio of (92 - 98):(1 - 2):(1 - 6).

[0018] Preferably, the resin includes at least one of terpene resin, C5 petroleum resin, and C9 petroleum resin.

[0019] Preferably, the mass ratio of the epoxy resin to the active diluent is (80 - 110):(9 - 11); further preferably, the active diluent includes at least one of butyl glycidyl ether, benzyl glycidyl ether, and ethylene glycol diglycidyl ether.

[0020] Preferably, the toughening agent includes polysulfide rubber and / or terminal epoxy nitrile rubber.

[0021] The highly tough and repeatedly recyclable epoxy plant-mixed hot recycled asphalt pavement material is a multi-recycled asphalt mixture. The multi-recycled asphalt mixture includes the following components in parts by weight: 100 parts of asphalt mixture waste, 0.6 - 1.2 parts of epoxy regenerant, and 0.2 - 0.6 parts of matrix asphalt. The epoxy regenerant is the above-mentioned epoxy regenerant.

[0022] The present invention also provides a method for preparing the high-toughness and repeatable regenerable epoxy plant-mixed hot recycled asphalt pavement material, which comprises the following steps:

[0023] P1. After crushing the asphalt mixture waste, it is classified into coarse materials and fine materials according to the particle size. Then, the coarse materials and fine materials are added in proportion and mixed evenly at 125-135 °C to obtain a mixture; the base asphalt is heated to a flowing state.

[0024] P2. The epoxy regenerant is heated to 110-120 °C and stirred evenly, then added to the mixture and mixed evenly, and then the base asphalt is added and mixed evenly to obtain the plant-mixed hot recycled asphalt pavement material.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] (1) In the recycled asphalt pavement material of the present invention, the dosage of RAP can reach more than 97%, which is much higher than that of traditional plant-mixed hot recycling and warm mixing recycling; the high-temperature rutting resistance, low-temperature deformation resistance and water damage resistance of the recycled asphalt pavement material of the present invention are strong, and all performances are far superior to those of newly prepared SBS modified asphalt mixture.

[0027] (2) The secondary regeneration performance of the recycled asphalt pavement material of the present invention is far superior to that of traditional epoxy recycled asphalt mixture, and multiple regeneration can be realized, and the performance of the mixture is still excellent after multiple regeneration. Specific Embodiments

[0028] The technical solutions of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work fall within the protection scope of the present invention.

[0029] Example 1

[0030] This example provides a method for preparing a high-toughness and repeatable regenerable epoxy plant-mixed hot recycled asphalt pavement material, which comprises the following steps:

[0031] P1. After crushing the asphalt mixture waste, it is classified into two grades of 0-4.75 mm and 4.75-16 mm according to the particle size. Then, 77 parts of RAP with a particle size less than 4.75 mm and 23 parts of RAP with a particle size of 4.75-16 mm are heated to 130 °C and mixed for 90 s to obtain a mixture; the base asphalt is placed at 140 °C and heated to a good flowing state.

[0032] P2. Take 1.4 parts of epoxy regenerant, heat it to 110 °C and mix evenly, then add the mixture and mix for 90 s, and then add 0.6 part of flowing matrix asphalt and mix for 90 s to obtain the first recycled asphalt surface course mixture.

[0033] Specifically, the epoxy regenerant is composed of modified epoxy resin, toughened flexible curing agent and compatible regenerant with a mass ratio of 10:24:9;

[0034] More specifically, the preparation method of the modified epoxy resin is as follows: Mix bisphenol A type E51 epoxy resin and butyl glycidyl ether with a mass ratio of 90:10 evenly at 30 °C to obtain the modified epoxy resin;

[0035] The preparation method of the toughened flexible curing agent is as follows:

[0036] S1. Prepare an accelerating curing agent: Mix polyetheramine with an average molecular weight of 230 and modified epoxy resin evenly according to a mass ratio of 5:8.6, and react at 70 °C for 2 h to obtain the accelerating curing agent;

[0037] S2. Prepare a toughening curing agent: Mix polyetheramine with an average molecular weight of 400 and modified epoxy resin evenly according to a mass ratio of 1:1, and react at 70 °C for 4 h to obtain the toughening curing agent;

[0038] S3. Prepare a plasticizing curing agent: Mix polyetheramine with an average molecular weight of 2000 and modified epoxy resin evenly according to a mass ratio of 20:3, and react at 70 °C for 10 h to obtain the plasticizing curing agent;

[0039] S4. Prepare a toughened flexible curing agent: Mix the accelerating curing agent, toughening curing agent, plasticizing curing agent and terminal epoxy nitrile rubber evenly at 30 °C according to a mass ratio of 5:16:24:1 to obtain the toughened flexible curing agent;

[0040] The preparation method of the compatible regenerant is as follows: Heat 70# petroleum asphalt to 140 °C, and then stir 70# petroleum asphalt, terpene resin and aromatic oil evenly according to a mass ratio of 95:1:4, and cool to room temperature to obtain the compatible regenerant.

[0041] Example 2

[0042] This example provides a preparation method of a highly tough and recyclable epoxy plant-mixed hot recycled asphalt pavement material, including the following steps:

[0043] P1. After crushing the asphalt mixture waste, it is divided into two grades according to particle size: 0 - 4.75 mm and 4.75 - 25 mm. Then, 75 parts of RAP with a particle size less than 4.75 mm and 25 parts of RAP with a particle size of 4.75 - 25 mm are heated to 130 °C and mixed for 90 s to obtain a mixture; the base asphalt is heated to 140 °C until it has a good flow state;

[0044] P2. Take 1.2 parts of epoxy regenerant, heat it to 110 °C and mix evenly, then add it to the mixture and mix for 90 s, and then add 1.2 parts of flowing base asphalt and mix for 90 s to obtain the first - stage recycled asphalt middle - surface layer mixture.

[0045] Specifically, the epoxy regenerant is composed of modified epoxy resin, toughened flexible curing agent and compatible regenerant with a mass ratio of 11:21:5;

[0046] More specifically, the preparation method of the modified epoxy resin is as follows: bisphenol A type E51 epoxy resin and butyl glycidyl ether with a mass ratio of 110:9 are mixed evenly at 30 °C to obtain the modified epoxy resin;

[0047] The preparation method of the toughened flexible curing agent is as follows:

[0048] S1. Prepare an accelerating curing agent: polyetheramine with an average molecular weight of 300 and modified epoxy resin are mixed evenly according to a mass ratio of 6:8 and reacted at 70 °C for 3 h to obtain the accelerating curing agent;

[0049] S2. Prepare a toughening curing agent: polyetheramine with an average molecular weight of 550 and modified epoxy resin are mixed evenly according to a mass ratio of 1:1.1 and reacted at 70 °C for 5 h to obtain the toughening curing agent;

[0050] S3. Prepare a plasticizing curing agent: polyetheramine with an average molecular weight of 2500 and modified epoxy resin are mixed evenly according to a mass ratio of 19:5 and reacted at 70 °C for 11 h to obtain the plasticizing curing agent;

[0051] S4. Prepare a toughened flexible curing agent: the accelerating curing agent, toughening curing agent, plasticizing curing agent and terminal epoxy nitrile rubber are mixed evenly at 30 °C according to a mass ratio of 4:17:25:1 to obtain the toughened flexible curing agent;

[0052] The preparation method of the compatible regenerant is as follows: heat 70# petroleum asphalt to 140 °C, then stir 70# petroleum asphalt, C5 petroleum resin and aromatic oil evenly according to a mass ratio of 92:2:6, and cool to room temperature to obtain the compatible regenerant.

[0053] Example 3

[0054] The preparation method of the high-toughness and recyclable epoxy plant-mixed hot recycled asphalt pavement material in this embodiment includes the following steps:

[0055] P1. After crushing the asphalt mixture waste, it is divided into two grades of 0 - 4.75 mm and 4.75 - 31 mm according to the particle size. Then, 70 parts of RAP with a particle size less than 4.75 mm and 30 parts of RAP with a particle size of 4.75 - 31 mm are heated to 130 °C and mixed for 90 s to obtain a mixture; the base asphalt is heated to 140 °C until it has a good flow state.

[0056] P2. Take 2.4 parts of epoxy regenerant and heat it to 110 °C and mix it evenly. Then add it to the mixture and mix for 90 s. Then add 0.4 parts of the flowing base asphalt and mix for 90 s to obtain the primary recycled asphalt lower surface course mixture.

[0057] The epoxy regenerant in this embodiment is the same as that in Embodiment 1.

[0058] Embodiment 4

[0059] In this embodiment, the primary recycled asphalt upper surface course mixture in Embodiment 1, the primary recycled asphalt middle surface course mixture in Embodiment 2, and the primary recycled asphalt lower surface course mixture in Embodiment 3 are respectively crushed and recycled (the epoxy regenerant used is the same as that in Embodiment 1) to obtain the secondary recycled asphalt mixture, specifically as follows:

[0060] The primary recycled asphalt upper surface course mixture prepared in Embodiment 1 is crushed and screened by a hammer crusher and divided into two grades of 0 - 4.75 mm and 4.75 - 16 mm according to the particle size. Then, 77 parts of RAP with a particle size less than 4.75 mm and 23 parts of RAP with a particle size of 4.75 - 16 mm are heated to 130 °C and mixed for 90 s to obtain a mixture; the base asphalt is heated to 140 °C until it has a good flow state; take 0.7 parts of epoxy regenerant and heat it to 110 °C, then add it to the mixture and mix for 90 s, and then add 0.3 parts of the flowing base asphalt and mix for 90 s to obtain the secondary recycled asphalt upper surface course mixture.

[0061] The primary recycled asphalt middle surface course mixture in Embodiment 2 is crushed and screened by a hammer crusher and divided into two grades of 0 - 4.75 mm and 4.75 - 25 mm according to the particle size. Then, 75 parts of RAP with a particle size less than 4.75 mm and 25 parts of RAP with a particle size of 4.75 - 25 mm are heated to 130 °C and mixed for 90 s to obtain a mixture; the base asphalt is heated to 140 °C until it has a good flow state; take 0.7 parts of epoxy regenerant and heat it to 110 °C and mix it evenly, then add it to the mixture and mix for 90 s, and then add 0.3 parts of the flowing base asphalt and mix for 90 s to obtain the secondary recycled asphalt middle surface course mixture.

[0062] The primary recycled asphalt base course mixture of Example 3 was crushed and screened by a hammer crusher and then divided into two grades by particle size: 0 - 4.75 mm and 4.75 - 31 mm. Then, 70 parts of RAP with a particle size less than 4.75 mm and 30 parts of RAP with a particle size of 4.75 - 31 mm were heated to 130 °C and mixed for 90 s to obtain a mixture; the base asphalt was heated to 140 °C until it had a good flow state; 0.7 part of epoxy recycling agent was heated to 110 °C and mixed evenly, then added to the mixture and mixed for 90 s, and then 0.3 part of the flowing base asphalt was added and mixed for 90 s to obtain the secondary recycled asphalt base course mixture.

[0063] Example 5

[0064] In this example, the secondary recycled asphalt surface course mixture, the secondary recycled asphalt intermediate course mixture, and the secondary recycled asphalt base course mixture obtained in Example 4 were respectively crushed and recycled (the epoxy recycling agent used was the same as that in Example 1) to obtain the tertiary recycled asphalt mixture, which is specifically as follows:

[0065] The secondary recycled asphalt surface course mixture prepared in Example 4 was crushed and screened by a hammer crusher and then divided into two grades by particle size: 0 - 4.75 mm and 4.75 - 16 mm. Then, 77 parts of RAP with a particle size less than 4.75 mm and 23 parts of RAP with a particle size of 4.75 - 16 mm were heated to 130 °C and mixed for 90 s to obtain a mixture; the base asphalt was heated to 140 °C until it had a good flow state; 0.7 part of epoxy recycling agent was heated to 110 °C, then added to the mixture and mixed for 90 s, and then 0.3 part of the flowing base asphalt was added and mixed for 90 s to obtain the tertiary recycled asphalt surface course mixture.

[0066] The secondary recycled asphalt intermediate course mixture of Example 4 was crushed and screened by a hammer crusher and then divided into two grades by particle size: 0 - 4.75 mm and 4.75 - 25 mm. Then, 75 parts of RAP with a particle size less than 4.75 mm and 25 parts of RAP with a particle size of 4.75 - 25 mm were heated to 130 °C and mixed for 90 s to obtain a mixture; the base asphalt was heated to 140 °C until it had a good flow state; 0.7 part of epoxy recycling agent was heated to 110 °C and mixed evenly, then added to the mixture and mixed for 90 s, and then 0.3 part of the flowing base asphalt was added and mixed for 90 s to obtain the tertiary recycled asphalt intermediate course mixture.

[0067] The secondary recycled asphalt base course mixture of Example 4 was crushed and screened by a hammer crusher, and then divided into two grades according to particle size: 0-4.75 mm and 4.75-31 mm. Then, 70 parts of RAP with a particle size less than 4.75 mm and 30 parts of RAP with a particle size of 4.75-31 mm were heated to 130 °C and mixed for 90 s to obtain a mixture; the base asphalt was heated to 140 °C until it had a good flow state; 0.7 part of epoxy regenerant was heated to 110 °C and mixed evenly, then added to the mixture and mixed for 90 s, and then 0.3 part of the flowing base asphalt was added and mixed for 90 s to obtain the tertiary recycled asphalt base course mixture.

[0068] Comparative Examples 1-6

[0069] According to the grading requirements of asphalt mixture in the "Technical Specification for Construction of Highway Asphalt Pavement JTG F40-2004", Comparative Examples 1-6 were set as follows:

[0070] Comparative Example 1: 88 parts of graded crushed stone, 12 parts of limestone powder filler, and 6 parts of I-D SBS modified asphalt were mixed to obtain SMA-13 mixture;

[0071] Comparative Example 2: 96 parts of graded crushed stone, 4 parts of limestone powder filler, and 4.5 parts of I-D SBS modified asphalt were mixed to obtain AC-20 modified asphalt mixture;

[0072] Comparative Example 3: 97 parts of graded crushed stone, 3 parts of limestone powder filler, and 4.2 parts of I-D SBS modified asphalt were mixed to obtain AC-25 modified asphalt mixture;

[0073] Comparative Example 4: 67 parts of graded crushed stone, 30 parts of RAP with a particle size < 26 mm, 3 parts of limestone powder filler, 3.5 parts of I-D SBS modified asphalt, and 0.0075 part of aromatic oil regenerant were mixed to obtain a common hot recycled intermediate course mixture;

[0074] Comparative Example 5: 68 parts of graded crushed stone, 30 parts of RAP with a particle size < 31 mm, 2 parts of limestone powder filler, 3.2 parts of I-D SBS modified asphalt, and 0.0075 part of aromatic oil regenerant were mixed to prepare a common hot recycled base course mixture;

[0075] Comparative Example 6: 100 parts of RAP with a particle size < 16 mm and 2 parts of epoxy asphalt were mixed to obtain an epoxy recycled surface course mixture.

[0076] Comparative Example 7

[0077] The preparation method of the plant-mixed hot recycled asphalt pavement material in this comparative example was the same as that of Example 1, except that,

[0078] The epoxy regenerant is composed of modified epoxy resin, curing agent and compatible regenerant with a mass ratio of 10:24:9;

[0079] Among them, the modified epoxy resin and the compatible regenerant are the same as those in Example 1;

[0080] The preparation method of the curing agent is as follows:

[0081] Mix polyetheramine with an average molecular weight of 230 and modified epoxy resin evenly according to a mass ratio of 5:8.6, react at 70 °C for 2 h to obtain an accelerating curing agent; then mix the accelerating curing agent and terminal epoxy nitrile rubber evenly at 30 °C according to a mass ratio of 45:1 to obtain the curing agent.

[0082] Comparative Example 8

[0083] The preparation method of the plant-mixed hot recycled asphalt pavement material in this comparative example is the same as that in Example 1, except that

[0084] The epoxy regenerant is composed of modified epoxy resin, curing agent and compatible regenerant with a mass ratio of 17.6:16.4:9;

[0085] Among them, the modified epoxy resin and the compatible regenerant are the same as those in Example 1;

[0086] The preparation method of the toughened flexible curing agent is as follows:

[0087] Mix polyetheramine with an average molecular weight of 230, polyetheramine with an average molecular weight of 400, polyetheramine with an average molecular weight of 2000 and terminal epoxy nitrile rubber evenly at 30 °C according to a mass ratio of 1.84:8:20.86:1 to obtain the toughened flexible curing agent;

[0088] That is, compared with Example 1, the toughened flexible curing agent in this comparative example does not contain modified epoxy resin, and the amount of modified epoxy resin in the regenerant is correspondingly increased.

[0089] According to the "Test Regulations for Asphalt and Asphalt Mixtures in Highway Engineering" (JTGE20 - 2011), the recycled asphalt mixture specimens of Examples 1 - 5 and Comparative Examples 1 - 8 are formed into Marshall specimens, rutting plate specimens and beam specimens, and then the high-temperature stability, low-temperature performance and water stability of the specimens are tested. The test results are shown in Tables 1 and 2.

[0090] Table 1 Test Results of Recycled Asphalt Mixture Performance

[0091]

[0092] Analysis of the data in Table 1 shows that when comparing Example 1 with Comparative Example 1 and Comparative Example 6, Example 2 with Comparative Example 2 and Comparative Example 4, and Example 3 with Comparative Example 3 and Comparative Example 5, it can be seen that the high-temperature performance, low-temperature performance, and water stability of the high-toughness and recyclable epoxy plant-mixed hot recycled asphalt pavement material of the present invention are significantly higher than those of SBS modified asphalt mixtures, far higher than those of ordinary plant-mixed hot recycled asphalt mixtures with insufficient low-temperature deformation ability and water stability, and the low-temperature toughness exceeds that of ordinary epoxy resin recycled mixtures.

[0093] Compared with Example 1, Comparative Example 7 uses a polyetheramine curing agent with an average molecular weight of 230. Since the curing agent reacts rapidly, the recycled asphalt mixture is difficult to be compacted. Its strength and high-temperature rutting resistance are relatively high, but the overall brittleness of the material is relatively large, and the low-temperature bending deformation ability is poor.

[0094] Compared with Example 1, the curing agent in Comparative Example 8 does not add modified epoxy resin. Since the curing agent reacts rapidly, the recycled asphalt mixture is difficult to be compacted. Its strength and high-temperature rutting resistance are relatively high, even higher than those of Comparative Example 7; however, the overall brittleness of the material is relatively large, and the low-temperature bending deformation ability is extremely poor, lower than that of Comparative Example 7.

[0095] Table 2 Performance test results of repeatedly recycled asphalt mixtures

[0096]

[0097]

[0098] Analysis of the data in Table 2 shows that when comparing Examples 4 and 5 with Examples 1 to 3, the Marshall stability, low-temperature bending deformation ability, and water stability of the asphalt mixtures after secondary and tertiary recycling are slightly improved compared with those of the asphalt mixtures after primary recycling, while the porosity and high-temperature rutting deformation decrease slightly, and the change range is small; this shows that the high-toughness and recyclable epoxy plant-mixed hot recycled asphalt pavement material of the present invention has strong recyclable ability, can achieve multiple recycling, and the performance of the mixture is still excellent after multiple recycling.

[0099] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A highly tough and recyclable epoxy plant-mixed hot recycled asphalt pavement material, characterized in that, Comprising the following components in parts by weight: 100 parts of asphalt mixture waste, 1.2 - 2.4 parts of epoxy regenerant, and 0.4 - 1.2 parts of base asphalt; The epoxy regenerant includes modified epoxy resin, toughened flexible curing agent, and compatible regenerant; The modified epoxy resin is formed by mixing epoxy resin and reactive diluent; The preparation method of the toughened flexible curing agent includes the following steps: S1. Prepare the accelerating curing agent: Mix polyetheramine with an average molecular weight of 220 - 240 and modified epoxy resin in a mass ratio of (4 - 6):(8 - 9) evenly, and react at 60 - 80 °C for 2 - 4 h to obtain the accelerating curing agent; S2. Prepare the toughening curing agent: Mix polyetheramine with an average molecular weight of 390 - 410 and modified epoxy resin in a mass ratio of 1:(1 - 1.5) evenly, and react at 60 - 80 °C for 4 - 6 h to obtain the toughening curing agent; S3. Prepare the plasticizing curing agent: Mix polyetheramine with an average molecular weight of 1900 - 2100 and modified epoxy resin in a mass ratio of (19 - 21):(3 - 5) evenly, and react at 60 - 80 °C for 10 - 12 h to obtain the plasticizing curing agent; S4. Prepare the toughened flexible curing agent: Mix the accelerating curing agent, toughening curing agent, plasticizing curing agent, and toughening agent in a mass ratio of (4 - 6):(15 - 17):(23 - 25):1 evenly to obtain the toughened flexible curing agent.

2. A highly tough and recyclable epoxy plant-mixed hot recycled asphalt pavement material according to claim 1, characterized in that, The mass ratio of the modified epoxy resin, toughened flexible curing agent, and compatible regenerant is (10 - 11):(21 - 24):(5 - 9).

3. A highly tough and recyclable epoxy plant-mixed hot recycled asphalt pavement material according to claim 1, characterized in that, The compatible regenerant is formed by mixing 70# petroleum asphalt, resin, and rubber oil in a mass ratio of (92 - 98):(1 - 2):(1 - 6).

4. A highly tough and recyclable epoxy plant-mixed hot recycled asphalt pavement material according to claim 3, characterized in that, The resin includes at least one of terpene resin, C5 petroleum resin, and C9 petroleum resin.

5. A high-toughness and recyclable epoxy plant-mixed hot recycled asphalt pavement material according to claim 1, characterized in that, The reactive diluent includes at least one of butyl glycidyl ether, benzyl glycidyl ether, and ethylene glycol diglycidyl ether.

6. A highly tough and recyclable epoxy plant-mixed hot recycled asphalt pavement material according to claim 1, characterized in that, The toughening agent includes polysulfide rubber and / or terminal epoxy nitrile rubber.

7. The preparation method of the high-toughness and recyclable epoxy plant-mixed hot recycled asphalt pavement material according to any one of claims 1 to 6, characterized in that, Including the following steps: P1. After crushing the asphalt mixture waste, divide it into coarse materials and fine materials according to the particle size, then add the coarse materials and fine materials in proportion and mix evenly at 125 - 135 °C to obtain a mixture; Heat the base asphalt to a flowing state; P2. Heat the epoxy regenerant to 110 - 120 °C and mix evenly, then add it to the mixture and mix evenly, and then add the base asphalt and mix evenly to obtain the plant-mixed hot recycled asphalt pavement material.

Images