Method for recycling waste asphalt

Abstract

This invention discloses a method for recycling waste asphalt, belonging to the field of road engineering technology. The technical problem this invention aims to solve is how to rapidly restore aged asphalt in waste asphalt pavement materials and accurately determine the proportion of recycling agent added. The technical solution adopted is as follows: Select waste asphalt pavement materials and initially determine the asphalt-aggregate ratio in each grade of waste asphalt pavement material; prepare RAP compound materials, ensuring that the asphalt-aggregate ratio of waste asphalt to aggregate in the RAP compound materials is not less than 5.0; prepare experimental group mixtures; prepare control group mixtures; determine the optimal ratio of recycling agent added mass to old asphalt mass, using the following formula: D 最佳 =(D 孔隙率 +D 劈裂 +D 低温 ) / 3; where D 最佳 Indicates the ratio of the optimal recycling agent mass to the mass of old asphalt; D 孔隙率 This indicates the porosity of the experimental group specimens prepared from the experimental group mixture and the porosity of the control group specimens prepared from the control group mixture.

Description

Technical Field

[0001] This invention relates to the field of road engineering technology, specifically a method for recycling waste asphalt. Background Technology

[0002] With the gradual formation of road networks in recent years, road maintenance, repair, and expansion have become the main directions of road development. As major road repairs and expansions are carried out, a large amount of waste asphalt pavement material is generated. Hot recycling technology for asphalt pavement is a key technology for achieving high-quality application of waste asphalt pavement. However, when using this technology, the appropriate amount of recycling agent to add to the mixture needs to be determined. Determining the ratio of recycling agent to aged asphalt first requires assessing the degree of performance degradation of the old asphalt pavement material, mainly including the aging performance of the asphalt and the degradation performance of its gradation. Grading degradation can be assessed through extraction and sieving tests of the old asphalt pavement material, which is relatively simple and quick. However, testing the aging performance of asphalt is more cumbersome, requiring repeated extraction of the waste asphalt pavement material to obtain a recovery liquid containing old asphalt and trichloroethylene. Multiple rotary evaporation experiments are then conducted to obtain a sufficient number of asphalt samples to evaluate the performance of aged asphalt. Finally, the optimal recycling agent addition ratio for restoring aged asphalt is calculated using the viscosity values ​​of aged asphalt and recycling agent at 60°C. However, extensive practical experience has revealed the following shortcomings in existing technologies:

[0003] ① The process of recycling aged asphalt is relatively expensive and wastes a lot of time. The experimental time in the existing technology is often 10-15 days.

[0004] ② The viscosity test results of aged asphalt have a large dispersion, mainly because the recovered aged asphalt samples often contain residual trichloroethylene that has not been completely evaporated, which increases the variability of the experimental results and reduces the guiding significance of the experimental results.

[0005] ③ The fusion of aged asphalt and recycling agent in asphalt mixture is a complex process. The asphalt index of recycled asphalt fused together by calculating viscosity cannot meet the requirements of the mixture, nor can it reflect the performance of the recycling agent in the recycled asphalt mixture. Therefore, the method given in the specification can only be used as a reference in actual use, and cannot accurately determine the addition ratio of recycling agent.

[0006] ④ The test method for extracting aged asphalt requires a rotary evaporator and a large fully automated extraction instrument. These devices are relatively expensive and are generally equipped by Class A qualified laboratories. It is difficult to conduct the corresponding experiments in real time in the project, so they cannot be widely used.

[0007] Therefore, how to quickly restore aged asphalt in waste asphalt pavement materials and accurately determine the proportion of recycling agent is a technical problem that urgently needs to be solved. Summary of the Invention

[0008] The technical objective of this invention is to provide a method for recycling waste asphalt to address the problem of how to rapidly restore aged asphalt in waste asphalt pavement materials and accurately determine the proportion of recycling agent added.

[0009] The technical objective of this invention is achieved in the following manner: a method for recycling waste asphalt, the specific details of which are as follows:

[0010] Select waste asphalt pavement materials and preliminarily determine the asphalt-aggregate ratio in each grade of waste asphalt pavement materials;

[0011] When preparing RAP compound materials, ensure that the asphalt-aggregate ratio (mass ratio) of waste asphalt in the RAP compound material to aggregate in the RAP compound material is not less than 5.0;

[0012] Prepare the experimental group mixture;

[0013] Prepare the control group mixture;

[0014] The experimental and control asphalt mixtures were molded into specimens at their respective molding temperatures. Data from these specimens were then collected for both groups. Linear regression was performed on the same coordinate system, with the abscissas of the data from both groups being identical. The optimal ratio D of the recycled agent mass to the old asphalt mass was determined based on the intersection of the regression lines from both groups. 孔隙率 D 劈裂 and D 低温 ;

[0015] The optimal ratio of recycling agent mass to old asphalt mass is determined by the following formula:

[0016] D 最佳 =(D 孔隙率 +D 劈裂 +D 低温 ) / 3;

[0017] Among them, D 最佳 Indicates the ratio of the optimal recycling agent mass to the mass of old asphalt; D 孔隙率 This indicates the porosity of the experimental group specimens prepared from the experimental group mixture and the porosity of the control group specimens prepared from the control group mixture.

[0018] As a preferred option, the following specific waste asphalt pavement materials are selected:

[0019] Select waste asphalt pavement material in the 0-5mm grade;

[0020] Place the waste asphalt pavement material in an 80℃ oven for 3-4 hours to fully disperse the waste asphalt pavement material and sieve out the material with a thickness greater than 4.75mm.

[0021] The old asphalt pavement material is divided into three grades: 0-1.18mm, 1.18mm-2.35mm, and 2.35mm-4.75mm. These three grades are respectively referred to as RAP Fine, RAP Medium, and RAP Coarse.

[0022] More preferably, the specific formulation of RAP compound materials is as follows:

[0023] The fine, medium, and coarse RAP are blended together, with the following quality grades:

[0024] RAP is 30%-50% finer, RAP is 20%-30% finer, and RAP is 30%-40% finer.

[0025] The total mass ratio of RAP fine, RAP medium, and RAP coarse is 100%. The material composed of these three components is called RAP compound material. By adjusting the composition ratio of RAP fine, RAP medium, and RAP coarse, the mass ratio (asphalt-aggregate ratio) of the old asphalt in the RAP compound material to the aggregate in the RAP compound material is ensured to be not less than 5.0.

[0026] More preferably, the experimental group mixture should be prepared as follows:

[0027] The prepared RAP compound material was divided into three groups and heated to the mixing temperature corresponding to the type of old asphalt. The recycling agent was added to the RAP compound material at a mass ratio of 5%, 10%, and 15% of the old asphalt, respectively. After thorough mixing, the mixture was placed at the old asphalt mixing temperature for 2 hours.

[0028] More preferably, the control group mixture is prepared as follows:

[0029] The RAP compound materials were divided into three groups, and extraction experiments were carried out on the three groups of RAP compound materials to obtain the aggregates and mineral powders corresponding to the three groups of RAP compound materials.

[0030] The aggregates and mineral powders corresponding to the three groups of RAP compound materials were heated to the mixing temperature of the corresponding new asphalt, wherein the type of new asphalt was the same as that of the old asphalt.

[0031] New asphalt with the same mass as the old asphalt and recycling agent was added to the aggregate and mineral powder corresponding to the three groups of RAP compound materials. After the three groups of RAP compound materials were thoroughly mixed, they were placed at the mixing temperature of aged asphalt for 2 hours.

[0032] As a preferred option, the experimental group data is obtained as follows:

[0033] The experimental group mixture was molded into rotary compaction specimens according to the rotary compaction test method at the corresponding molding temperature, and rutted specimens were molded into rutted specimens according to the rutted test molding method.

[0034] The porosity α of the rotary compacted specimens in the experimental group was obtained by detection. 实验5 a 实验10 and a 实验15 ;

[0035] The splitting tensile strength test at 25°C was conducted on the rotary compacted specimens of the experimental group. 实验5 b 实验10 and b 实验15 ;

[0036] The low-temperature bending failure strain c of the rutted specimens in the experimental group was obtained by detection. 实验5 c 实验10 and c 实验15 .

[0037] As a preferred option, the data for the comparison group is obtained as follows:

[0038] The comparative group mixture was molded into comparative group rotary compaction specimens according to the rotary compaction test method at the corresponding molding temperature, and the comparative group rutting specimens were molded according to the rutting test molding method.

[0039] The porosity α of the rotary compacted specimens in the control group was obtained by detection. 对比5 a 对比10 and a 对比15 ;

[0040] The splitting tensile strength test at 25°C was conducted on the rotationally compacted specimens of the control group. 对比5 b 对比10 and b 对比15 ;

[0041] The low-temperature bending test failure strain c of the control group rutted specimens was obtained by detection. 对比5 c 对比10 and c 对比15 .

[0042] More preferably, the diameter of the rotary compaction specimens in both the experimental group and the control group is 150 mm, the height of the rotary compaction specimens in both the experimental group and the control group is 100 mm ± 2.5 mm, and the number of rotary compaction cycles for both the experimental group and the control group is 100.

[0043] The waste asphalt recycling method of the present invention has the following advantages:

[0044] (i) This invention can quickly restore the performance of aged asphalt in waste asphalt pavement materials and determine the optimal mass ratio of recycling agent. The experimental method is accurate and reliable, reduces the dependence on advanced equipment, and also reduces experimental costs. It is worth promoting widely.

[0045] (II) This invention, combining engineering experience and focusing on the perspective of mixtures, integrates waste asphalt pavement materials into the mixture evaluation system. Through the mixture evaluation method, it can achieve rapid restoration of aged asphalt in waste asphalt pavement materials and accurately determine the proportion of recycling agent added. This invention has the following characteristics:

[0046] ① The experiment has low cost, does not require expensive experimental equipment, can be carried out in most laboratories, and has great potential for promotion;

[0047] ② The experiment is short, with a cycle of 3-5 days, which can greatly shorten the evaluation cycle;

[0048] ③ The experimental results are minimally affected by subjective human factors and have good reproducibility;

[0049] ④ It eliminates the influence of the interaction between aggregates in waste pavement materials and new aggregates, minimizing external interference factors. Attached Figure Description

[0050] The invention will be further described below with reference to the accompanying drawings.

[0051] Appendix Figure 1 This is a schematic diagram showing the comparison of porosity.

[0052] Appendix Figure 2 A schematic diagram showing the comparison of splitting strength at 25℃;

[0053] Appendix Figure 3 This is a schematic diagram comparing low-temperature bending tests. Detailed Implementation

[0054] The following detailed description of a waste asphalt recycling method of the present invention is based on the accompanying drawings and specific embodiments.

[0055] Example 1:

[0056] This embodiment provides a method for recycling waste asphalt, as detailed below:

[0057] S1. Select waste asphalt pavement materials and preliminarily determine the asphalt-aggregate ratio in each grade of waste asphalt pavement materials;

[0058] S2. Prepare RAP compound materials to ensure that the asphalt-aggregate ratio (mass ratio) of waste asphalt in the RAP compound materials to aggregate in the RAP compound materials is not less than 5.0;

[0059] S3. Prepare the experimental group mixture;

[0060] S4. Prepare the control group mixture;

[0061] S5. The experimental and control group mixtures were molded into specimens at their respective molding temperatures. Data from the experimental and control group was obtained from these specimens. Linear regression was performed on the experimental and control group data in the same coordinate system, with the abscissas of the data being the same. The optimal ratio D of the recycled agent mass to the old asphalt mass was determined based on the intersection of the regression lines from the experimental and control group data. 孔隙率 D 劈裂 and D 低温 ;

[0062] S6. Determine the optimal ratio of the recycling agent mass to the old asphalt mass, using the following formula:

[0063] D 最佳 =(D 孔隙率 +D 劈裂 +D 低温 ) / 3;

[0064] Among them, D 最佳 Indicates the ratio of the optimal recycling agent mass to the mass of old asphalt; D 孔隙率 This indicates the porosity of the experimental group specimens prepared from the experimental group mixture and the porosity of the control group specimens prepared from the control group mixture.

[0065] The specific selection of waste asphalt pavement material in step S1 of this embodiment is as follows:

[0066] S101, Select 0-5mm grade waste asphalt pavement material;

[0067] S102. Place the waste asphalt pavement material in an 80℃ oven for 3-4 hours to fully disperse the waste asphalt pavement material and sieve out the material with a thickness greater than 4.75mm.

[0068] S103. Old asphalt pavement materials are divided into three grades: 0-1.18mm, 1.18mm-2.35mm, and 2.35mm-4.75mm. These three grades are respectively referred to as RAP Fine, RAP Medium, and RAP Coarse.

[0069] The specific preparation of the RAP compound material in step S2 of this embodiment is as follows:

[0070] The fine, medium, and coarse RAP are blended together, with the following quality grades:

[0071] RAP fine 30%-50%, RAP fine 20%-30%, RAP fine 30%-40%; wherein, the total mass ratio of RAP fine, RAP medium and RAP coarse is 100%; the material composed of RAP fine, RAP medium and RAP coarse is called RAP compound material. The RAP compound material is made by adjusting the composition ratio of RAP fine, RAP medium and RAP coarse to ensure that the mass ratio (asphalt-aggregate ratio) of old asphalt to aggregate in the RAP compound material is not less than 5.0.

[0072] The specific preparation of the experimental group mixture in step S3 of this embodiment is as follows:

[0073] The prepared RAP compound material was divided into three groups and heated to the mixing temperature corresponding to the type of old asphalt. The recycling agent was added to the RAP compound material at a mass ratio of 5%, 10%, and 15% of the old asphalt, respectively. After thorough mixing, the mixture was placed at the old asphalt mixing temperature for 2 hours.

[0074] The specific preparation of the comparison group mixture in step S4 of this embodiment is as follows:

[0075] S401. Divide the RAP compound material into three groups, and conduct extraction experiments on the three groups of RAP compound materials respectively to obtain the aggregate and mineral powder corresponding to the three groups of RAP compound materials.

[0076] S402. Heat the aggregates and mineral powders corresponding to the three groups of RAP compound materials to the mixing temperature of the corresponding new asphalt, wherein the type of new asphalt is the same as that of old asphalt.

[0077] S403. Add new asphalt of the same mass as the sum of old asphalt and recycling agent to the aggregate and mineral powder corresponding to the three groups of RAP compound materials. After the three groups of RAP compound materials are fully mixed, place them at the mixing temperature of aged asphalt for 2 hours.

[0078] The specific steps for obtaining experimental group data in step S5 of this embodiment are as follows:

[0079] S501. The experimental group mixture is molded into experimental group rotary compaction specimens according to the rotary compaction test method at the corresponding molding temperature, and experimental group rutting specimens are molded according to the rutting test molding method.

[0080] S502. Detect and obtain the porosity a of the rotary compacted specimens in the experimental group. 实验5 a 实验10 and a 实验15 ;

[0081] S503, Test the splitting tensile strength of the rotary compacted specimens at 25°C. 实验5 b 实验10 and b 实验15 ;

[0082] S504. Detect and obtain the low-temperature bending failure strain c of the rutted specimens in the experimental group. 实验5 c 实验10 and c 实验15 .

[0083] The specific steps for obtaining the comparison group data in step S5 of this embodiment are as follows:

[0084] S501. The comparative group mixture is molded into comparative group rotary compaction specimens according to the rotary compaction test method at the corresponding molding temperature, and the comparative group rutting specimens are molded according to the rutting test molding method.

[0085] S502. Detect and obtain the porosity a of the rotary compacted specimens in the control group. 对比5 a 对比10 and a 对比15 ;

[0086] S503, Test the splitting tensile strength at 25°C of the rotationally compacted specimens in the control group. 对比5 b 对比10 and b 对比15 ;

[0087] S504. Detect and obtain the low-temperature bending failure strain c of the comparative group rutted specimens. 对比5 c 对比10 and c 对比15 .

[0088] In this embodiment, the diameter of the rotary compaction specimens in both the experimental group and the control group was 150 mm, the height of both groups was 100 mm ± 2.5 mm, and the number of rotary compaction cycles for both groups was 100.

[0089] Example 2:

[0090] This embodiment provides a method for recycling waste asphalt, and the specific steps are as follows:

[0091] Step 1: Prepare experimental materials. Select waste asphalt pavement material in the 0-5mm range, disperse it thoroughly according to a certain method, and classify it into grades. Preliminarily determine the asphalt content, gradation composition and asphalt type in each grade of waste asphalt pavement material.

[0092] Step 2: The graded waste asphalt pavement materials are mixed into experimental and control groups according to a certain proportion;

[0093] Step 3: Based on the experimental groups determined in Step 2, add 5%, 10%, and 15% of the aged asphalt mass of the rejuvenator respectively.

[0094] Step 4: Extract the waste asphalt pavement material from the control group to obtain the extracted aggregate and powder. Mix the aggregate and powder with new asphalt of the same type as the waste asphalt pavement material. The amount of new asphalt added is the same as the total amount of aged asphalt and recycling agent in Step 3.

[0095] Step 5: Test the experimental group and the control group for shaped rotary compaction specimens and low-temperature beam bending specimens respectively, and obtain the experimental results;

[0096] Step 6: Using the control group as a benchmark, perform linear regression on the porosity, 25℃ splitting test, and low-temperature beam bending test results of the experimental groups with different recycling agent addition ratios. Take the average of the three optimal solutions after linear regression as the optimal recycling agent addition mass ratio for the restoration of aged asphalt.

[0097] In this embodiment, standard materials were prepared by selecting 0-5mm waste asphalt pavement material used in the target project, with SBS modified asphalt as the asphalt type. The material was heated in an 80℃ oven for 4 hours to fully disperse it. The "pseudo-particles" were broken up by hand, and the material was allowed to cool. It was then sieved into three grades: fine RAP (0-1.18mm), medium RAP (1.18mm-2.35mm), and coarse RAP (2.35mm-4.75mm). Extraction experiments were conducted on each grade to obtain the asphalt-aggregate ratio. The extraction results for the three grades of fine RAP (0-1.18mm), medium RAP (1.18mm-2.35mm), and coarse RAP (2.35mm-4.75mm) are shown in Table 1.

[0098] Table 1

[0099] Material Type RAP Fine RAP Medium RAP Coarse Oil to Rock Ratio, % 6.9 5.3 4.2

[0100] In this embodiment, fine RAP, medium RAP, and coarse RAP are blended according to the following mass ratios: fine RAP mass ratio is (30-50%), fine RAP mass ratio is (20-30%), and fine RAP mass ratio is (30-40%). The three blending ratios are shown in Table 2.

[0101] Table 2

[0102] Material Type RAP Fine RAP Medium RAP Coarse Cumulative Oil to Rock Ratio, % 6.9 5.3 4.2 / Proportion, % 45 25 30 100 Synthetic Oil to Rock Ratio, % 3.11 1.33 1.26 5.69

[0103] The total asphalt-aggregate ratio of the blended mixture must be greater than 5.0.

[0104] The experimental group in this embodiment is specifically constructed as follows:

[0105] Three groups of RAP were prepared, containing fine, medium, and coarse RAP respectively, according to the above proportions. The three groups were heated to 165℃ according to the heating temperature of SBS modified asphalt. The recycling agent was then added to the RAP compound at proportions of 5%, 10%, and 15% of the aged asphalt mass, respectively, i.e., (5.69 × 0.05, 5.69 × 0.1, and 5.69 × 0.15). The recycling agent can actually be considered as a component of the asphalt. The statistical results are shown in Table 3.

[0106] Table 3

[0107] Material Type 5% Group 10% Group 15% Group 1) Oil to Rock Ratio, % 5.69 5.69 5.69 2) Regenerant Proportion, % 0.28 0.57 0.85 ①+② 5.97 6.26 6.54

[0108] After thoroughly mixing the above three groups, place them at the mixing temperature of aged asphalt for 2 hours.

[0109] The three experimental groups were subjected to a rotary compaction test, with 100 rotary compaction cycles. The diameter of the mold was... The specimen molding height was controlled at 100mm ± 2.5mm, and specimens for low-temperature bending tests were also molded.

[0110] The specific details of the comparison group in this embodiment are as follows:

[0111] Using the same RAP fine, RAP medium, and RAP coarse as the experimental group, three groups were prepared in the same proportions as above. A large fully automatic extractor was used to extract the aggregate and recovered mineral powder from the three groups. For the recovery of mineral powder, the mineral powder on the filter paper was gently brushed off with a brush to prevent loss of mineral powder. At the same time, the brushed-off clumps of mineral powder were fully dispersed for subsequent experiments.

[0112] The three groups of recycled aggregates were placed in a 165℃ oven and heated continuously for 4 hours. New SBS modified asphalt was added to each group at percentages of 5.97%, 6.26%, and 6.54% of the total mass of asphalt, aggregate, and recycled mineral powder, respectively. After thorough mixing, the recycled mineral powder was added and the mixture was stirred again until homogeneous. This resulted in three control groups.

[0113] The three control groups were subjected to a rotary compaction test, with 100 rotary compaction cycles and a mold diameter of [missing information]. The specimen molding height was controlled at 100mm ± 2.5mm, and specimens for low-temperature bending tests were also molded.

[0114] Data Analysis

[0115] Experimental results

[0116] The experimental results for the experimental group and the control group are shown in Tables 4 and 5 after testing.

[0117] Table 4 Experimental data of the experimental group

[0118]

[0119] Table 5. Experimental data for the control group

[0120]

[0121] As attached Figure 1 , 2 As shown in Figures 3 and 4, based on the results of linear regression, the optimal ratio of the recycling agent mass to the aged asphalt mass was determined to be D. 孔隙率 The ratio is 7.9:100, D 劈裂 10.8; 100, D 低温 The ratio is 9.6:100.

[0122] Determine the optimal ratio D of the recycler admixture mass to the aged asphalt mass. 最佳 = (7.9 + 10.8 + 9.6) / 3:100 = 9.4:100.

[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for recycling waste asphalt, characterized in that, The method is as follows: Select waste asphalt pavement materials and preliminarily determine the asphalt-aggregate ratio in each grade of waste asphalt pavement materials; When preparing RAP compound materials, ensure that the ratio of waste asphalt to aggregate in the RAP compound materials is not less than 5.

0. Prepare the experimental group mixture; Prepare the control group mixture; The experimental and control asphalt mixtures were molded into specimens at their respective molding temperatures. Data from these specimens were then collected for both groups. Linear regression was performed on the same coordinate system, with the abscissas of the data from both groups being identical. The optimal ratio D of the recycled agent mass to the old asphalt mass was determined based on the intersection of the regression lines from both groups. 孔隙率 D 劈裂 and D 低温 ; The optimal ratio of recycling agent mass to old asphalt mass is determined by the following formula: D 最佳 =(D 孔隙率 + D 劈裂 + D 低温 ) / 3; Among them, D 最佳 Indicates the ratio of the optimal recycling agent mass to the mass of old asphalt; D 孔隙率 This represents the ratio of the mass of recycling agent added to the mass of old asphalt when the porosity of the experimental group specimens prepared from the experimental mixture is the same as that of the control group specimens prepared from the control mixture; D 劈裂 D represents the ratio of the mass of recycling agent added to the mass of old asphalt when the 25℃ splitting tensile strength of the experimental group specimens prepared from the experimental mixture is the same as that of the control group specimens prepared from the control mixture; 低温 The ratio of the mass of recycling agent added to the mass of old asphalt is the same when the low-temperature bending test failure strain results of the experimental group specimens prepared from the experimental group mixture are the same as those of the control group specimens prepared from the control group mixture. The specific preparation of the experimental group mixture is as follows: The prepared RAP compound material was divided into three groups and heated to the mixing temperature corresponding to the type of old asphalt. The recycling agent was added to the RAP compound material at a mass ratio of 5%, 10%, and 15% of the old asphalt, respectively. After thorough mixing, the mixture was placed at the old asphalt mixing temperature for 2 hours. The specific preparation of the control group mixture is as follows: The RAP compound materials were divided into three groups, and extraction experiments were carried out on the three groups of RAP compound materials to obtain the aggregates and mineral powders corresponding to the three groups of RAP compound materials. The aggregates and mineral powders corresponding to the three groups of RAP compound materials were heated to the mixing temperature of the corresponding new asphalt, wherein the type of new asphalt was the same as that of the old asphalt. New asphalt with the same mass as the old asphalt and recycling agent was added to the aggregate and mineral powder corresponding to the three groups of RAP compound materials. After the three groups of RAP compound materials were thoroughly mixed, they were placed at the mixing temperature of aged asphalt for 2 hours.

2. The waste asphalt recycling method according to claim 1, characterized in that, The specific selection of waste asphalt pavement materials is as follows: Select waste asphalt pavement material in the 0-5mm grade; Place the waste asphalt pavement material in an 80℃ oven for 3-4 hours to fully disperse the waste asphalt pavement material and sieve out the material with a thickness greater than 4.75mm. The old asphalt pavement material is divided into three grades: 0-1.18mm, 1.18mm-2.35mm, and 2.35mm-4.75mm. These three grades are respectively referred to as RAP Fine, RAP Medium, and RAP Coarse.

3. The method for recycling waste asphalt according to claim 1 or 2, characterized in that, The specific steps for preparing RAP compound materials are as follows: The fine, medium, and coarse RAP are blended together, with the following quality grades: RAP 30%-50%, RAP medium 20%-30%, RAP coarse 30%-40%; The total mass ratio of RAP fine, RAP medium, and RAP coarse is 100%. The material composed of these three components is called RAP compound material. By adjusting the composition ratio of RAP fine, RAP medium, and RAP coarse, the mass ratio of old asphalt to aggregate in the RAP compound material is ensured to be no less than 5.

0.

4. The waste asphalt recycling method according to claim 1, characterized in that, The experimental group data were obtained as follows: The experimental group mixture was molded into rotary compaction specimens according to the rotary compaction test method at the corresponding molding temperature, and rutted specimens were molded into rutted specimens according to the rutted test molding method. The porosity α of the rotary compacted specimens in the experimental group was obtained by detection. 实验5 a 实验10 and a 实验15 ; The splitting tensile strength test at 25°C was conducted on the rotary compacted specimens of the experimental group. 实验5 b 实验10 and b 实验15 ; The low-temperature bending failure strain c of the rutted specimens in the experimental group was obtained by detection. 实验5 c 实验10 and c 实验15 .

5. The waste asphalt recycling method according to claim 1 or 4, characterized in that, The specific steps for obtaining the comparison group data are as follows: The comparative group mixture was molded into comparative group rotary compaction specimens according to the rotary compaction test method at the corresponding molding temperature, and the comparative group rutting specimens were molded according to the rutting test molding method. The porosity α of the rotary compacted specimens in the control group was obtained by detection. 对比5 a 对比10 and a 对比15 ; The splitting tensile strength test at 25°C was conducted on the rotationally compacted specimens of the control group. 对比5 b 对比10 and b 对比15 ; The low-temperature bending test failure strain c of the control group rutted specimens was obtained by detection. 对比5 c 对比10 and c 对比15 .

6. The waste asphalt recycling method according to claim 5, characterized in that, The diameter of the rotary compaction specimens in both the experimental and control groups was 150 mm, the height of both groups was 100 mm ± 2.5 mm, and the number of rotary compaction cycles for both groups was 100.

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