A method for rapidly detecting aging performance of waste asphalt pavement material asphalt

Abstract

The application discloses a kind of waste asphalt pavement material asphalt aging performance rapid detection method, belong to road engineering technical field, the technical problem that the present application wants to solve is how to can conveniently and efficiently and low cost realize the evaluation of aging asphalt in waste asphalt pavement material, the technical scheme for using is as follows: the method is as follows: selecting waste asphalt pavement material, and the asphalt oil stone ratio in waste asphalt pavement material and gradation composition are preliminarily determined;Standard material is made;Preparation standard group mixture;Preparation comparison group mixture;Calculate the asphalt aging degree D of old asphalt pavement material, formula is as follows: D=[0.3× ((1-a 对比 ) / (1-a 标准 ))+0.3×(b 对比 / b 标准 )+0.4×(c 对比 / c 标准 )]×100;Wherein, a 标准 It indicates that the porosity of standard rotary compaction test piece;B 标准 It indicates that the 60 DEG C stability of standard rotary compaction test piece;C 标准 It indicates that the low-temperature bending test damage strain of standard track test piece.

Description

Technical Field

[0001] This invention relates to the field of road engineering technology, specifically to a rapid testing method for the asphalt aging performance of waste asphalt pavement materials. 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 proceed, 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, it is first necessary to determine the degree of performance degradation of the old asphalt pavement material, mainly including the asphalt aging performance and gradation degradation performance. Grading degradation can be assessed through extraction and sieving tests of old asphalt pavement material, which is relatively simple and quick. However, testing the aging performance of asphalt is more cumbersome. It requires repeated extraction of waste asphalt pavement material to obtain a recovery liquid containing old asphalt and trichloroethylene, followed by multiple rotary evaporation experiments to obtain a sufficient number of asphalt samples to evaluate the performance of aged asphalt. Extensive practical experience has revealed the following shortcomings of the above experimental methods:

[0003] ① The experimental process is relatively expensive and wastes a lot of time, often taking 10-15 days;

[0004] ② The experimental results also exhibit significant dispersion. Incompletely evaporated trichloroethylene often remains in the recovered aged asphalt samples, leading to increased variability in the experimental results and reduced indicative value of the results.

[0005] ③ Existing evaluation methods for aged asphalt cannot reflect the performance status of asphalt in waste asphalt pavement materials in hot recycled mixtures, and the evaluation test results are not related to the actual road performance.

[0006] ④ Existing methods for testing aged asphalt require rotary evaporators and large-scale fully automated extraction instruments. These devices are relatively expensive and are generally only available in Class A qualified laboratories. It is difficult to conduct this experiment in real time in projects, so it cannot be widely used.

[0007] Therefore, how to conveniently, efficiently, and cost-effectively evaluate the aged asphalt in waste asphalt pavement materials is a pressing technical problem that needs to be solved. Summary of the Invention

[0008] The technical objective of this invention is to provide a rapid detection method for the asphalt aging performance of waste asphalt pavement materials, thereby addressing the problem of how to conveniently, efficiently, and cost-effectively evaluate the aging asphalt in waste asphalt pavement materials.

[0009] The technical objective of this invention is achieved as follows: a rapid detection method for the asphalt aging performance of waste asphalt pavement materials, the specific method of which is as follows:

[0010] Waste asphalt pavement materials were selected, and the asphalt-aggregate ratio and gradation composition in the waste asphalt pavement materials were preliminarily determined.

[0011] Produce standard materials;

[0012] Prepare standard batch mixtures;

[0013] Prepare the control group mixture;

[0014] The formula for calculating the degree of asphalt aging, D, of old asphalt pavement materials is as follows:

[0015] D = [0.3 × ((1-a)] 对比 ) / (1-a 标准 ))+0.3×(b 对比 / b 标准 )+0.4×(c 对比 / c

[0016] 标准 )]×100;

[0017] Where D represents the degree of asphalt aging of the old asphalt pavement material, in percentage (%); a 标准 Indicates the porosity of a standard rotary compacted specimen; b 标准 This indicates the stability of the standard rotary compacted specimen at 60°C; c 标准 Indicates the failure strain of a standard rutted specimen during a low-temperature bending test; a 对比 This indicates the porosity of the comparative rotary compacted specimens; b 对比 This indicates the stability of the comparative rotary compacted specimen at 60°C; c 对比 The strain represents the failure strain of the low-temperature bending test of the rutted specimen.

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

[0019] Select waste asphalt pavement materials in the 0-5mm range and screen out materials larger than 4.75mm.

[0020] Waste asphalt pavement materials are divided into two grades: 0-2.35mm and 2.35-4.7mm. Among them, waste asphalt pavement materials with a thickness of 0-2.35mm are referred to as RAP fine, and waste asphalt pavement materials with a thickness of 2.35-4.7mm are referred to as RAP coarse.

[0021] More preferably, the standard materials are produced as follows:

[0022] Select 0-5mm manufactured sand for the target project, use water washing to clean the part of manufactured sand below 0.075mm, and dry the remaining manufactured sand;

[0023] The dried manufactured sand was screened into four grades: 0-0.3mm, 0.3mm-1.18mm, 1.18mm-2.36mm, and 2.35-4.75mm.

[0024] More preferably, the standard group mixture is prepared as follows:

[0025] The standard materials and mineral powder are blended according to the set gradation range;

[0026] The mass ratio of aggregate to asphalt after blending is 100:7.0, and the type of newly added asphalt is the same as the type of asphalt in the waste asphalt pavement material.

[0027] Using the rotary compaction test method, by adjusting the proportion of each grade of standard material, the porosity of the mixture specimen is made to be 3.0% ± 0.3%. At this point, the gradation synthesized from each grade of standard material and mineral powder is called the standard gradation, and the mixture prepared is called the standard group.

[0028] More preferably, the specific gradation range is as follows:

[0029] The 4.75mm grade has a 100% pass rate.

[0030] The quality pass rate for the 2.36mm grade is 60%-85%.

[0031] The quality pass rate for the 1.18mm grade is 40%-65%.

[0032] The pass rate for the 0.6mm grade is 25%-45%;

[0033] The pass rate for the 0.3mm grade is 15%-33%;

[0034] The pass rate for the 0.15mm grade is 10%-22%;

[0035] The pass rate for the 0.075mm grade is 5%-10%.

[0036] More preferably, the control group mixture is prepared as follows:

[0037] RAP coarse and fine RAP were blended at a mass ratio of 1:2 to obtain a RAP synthetic material. The oil-aggregate ratio of the RAP synthetic material was calculated. The RAP synthetic material was then blended with four grades of standard materials (0-0.3mm, 0.3mm-1.18mm, 1.18mm-2.36mm, and 2.35mm-4.75mm) and mineral powder to obtain a RAP mineral powder mixture. The blending requirements are as follows:

[0038] The ratio of aged asphalt quality of RAP synthetic material to RAP mineral powder mixture is 3:100. RAP mineral powder mixture includes the aggregate, 0-0.3mm grade, 0.3mm-1.18mm grade, 1.18mm-2.36mm grade, and 2.35mm-4.75mm grade of standard materials and mineral powder from RAP synthetic material.

[0039] While ensuring that the quality of the RAP mineral powder mixture remains unchanged, adjust the proportions of the four standard materials in the 0-0.3mm, 0.3mm-1.18mm, 1.18mm-2.36mm, and 2.35mm-4.75mm ranges to ensure that the aggregate gradation after synthesis is the same as the standard gradation.

[0040] After the adjustment was completed, new asphalt was added to the system consisting of four standard aggregate grades (0-0.3mm, 0.3mm-1.18mm, 1.18mm-2.36mm, and 2.35mm-4.75mm) and mineral powder of RAP synthetic material. The mass ratio of the new asphalt to the mass of RAP mineral powder mixture was 4:100 to prepare the mixture and obtain the control group mixture.

[0041] Preferably, the standard mixture is molded into standard rotary compaction specimens according to the rotary compaction test method at the molding temperature corresponding to the newly added asphalt, and standard rutting specimens are molded according to the rutting test method; simultaneously, the porosity α is tested using the standard rotary compaction specimens. 标准 and 60℃ stability b 标准 The low-temperature bending test strain c was tested using standard rutted specimens. 标准 .

[0042] More preferably, the control group mixture is molded into control rotary compaction specimens according to the rotary compaction test method at the molding temperature corresponding to the newly added asphalt, and control rutting specimens are molded according to the rutting test method. At the same time, the porosity α is tested using the control rotary compaction specimens. 对比 and 60℃ stability b 对比 The low-temperature bending test failure strain c was detected using comparative rutted specimens. 对比 .

[0043] More preferably, the diameter of both the standard rotary compaction specimen and the comparative rotary compaction specimen is 150 mm, the height of both the standard rotary compaction specimen and the comparative rotary compaction specimen is 100 mm ± 2.5 mm, and the number of rotary compaction cycles for both the standard rotary compaction specimen and the comparative rotary compaction specimen is 100.

[0044] Preferably, the standard group mixture and the control group mixture have the same gradation and the same total asphalt-aggregate ratio;

[0045] The proportion of waste asphalt pavement material in the comparison group mixture was determined based on the fact that the weight of waste asphalt in the waste asphalt pavement material accounted for 3% of the total mass of the comparison group mixture. After determining the mass ratio of waste asphalt pavement material in the comparison group, the proportions of manufactured sand in the 0-0.3mm, 0.3mm-1.18mm, 1.18mm-2.36mm, and 2.35mm-4.75mm ranges were adjusted to make the gradation of the comparison group mixture the same as that of the standard group mixture.

[0046] The rapid testing method for asphalt aging performance of waste asphalt pavement materials of the present invention has the following advantages:

[0047] (i) This invention can quickly determine the performance degradation law of aged asphalt in waste asphalt pavement materials. The experimental method is accurate and reliable, reducing reliance on advanced equipment and reducing experimental costs.

[0048] (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 is possible to evaluate the aged asphalt in waste asphalt pavement materials, and has the following characteristics:

[0049] 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;

[0050] ② The present invention has a short testing time, with an experimental cycle of 3-5 days, which can greatly shorten the evaluation cycle;

[0051] ③ The test results of this invention are less affected by subjective human factors and have good reproducibility. Attached Figure Description

[0052] The invention will be further described below with reference to the accompanying drawings.

[0053] Appendix Figure 1 This is a standard group gradation curve diagram;

[0054] Appendix Figure 2 For comparison of the group gradation curves. Detailed Implementation

[0055] The following detailed description of a rapid testing method for the asphalt aging performance of waste asphalt pavement materials, with reference to the accompanying drawings and specific embodiments, is provided in the specification.

[0056] Example 1:

[0057] This embodiment provides a rapid testing method for the asphalt aging performance of waste asphalt pavement materials, as detailed below.

[0058] S1. Select waste asphalt pavement materials and preliminarily determine the asphalt-aggregate ratio and gradation composition in the waste asphalt pavement materials;

[0059] S2, Producing standard materials;

[0060] S3. Prepare standard group mixture;

[0061] S4. Prepare the control group mixture;

[0062] S5. Calculate the asphalt aging degree D of the old asphalt pavement material using the following formula:

[0063] D = [0.3 × ((1-a)] 对比 ) / (1-a 标准 ))+0.3×(b 对比 / b 标准 )+0.4×(c 对比 / c

[0064] 标准 )]×100;

[0065] Where D represents the degree of asphalt aging of the old asphalt pavement material, in percentage (%); a 标准 Indicates the porosity of a standard rotary compacted specimen; b 标准 This indicates the stability of the standard rotary compacted specimen at 60°C; c 标准 Indicates the failure strain of a standard rutted specimen during a low-temperature bending test; a 对比 This indicates the porosity of the comparative rotary compacted specimens; b 对比 This indicates the stability of the comparative rotary compacted specimen at 60°C; c 对比 The strain represents the failure strain of the low-temperature bending test of the rutted specimen.

[0066] The specific steps for selecting waste asphalt pavement materials in step S1 of this embodiment are as follows:

[0067] S101. Select waste asphalt pavement material in the 0-5mm range and screen out the portion of waste asphalt pavement material larger than 4.75mm.

[0068] S102. Waste asphalt pavement materials are divided into two grades: 0-2.35mm and 2.35-4.7mm. Among them, waste asphalt pavement materials with a thickness of 0-2.35mm are referred to as RAP fine, and waste asphalt pavement materials with a thickness of 2.35-4.7mm are referred to as RAP coarse.

[0069] The specific steps for preparing the standard material in step S2 of this embodiment are as follows:

[0070] S201. Select 0-5mm manufactured sand used in the target project, use water washing to clean the part of manufactured sand below 0.075mm, and dry the remaining manufactured sand.

[0071] S202. The dried manufactured sand is screened into 0-0.3mm, 0.3mm-1.18mm, 1.18mm-2.36mm and 2.35-4.75mm grades.

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

[0073] S301. Mix the standard material and mineral powder according to the set gradation range;

[0074] S302, The mass ratio of aggregate to asphalt after blending is 100:7.0, and the type of new asphalt used is the same as the type of asphalt in the waste asphalt pavement material;

[0075] S303. Using the rotary compaction test method, by adjusting the proportion of each grade of standard material, the porosity of the mixture specimen is made to be 3.0% ± 0.3%. At this time, the gradation synthesized by each grade of standard material and mineral powder is called the standard gradation, and the mixture is called the standard group.

[0076] The specific gradation range in step S301 of this embodiment is as follows:

[0077] The 4.75mm grade has a 100% pass rate.

[0078] The quality pass rate for the 2.36mm grade is 60%-85%.

[0079] The quality pass rate for the 1.18mm grade is 40%-65%.

[0080] The pass rate for the 0.6mm grade is 25%-45%;

[0081] The pass rate for the 0.3mm grade is 15%-33%;

[0082] The pass rate for the 0.15mm grade is 10%-22%;

[0083] The pass rate for the 0.075mm grade is 5%-10%.

[0084] The specific preparation of the comparison group mixture in step S4 of this embodiment is as follows:

[0085] RAP coarse and fine RAP were blended at a mass ratio of 1:2 to obtain a RAP synthetic material. The oil-aggregate ratio of the RAP synthetic material was calculated. The RAP synthetic material was then blended with four grades of standard materials (0-0.3mm, 0.3mm-1.18mm, 1.18mm-2.36mm, and 2.35mm-4.75mm) and mineral powder to obtain a RAP mineral powder mixture. The blending requirements are as follows:

[0086] The ratio of aged asphalt quality of RAP synthetic material to RAP mineral powder mixture is 3:100. RAP mineral powder mixture includes the aggregate, 0-0.3mm grade, 0.3mm-1.18mm grade, 1.18mm-2.36mm grade, and 2.35mm-4.75mm grade of standard materials and mineral powder from RAP synthetic material.

[0087] While ensuring that the quality of the RAP mineral powder mixture remains unchanged, adjust the proportions of the four standard materials in the 0-0.3mm, 0.3mm-1.18mm, 1.18mm-2.36mm, and 2.35mm-4.75mm ranges to ensure that the aggregate gradation after synthesis is the same as the standard gradation.

[0088] After the adjustment was completed, new asphalt was added to the system consisting of four standard aggregate grades (0-0.3mm, 0.3mm-1.18mm, 1.18mm-2.36mm, and 2.35mm-4.75mm) and mineral powder of RAP synthetic material. The mass ratio of the new asphalt to the mass of RAP mineral powder mixture was 4:100 to prepare the mixture and obtain the control group mixture.

[0089] In this embodiment, the standard mixture was molded into standard rotary compaction specimens at the molding temperature corresponding to the newly added asphalt, and standard rutting specimens were molded according to the rotary compaction test method. Simultaneously, the porosity α was tested using the standard rotary compaction specimens. 标准 and 60℃ stability b 标准 The low-temperature bending test strain c was tested using standard rutted specimens. 标准 .

[0090] In this embodiment, the comparative group mixture was molded into comparative rotary compaction specimens at the molding temperature corresponding to the newly added asphalt, and comparative rutting specimens were molded according to the rotary compaction test method. Simultaneously, the porosity α was measured using the comparative rotary compaction specimens. 对比 and 60℃ stability b 对比 The low-temperature bending test failure strain c was detected using comparative rutted specimens. 对比 .

[0091] In this embodiment, the diameter of both the standard rotary compaction specimen and the comparative rotary compaction specimen is 150 mm, the height of both the standard rotary compaction specimen and the comparative rotary compaction specimen is 100 mm ± 2.5 mm, and the number of rotary compaction cycles for both the standard rotary compaction specimen and the comparative rotary compaction specimen is 100.

[0092] In this embodiment, the standard group mixture and the control group mixture have the same gradation and the same total asphalt-aggregate ratio.

[0093] The proportion of waste asphalt pavement material in the comparison group mixture was determined based on the fact that the weight of waste asphalt in the waste asphalt pavement material accounted for 3% of the total mass of the comparison group mixture. After determining the mass ratio of waste asphalt pavement material in the comparison group, the proportions of manufactured sand in the 0-0.3mm, 0.3mm-1.18mm, 1.18mm-2.36mm, and 2.35mm-4.75mm ranges were adjusted to make the gradation of the comparison group mixture the same as that of the standard group mixture.

[0094] Example 2:

[0095] The specific method for rapid testing of the asphalt aging performance of waste asphalt pavement materials in this embodiment is as follows:

[0096] (1) Prepare standard materials. Select 0-5mm manufactured sand used in the target project. Use water washing to clean the portion below 0.075mm from the manufactured sand, and dry the remaining manufactured sand. Screen the dried manufactured sand into four grades: 0-0.3mm, 0.3mm-1.18mm, 1.18mm-2.36mm, and 2.35mm-4.75mm. The cumulative percentage of passing mass of the four grades of standard materials and mineral powder is shown in Table 1.

[0097] Table 1

[0098] sieve aperture size 4.75mm 2.36mm 1.18mm 0.6mm 0.3mm 0.15mm 0.075mm New material 2.36-4.75mm 100.0 2.0 0.0 0.0 0.0 0.0 0.0 New material 1.18-2.36mm 100.0 100.0 1.0 0.0 0.0 0.0 0.0 New material 0.3-1.18mm 100.0 100.0 100.0 33.0 1.0 0.0 0.0 New material 0-0.3mm 100.0 100.0 100.0 100.0 100.0 46.4 1.0 Mineral powder 100 100 100 100 100 99.0 84.7

[0099] (2) Select waste asphalt pavement material in the 0-5mm range, sieve out the portion of material larger than 4.75mm, and then divide the old asphalt pavement material into two grades: 0-2.35mm and 2.35mm-4.75mm, referred to as RAP fine and RAP coarse, respectively. Through extraction and sieving experiments, the asphalt-aggregate ratio (mass percentage of asphalt to aggregate) in the remaining waste asphalt pavement material and the cumulative mass percentage of aggregate after extraction were preliminarily determined, as shown in Table 2:

[0100] Table 2

[0101] sieve aperture size 4.75mm 2.36mm 1.18mm 0.6mm 0.3mm 0.15mm 0.075mm Oil-stone ratio, % RAP coarseness 2.36-4.75mm 100.0 64.7 38.3 19.6 9.8 6.4 3.9 4.8 RAP fineness 0-2.36mm 100 100 73.2 52.5 36.1 22.4 10.6 8.2

[0102] (3) Determination of standard groups: Based on the gradation range, the pass rate for the 4.75mm grade is 100%, for the 2.36mm grade it is 60%-85%, for the 1.18mm grade it is 40%-65%, for the 0.6mm grade it is 25%-45%, for the 0.3mm grade it is 15%-33%, for the 0.15mm grade it is 10%-22%, and for the 0.075mm grade it is 5%-10%. The mass percentages of the four grades of new aggregate and mineral powder are determined as follows:

[0103] Mineral powder: 0-0.3mm grade of new material: 0.3mm-1.18mm grade of new material: 1.18mm-2.36mm grade of new material: 2.35mm-4.75mm grade of new material = 8:18:26:20:28, gradation as shown in the attached figure. Figure 1 And as shown in Table 3:

[0104] Table 3

[0105] sieve aperture size 4.75mm 2.36mm 1.18mm 0.6mm 0.3mm 0.15mm 0.075mm Standard group gradation 100 72.6 52.2 34.6 26.3 16.3 7.0

[0106] After the aggregate is heated, it is mixed with asphalt. The mass ratio of the synthesized aggregate to asphalt is 100:7.0. The asphalt type used in this embodiment is SBS modified asphalt, and the temperature of the mixture after mixing is 165℃.

[0107] The rotary compaction test method was used, with 100 rotary compaction cycles, and the mold diameter was... The specimen molding height was controlled at 100mm ± 2.5mm. By adjusting the proportion of each standard material, the porosity of the mixed material specimen was found to be 3.1%.

[0108] (4) The control group was determined as follows:

[0109] ① RAP is compounded by mixing coarse and fine RAP at a mass ratio of 1:2 to obtain RAP. 合成 Materials, and calculate RAP 合成 The oil-stone ratio = (4.8 × 1 + 8.2 × 2) / 3 = 7.07. (The last part, "RAP," appears to be a typo and can be omitted.) 合成 The materials are blended with four standard grades of raw materials and mineral powder to ensure RAP 合成 The quality of aged asphalt in materials and (RAP) 合成 Under the condition that the mass ratio of aggregate (mass of 4 standard materials + mass of mineral powder) is 3:100, determine the RAP. 合成 The mass of aggregate in the RAP (Race Portion) 合成 The mass ratio of aggregate mass + 4-grade standard aggregate mass + mineral powder mass in the material is 3 / 7.07 = 42.9%. Therefore, the mass of coarse aggregate in RAP is calculated as a percentage of (RAP) 合成 The mass ratio of aggregate (aggregate mass + 4-grade standard aggregate mass + mineral powder mass) in the material is 42.9% / 3 = 14.3%. The mass of fine aggregate (RAP) accounts for (RAP...) 合成 The mass ratio of aggregate (total mass of 4 standard materials) to mineral powder (total mass of mineral powder) is 42.9% - 14.3% = 28.6%.

[0110] ② Determine the ratio of coarse and fine aggregates in RAP (RAP) 合成After determining the proportions of aggregate mass + 4-grade standard aggregate mass + mineral powder mass in the material, adjust the mass ratio of the 4-grade standard aggregate and mineral powder according to the gradation of the standard group to ensure that the gradation of the comparison group is close to that of the standard group, thus obtaining the mass percentage of the comparison group as follows:

[0111] Mineral powder: RAP fine aggregate: RAP coarse aggregate: new material 0-0.3mm grade: new material 0.3mm-1.18mm grade: new material 1.18mm-2.36mm grade: new material 2.35mm-4.75mm grade = 4:28.6:14.3:11:10:9.1:23.

[0112] As attached Figure 2 As shown in Table 4, the cumulative mass percentage of the synthesized gradation is as follows:

[0113] sieve aperture size 4.75mm 2.36mm 1.18mm 0.6mm 0.3mm 0.15mm 0.075mm Standard group gradation 100 72.4 51.5 36.1 26.8 16.4 7.1

[0114] The rotary compaction test method was used, with 100 rotary compaction cycles, and the mold diameter was... The specimen molding height was controlled at 100mm ± 2.5mm. By adjusting the proportion of each standard material, the porosity of the mixed material specimen was found to be 5.2%.

[0115] (5) Performance test

[0116] The stability and low-temperature bending tests of the mixtures in the standard and control groups were conducted, and the results are as follows:

[0117] ① The Marshall stability of the standard group is 24.8 kN, and the failure strain in the low-temperature bending test is 3230 με.

[0118] ②The Marshall stability of the control group was 21.3 kN, and the failure strain in the low-temperature bending test was 2140 με.

[0119] Substitute the experimental results of the experimental group and the control group into D = [0.3 × ((1-a 对比 ) / (1-a 标准 ))+0.3×(b 对比 / b 标准 )+0.4×(c 对比 / c 标准 From the formula ]×100, we get:

[0120] D=[0.3×((1-5.2%) / (1-3.1%))+0.3×(21.3 / 24.8)+0.4×(2140 / 3230)]×100=81.6%;

[0121] Therefore, the asphalt aging performance (D) of waste asphalt pavement materials is 81.6%.

[0122] 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; and these 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 rapidly detecting asphalt aging performance of waste asphalt pavement material, characterized in that, The method is specifically as follows: Selecting waste asphalt pavement materials, and preliminarily determining asphalt oil stone ratio and gradation composition in the waste asphalt pavement materials; Making standard materials; Preparing standard group mixtures; Preparing comparative group mixtures; Calculating the aging degree D of the old asphalt pavement materials, and the formula is as follows: D = [0.3 x ((1 - a 对比 ) / (1 - a 标准 )) + 0.3 x (b 对比 / b 标准 ) + 0.4 x (c 对比 / c 标准 )] x 100; wherein D is the degree of aging of the asphalt of the old asphalt pavement material, in %; a 标准 represents the porosity of the standard gyratory compacted specimen; b 标准 represents the 60 °C stability of the standard gyratory compacted specimen; c 标准 represents the failure strain of the low temperature bending test of the standard rut specimen; a 对比 represents the porosity of the comparative gyratory compacted specimen; b 对比 represents the 60 °C stability of the comparative gyratory compacted specimen; c 对比 represents the failure strain of the low temperature bending test of the comparative rut specimen; The making of the standard materials is specifically as follows: Selecting 0-5mm machine-made sand used in the target project, washing the part below 0.075mm in the machine-made sand by using a water washing method, and drying the remaining machine-made sand; Screening the dried machine-made sand into 0-0.3mm, 0.3mm-1.18mm, 1.18mm-2.36mm and 2.35-4.75mm grades; The preparation of the standard group mixtures is specifically as follows: Mixing the standard materials and the mineral powder according to the set gradation range; The mass ratio of the mixed aggregate and the asphalt is 100:7.0, and the new asphalt used is of the same type as that in the waste asphalt pavement materials; Using a rotary compaction test method, adjusting the proportion of each grade of the standard materials, so that the porosity of the mixture test piece is 3.0%±0.3%, at this time, the gradation composed of each grade of the standard materials and the mineral powder is called a standard gradation, and the mixture prepared is called a standard group; The preparation of the comparative group mixtures is specifically as follows: Compounding according to the mass ratio of RAP coarse and RAP fine of 1:2 to obtain RAP synthetic materials, and calculating the oil stone ratio of the RAP synthetic materials, mixing the RAP synthetic materials with 0-0.3mm, 0.3mm-1.18mm, 1.18mm-2.36mm and 2.35mm-4.75mm standard materials and the mineral powder to obtain RAP mineral powder mixed materials, and the mixing requirements are as follows: The mass ratio of the aged asphalt of the RAP synthetic materials to the RAP mineral powder mixed materials is 3:100; the RAP mineral powder mixed materials include the aggregate in the RAP synthetic materials, 0-0.3mm, 0.3mm-1.18mm, 1.18mm-2.36mm and 2.35mm-4.75mm standard materials and the mineral powder; Under the condition of ensuring the quality of the RAP mineral powder mixed materials, adjusting the proportion of 0-0.3mm, 0.3mm-1.18mm, 1.18mm-2.36mm and 2.35mm-4.75mm standard materials to ensure that the gradation of the synthesized aggregate is the same as the standard gradation; After the adjustment, new asphalt is added to the system composed of the aggregate in the RAP synthetic materials, 0-0.3mm, 0.3mm-1.18mm, 1.18mm-2.36mm and 2.35mm-4.75mm standard materials and the mineral powder, and the mass ratio of the new asphalt to the RAP mineral powder mixed materials is 4:100 for mixture preparation to obtain the comparative group mixtures.

2. The method for rapidly detecting asphalt aging performance of waste and old asphalt pavement material according to claim 1, characterized in that, The selection of the waste asphalt pavement materials is specifically as follows: Selecting 0-5mm waste asphalt pavement materials, and screening out the materials above 4.75mm in the waste asphalt pavement materials; The waste asphalt pavement material is divided into two grades of 0-2.35 mm and 2.35-4.7 mm; wherein the waste asphalt pavement material of 0-2.35 mm is referred to as RAP fine, and the waste asphalt pavement material of 2.35-4.7 mm is referred to as RAP coarse.

3. The method for rapidly detecting asphalt aging performance of waste and old asphalt pavement material according to claim 1 or 2, characterized in that, The grading range is specifically as follows: The mass passing rate of 4.75 mm grade is 100%; The mass passing rate of 2.36 mm grade is 60%-85%; The mass passing rate of 1.18 mm grade is 40%-65%; The mass passing rate of 0.6 mm grade is 25%-45%; The mass passing rate of 0.3 mm grade is 15%-33%; The mass passing rate of 0.15 mm grade is 10%-22%; The mass passing rate of 0.075 mm grade is 5%-10%.

4. The method for rapidly detecting asphalt aging performance of waste and old asphalt pavement material according to claim 1, characterized in that, The standard group mixture is molded into a standard gyratory compacted specimen according to the gyratory compaction test method and a standard rut specimen according to the rut test molding method at a molding temperature corresponding to the new asphalt; meanwhile, the standard gyratory compacted specimen is used to detect porosity a 标准 and 60℃ stability b 标准 , and the standard rut specimen is used to detect the low-temperature bending test failure strain c 标准 .

5. The method for rapidly detecting asphalt aging performance of waste and old asphalt pavement material according to claim 1 or 4, characterized in that, The comparative mixture is molded into a comparative gyratory compaction test piece according to the gyratory compaction test method and a comparative rut test piece according to the rut test molding method at a molding temperature corresponding to the new added asphalt, and the porosity a of the comparative gyratory compaction test piece is detected 对比 and the stability b at 60℃ 对比 , and the damage strain c of the low-temperature bending experiment is detected by using the comparative rut test piece 对比 .

6. The method for rapidly detecting asphalt aging performance of waste and old asphalt pavement material according to claim 5, characterized in that, The diameter of the standard rotary compacted test piece and the comparative rotary compacted test piece is 150 mm, the height of the standard rotary compacted test piece and the comparative rotary compacted test piece is 100 mm±2.5 mm, and the rotary compacting times of the standard rotary compacted test piece and the comparative rotary compacted test piece is 100.

7. The method for rapidly detecting asphalt aging performance of waste and old asphalt pavement material according to claim 1, characterized in that, The gradings of the standard group mixture and the comparative group mixture are the same, and the total oil-stone ratio of the standard group mixture and the comparative group mixture is the same; The mixing ratio of the waste asphalt pavement material in the comparative group mixture is determined according to that the weight of the waste asphalt in the waste asphalt pavement material accounts for 3% of the mass of the whole comparative group mixture; after the mass ratio of the comparative group waste asphalt pavement material is determined, the proportions of the 0-0.3 mm grade, 0.3 mm-1.18 mm grade, 1.18 mm-2.36 mm grade and 2.35 mm-4.75 mm grade of the machine-made sand are adjusted, so that the gradings of the comparative group mixture and the standard group mixture are the same.

Images