Method for preparing low-carbon durable recycled asphalt concrete and evaluating performance of low-carbon durable recycled asphalt concrete

Abstract

The invention relates to the technical field of road engineering, in particular to a low-carbon durable recycled asphalt concrete preparation and performance evaluation method, which comprises the following steps: detecting and calculating the activity and content of an aged asphalt / SBS polymer; designing low-carbon durable recycled asphalt; preparing the low-carbon durable recycled asphalt concrete; and evaluating the long-term performance of the recycled asphalt concrete. The regeneration technology based on aged asphalt performance regulation and control is innovatively provided, the design limitation of traditional recycled asphalt concrete is broken through by constructing a material-structure-performance multi-dimensional correlation model, and finally a complete technical system covering raw material evaluation, mix proportion design, construction quality control and performance prediction is formed. And theoretical support and technical guarantee are provided for realizing high-valued and large-scale application of RAP.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of road engineering, in particular to a low-carbon durable recycled asphalt concrete preparation and a performance evaluation method thereof. BACKGROUND

[0002] After long-term service aging of asphalt pavement, it still has strong recyclability. The technical process of preparing recycled asphalt concrete by mixing RAP with a proper proportion of new asphalt and new aggregate for paving new or maintained roads is called asphalt pavement recycling technology.

[0003] Firstly, the existing technology often adds a recycling agent according to the content of the aged asphalt in RAP according to experience, ignores the quantitative detection of the activity and content of the aged asphalt / SBS polymer in RAP, and cannot accurately customize a recycling agent for a batch of RAP, which leads to poor recycling effect and affects the long-term durability of recycled asphalt concrete.

[0004] Secondly, for aged SBS polymer modified asphalt mixture, the recycling agent proposed by the current research can only restore the component balance of the base asphalt in the aged SBS modified asphalt, and cannot rebuild the cross-linking network structure of the aged and broken SBS polymer. At the same time, the existing technology generally uses hot-mix recycling technology to recycle RAP, and the mixing and compaction temperature is usually as high as 180℃ or above to ensure sufficient compaction effect, which will cause secondary aging of recycled asphalt.

[0005] In addition, in recycled asphalt pavement, "pseudo-particles" are a problem worth attention. Pseudo-particles refer to the un-dispersed aggregate clumps formed by the bonding effect of aged asphalt during the recycling process of old asphalt mixture. These clumps look like independent particles, but in fact they are the bonding body of multiple fine aggregates and aged asphalt, which may affect the performance of recycled mixture. Moreover, recycled asphalt mixture contains both new aggregate and old aggregate, so the design of the grading curve will face more complex situations.

[0006] Moreover, current researches generally hold two views, one is that the new-old asphalt is in a 100% fusion state, that is, the RAP aged asphalt is 100% fused with the new asphalt, and the same cohesive performance as the new asphalt is exhibited, at this time the new asphalt addition amount in the recycled mixture is the optimal asphalt dosage minus the total amount of aged asphalt contained in the RAP mixture, and no correction is needed; the other is that the new-old asphalt is in a 0% fusion state, that is, the RAP aged asphalt does not fuse with the new asphalt at all, and does not exhibit the same cohesive performance as the new asphalt, at this time the new asphalt addition amount in the recycled mixture is the optimal asphalt dosage. However, both of the two assumptions are unreasonable, and the new-old asphalt in the actual recycled mixture will partially diffuse and fuse, that is, the RAP aged asphalt can exhibit a certain new asphalt effect, and the addition amount of the new asphalt should be equal to the optimal asphalt dosage minus the total amount of the aged asphalt in the RAP aged asphalt that diffuses and fuses, and correction is needed.

[0007] In addition, according to the Technical Specification for Highway Asphalt Pavement Recycling (JTG / T 5521-2019), the construction temperature of plant-mixed hot recycled asphalt mixture needs to be increased by 5-10℃ than that of ordinary hot-mixed asphalt mixture to ensure the compaction quality of the recycled pavement. However, the excessively high construction temperature and insufficient temperature control precision not only aggravate the consumption of fossil energy and greenhouse gas emissions, but also may cause performance degradation of the recycled asphalt concrete. Although the current Technical Specification for Highway Asphalt Pavement Construction (JTG F40-2004) proposes a construction temperature control method based on the viscosity-temperature curve for base asphalt, it does not clearly define the standard for determining the optimal construction temperature of modified asphalt and recycled asphalt mixture. It is worth noting that the modified asphalt and recycled asphalt have complex colloidal structures, and the apparent viscosity measured by the Brookfield at high temperature may be distorted, because the asphalt exhibits non-Newtonian fluid characteristics under this condition, resulting in that the viscosity index cannot accurately reflect the actual construction and workability.

[0008] Finally, most of the existing evaluation methods ignore the research on the aging characteristics of asphalt materials themselves. In fact, the performance of the new-old asphalt after fusion during the service of the recycled asphalt concrete has an important influence on its long-term service performance, but there are few methods to establish a correlation model between material aging and performance degradation from the perspective of asphalt, which directly leads to the limitation of the prediction of the long-term service performance of the recycled asphalt concrete. SUMMARY

[0009] In view of the deficiencies of the prior art, the present application provides a low-carbon durable recycled asphalt concrete preparation and performance evaluation method, forming a complete technical system covering raw material evaluation, mix proportion design, construction quality control and performance prediction, providing theoretical support and technical support for realizing high-value and large-scale application of RAP.

[0010] To achieve the above object, the present invention provides the following technical solution: a performance evaluation method for low-carbon durable recycled asphalt concrete, comprising the following steps: (1) After obtaining asphalt samples from recycled asphalt concrete, they are pressed into sheets to produce asphalt films; (2) Perform infrared spectrum test on asphalt film and calculate its infrared spectrum at 950cm based on the acquired infrared spectrum data. -1 ~1050cm -1 The characteristic peak area enclosed by the wavelength range is recorded as A ; (3) Based on the area of ​​the characteristic peak A , calculate the evaluation index of long-term performance of recycled asphalt concrete n ', the calculation formula is as follows: Where, It is an indicator for evaluating the long-term performance of recycled asphalt concrete. The smaller the value, the better its long-term service performance.

[0011] Preferably, in step (1), the preparation method of recycled asphalt concrete is as follows: S1. Using the aging index of the RAP material to identify the pseudo-particle content therein to assess whether it meets the use standard; S2. Determining the aged asphalt content and the aged SBS polymer content in the RAP material; S3. Determining the type of composite warm mix regeneration agent, and determining the blending ratio of each component therein based on the aged asphalt content and the aged SBS polymer content in the RAP material; S4. Determining the mix ratio of new aggregate and RAP material; S5. Determining the optimal construction temperature of warm mix recycled asphalt; S6. Determining the optimal amount of new asphalt; S7. Determining the specific preparation of recycled asphalt concrete.

[0012] Preferably, in step S1, a near infrared NIR imaging system is used to quickly identify and screen the RAP material, and the 1650 cm -1 ~ 1700cm -1 The C=O characteristic peak area in the wavelength range is used to calculate the aging index of the recycled material CIA , the calculation formula is as follows: ; Where: For RAP materials at 1650cm -1 ~ 1700cm -1 The characteristic peak area of ​​the wavelength range, The original asphalt corresponding to the RAP material is at 1650cm -1 ~ 1700cm -1 Characteristic peak area in wavelength range; in, CIA1~2 indicates that the false particle content is very low; CIA 3~5 indicates that there are some false particles; CIA >5 indicates that the false particles are enriched and cannot be used to prepare reclaimed asphalt concrete.

[0013] Preferably, in step S2, the RAP material is subjected to infrared spectrum test: the test wave number range is 400cm -1 ~4000cm -1 , the scanning number is 32 times to obtain the infrared spectrum graph, and then the OMNIC analysis software is used to calculate the characteristic peak area of the carbonyl at 1700cm -1 , the sulfoxide group at 1030cm -1 , the carbon-carbon double bond of polybutadiene in aged SBS polymer at 986cm -1 , and the reference peak at 2700cm -1 ~3000cm -1 .

[0014] Preferably, according to the characteristic peak area, the sulfoxide index SI , the carbonyl index CI , and the carbon-carbon double bond index PB are calculated, and the calculation formula is: ; ; ; In the formula, is the characteristic peak area of the sulfoxide group at 1030cm -1 ; is the characteristic peak area of the carbonyl at 1700cm -1 ; is the characteristic peak area of the carbon-carbon double bond at 968cm -1 ; is the characteristic peak area of the reference peak at 2700cm -1 ~3000cm -1 .

[0015] Preferably, according to the sulfoxide index SI and the carbonyl index CI , an aging asphalt index prediction model AI and an aging SBS polymer index prediction model PBI are established, as follows: ; In the formula, and are weight coefficients, which are calibrated by standard asphalt samples in the laboratory, and the lower the aging asphalt index AI , the lower the activity of the aging asphalt. ; wherein the aging SBS polymer index PBI is greater, the more active the aging SBS polymer is.

[0016] Preferably, more than five groups of RAP materials with different aging degrees are selected to establish a mathematical relationship prediction model between the infrared spectrum absorption peak area and the actual aging asphalt content and the aging SBS polymer content, as follows: ; ; wherein, , and are the aging asphalt content prediction model coefficients; and are the content prediction model coefficients; , , , and are calculated by least square fitting; The unknown carbonyl index CI , sulfoxide index SI and carbon-carbon double bond index PB of the RAP material are substituted into the mathematical relationship prediction model, and the aging asphalt and aging SBS polymer contents can be calculated.

[0017] Preferably, in step S3, the method for determining the mixing ratio of each component in the composite warm-mixing recycling agent is as follows: the softening agent, SBS crosslinking agent, viscosity reducer, interface enhancer and anti-aging agent in the composite warm-mixing recycling agent are respectively denoted as X i1 , X i2 , X i3 , X i4 and X i5 , X i1 + X i2 + X i3 + X i4 + X i5 = 100, wherein the mixing amount of the softening agent and SBS crosslinking agent is calculated according to the actual aging index of the aging asphalt and aging SBS polymer in the RAP material; then according to X i1 ~X i5 The uniformity design of the content of each component obtains several groups of experimental groups; then, the key evaluation indexes are determined according to the efficacy of each component in the composite warm-mixing recycling agent, wherein, X i1 corresponding to penetration, X i2 corresponding to ductility, X i3 corresponding to viscosity, X i4 corresponding to tensile strength, X i5 corresponding to softening point, and then the five key evaluation indexes are converted into their performance contribution degrees Y i1 , Y i2 , Y i3 , Y i4 and Y i5 The sum of each contribution degree can be regarded as a comprehensive performance score, that is, Y i , and the calculation formula is as follows: ( i =1,2,3……; j =1,2,3……) ( i =1,2,3……) Finally, according to the experimental data of several groups, the performance test is carried out to determine Y j and Y ij, and the regression equation between Y and X i is obtained through repeated iteration by combining the cubic regression model, so that Y The maximum corresponding X i1, X i2, X i3, X i4 and X i5 is the best ratio of the composite warm-mixing recycling agent.

[0018] Preferably, the softening agent is any one of paraffin oil, naphthenic oil, aromatic oil, alkane oil, biodiesel, microbial oil, ester oil, coal tar, pine tar, lubricating oil; the SBS crosslinking agent is any one of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, bisphenol A type epoxy resin, phenolic epoxy resin, butyl glycidyl ether, isophorone diisocyanate, naphthalene diisocyanate, polyurethane prepolymer, epoxy polybutadiene resin; the viscosity reducer is any one of APTL type viscosity reducer, Dow-Y type viscosity reducer, Asphaltan-B lignite wax, EC-120 aliphatic hydrocarbon, Aspha-Min, Advera, Messo; the interface reinforcing agent is any one of silane coupling agent, aluminate coupling agent, titanate coupling agent, nano silicon dioxide, nano clay, carbon nanotube, lignin, rosin derivative; the anti-aging agent is any one of phenyl-alpha-naphthylamine, 2,6-di-tert-butyl-p-cresol, dilauryl thiodipropionate, 2-hydroxy-4-methoxybenzophenone, benzotriazole, tea polyphenol, rutin.

[0019] Preferably, in step S4, the method for determining the mixing ratio of the new aggregate and the RAP material is as follows: determining the sieve analysis results of the new aggregate and the RAP material; constructing a mixing ratio optimization design objective function; and solving to obtain the optimized design of the mixing ratio of the new aggregate and the RAP material.

[0020] Preferably, in step S5, the method for determining the optimal construction temperature of the warm-mix recycled asphalt is as follows: the warm-mix recycled asphalt is made into a cylindrical sample, a dynamic shear rheometer rotating plate is used to test the sample at different temperatures, the viscosity at different temperatures is calculated based on the sample test data, and the calculation formula is as follows: In the formula, is the viscosity; is the resistance at the time of testing; is the set angular velocity; and are the thickness and the moment of inertia of the sample, respectively.

[0021] Preferably, a rotating plate viscosity scatter plot of the warm-mix recycled asphalt at different test temperatures is drawn, a corresponding viscosity-temperature curve equation is obtained, and the optimal mixing and construction viscosity of the corresponding warm-mix recycled asphalt is calculated by using the equal viscosity method.

[0022] Preferably, in step S5, the method for determining the optimal amount of new asphalt is as follows: square fixed aggregate is added as tracer aggregate during the mixing of recycled asphalt concrete, the tracer aggregate is taken out after cooling, and the asphalt on the surface of the tracer aggregate is scraped and recorded as recycled asphalt; RAP aged asphalt is extracted from the RAP material; infrared spectrum testing is performed on the new asphalt, the RAP aged asphalt, and the recycled asphalt to detect the absorption peak at 1030 cm-1, 1650 cm-1, and 1720 cm-1, respectively; the amount of new asphalt is determined according to the absorption peak area ratio of the new asphalt to the RAP aged asphalt. -1, 1700cm -1 and 2700cm -1 ~ 3000 cm -1 The absorbance at .

[0023] Preferably, the OMNIC analysis software is used to calculate the sulfoxide functional group of new asphalt, aged asphalt and recycled asphalt at 1030 cm -1 , carbonyl functional group 1700cm -1 and aliphatic hydrocarbons at 2700 cm -1 ~ 3000cm -1 The peak area at , and then calculate the sulfoxide / carbonyl index of the new asphalt / , sulfoxide / carbonyl index of aged asphalt / , sulfoxide / carbonyl index of recycled asphalt / , the calculation formula is as follows: ; ; ; ; ; ; Where, 、 、 New asphalt at 1030cm -1 , 1700cm -1 and 2700cm -1 ~ 3000cm -1 The peak area at 、 、 The aged asphalt at 1030cm -1 , 1700cm -1 and 2700cm -1 ~ 3000cm -1 The peak area at 、 、 They are Asphalt at 1030cm -1 , 1700cm -1 and 2700cm -1 ~ 3000cm -1 The peak area at .

[0024] Preferably, the sulfoxide transfer efficiency of RAP aged asphalt is calculated based on the sulfoxide and carbonyl indices. And the carbonyl transfer efficiency The calculation formula is as follows: ; .

[0025] Preferably, according to the sulfoxyl group transfer efficiency And the carbonyl transfer efficiency The new-old asphalt diffusion fusion degree DOB in the recycled asphalt concrete is calculated, and the calculation formula is as follows: ; In the formula, The ratio of RAP aged asphalt to optimal asphalt in the recycled asphalt concrete; The actual optimal new asphalt addition amount in the recycled asphalt concrete is calculated, and the calculation formula is as follows: .

[0026] Preferably, the optimal asphalt amount of the recycled concrete is determined by the Marshall mix design, and the optimal asphalt amount includes the new asphalt amount and the recycled asphalt amount; the RAP aged asphalt content in the RAP material is determined by the combustion method.

[0027] Preferably, in step S6, the specific preparation method of the recycled asphalt concrete is as follows: the RAP material is mixed with the composite warm-mixing recycling agent to be cold-mixed, and the warm-mixing recycled asphalt is obtained after pretreatment, and then the warm-mixing recycled asphalt is mixed with new aggregate and new asphalt, and the recycled asphalt concrete is obtained.

[0028] The application provides a low-carbon durable recycled asphalt concrete preparation and performance evaluation method, and has the following beneficial effects compared with the prior art: The application innovatively proposes a recycling technology based on aging asphalt performance regulation, breaks through the design limitations of traditional recycled asphalt concrete by constructing a “material-structure-performance” multidimensional correlation model, and finally forms a complete technical system covering raw material evaluation, mix design, construction quality control and performance prediction, thereby providing theoretical support and technical support for realizing high-value and large-scale application of RAP.

[0029] Compared with traditional performance test methods such as direct tensile test, the evaluation method of the recycled asphalt concrete long-term performance in the application has obvious advantages. The traditional method needs to repeatedly load the test piece until it is damaged under the actual stress state, and the test period is long, the operation is complicated, the preparation accuracy of the test piece is extremely high, and the manpower and material resources investment is large. The performance evaluation method proposed in the application is based on infrared spectroscopy technology, and the performance data can be quickly and conveniently obtained, and at the same time, complex mechanical loading equipment and a large number of test pieces are not needed, and the fatigue performance of the material can be monitored in real time and dynamically under the condition of no damage, thereby providing an efficient, accurate and economical detection means for long-term performance evaluation of recycled asphalt mixture. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings: Figure 1 The infrared spectrum test charts of various RAP materials of the present invention are as follows; Figure 2 This is the infrared spectrum test chart of sample 1 of the present invention; Figure 3 This is the infrared spectrum test chart of sample 2 of the present invention; Figure 4 This is the optimized design diagram of the synthetic gradation curve of the present invention; Figure 5 This is a viscosity test chart of the original SBS asphalt and warm mix recycled asphalt of the present invention. DETAILED DESCRIPTION

[0031] The following examples illustrate the implementation methods of the present application in detail, so that the implementation process of how the present application applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0032] Example 1 A performance evaluation method for low-carbon durable recycled asphalt concrete, comprising the following steps: (1) After obtaining asphalt samples from recycled asphalt concrete, they were pressed into asphalt films with a diameter of about 3 mm. (2) Infrared spectrum test of asphalt film was conducted using ATR module with a resolution of 4.0 cm -1 , the range of sample scan times is 32, the background scan times is 16, the scanning speed is 7.5KHz, and the wave number range is 4000cm -1 ~ 400cm -1 According to the infrared spectrum data obtained, the -1 ~ 1050cm -1 The characteristic peak area enclosed by the wavelength range is recorded as A ; (3) Based on the area of ​​the characteristic peak A , calculate the evaluation index of long-term performance of recycled asphalt concrete n' , the calculation formula is as follows: Where, It is an indicator for evaluating the long-term performance of recycled asphalt concrete. The smaller the value, the better its long-term service performance.

[0033] Example 2 After obtaining the samples from three different recycled asphalt pavement cores (named pavement core samples 1, 2, and 3), the asphalt samples of the pavement core samples were obtained by extraction, and then detected according to the method in Example 1, and the detection results were compared with the recycled asphalt concrete in Example 1. The specific results are shown in Table 1.

[0034] Table 1. Results of long-term performance evaluation

[0035] According to the long-term performance evaluation index of the asphalt mixture, The smaller the value, the better the fatigue resistance performance. The results show that the order of service performance from good to bad is: recycled asphalt concrete > pavement core sample 1 > pavement core sample 3 > pavement core sample 2.

[0036] In this embodiment, the recycled asphalt concrete is prepared as follows: the RAP material is cold-mixed with the composite warm-mixing recycling agent, and after pretreatment at 140°C for 2h, the warm-mixing recycled asphalt is obtained, which is then mixed with new aggregate and new asphalt at 154°C for 75s to obtain the recycled asphalt concrete.

[0037] Taking 100 kg of recycled concrete as an example, the RAP material is SBS modified RAP mixture (aging RAP asphalt content is 4.75%) of highway surface layer milling material, the addition amount is 40%, and the mass is 40 kg; the type of the composite warm-mixing recycling agent is aromatic oil as an aging base asphalt softener, 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide as an SBS crosslinking agent, EC-120 as a viscosity reducer, nano silicon dioxide as an interface reinforcing agent, and 2,6-di-tert-butyl-p-cresol as an anti-aging agent, and the addition amounts are aromatic oil 40 x 4.75% x 48.6% x 27.5% (aging asphalt activity index) = 0.25 kg; 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide 40 x 4.75% x 27.2% x 94% (aging SBS polymer activity index) = 0.49 kg; EC-120 40 x 4.75% x 10.1% = 0.19 kg; nano silicon dioxide 40 x 4.75% x 7.7% = 0.15 kg; 2,6-di-tert-butyl-p-cresol 40 x 4.75% x 6.4% = 0.12 kg; the new asphalt is SBS modified asphalt provided by a company in Hubei Province as original, and the addition amount is 100 x 6.1% - 40 x 4.75% x 66.89% (fusion degree) = 4.83 kg, and the new aggregate is diabase, and the addition amount is 100 - 40 - 4.83 - 0.25 - 0.49 - 0.19 - 0.15 - 0.12 = 53.97 kg.

[0038] Example 3 A preparation method of a low-carbon durable recycled asphalt concrete is as follows: S1, identifying the content of false particles in the RAP material by using the aging index of the RAP material to evaluate whether it meets the use standard; S2, determining the content of aged asphalt and aged SBS polymer in the RAP material; S3, determining the type of the composite warm-mixing regenerating agent and the mixing ratio of each component in the composite warm-mixing regenerating agent according to the content of aged asphalt and aged SBS polymer in the RAP material; S4, determining the mixing ratio of the new aggregate and the RAP material; S5, determining the optimal construction temperature of the warm-mixing regenerated asphalt; S6, determining the optimal amount of new asphalt; S7, mixing the RAP material with the composite warm-mixing regenerating agent, obtaining the warm-mixing regenerated asphalt after pre-treatment at 140℃ for 2h, and mixing the warm-mixing regenerated asphalt with the new aggregate and the new asphalt at 154℃ for 75s to obtain the regenerated asphalt concrete.

[0039] ① For step S1, the aging index of the RAP material is determined to evaluate whether it can be used to prepare the regenerated asphalt concrete.

[0040] A near-infrared NIR imaging system is installed above the conveyor belt, and the distance between the detection device and the conveyor belt is about 50cm. The installation distance is preferably not more than 80cm, otherwise the NIR signal will be attenuated, the signal-to-noise ratio will be reduced, and the result will be deviated. The angle between the imaging device camera and the conveyor belt is selected to be 20°. During the test, the camera of the imaging system should not be perpendicular to the conveyor belt to avoid the reflection of light on the surface of the aggregate, which will cause the distortion of the test spectrum. The speed of the conveyor belt is set to be 2m / s, and the spectral range collected is 1000cm -1 ~ 4000cm -1 .

[0041] Two batches of samples are selected for testing. The RAP materials in the two batches are rapidly identified and screened by using the near-infrared NIR imaging system. The test results are shown in Figure 2 and Figure 3 . The C=O characteristic peak area in the wavelength interval of 1650cm -1 ~ 1700cm -1 is calculated by using the OMINC software to calculate the aging index of the regenerated material CIA . The calculation formula is as follows: In the formula, is the characteristic peak area of the RAP material in the wavelength interval of 1650cm -1 ~ 1700cm -1 , is the characteristic peak area of the corresponding original asphalt of the RAP material in the wavelength interval of 1650cm -11700 cm -1 Characteristic peak area of wavelength interval; False particles due to aged asphalt enrichment, aging index CIA Significantly higher than the real recycled aggregate, the presence of false particles in waste asphalt mixture is determined by the following criteria, as shown in Table 2.

[0042] Table 2 RAP material false particle discrimination criteria

[0043] Wherein, CIA 1-2 indicates that the false particle content is very low; CIA 3-5 indicates that there are some false particles; CIA > 5 indicates that false particles are enriched and cannot be used to prepare recycled asphalt concrete.

[0044] Table 3 Test results of samples

[0045] 2, in terms of step S2, the content of aged asphalt and the content of aged SBS polymer in RAP material are determined.

[0046] Infrared spectrum test of RAP material: the test wave number range is 400cm -1 -4000cm -1 , the scanning number is 32 to obtain the infrared spectrum, and then the OMNIC analysis software is used to calculate the characteristic peak area of 1700cm -1 , 1030cm -1 , 986cm -1 , 2700cm -1 -3000cm -1 of carbonyl, sulfoxide group, polybutadiene carbon-carbon double bond in aged SBS polymer and reference peak respectively.

[0047] According to the characteristic peak area, the sulfoxide index SI , carbonyl index CI and carbon-carbon double bond index PB are calculated, and the calculation formula is: ; ; ; In the formula, is the characteristic peak area of sulfoxide group at 1030cm -1 ; is the characteristic peak area of carbonyl at 1700cm -1 ; is the characteristic peak area of 968cm-1 The characteristic peak area of ​​carbon-carbon double bond at 1030cm -1 The characteristic peak area of ​​the reference peak.

[0048] According to the sulfoxide index SI and carbonyl index CI Establishing a prediction model for aged asphalt index AI , and the prediction model for the aged SBS polymer index PBI ,as follows: ; Where, and is the weight coefficient, which is calibrated by laboratory standard asphalt samples and is 83.3% and 16.7% respectively. The aged asphalt index AI The lower the value, the lower the activity of the aged asphalt; ; Where, the aged SBS polymer index PBI The larger the value, the lower the activity of the aged SBS polymer. The activity of aged asphalt can be classified by the aged asphalt / SBS polymer index, and the activity thresholds for aged asphalt and aged SBS polymer can be established.

[0049] More than five groups of RAP materials with different aging degrees were selected to establish a mathematical prediction model of the relationship between the infrared spectrum absorption peak area and the actual aged asphalt content and aged SBS polymer content, as follows: ; ; Where, 、 and is the coefficient of the prediction model for aged asphalt content; and yes Content prediction model coefficients; 、 、 、 and Calculated by least squares fitting; The carbonyl index of the unknown RAP material CI , sulfoxide index SI and carbon-carbon double bond index PB By substituting them into the mathematical relationship prediction model, the content of aged asphalt and aged SBS polymer can be calculated.

[0050] Seven different sources and service state of RAP materials were selected in this example, and infrared spectrum test was carried out, in which two were standard and extended pressure aging test box long-term aging SBS modified asphalt, two were highway milling material SBS modified RAP mixture, three were SBS modified asphalt with different oven aging time, and in addition, the original SBS modified asphalt provided by a company in Hubei Province was selected as the control group. FTIR test was carried out on the above asphalt samples by using FTIR-DR test module and FTIR-ATR test module, and the test wave number range covered 400cm -1 ~ 4000cm -1 , and the scanning number was 32 times.

[0051] The obtained infrared spectrum is shown in Figure 1 ; the RAP material characteristic peak area calculation results are shown in Table 4; the sulfoxide index, carbonyl index and carbon-carbon double bond index calculation results are shown in Table 5; and the aging asphalt / aging SBS polymer activity index calculation results are shown in Table 6.

[0052] Table 4 RAP material characteristic peak area calculation results

[0053] Table 5 Sulfoxide index, carbonyl index and carbon-carbon double bond index calculation results

[0054] Table 6 Aging asphalt / aging SBS polymer activity index calculation results

[0055] From Table 6, it can be seen that the aging asphalt activity degree of the seven SBS modified asphalts from small to large is in turn: 40h oven heating aging asphalt, 60h oven heating aging asphalt, 20h oven heating aging asphalt, middle surface milling RAP aging asphalt, RTFO+20h PAV aging asphalt, RTFO+40h PAV aging asphalt and upper surface milling RAP aging asphalt, and the SBS polymer from small to large is in turn: upper surface milling RAP aging asphalt, 60h oven heating aging asphalt, middle surface milling RAP aging asphalt, RTFO+40h PAV aging asphalt, 40h oven heating aging asphalt, RTFO+20h PAV aging asphalt and 20h oven heating aging asphalt.

[0056] ③ As for step S3, the type of composite warm-mixing recycling agent is determined, and the mixing ratio of each component is determined according to the content of aging asphalt and aging SBS polymer in the RAP material.

[0057] Taking the upper layer milled RAP material in Table 6 as an example, aromatic oil is selected as the aging matrix asphalt softener, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide is selected as the SBS crosslinking agent, EC-120 is selected as the viscosity reducer, nano silicon dioxide is selected as the interface reinforcing agent, and 2,6-di-tert-butyl-p-cresol is selected as the anti-aging agent, and the softener, SBS crosslinking agent, viscosity reducer, interface reinforcing agent and anti-aging agent are respectively denoted as X i1 , X i2 , X i3 , X i4 and X i5 , X i1 + X i2 + X i3 + X i4 + X i5 =100, wherein the dosages of the softener and the SBS crosslinking agent are calculated according to the actual aging index of the aging asphalt and the aging SBS polymer in the RAP material; then a number of experimental groups are obtained according to the uniformity design of the dosages of X i1 ~ X i5 , as shown in Table 7.

[0058] Table 7 Experimental design scheme

[0059] Taking the RAP material as the performance recovery object, 12 groups of composite warm-mixing recycling agents shown in Table 7 are respectively added to prepare warm-mixing recycling asphalts in different recycling states, and the penetration, ductility, viscosity, tensile strength and softening point of each group of warm-mixing recycling asphalts are respectively tested. Among them X i1 corresponds to the penetration, X i2 corresponds to the ductility, X i3 corresponds to the viscosity, X i4 corresponds to the tensile strength, X i5 corresponds to the softening point. As shown in Table 8.

[0060] Table 8 Performance recovery test results of warm-mixing recycling asphalts

[0061] The five key evaluation indexes in Table 4 are converted into their performance contribution degrees Y i1 、 Y i2 、 Y i3 、 Y i4 and Y i5 The sum of each contribution degree can be regarded as the comprehensive performance score, i.e. Y i The calculation formula is as follows: ( i =1,2,3……; j =1,2,3……) ( i =1,2,3……) The calculation results are shown in Table 9.

[0062] Table 9 Test results of performance contribution degrees and comprehensive performance scores

[0063] Finally, according to the experimental data in Table 8 and Table 9, the performance test is carried out to determine Y j and Y ij The regression equation between Y and X i is obtained through repeated iteration combined with the cubic regression model. The comprehensive performance score Y corresponding to the maximum X i1 , X i2 , X i3 , X i4 and X i5 is the best ratio of the composite warm-mixing recycling agent. The finally determined best formula is that the aromatic oil is selected as 48.6%, 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide is selected as 27.2%, EC-120 is selected as 10.1%, nano-silicon dioxide is selected as 7.7%, and 2,6-di-tert-butyl-p-cresol is selected as 6.4%.

[0064] ④ As to step S4, the mixing ratio of the new aggregate and the RAP material (old aggregate) is determined.

[0065] Firstly, the screening results of each grade of new and old aggregates are determined. For the new aggregate, the required test mass is obtained by stratified multi-point sampling method, in particular, the test mass is not less than 5 kg, and the screening of the new aggregate is realized by a vibrating screen machine, and the screening results of each grade are recorded. For the old aggregate, samples are taken from different places in the RAP yard to avoid test contingency, in particular, 5 sub-samples are taken from different positions, each not less than 1 kg, and the screening calculation is carried out after mixing. The screening results of the old aggregate are shown in Tables 10 and 11, and the passing rate of the target SMA-13 synthetic gradation is shown in Table 12.

[0066] Table 10 Screening results of new aggregate

[0067] Table 11 Screening results of old aggregate

[0068] Table 12 Passing rate of target synthetic gradation

[0069] The screening results of each grade of new and old aggregates are determined; the new aggregate is divided into 4 grades according to the screening results, i.e. 0-3 mm, 3-6 mm, 6-11 mm and 11-16 mm, and the dosages of each grade of the new aggregate are recorded as N 1, N 2, N 3, N 4 respectively; the old aggregate is divided into 2 grades, i.e. 0-8 mm and 8-12 mm, and the dosages of each grade of the old aggregate are recorded as O 1 and O 2 respectively; the dosage of mineral powder is recorded as K 1, and the dosage of cement is recorded as K 2; the synthetic gradation screening hole passing rate results from 16 mm, 13.2 mm, 9.5 mm, 4.75 mm, 2.36 mm, 1.18 mm, 0.6 mm, 0.3 mm, 0.15 mm, 0.075 mm are recorded as S 1, S 2, S 3… S 10, and the median of the screening hole passing rate is recorded as M 1, M 2, M 3… M 10; the passing rates of the new aggregate from 16 mm to 0.075 mm in the 0-3 mm grade are recorded as PN 11, PN 12, PN 13… PN110, the passing rates of the 10 gears of old aggregate from 16mm to 0.075mm are PO 11. PO 12. PO 13…… PO 110; Similarly, under the gears of 3~6mm, 6~11mm and 11~16mm, the passing rates of the 10 gears of new aggregate from 16mm to 0.075mm are PN twenty one, PN twenty two, PN twenty three…… PN 210; PN 31. PN 32. PN 33…… PN 310; PN 41. PN 42. PN 43…… PN 410; The passing rates of the 10 gears of old aggregate from 16mm to 0.075mm are PO twenty one, PO twenty two, PO twenty three…… PO 210; PO 31. PO 32. PO 33…… PO 310; the passing rates of the 10 gears of mineral powder from 16mm to 0.075mm are PK 11. PK 12. PK 13…… PK 10; The pass rates of cement in 10 gears from 16mm to 0.075mm are PK twenty one, PK twenty two, PK twenty three…… PK 20; the error between the composite gradation and the median gradation of 10 gears from 16mm to 0.075mm is R 1. R 2. R 3…… R 10. The total error of the optimized mix ratio of the total gradation curve of new aggregate and old aggregate is RR; the final mix ratio optimization design objective function is: in, RR The total error of the optimized mix ratio of new and old aggregates is calculated. Ri The total error of the optimized mix ratio of new and old aggregates at each level is calculated. iFrom 1 to 10 represent 16mm, 13.2mm, 9.5mm, 4.75mm, 2.36mm, 1.18mm, 0.6mm, 0.3mm, 0.15mm, 0.075mm sieve size respectively. Ri The calculation formula is: Wherein, Ri , Si , Mi is the error value of the i-th gear, the synthetic gradation passing rate, the median gradation passing rate, i From 1 to 10 represent 16mm, 13.2mm, 9.5mm, 4.75mm, 2.36mm, 1.18mm, 0.6mm, 0.3mm, 0.15mm, 0.075mm sieve size respectively.

[0070] The median gradation passing rate Mi The passing rate of the synthetic gradation Ri can be determined by referring to the passing gradation type and the maximum particle size parameter in the Technical Specification for Construction of Highway Asphalt Pavement (JTG F40-2004), and the calculation formula is: ; Wherein, Si is the synthetic gradation passing rate of the i-th gear, i 1, N 2, N 3, N 4 is the mixing amount of each gear of the new asphalt, N 1, O 2 is the mixing amount of each gear of the old asphalt, O 1, K 2 is the mixing amount of the mineral powder and cement, K 1 is the new aggregate content ratio in the recycled asphalt concrete, X 2 is the old aggregate content ratio in the recycled asphalt concrete, X 1 PN is the sieve passing rate of the i-th gear in the first gear of the new aggregate, i 1 i is the sieve passing rate of the i-th gear in the first gear of the old aggregate, PO 2 i , PN 2 i , PO 2 i , PK 1 i and the like are similarly analogized, iFrom 1 to 10 represent 16mm, 13.2mm, 9.5mm, 4.75mm, 2.36mm, 1.18mm, 0.6mm, 0.3mm, 0.15mm, 0.075mm sieve size, respectively.

[0071] According to the error solving function, the total error RR , the fitting target function argument is N 1、 N 2、 N 3、 N 4、 O 1、 O 2、 K 1、 K 2, it is rewritten as follows:

[0072] Wherein, y is the fitting target function, X is the argument vector of the fitting target function, that is X =[ N 1, N 2, N 3, N 4, O 1, O 2, K 1, K 2] T , β =[ β 0, β 1, β 2, β 3, β 4, β 5, β 6, β 7, β 8] T , is the parameter vector, Ri is the error value of the i th.

[0073] The least square fitting target function is used, and according to the L2 norm, the error function is as follows: Wherein, is the error function, Ri is the error value of the i th, β =[ β 0, β 1, β 2, β 3, β 4, β 5, β 6,β 7,β8] T , is the parameter vector, Xi is the argument vector of the fitting objective function, i.e. Xi =[ N 1, N 2, N 3, N 4, O 1, O 2, K 1, K 2] T .

[0074] The optimal parameters are calculated by the Solver in Excel, and the best mixing amount results are obtained X O =[ N 1, N 2, N 3, N 4, O 1, O 2, K 1, K 2] T , the new and old aggregate mix design optimization is completed.

[0075] For example: the synthetic gradation under the size of 4.75mm sieve is: S4= ( N 1*0.2+ N 2*0.9+ N 3*61.5+ N 4*100+ K 1*100+ K 2*100)+ X 2*( O 1*32.3+ O 2*84.6),the error value under this gear R 4=( S 4-27) 2 .

[0076] Assuming X 1 is 60%, X 2 is 40%, the final result value of different mixing amount is obtained, which is N 1=33%, N 2=45%, N 3=2%, N 4=5%, O 1=15%, O 2=85%, K 1=12%, K 2=3%. The final synthetic gradation curve diagram is as followsFigure 4 as shown.

[0077] V. For step S5, the optimum construction temperature of warm mix recycled asphalt is determined.

[0078] The viscosity of warm mix recycled asphalt is detected at 95-185℃ by dynamic shear rheometer (DSR) rotating plate test, the proportion of original SBS modified asphalt and RAP aged asphalt in warm mix recycled asphalt is 50%, the sample diameter of rotating plate test is 25mm, the thickness is 1mm, the load mode is stress control, the shear rate is 40s -1 , the temperature gradient is 10℃, and the termination condition of rotating plate test is that the viscosity of asphalt sample is not more than 0.1Pa·s; Based on the original data of DSR rotating plate test, the viscosity of warm mix recycled asphalt at different test temperatures is calculated by formula is the viscosity; is the resistance at test; is the set angular velocity; and are the thickness and inertia moment of the sample respectively. The rotating plate viscosity scatter plot of warm mix recycled asphalt at different test temperatures is drawn, and the corresponding viscosity-temperature curve equation is obtained. When the conventional viscosity requirements of asphalt mixture mixing (0.17±0.02 Pa·s) and compaction (0.28±0.02 Pa·s) processes recommended in “Technical Specification for Construction of Highway Asphalt Pavements” (JTG F40-2004) are taken as references, the optimum mixing and construction viscosities of corresponding warm mix recycled asphalt are calculated, as shown in

[0079] From the figure, it can be seen that the mixing temperature of warm mix recycled asphalt is 154℃, while the mixing temperature of original SBS modified asphalt is 179℃, and the warm mix temperature reduction range can reach 25℃. Figure 5

[0080] VI. In step S6, the optimum dosage of new asphalt is determined.

[0081] Square fixed aggregate is added as tracer aggregate during the mixing of recycled asphalt concrete, and the asphalt on the surface of the tracer aggregate is scraped after cooling and recorded as recycled asphalt. RAP aged asphalt is extracted from RAP material by extraction. The optimum asphalt dosage in recycled asphalt concrete is determined to be 6.1% by Marshall mix proportion design, including the dosage of new asphalt and recycled asphalt. The content of RAP aged asphalt in RAP material is determined to be 4.75% by combustion method. The composition of AC-13 recycled concrete is carried out in the proportion of 40% RAP material and 60% new aggregate.

[0082] ​The infrared spectrum test is conducted on the new asphalt, RAP aged asphalt and recycled asphalt, the wave number range is 400cm -1 4000cm -1 , the absorbance at 1030cm -1 , 1700cm -1 and 2700cm -1 ~3000cm -1 is detected; The OMNIC analysis software is used to calculate the peak area of the three kinds of asphalt at the sulfide group functional group 1030cm -1 , the carbonyl functional group 1700cm -1 and the aliphatic hydrocarbon 2700cm -1 ~3000cm -1 , respectively, which are recorded as A 1030 , A 1700 and A 2700~3000 , and then the sulfide group / carbonyl index of the new asphalt is calculated in turn ; the sulfide group / carbonyl index of the RAP aged asphalt ; and the sulfide group / carbonyl index of the recycled asphalt ; , as shown in Table 13.

[0083] Table 13 FTIR peak area calculation results

[0084] According to the sulfide group and carbonyl index, the sulfide group transfer efficiency and the carbonyl transfer efficiency of the RAP aged asphalt are calculated, , .

[0085] Assuming that 5kg of recycled asphalt concrete is prepared, the optimal asphalt dosage (total asphalt) is 6.1%, the optimal asphalt content is 0.3050kg, the RAP aged asphalt content in the RAP is 5x40%x4.75%=0.095kg, and the proportion of RAP aged asphalt in the total asphalt , therefore the fusion degree of the recycled asphalt concrete is , according to the fusion degree calculation result, up to 66.89% of the aged asphalt in the RAP has co-melted with the new asphalt. For 5kg of recycled asphalt concrete, the actual optimal addition amount of new asphalt =0.0.2415kg, which is not 0.21kg obtained by directly subtracting the RAP aged asphalt content 0.095kg from the total asphalt content 0.3050kg.

[0086] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and adaptions can be effected without departing from the spirit and scope of the present application, which is not limited to the exact construction and arrangement described. It is intended, therefore, to cover all modifications and adaptions that fall within the scope of the claims and their equivalents.

Claims

1. A performance evaluation method for low-carbon durable recycled asphalt concrete, characterized in that: The following steps are involved: (1) After obtaining asphalt samples from recycled asphalt concrete, they are pressed into sheets to produce asphalt films; (2) Perform infrared spectrum test on asphalt film and calculate its infrared spectrum at 950cm based on the acquired infrared spectrum data. -1 ~1050cm -1 The characteristic peak area enclosed by the wavelength range is recorded as A ; (3) Based on the area of ​​the characteristic peak A , calculate the evaluation index of long-term performance of recycled asphalt concrete n' , the calculation formula is as follows: ； Where, It is an indicator for evaluating the long-term performance of recycled asphalt concrete. The smaller the value, the better its long-term service performance.

2. The performance evaluation method of low-carbon durable regenerated asphalt concrete according to claim 1, characterized in that: In step (2), the ATR module is used for testing with a resolution of 4.0 cm -1 , the range of sample scans is 32, the number of background scans is 16, the scanning speed is 7.5kHz, and the wave number range is 4000cm -1 ~ 400cm -1 .

3. The performance evaluation method of low-carbon durable regenerated asphalt concrete according to claim 1, characterized in that: In step (1), the preparation method of recycled asphalt concrete is as follows: S1. Use the aging index of RAP material to identify the content of false particles in it to assess whether it meets the use standards; S2. Determine the aged asphalt content and aged SBS polymer content in the RAP material; S3. Determine the type of composite warm mix regeneration agent and determine the blending ratio of each component based on the aged asphalt content and aged SBS polymer content in the RAP material; S4. Determine the mix ratio of new aggregate and RAP materials; S5. Determine the optimal construction temperature for warm mix recycled asphalt; S6. Determine the optimal amount of new asphalt; S7. Determine the specific preparation parameters of recycled asphalt concrete.

4. The performance evaluation method of low-carbon durable regenerated asphalt concrete according to claim 3, characterized in that: In step S1, the near infrared NIR imaging system is used to quickly identify and screen the RAP material and calculate the 1650cm -1 ~ 1700cm -1 The C=O characteristic peak area in the wavelength range is used to determine the aging index of the recycled material CIA , the calculation formula is as follows: ； Where: For RAP materials at 1650cm -1 ~ 1700cm -1 The characteristic peak area of ​​the wavelength range, The original asphalt corresponding to the RAP material is at 1650cm -1 ~ 1700cm -1 Characteristic peak area in wavelength range; in, CIA A value of 1 to 2 indicates that the content of false particles is extremely low; CIA 3 to 5 indicates the presence of some false particles; CIA >5 indicates that pseudo-particles are enriched and cannot be used to prepare recycled asphalt concrete.

5. The performance evaluation method of low-carbon durable regenerated asphalt concrete according to claim 3, characterized in that: In step S2, the RAP material is subjected to infrared spectrum testing: the test wave number range is 400cm -1 ~ 4000cm -1 The infrared spectrum was obtained by scanning 32 times, and then the OMNIC analysis software was used to calculate the 1700cm -1 carbonyl group at 1030 cm -1 Sulfoxide groups at 986 cm in aged SBS polymer -1 The carbon-carbon double bond on polybutadiene at 2700 cm -1 ~ 3000cm -1 The characteristic peak area of ​​the reference peak at .

6. The performance evaluation method of low-carbon durable regenerated asphalt concrete according to claim 5, characterized in that: Calculate the sulfoxide index based on the characteristic peak area SI , carbonyl index CI and carbon-carbon double bond index PB , the calculation formula is: ； ； ； Where, 1030cm -1 The characteristic peak area of ​​sulfoxide group; 1700cm -1 The characteristic peak area of ​​carbonyl group; 968cm -1 The characteristic peak area of ​​carbon-carbon double bond at 2700cm -1 ~ 3000cm -1 The characteristic peak area of ​​the reference peak.

7. The performance evaluation method of low-carbon durable regenerated asphalt concrete according to claim 6, characterized in that: According to the sulfoxide index SI and carbonyl index CI Establishing a prediction model for aged asphalt index AI , and the prediction model for the aged SBS polymer index PBI ,as follows: ； Where, and is the weight coefficient, which is calibrated by laboratory standard asphalt samples. The aged asphalt index AI The lower the value, the lower the activity of the aged asphalt; ； Where, the aged SBS polymer index PBI A larger value indicates that the activity of the aged SBS polymer is lower.

8. The performance evaluation method of low-carbon durable regenerated asphalt concrete according to claim 6, characterized in that: More than five groups of RAP materials with different aging degrees were selected to establish a mathematical prediction model of the relationship between the infrared spectrum absorption peak area and the actual aged asphalt content and aged SBS polymer content, as follows: ； ； Where, 、 and is the coefficient of the prediction model for aged asphalt content; and yes Content prediction model coefficients; 、 、 、 and Calculated by least squares fitting; The carbonyl index of the unknown RAP material CI , sulfoxide index SI and carbon-carbon double bond index PB By substituting them into the mathematical relationship prediction model, the content of aged asphalt and aged SBS polymer can be calculated.

9. The performance evaluation method of low-carbon durable regenerated asphalt concrete according to claim 8, characterized in that: In step S3, the method for determining the blending ratio of each component in the composite warm mix regeneration agent is as follows: the softener, SBS cross-linking agent, viscosity reducer, interface enhancer and anti-aging agent in the composite warm mix regeneration agent are respectively recorded as X i1 , X i2 , X i3 , X i4 and X i5 , X i1 + X i2 + X i3 + X i4 + X i5 =100, where the amount of softener and SBS crosslinker is calculated based on the actual aging index of aged asphalt and aged SBS polymer in RAP material; then X i1 ~ X i5 The dosage uniformity design was used to obtain several experimental groups; then the key evaluation indicators were determined according to the efficacy of each component in the composite warm mix regeneration agent, among which, X i1 Corresponding needle penetration, X i2 Corresponding to the elongation, X i3 The corresponding viscosity, X i4 Corresponding tensile strength, X i5 Corresponding to the softening point, the five key evaluation indicators are then converted into their performance contribution Y i1 、 Y i2 、 Y i3 、 Y i4 and Y i5 , the sum of each contribution can be regarded as the comprehensive performance score, that is Y i , the calculation formula is as follows: （ i =1,2,3……； j =1,2,3……） （ i =1,2,3……） Finally, performance tests were carried out based on several groups of experimental data to determine Y j and Y ij, combined with the cubic regression model, is obtained through repeated iterations Y and X The regression equation between i and the comprehensive performance score Y The maximum corresponding X i1, X i2, X i3, X i4 and X i5 is the optimal ratio of composite warm mix regeneration agent.

10. The performance evaluation method of low-carbon durable recycled asphalt concrete according to claim 9, characterized in that: The softener is any one of paraffin oil, naphthenic oil, aromatic oil, paraffin oil, biodiesel, microbial decomposition oil, ester oil, coal tar, pine tar, and lubricating oil; the SBS crosslinker is any one of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, bisphenol A epoxy resin, novolac epoxy resin, butyl glycidyl ether, isophorone diisocyanate, naphthalene diisocyanate, polyurethane prepolymer, and epoxy polybutadiene resin; the viscosity reducer is any one of APTL type viscosity reducer, Dow-Y type viscosity reducer, Asphalt Any one of an-B montan wax, EC-120 aliphatic hydrocarbons, Aspha-Min, Advera, and Messo; the interface enhancer is any one of a silane coupling agent, an aluminate coupling agent, a titanate coupling agent, nano-silica, nano-clay, carbon nanotubes, lignin, and a rosin derivative; the anti-aging agent is any one of phenyl-α-naphthylamine, 2,6-di-tert-butyl-p-cresol, dilauryl thiodipropionate, 2-hydroxy-4-methoxybenzophenone, benzotriazole, tea polyphenols, and rutin.

11. The performance evaluation method of low-carbon durable regenerated asphalt concrete according to claim 3, characterized in that: In step S4, the method for determining the mix ratio of new aggregate and RAP material is as follows: determining the screening results of each grade of new aggregate and RAP material; constructing the mix ratio optimization design objective function; and solving to obtain the optimized design of the mix ratio scheme of new aggregate and RAP material.

12. The performance evaluation method of low-carbon durable regenerated asphalt concrete according to claim 3, characterized in that: In step S5, the method for determining the optimal construction temperature of warm-mix recycled asphalt is as follows: the warm-mix recycled asphalt is made into a cylindrical sample, and the sample is tested at different temperatures using a rotating plate of a dynamic shear rheology tester. The viscosity at different temperatures is calculated based on the sample test data, and the calculation formula is as follows: ； Where, is viscosity; is the resistance during testing; is the set angular velocity; and are the thickness and moment of inertia of the sample, respectively.

13. The performance evaluation method of low-carbon durable regenerated asphalt concrete according to claim 12, characterized in that: The rotating plate viscosity scatter plot of warm-mix recycled asphalt at different test temperatures was drawn to obtain the corresponding viscosity-temperature curve equation. The optimal mixing and construction viscosity of the corresponding warm-mix recycled asphalt was calculated using the equal viscosity method.

14. The performance evaluation method of low-carbon durable regenerated asphalt concrete according to claim 3, characterized in that: In step S5, the method for determining the optimal amount of new asphalt is as follows: square fixed aggregate is added as tracer aggregate when mixing the recycled asphalt concrete, and after cooling, the tracer aggregate is removed and the asphalt on its surface is scraped off and recorded as recycled asphalt; RAP material is extracted to prepare RAP aged asphalt; infrared spectroscopy is performed on the new asphalt, RAP aged asphalt and recycled asphalt to detect their infrared spectroscopy at 1030 cm -1 , 1700cm -1 and 2700cm -1 ~ 3000 cm -1 The absorbance at .

15. The performance evaluation method of low-carbon durable regenerated asphalt concrete according to claim 14, characterized in that: OMNIC analysis software was used to calculate the sulfoxide functional group of new asphalt, aged asphalt and recycled asphalt at 1030 cm -1 , carbonyl functional group 1700cm -1 and aliphatic hydrocarbons at 2700 cm -1 ~ 3000cm -1 The peak area at , and then calculate the sulfoxide / carbonyl index of the new asphalt / , sulfoxide / carbonyl index of aged asphalt / , sulfoxide / carbonyl index of recycled asphalt / , the calculation formula is as follows: ； ； ； ； ； ； Where, 、 、 New asphalt at 1030cm -1 , 1700cm -1 and 2700cm -1 ~ 3000cm -1 The peak area at 、 、 The aged asphalt at 1030cm -1 , 1700cm -1 and 2700cm -1 ~ 3000cm -1 The peak area at 、 、 They are Asphalt at 1030cm -1 , 1700cm -1 and 2700cm -1 ~ 3000cm -1 The peak area at .

16. The performance evaluation method of low-carbon durable regenerated asphalt concrete according to claim 15, characterized in that: Calculation of sulfoxide transfer efficiency of RAP aged asphalt based on sulfoxide and carbonyl indices and carbonyl transfer efficiency , the calculation formula is as follows: ； 。 17. The performance evaluation method of low-carbon durable regenerated asphalt concrete according to claim 16, characterized in that: According to the sulfoxide transfer efficiency and carbonyl transfer efficiency Calculate the degree of diffusion and fusion of new and old asphalt in recycled asphalt concrete (DOB) using the following formula: ； Where, is the ratio of RAP aged asphalt to optimal asphalt in recycled asphalt concrete; The actual optimal amount of new asphalt added to recycled asphalt concrete is calculated as follows: 。 18. The performance evaluation method of low-carbon durable regenerated asphalt concrete according to claim 17, characterized in that: The optimal asphalt dosage of recycled concrete is determined through Marshall mix design, which includes the dosage of new asphalt and recycled asphalt. The content of RAP aged asphalt in RAP material is determined by combustion method.

19. The performance evaluation method of low-carbon durable regenerated asphalt concrete according to claim 18, characterized in that: In step S6, the specific preparation method of the recycled asphalt concrete is as follows: cold-mixing the RAP material with the composite warm-mix regeneration agent, obtaining warm-mix recycled asphalt after pretreatment, and mixing it with new aggregate and new asphalt to obtain recycled asphalt concrete.

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