Recycled mixture mix proportion design method based on long-term service performance

Abstract

The invention provides a recycled mixture mix proportion design method based on long-term service performance, which is characterized in that ruts and cracks of an asphalt mixture are quantified by utilizing a dynamic modulus test, so that a regression relationship between various viscoelastic parameters and the ruts and cracks of the asphalt mixture is established, and the water stability is detected. The method comprises the following steps of: providing track (V track) and fatigue cracking (V fatigue) performance threshold values, applying the track (V track) and fatigue cracking (V fatigue) performance threshold values to engineering for verification and correction, providing threshold values meeting cracking and track performance requirements, detecting dynamic modulus changes before and after test piece condition treatment, comparing and evaluating the performance of the asphalt mixture, and obtaining an optimal interval of performance balance and a target asphalt amount.

Description

Technical Field

[0001] The present invention relates to the field of traffic civil engineering, and particularly to a mix proportion design method for surface course asphalt pavement mixture based on long-term service performance. Background Art

[0002] As a kind of polymer synthetic material, asphalt mixture has begun to be applied in the field of road engineering due to its advantages such as strong bonding force, stable performance, and low energy consumption. From the perspective of the design method of surface course materials, the current specifications in China stipulate that the mix proportion design of asphalt mixture adopts the Marshall mix proportion design method: that is, first, according to the corresponding construction specifications, the gradation range of aggregates is given, the gradation is determined empirically, then the optimum asphalt content is determined by the Marshall method, and the mixture composition with all volume indexes meeting the specification requirements is designed. Finally, rutting test, immersion Marshall test, freeze-thaw splitting test, low-temperature bending test, and permeability test are carried out to respectively test the high-temperature stability, water stability, low-temperature crack resistance, and impermeability of asphalt mixture. The Marshall method has been used for many years and has many advantages naturally, but its inherent drawbacks cannot be ignored. A large number of studies and practices have proved that since the road performance requirements of asphalt mixture are contradictory in many aspects, the most prominent are the following two pairs of contradictions: the contradiction between high-temperature stability and low-temperature crack resistance and fatigue resistance; the contradiction between skid resistance and water stability. The Marshall design method only judges whether the mix proportion design of asphalt mixture is reasonable by testing the high-temperature stability, low-temperature crack resistance, water stability, and impermeability of asphalt mixture with the specified design standards. This method cannot find the best balance point between these two pairs of contradictions, and often one performance is very good, but the performance contradictory to it is poor. In this way, early diseases such as rutting and cracking often occur in asphalt pavement during engineering application. Summary of the Invention

[0003] To solve the problems existing in the prior art, the present invention provides a mix proportion design method for recycled mixture based on long-term service performance: by designing and calculating and setting the performance thresholds of rutting (V 车辙 ) and fatigue cracking (V 疲劳 ), the mix proportion design scheme of asphalt mixture is standardized to balance the rutting and fatigue cracking performance of asphalt mixture and ensure that the mix proportion design of asphalt mixture meets the performance requirements.

[0004] The technical solution is as follows:

[0005] A mix proportion design method for recycled mixture based on long-term service performance includes the following steps:

[0006] Step 1: Construct the DM master curve of asphalt mixture at the same aging level;

[0007] Step 2: Quantify the rutting resistance of asphalt mixtures using the cumulative PD of the RLPD test;

[0008] Step 3: Establish the regression relationship between various viscoelastic parameters and the rutting resistance potential of asphalt mixtures;

[0009] Step 4: Propose the performance thresholds for rutting (V CZ ) and fatigue cracking (V 疲劳 );

[0010] Step 5: Calculate the anti-cracking performance factor and the anti-rutting performance factor based on the dynamic modulus master curve coefficient and compare with the thresholds;

[0011] Step 6: Test the anti-cracking performance factor, anti-rutting performance factor and water stability performance of the specimens;

[0012] Step 7: If the cracking, rutting and water stability thresholds and requirements are not met, adjust the mix ratio or add additives to meet the minimum performance requirements for cracking, rutting and water stability;

[0013] Step 8: When the cracking, rutting and water stability performance meet the technical requirements, establish the performance balance interval and obtain the optimal asphalt content for performance balance.

[0014] Preferably, in Step 1, the loose asphalt mixture is aged for different durations according to the temperature of the asphalt mixture PG grading to simulate the aging of the asphalt pavement.

[0015] Preferably, in Step 1, prepare dynamic modulus cylindrical specimens of asphalt mixtures with a 7±1% target porosity and three different asphalt contents, with at least 3 specimens corresponding to each different asphalt content.

[0016] Preferably, the specimen has a diameter of 150 mm and a height of 100 mm.

[0017] Preferably, in Step 1, use an asphalt mixture performance tester (AMPT) in strain control mode to conduct DM tests at test temperatures of -10, 4, 21, 38 and 55°C and test frequencies of 0.1, 0.5, 1, 5, 10 and 25 Hz.

[0018] Preferably, in Step 3, bond strain gauges and conduct dynamic modulus tests in the UTM at test temperatures of -10, 4, 21, 38 and 55°C and test frequencies of 0.1, 0.5, 1, 5, 10 and 25 Hz.

[0019] Preferably, in Step 4, rutting (V 车辙)The performance threshold is determined according to the cumulative fatigue strain of RLPD εp = 1*10^4 to control the rutting performance of the asphalt mixture and prevent the rutting performance from being too low. According to the traditional N OT ≥300 can meet the cracking performance. However, for this study and the in-situ pavement performance, N OT ≥150 shows the performance that can meet the pavement performance requirements. Therefore, in this study, N OT ≥150 is tentatively set as the qualified-unqualified standard, and N OT = 150 corresponds to V 疲劳 = 0.04. Considering the additional cracking performance reserve and practical convenience, V 疲劳 ≥0.05 is taken as the threshold.

[0020] Preferably, in step four, the rutting (V 车辙 ) performance threshold is 55 and the fatigue cracking (V 疲劳 ) performance threshold is 0.05.

[0021] Preferably, in step five, for a certain type of recycled mixture, control group dynamic modulus specimens are prepared, and the anti-cracking factor and anti-rutting factor based on the dynamic modulus master curve coefficient are established under this dosage condition, and the magnitude sum is calculated and compared with the threshold.

[0022] Preferably, in step six, the freeze-thaw condition is to vacuum-saturate the dynamic modulus specimens of the asphalt mixture for 15 min, keep them in water at 25°C for 30 min, put the specimens into plastic bags, place them in a refrigerator at -18°C for 16 h, then keep them in water at 60°C for 24 h, and calculate the ratio of the dynamic modulus after the freeze-thaw condition to the dynamic modulus before the freeze-thaw condition.

[0023] The present invention simulates the environment and stress state after the actual pavement is opened to traffic through the dynamic modulus test. Taking the anti-cracking factor, anti-rutting factor, anti-skid and water stability requirements as evaluation indexes, the reasonable mix ratio of the mixture can be determined through laboratory tests, providing a reference for the mix ratio design of the recycled mixture pavement layer. This method is simple to operate and has good repeatability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show the embodiments of the present invention, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 FIG. is a schematic flow chart of a preferred embodiment of a method for determining a mix ratio design of a recycled mixture based on long-term service performance according to the present invention;

[0026] Figure 2 A fitting correlation diagram established based on the fatigue cracking threshold and cumulative strain in the mix proportion design method of recycled mixture based on long-term service performance according to the present invention;

[0027] Figure 3 A fitting correlation diagram established based on the high-temperature rutting threshold and cracking performance in the mix proportion design method of recycled mixture based on long-term service performance according to the present invention;

[0028] Figure 4 A threshold range diagram determined by comprehensively considering fatigue cracking and high-temperature rutting in the mix proportion design method of recycled mixture based on long-term service performance according to the present invention. The performance thresholds of asphalt mixture are divided into four regions A, B, C, and D by the rutting (V 车辙 ) performance threshold and the fatigue cracking (V 疲劳 ) performance threshold;

[0029] Region A = Asphalt mixture with durable and balanced design, having satisfactory laboratory rutting and crack resistance performance;

[0030] Region B = Flexible asphalt mixture with acceptable laboratory crack resistance but prone to rutting problems;

[0031] Region C = Hard asphalt mixture with sufficient laboratory rutting resistance performance but prone to cracking;

[0032] Region D = Inferior asphalt mixture that needs to be modified and / or redesigned. Specific embodiments

[0033] The present invention will be further described below in conjunction with specific examples, but the content of the present invention is not limited to the following examples.

[0034] In Examples 1 to 3, waste materials of the same SBS modified asphalt mixture were selected, and 3 groups of recycled asphalt mixtures were prepared with different dosages of waste asphalt mixture. The new asphalt during recycling was SBS modified asphalt. In Example 4, waste materials of matrix asphalt mixture were selected for recycling, and the new asphalt added during recycling was 70# asphalt.

[0035] Example 1

[0036] In this example, 50 parts of waste asphalt mixture and 50 parts of new gradation mineral aggregate were selected to prepare recycled asphalt mixture.

[0037] Its preparation method includes the following steps:

[0038] (1) According to the volume parameter design principle, the gradation curve is determined by selecting the gradation - optimizing the gradation, and asphalt mixtures with three different asphalt contents (the asphalt - aggregate ratios are 4.5%, 5.0% and 5.5% respectively) and a target air void of 7% ± 1% are prepared. The loose asphalt mixtures are subjected to simulated outdoor aging for 2 hours and 4 hours respectively according to the temperatures of the asphalt mixture PG grading.

[0039] (2) The aged loose materials are formed into dynamic modulus cylinder specimens (150 mm in diameter and 100 mm in height), and at least 3 specimens are corresponding to each different asphalt content situation.

[0040] (3) Strain gauges are bonded to the dynamic modulus cylinder specimens, and dynamic modulus tests are carried out in the UTM. The test temperatures are - 10, 4, 21, 38 and 55 °C, and the test frequencies are 0.1, 0.5, 1, 5, 10 and 25 Hz.

[0041] (4) For a certain recycled mixture, control group dynamic modulus specimens are prepared, and then the anti - cracking factor, anti - rutting factor and water stability performance under this dosage condition are calculated and compared with the thresholds; if the cracking, rutting thresholds and water stability requirements are not met, the mix proportion (gradation, asphalt grade, etc.) needs to be adjusted or additives need to be added to make it meet the minimum performance requirements of cracking, rutting and water stability; if the cracking, rutting thresholds and water stability performance requirements are met, another group of specimens are prepared for anti - skid and permeability detection to obtain the best interval of performance balance and the target asphalt dosage.

[0042] (5) Design the mix proportion of the recycled asphalt mixture according to the Marshall method, and conduct a comparison of the mixture performance of the two methods as a control group.

[0043] Figure 1 It is a schematic flow chart of a preferred embodiment of a method for designing the mix proportion of recycled mixtures based on long - term service performance.

[0044] A method for designing the mix proportion of recycled mixtures based on long - term service performance includes the following steps:

[0045] Step 1: Use an asphalt mixture performance tester (AMPT) under strain - controlled mode to conduct DM tests at test temperatures of - 10, 4, 21, 38 and 55 °C and test frequencies of 0.1, 0.5, 1, 5, 10 and 25 Hz. Generate the main curve of DM (i.e., |E*|) of the asphalt mixture decreasing with the decrease of the loading frequency by using the sigmodal function in Equation 1;

[0046]

[0047] In the formula: f r is the decreasing load frequency;

[0048] δ, α, β, γ, and λ are regression parameters;

[0049] Step 2: Quantify the rutting resistance of asphalt mixtures using the cumulative PD of the RLPD test; The cumulative PD of the RLPD can be used as the rutting performance of asphalt mixtures. Asphalt mixtures ε with vulnerable structures and low rutting resistance p are significantly larger;

[0050] Step 3: Establish the regression relationship between various viscoelastic parameters and the rutting resistance potential of asphalt mixtures;

[0051] Step 4: Propose the performance thresholds for rutting (V 车辙 ) and fatigue cracking (V 疲劳 ); The rutting (V 车辙 ) performance threshold is determined based on the RLPD cumulative fatigue strain εp = 1*10^4, which can control the rutting performance of asphalt mixtures and prevent low rutting performance; According to the traditional NOT≥300, the cracking performance can be satisfied. However, for this study and the in-situ road performance, the performance shown by NOT≥150 can meet the employment performance requirements. Therefore, this study tentatively sets NOT≥150 as the pass-fail standard. NOT = 150 corresponds to V 疲劳 = 0.04. Considering additional cracking performance reserves and practical convenience, take V 疲劳 ≥0.05 as the threshold;

[0052] Step 5: Establish the anti-cracking performance factor and anti-rutting performance factor based on the dynamic modulus master curve coefficient, and calculate their magnitudes and compare with the thresholds; According to Equation 1 in Step 1, establish the anti-cracking performance factor and anti-rutting performance factor based on the dynamic modulus master curve coefficient. The calculation method is as follows:

[0053]

[0054] Where: |E*| 拐点 ——The inflection point frequency of DM(|E*|);

[0055] |E*| 1 / 1000*拐点 ——The inflection point frequency of 1 / 1000DM(|E*|);

[0056] f 降载 ——The unloading frequency of DM(|E*|);

[0057] f 1 / 1000*降载 ——The unloading frequency of 1 / 1000DM(|E*|).

[0058]

[0059] Step 6: Test the anti-cracking performance factor, anti-rutting performance factor, and water stability performance of the specimens;

[0060] Step 7: If the requirements for cracking, rutting threshold, and water stability performance are not met, adjust the mix proportion (grading, asphalt grade, etc.) or add additives to make it meet the minimum performance requirements for cracking, rutting, and water stability.

[0061] Step 8: When the cracking, rutting, and water stability performance meet the technical requirements, prepare another set of specimens, test the skid resistance and permeability performance, and obtain the optimal asphalt content for performance balance according to the established balance interval.

[0062] Properties of Reclaimed Asphalt Mixture with Different Mix Design Methods (50% Recycled Materials)

[0063]

[0064] Figure 2 It is a fitting correlation diagram established based on the fatigue cracking threshold and cumulative strain in the mix proportion design method of reclaimed mixture for long-term service performance. It is the relationship between V 车辙 and V 疲劳 versus the cumulative fatigue strain εp of RLPD. In the figure, the red area is the fitting correlation between the fatigue cracking factor calculated from 12 US highways and the cumulative strain; the blue area is the area satisfying the fatigue cracking performance.

[0065] Figure 3 It is a fitting correlation diagram established based on the high-temperature rutting threshold and cracking performance in the mix proportion design method of reclaimed mixture for long-term service performance. It is the relationship between V 车辙 and V 疲劳 versus NOT. In the figure, the red area is the fitting correlation between the rutting performance factor calculated from 12 US highways and N OT ; the blue area is the area satisfying the N OT performance.

[0066] It can be seen from Figure 4 that the asphalt mixture in area B has very excellent low-temperature cracking resistance but poor rutting performance; the asphalt mixture in area C has very excellent rutting performance in part but poor low-temperature cracking resistance. Therefore, the excellent rutting and low-temperature cracking performance of the asphalt mixture are relatively conflicting. So, the mix proportion design method of reclaimed mixture based on long-term service performance can balance the rutting and fatigue cracking performance of the asphalt mixture and ensure that the mix proportion design of the asphalt mixture meets the performance requirements.

[0067] Example 2

[0068] In this example, 60 parts of waste asphalt mixture and 40 parts of new graded aggregates are selected to prepare the reclaimed asphalt mixture.

[0069] Its preparation method includes the following steps:

[0070] (1) According to the design principle of volume parameters, the gradation curve is determined by selecting the gradation - optimizing the gradation, and asphalt mixtures with a target air void rate of 7% ± 1% and three different asphalt contents (the asphalt - aggregate ratios are 4.5%, 5.0%, and 5.5% respectively) are prepared. According to the temperatures of the PG grading of asphalt mixtures, the loose asphalt mixtures are subjected to simulated outdoor aging with aging durations of 2 hours and 4 hours respectively.

[0071] (2) The aged loose materials are formed into dynamic modulus cylinder specimens (150 mm in diameter and 100 mm in height), and at least 3 specimens are corresponding to each different asphalt content case.

[0072] (3) Strain gauges are bonded to the dynamic modulus cylinder specimens, and dynamic modulus tests are carried out in the UTM. The test temperatures are - 10, 4, 21, 38, and 55 °C, and the test frequencies are 0.1, 0.5, 1, 5, 10, and 25 Hz.

[0073] (4) For a certain recycled mixture, control group dynamic modulus specimens are prepared, and then the anti - cracking factor, anti - rutting factor, and water stability performance under this dosage condition are calculated and compared with the thresholds. If the cracking, rutting thresholds, and water stability requirements are not met, the mix proportion (gradation, asphalt grade, etc.) needs to be adjusted or additives need to be added to make it meet the minimum performance requirements for cracking, rutting, and water stability. If the cracking, rutting thresholds, and water stability performance requirements are met, another group of specimens is prepared for anti - skid and water permeability detection to obtain the best interval of performance balance and the target asphalt dosage.

[0074] (5) Design the mix proportion of the recycled asphalt mixture according to the Marshall method and conduct a comparison of the mixture performance of the two methods as a control group.

[0075] Performance of Recycled Asphalt Mixtures with Different Mix Proportion Design Methods (60% Waste Materials)

[0076]

[0077] Example 3

[0078] In this example, 70 parts of waste asphalt mixture and 30 parts of new gradation mineral aggregate are selected to prepare the recycled asphalt mixture.

[0079] Its preparation method includes the following steps:

[0080] (1) According to the design principle of volume parameters, the gradation curve is determined by selecting the gradation - optimizing the gradation, and asphalt mixtures with a target air void rate of 7% ± 1% and three different asphalt contents (the asphalt - aggregate ratios are 4.5%, 5.0%, and 5.5% respectively) are prepared. According to the temperatures of the PG grading of asphalt mixtures, the loose asphalt mixtures are subjected to simulated outdoor aging with aging durations of 2 hours and 4 hours respectively.

[0081] (2) Form dynamic modulus cylindrical specimens of the aged loose materials (150 mm in diameter and 100 mm in height), with at least 3 specimens corresponding to each different asphalt content.

[0082] (3) Bond strain gauges on the dynamic modulus cylindrical specimens and conduct dynamic modulus tests in the UTM. The test temperatures are -10, 4, 21, 38, and 55 °C, and the test frequencies are 0.1, 0.5, 1, 5, 10, and 25 Hz.

[0083] (4) For a certain recycled mixture, prepare control group dynamic modulus specimens, and then calculate the anti-cracking factor, anti-rutting factor, and water stability performance under this dosage condition and compare them with the thresholds. If the cracking, rutting thresholds, and water stability requirements are not met, the mix proportion (grading, asphalt grade, etc.) needs to be adjusted or additives need to be added to meet the minimum performance requirements for cracking, rutting, and water stability. If the cracking, rutting thresholds, and water stability performance requirements are met, prepare another group of specimens for anti-skid and water permeability tests to obtain the best interval of performance balance and the target asphalt dosage.

[0084] (5) Design the mix proportion of the recycled asphalt mixture according to the Marshall method and conduct a comparison of the mixture performance between the two methods as the control group.

[0085] Performance of Recycled Asphalt Mixtures with Different Mix Proportion Design Methods (70% Waste Materials)

[0086]

[0087] Example 4

[0088] In this example, 50 parts of waste 70# base asphalt mixture and 50 parts of new graded aggregates are selected to prepare the recycled asphalt mixture.

[0089] Its preparation method includes the following steps:

[0090] (1) According to the design principle of volume parameters, determine the grading curve in the way of selecting grading - optimizing grading, prepare asphalt mixtures with three different asphalt contents (oil - stone ratios are 4.5%, 5.0%, and 5.5% respectively) and a target air void rate of 7% ± 1%, and conduct simulated outdoor aging for 2 hours and 4 hours on the loose asphalt mixtures according to the temperatures of the PG grading of the asphalt mixtures.

[0091] (2) Form dynamic modulus cylindrical specimens of the aged loose materials (150 mm in diameter and 100 mm in height), with at least 3 specimens corresponding to each different asphalt content.

[0092] (3) Bond strain gauges on the dynamic modulus cylinder specimens and conduct dynamic modulus tests in the UTM. The test temperatures are -10, 4, 21, 38, and 55 °C, and the test frequencies are 0.1, 0.5, 1, 5, 10, and 25 Hz.

[0093] (4) For a certain type of recycled mixture, prepare control group dynamic modulus specimens, and then calculate the anti-cracking factor, anti-rutting factor, and water stability performance under this dosage condition, and compare them with the thresholds; if the cracking, rutting thresholds, and water stability requirements are not met, the mix proportion (grading, asphalt grade, etc.) needs to be adjusted or additives need to be added to make it meet the minimum performance requirements for cracking, rutting, and water stability; if the cracking, rutting thresholds, and water stability performance requirements are met, prepare another group of specimens for anti-skid and permeability detection to obtain the best interval of performance balance and the target asphalt dosage.

[0094] (5) Design the mix proportion of the recycled asphalt mixture according to the Marshall method and conduct a comparison of the mixture performance of the two methods as a control group.

[0095] Performance of Recycled Asphalt Mixtures with Different Mix Proportion Design Methods (50% Waste Material)

[0096]

[0097] In summary, the mixtures prepared by the mix proportion design method of recycled mixtures based on long-term service performance have higher high-temperature, low-temperature, water stability, and fatigue life than the traditional Marshall design method.

[0098] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the foregoing embodiments have described the present invention in detail, those skilled in the art should understand that they can modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features, and these replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. A method for designing the proportion of recycled mixture based on long-term service performance, comprising the following steps: Step 1: Construct the DM master curve of asphalt mixture at the same aging level; Step 2: Quantify the rutting resistance of asphalt mixture using the cumulative PD of the RLPD test; Step 3: Establish the regression relationship between various viscoelastic parameters and the rutting resistance potential of asphalt mixture; Step 4: Propose the rut (V 车辙 ) and fatigue cracking (V 疲劳 ) performance threshold; Step 5: Calculate the anti-cracking performance factor based on the dynamic modulus master curve coefficient and anti-rutting performance factor and compared with the threshold; Step 6: Calculate the dynamic modulus ratio before and after freeze-thaw conditions and establish the water stability performance evaluation standard; Step 7: If the cracking and rutting thresholds and water stability requirements are not met, adjust the mix ratio or add additives to meet the minimum cracking and rutting performance and water stability requirements; Step 8: When the cracking, rutting and water stability performance meet the technical requirements, establish a performance balance range to obtain the optimal asphalt dosage for performance balance.

2. The method for designing the proportion of recycled mixture based on long-term service performance according to claim 1, characterized in that: In step 1, the loose asphalt mixture is aged for different periods of time according to the temperature of the asphalt PG grading to simulate the aging of the asphalt pavement.

3. The method for designing the proportion of recycled mixture based on long-term service performance according to claim 1, characterized in that: In step 1, asphalt mixture dynamic modulus cylindrical specimens at a target porosity of 7±1% with three different asphalt contents are prepared, and each different asphalt content corresponds to at least 3 specimens.

4. The method for designing the proportion of recycled mixture based on long-term service performance according to claim 3, characterized in that: The test piece has a diameter of 100 mm and a height of 150 mm.

5. The method for designing the proportion of recycled mixture based on long-term service performance according to claim 1, characterized in that: In step 1, the asphalt mixture performance tester in strain control mode was used to perform DM tests at test temperatures of -10, 4, 21, 38, and 55°C and test frequencies of 0.1, 0.5, 1, 5, 10, and 25 Hz.

6. The method for designing the proportion of recycled mixture based on long-term service performance according to claim 1, characterized in that: In step 3, the strain gauges were bonded and dynamic modulus tests were performed in UTM at temperatures of -10, 4, 21, 38 and 55°C and frequencies of 0.1, 0.5, 1, 5, 10 and 25 Hz.

7. The method for designing the proportion of recycled mixture based on long-term service performance according to claim 1, characterized in that: In step 4, the rutting (V 车辙 )The performance threshold is determined based on the RLPD cumulative fatigue strain εp=1*10^4.

8. The method for designing the proportion of recycled mixture based on long-term service performance according to claim 1, characterized in that: The rutting (V 车辙 ) performance threshold is 55 and fatigue cracking (V 疲劳 )The performance threshold is 0.

05.

9. The method for designing the proportion of recycled mixture based on long-term service performance according to claim 1, characterized in that: In step five, for a certain recycled mixture, a control group dynamic modulus specimen is prepared, and under the dosage condition, the anti-cracking factor and anti-rutting factor based on the dynamic modulus master curve coefficient are established, and the size is calculated and compared with the threshold.

10. The method for designing the proportion of recycled mixture based on long-term service performance according to claim 1, characterized in that: In step six, the freeze-thaw conditions are to vacuum saturate the asphalt mixture dynamic modulus specimen with water for 15 minutes, keep it warm in 25°C water for 30 minutes, put the specimen in a plastic bag, place it in a -18°C refrigerator for 16 hours, then keep it warm in 60°C water for 24 hours, and calculate the ratio of the dynamic modulus after the freeze-thaw condition to the dynamic modulus before the freeze-thaw condition.

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