A method for evaluating the high-temperature service performance of road maintenance paving materials

Abstract

This invention discloses a method for evaluating the high-temperature service performance of road maintenance pavement materials. The method includes the following steps: molding asphalt mixture specimens of different sizes according to the design mix proportions; uniformly spreading the road maintenance pavement material on the surface of the asphalt mixture specimens and compacting it, storing it at a constant temperature until strength is achieved, and then marking the roller direction; subjecting the road maintenance pavement specimens to dynamic compaction treatment, recording the number of compaction terminations after reaching the service termination conditions; converting the number of compaction terminations into service time based on the standard axle load cycle; plotting a scatter plot of test temperature versus service time and fitting a linear regression prediction equation for service performance; defining and determining evaluation index values, and analyzing and evaluating the high-temperature service performance of the road maintenance pavement materials. This method can accurately and comprehensively evaluate and predict the high-temperature service performance of road maintenance pavement materials, providing a sound basis and guarantee for the application and promotion of road maintenance pavement materials.

Description

Technical Field

[0001] This invention relates to the field of road construction, and in particular to a method for evaluating the high-temperature service performance of road maintenance paving materials. Background Technology

[0002] With the development of road engineering and the increasingly advanced transportation industry, while transportation has become more convenient, the working environment of roads is becoming increasingly harsh due to factors such as high summer temperatures and increased vehicle axle loads. Asphalt pavements in the construction and maintenance phases are severely affected by various defects such as cracks, potholes, subsidence, rutting, and erosion. These defects not only affect the safety and comfort of driving but also lead to other defects such as water damage, seriously threatening the stability of the road structure. Road maintenance paving materials, as a preventative maintenance measure for asphalt pavements, play a role in restoring surface performance, repairing early defects, reducing the temperature of asphalt pavements, and alleviating high-temperature defects. However, existing research on road maintenance paving materials mainly focuses on their cooling performance, skid resistance, and durability, lacking a comprehensive evaluation method for their high-temperature service performance. High-temperature service performance, as an important road performance indicator, is crucial to its cooling performance and durability, significantly impacting the pavement's performance and service life.

[0003] Therefore, there is an urgent need for an evaluation method for the high-temperature service performance of road maintenance paving materials, so as to facilitate the promotion and application of such materials. Summary of the Invention

[0004] The purpose of this invention is to provide a method for evaluating the high-temperature service performance of road maintenance paving materials. This method can provide a good and accurate evaluation of the high-temperature performance of different types of road maintenance paving materials, thus providing a sound basis and guarantee for the application and promotion of road maintenance paving materials. The specific solution is as follows:

[0005] A method for evaluating the high-temperature service performance of road maintenance paving materials, comprising:

[0006] S1. Mold asphalt mixture specimens of different sizes according to the design mix proportions;

[0007] S2. Spread the road maintenance paving material to be tested evenly on the surface of the precast asphalt mixture specimen, and compact it with a roller roller. After the specimen is kept at a constant temperature and the strength is formed, mark the roller rolling direction on the surface of the specimen.

[0008] S3. Place the prepared pavement maintenance specimens into the pre-selected compaction equipment for dynamic compaction treatment. Once the predetermined service termination conditions are reached, record the number of compaction cycles experienced by the pavement maintenance material specimens.

[0009] S4. Based on the standard axle load cycle, the number of compaction cycles under the service termination condition is converted into service time;

[0010] S5. Based on the service time and the temperature range of the test, draw a scatter plot of test temperature-service time for the road maintenance pavement material specimens, and use the least squares method to fit a linear regression prediction equation for serviceability.

[0011] S6. Based on the serviceability linear regression curve, define and determine the evaluation index values ​​such as the ultimate service limit, temperature change rate A, ultimate service point t70, and effective service area S, and analyze and evaluate the high-temperature serviceability of relevant road maintenance paving materials.

[0012] In the method for evaluating the high-temperature serviceability of pavement materials for road maintenance provided in the embodiments of the present invention, asphalt mixture specimens of different sizes are molded according to the design mix proportion, specifically as follows:

[0013] The asphalt mixture specimens adopted discontinuous gradation, and the materials used were SBS modified asphalt, basalt for coarse and fine aggregates, and limestone powder for mineral powder. The mass of the materials was weighed according to the design dosage.

[0014] Mix the coarse and fine aggregates evenly and transfer them to the mixing pot with a shovel. Then add SBS modified asphalt, start the mixer according to the set mixing temperature and mixing time, and add limestone powder while stirring.

[0015] Apply the release agent evenly to the inner wall of the mold, then spread the mixed asphalt mixture evenly along the edge of the mold to the center in a clockwise direction. Use a standard axle load roller to compact the mixture into asphalt mixture specimens.

[0016] The gradation can be dense gradation, semi-open gradation, or open gradation.

[0017] The binder can be matrix asphalt or modified asphalt, and the aggregate can be basalt or diabase aggregate.

[0018] The size of the maintenance paving material test specimens can be 30cm×30cm×5cm, 60cm×60cm×10cm, 90cm×90cm×15cm, or other sizes.

[0019] The release agent can be dimethyl silicone oil emulsion, PETS release agent, or zinc stearate emulsion.

[0020] The vibratory compaction mold is welded from galvanized steel plates and can be made of martensitic steel, ferritic steel, austenitic steel, or other materials.

[0021] The mixing temperature of the mixer is 160-175℃, and the rolling temperature of the roller mill is 140-170℃.

[0022] In the high-temperature service performance evaluation method for road maintenance pavement materials provided in the embodiments of the present invention, the road maintenance pavement material to be tested is evenly spread on the surface of a precast asphalt mixture specimen, and then compacted using a roller mill. After being stored at a constant temperature and having developed strength, the roller mill direction is marked on the surface of the specimen. Specifically:

[0023] The maintenance paving material should be laid with a thickness of 1cm-3cm or a unit spreading rate of 0.5kg / m. 2 -1.2kg / m 2 Apply the mixture evenly to the surface of the asphalt mixture specimen and smooth the surface of the specimen with a small trowel.

[0024] After the specimens are formed, the curing paving material specimens are placed in a ventilated place to dry for 24 hours. After the strength is fully formed, the rolling mold is removed, and the rolling direction is marked on the surface of the specimens with an arrow using a white marker.

[0025] In the method for evaluating the high-temperature serviceability of pavement materials provided in the embodiments of the present invention, the prepared pavement specimens are placed in pre-selected compaction equipment for dynamic compaction treatment. Once the predetermined service termination conditions are reached, the number of compaction cycles experienced by the pavement specimens is recorded. Specifically:

[0026] Place the prepared curing pavement material specimen into the rectangular clamp of the metal base of the test trough according to the rolling direction, and fix it with screws. Install the deformation measurement sensor according to the horizontal position indicated by the track.

[0027] A crane was used to lift the compaction equipment into the temperature-controlled chamber, and all air ducts, the bottom of the chamber, and the opening cover of the chamber were sealed.

[0028] Start the heating system to control the test environment temperature and preheat the curing paving material specimens for 3 to 6 hours;

[0029] Set the loading speed, load application period, and loading pressure of the compaction equipment, and conduct accelerated wheel rolling tests on the pavement material specimens. When the test reaches the service termination conditions, the accelerated wheel rolling test is terminated.

[0030] Draw a table of test temperature and number of compaction cycles for the curing pavement specimens, and record the test data of the number of compaction cycles at the test temperature;

[0031] The heating system can be a hot air circulation heating system, an infrared heater, or a combination of infrared and hot air heaters.

[0032] The wheel rolling temperature value can be selected from 40℃, 50℃, 60℃, 70℃ or other four test temperature values ​​with a gradient of 10℃.

[0033] The loading pressure is set to 0.6–0.8 MPa.

[0034] The compaction equipment has a unidirectional loading speed of 6-9 km / h and a load application period of 2 seconds.

[0035] The compaction equipment includes a large full-scale accelerated loading device ALF, a heavy-duty vehicle simulator HVS, a mobile load simulator MLS, or an indoor small accelerated loading device MMLS3.

[0036] The environmental temperature control chamber can be a small environmental temperature control box or a constant temperature chamber constructed with a canvas insulated cover or insulated material.

[0037] The constant temperature chamber constructed with the insulation material must be equipped with a ventilation circulation system to ensure that the test temperature is uniform and constant.

[0038] The purpose of all air pipes, the bottom of the chamber, and the cover of the sealed temperature-controlled chamber is to prevent outside air from entering the temperature-controlled chamber, so as to ensure that the accelerated wheel rolling test is carried out within the set test temperature throughout the entire process.

[0039] The service termination conditions are: the dynamic stability of the maintenance pavement material specimen is less than 1000 cycles / mm, or ruts with a depth of 2mm to 5mm appear on the surface of the maintenance pavement material, or the binder in the road maintenance pavement material is obviously adhered to the contact surface of the load wheel.

[0040] The loading pressure is set to 0.6–0.8 MPa.

[0041] In the high-temperature serviceability evaluation method for road maintenance paving materials provided in the embodiments of the present invention, the number of compaction cycles under the service termination condition is converted into service time based on the standard axle load cycle, specifically as follows:

[0042] Draw a table of test temperature and service time for the maintenance pavement material specimens, and record the test data of the number of compaction times at different test temperatures;

[0043] The number of compaction cycles of the maintenance pavement material specimens is converted into service time according to the conversion formula, which is as follows:

[0044] Service life = Number of compaction cycles / (3600 * Loading cycle)

[0045] In the above-mentioned method for evaluating the high-temperature serviceability of road maintenance pavement materials provided in the embodiments of the present invention, a scatter plot of test temperature-service time of road maintenance pavement material specimens is drawn according to the service time and the test temperature range, and the least squares method is used to fit a linear regression prediction equation for serviceability, specifically as follows:

[0046] Using test temperature as the abscissa and ultimate service time as the ordinate, a Cartesian coordinate system was established using mathematical analysis software. A scatter plot of test temperature-service time for the maintenance paving material specimens was plotted. Based on the least squares calculation principle and the linear equation y=Ax+b, the scatter plot was fitted to form the optimal serviceability linear regression prediction curve.

[0047] The mathematical analysis software can be Excel, Matlab, Mathematica, or SPSS.

[0048] The extreme service limit is defined as the dynamic stability of the pavement material specimen under different test temperatures being less than 1000 cycles / mm, or the appearance of ruts 2mm-5mm deep on the surface of the pavement material, or the obvious adhesion of the binder in the pavement material to the contact surface of the load wheel, corresponding to the service time fitted into the corresponding function curve.

[0049] In the above-mentioned method for evaluating the high-temperature serviceability of road maintenance paving materials provided in the embodiments of the present invention, the temperature change rate A is defined as the slope of the limit service regression function curve;

[0050] In the high-temperature service performance evaluation method for road maintenance paving materials provided in the embodiments of the present invention, the extreme service point t 70 Defined as the function value corresponding to the ultimate service limit when the test temperature of the road maintenance paving material specimen is 70℃.

[0051] In the high-temperature service performance evaluation method for road maintenance paving materials provided in the embodiments of the present invention, the effective service product S is defined as the limit value of the integral of the limit service boundary regression function curve over the temperature range [40, 70], and the calculation formula is as follows:

[0052]

[0053] Where (Ax+b) is the serviceability linear regression prediction equation; A is the slope of the line, i.e., the temperature change rate; and b is the intercept of the line.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] This invention provides a method for evaluating the high-temperature service performance of road maintenance pavement materials. This method creatively defines the ultimate service limit and a linear regression prediction equation for service performance. Based on the regression equation, corresponding evaluation indicators are proposed. These indicators can accurately reflect the stability performance of maintenance pavement materials under different ambient temperatures, and can accurately evaluate and predict the service life and high-temperature service performance of maintenance pavement materials. For example, the temperature change rate A index can be used to deeply evaluate the stability performance of maintenance pavement materials under different service temperatures, and the ultimate service point t... 70The effective service volume S can be used to evaluate the high-temperature performance of maintenance paving materials, which provides a scientific basis for evaluating the high-temperature service performance of maintenance paving materials. It also provides targeted guidance for the application and promotion of functional maintenance materials, and has good practical application value. Attached Figure Description

[0056] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0057] Figure 1 A flowchart illustrating the method for evaluating the high-temperature serviceability of road maintenance paving materials provided in this embodiment of the invention.

[0058] Figure 2 This is a dimensional diagram of a road maintenance paving material specimen provided in an embodiment of the present invention.

[0059] Figure 3 Linear regression curve of service performance of road maintenance paving material provided in the embodiments of the present invention.

[0060] Figure 4 The measured values ​​of temperature-service time and linear regression fitting curves of the road maintenance paving material provided in the embodiments of the present invention. Detailed Implementation

[0061] The present invention will be further illustrated below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.

[0062] Unless otherwise specified, all reagents and materials used in the following examples are commercially available.

[0063] This invention provides a method for evaluating the high-temperature service performance of road maintenance paving materials, comprising:

[0064] S1. Mold asphalt mixture specimens of different sizes according to the design mix proportions;

[0065] S2. Spread the road maintenance paving material to be tested evenly on the surface of the precast asphalt mixture specimen, and compact it with a roller roller. After the specimen is kept at a constant temperature and the strength is formed, mark the roller rolling direction on the surface of the specimen.

[0066] S3. Place the prepared pavement maintenance specimens into the pre-selected compaction equipment for dynamic compaction treatment. Once the predetermined service termination conditions are reached, record the number of compaction cycles experienced by the pavement maintenance material specimens.

[0067] S4. Based on the standard axle load cycle, the number of compaction cycles under the service termination condition is converted into service time;

[0068] S5. Based on the service time and the temperature range of the test, draw a scatter plot of test temperature-service time for the road maintenance pavement material specimens, and use the least squares method to fit a linear regression prediction equation for serviceability.

[0069] S6. Define and determine the ultimate service limit, temperature variability A, and ultimate service point t based on the service performance linear regression curve. 70 The evaluation index values, such as effective service volume S, were determined, and the high-temperature service performance of relevant road maintenance paving materials was analyzed and evaluated.

[0070] The evaluation method for high-temperature serviceability of road maintenance paving materials proposed in this invention is used, and the specific steps are as follows:

[0071] The modified asphalt mixture specimen design gradation adopted SMA-16 dense medium-grained discontinuous gradation. The raw materials used were SBS modified asphalt, coarse aggregates were basalt with a particle size of 3-19mm, fine aggregates were basalt with a particle size of 0-3mm, and mineral powder was finely ground limestone powder. 559kg of modified asphalt mixture specimen raw materials were weighed using a platform scale.

[0072] The weighed coarse and fine aggregates are placed in a metal pan and mixed evenly. The finely ground limestone powder is placed separately in a small basin and then heated in a 190℃ oven for later use. The SBS modified asphalt is weighed according to the mix proportion and then heated and kept warm in a 175℃ oven. A mixing machine with a capacity of more than 30L is used, and the temperature of the mixing machine is adjusted to 175℃.

[0073] Using a small shovel, transfer the coarse and fine aggregates from the metal pan into the mixing pot, then add SBS modified asphalt, and wipe the asphalt adhering to the asphalt tank with some hot stone powder, then pour it into the mixing pot together; set the mixing temperature to 175℃ and start the mixer, while stirring and adjusting the mixing blades to insert into the mixture for mixing, pause mixing after 1.5 minutes and pour in the hot stone powder, then continue mixing until the mixture is uniform.

[0074] The PETS release agent was evenly applied to the inner wall of the austenitic steel mold. Then, the mixed asphalt mixture was evenly spread in a clockwise direction from the edge to the center of the mold into a mold with dimensions of 120cm×120cm×15cm. The roller mill was set to a rolling temperature of 160℃ and a rolling load of 300N / cm. The mixture was then rolled into modified asphalt mixture specimens using the roller mill.

[0075] After compaction, the modified asphalt mixture specimens were placed at room temperature to cool for 12 hours. Epoxy resin coating curing paving material was evenly applied to the surface of the asphalt mixture specimens at a thickness of 2 cm. The specimen surface was leveled and placed in a ventilated area to dry for 24 hours. After the strength was fully developed, the compaction mold was removed, and the roller direction was marked on the surface of the specimens with an arrow using a white marker.

[0076] Use a tire inflator to inflate the hollow rubber tire until the tire pressure gauge reads 0.8 MPa.

[0077] Place the prepared epoxy resin coating curing paving material specimen into the rectangular clamp of the rigid test groove metal base in the rolling direction, and fix the clamp with screws; install the rut deformation measuring instrument on the opposite side of the specimen according to the horizontal indication position of the track (50mm interval, between 2 indicator needles).

[0078] Specifically, the rectangular clamp in the test chamber has dimensions of 120cm × 120cm × 15cm.

[0079] The MMLS3 accelerated loading device was lifted by a truck crane and placed into a small environmental temperature control chamber with dimensions of 290cm×150cm×130cm. Then, all air pipes, bottom and opening of the temperature control chamber were sealed and a hot air circulation heating system was installed. The hot air circulation heating system was started to control the test temperature value, so that the epoxy resin coating curing paving material specimens were preheated and kept at the test temperature for 3 hours.

[0080] Specifically, the four test temperatures were 40℃, 50℃, 60℃, and 70℃.

[0081] The MMLS3 accelerated loading instrument was set to a loading speed of 8 km / h and a load application period of 2 s. The MMLS3 accelerated loading instrument was then started to accelerate the wheel rolling loading of the epoxy resin coated curing paving material specimen.

[0082] Specifically, the MMLS3 test wheel is a single half-shaft wheel, consisting of four hollow rubber pneumatic tires with a diameter of 30cm. The pneumatic tires are 8cm wide, the loading width is 24cm, and the loading belt length is 2.4m.

[0083] When the surface of the epoxy resin coating curing paving material specimen was observed, longitudinal strip-shaped grooves with a depth of 2mm to 5mm appeared on the specimen surface under the action of the rubber wheel, and the sides of the rubber wheel showed raised deformation. The acceleration of the wheel rolling was stopped.

[0084] After stopping the roller rolling, draw a table of test temperature and number of rolling cycles for the epoxy resin coated paving material specimens, and record the number of rolling cycles at the test temperature.

[0085] The MMLS3 accelerated loading device was lifted by a truck crane. After the specimen cooled for 30 minutes at room temperature, the screws of the rectangular clamp were removed, the specimen was removed, and the next specimen was installed in the rectangular clamp of the test slot. The accelerated wheel rolling loading was repeated under the same test conditions until the accelerated wheel rolling loading of all test temperatures was completed and the rolling number data of all test temperatures were recorded.

[0086] According to the conversion formula: service time = number of compaction cycles / (3600 * load cycle), the number of compaction cycles at different test temperatures is converted into service time.

[0087] The rolling count and service time data of epoxy resin coated pavement material specimens and SBS modified asphalt mixture specimens (non-paved pavement material) are shown in Tables 1 and 2.

[0088] Table 1. Test Temperature, Number of Rolling Cycles, and Service Time of Epoxy Resin Coated Pavement Specimens

[0089] Test temperature / °C 40 50 60 70 Number of compaction cycles / times 6539332 548643 447528 325931 Service time / h 90.8 76.2 62.2 45.3

[0090] Table 2 Test Temperature, Number of Compactions, and Service Time of SBS Modified Asphalt Mixture Specimens

[0091] Test temperature / °C 40 50 60 70 Number of compaction cycles / times 603496 462598 346315 239056 Service time / h 83.8 64.2 48.1 33.2

[0092] Based on the service time and the temperature range of the test, the test temperature-service time scatter plot of the road maintenance paving material specimen was plotted using the mathematical analysis software Matlab. The best fit was determined by the least squares method to form the serviceability linear regression prediction equation y=Ax+b.

[0093] In step S6 of the method for evaluating the high-temperature serviceability of road maintenance paving materials provided by this invention, the temperature change rate A is defined as the slope of the limit service regression function curve y = Ax + b; the limit service point t 70 Defined as the function value y corresponding to the limit service limit y=Ax+b at a test temperature of 70℃; the effective service product S is defined as the limit value of the integral of the limit service limit regression function curve y=Ax+b over the temperature range [40, 70], and the calculation formula is as follows:

[0094]

[0095] Based on the definitions of the high-temperature service performance evaluation indicators mentioned above, the values ​​of three evaluation indicators were calculated. On this basis, the high-temperature service performance of epoxy resin coated curing paving materials was accurately analyzed and evaluated. The results are shown in Table 3. Figure 4 As shown.

[0096] Table 3 Evaluation index values ​​for high-temperature service performance of epoxy resin coated pavement material specimens and SBS modified asphalt mixture specimens.

[0097]

[0098] According to Table 1, Table 2, Table 3 and Figure 4 The results show that the linear regression prediction equation for the serviceability of the epoxy resin coated pavement material specimen is y = -1.51x + 151.5. Therefore, the temperature change rate A of the epoxy resin coated pavement material specimen is -1.51, and the ultimate service point t is... 70 The effective service area S is 2058.3, with a service life of 46.0 h. The linear regression prediction equation for the serviceability of the SBS modified asphalt mixture specimen is y = -1.68x + 149.74. Therefore, the temperature change rate A of the SBS modified asphalt mixture specimen is -1.68, and the ultimate service point t is... 70 The effective service volume S is 1720.2, with a time of 32.1 hours.

[0099] Compared with unpaved pavement material specimens (SBS modified asphalt mixture specimens), epoxy resin coated pavement material specimens showed higher temperature change rate (A) and lower service limit (t). 70 The effective service area (S) of the epoxy resin-coated pavement specimens was larger than that of the SBS modified asphalt mixture specimens. This indicates that, on the one hand, applying a certain thickness of epoxy resin curing pavement layer can extend the service life of asphalt pavements and improve pavement durability; on the other hand, the service life of the epoxy resin-coated pavement specimens varied less under different ambient temperatures, making them more stable under extreme conditions and more suitable for use in high-temperature summer road sections. Therefore, the epoxy resin-coated pavement material exhibits superior high-temperature service performance.

[0100] In summary, the present invention provides a method for evaluating the high-temperature service performance of road maintenance paving materials, which can accurately and scientifically evaluate the maintenance paving materials.

[0101] The above-described embodiments are preferred embodiments for ease of understanding of the present invention. However, the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for evaluating the high-temperature service performance of road maintenance paving materials, characterized in that, include: S1. Mold asphalt mixture specimens of different sizes according to the design mix proportions; S2. Spread the road maintenance paving material to be tested evenly on the surface of the precast asphalt mixture specimen, and compact it with a roller roller. After the specimen is stored at a constant temperature and the strength is formed, mark the roller rolling direction on the surface of the specimen. S3. Place the prepared pavement maintenance specimens into the pre-selected compaction equipment for dynamic compaction treatment. Once the predetermined service termination conditions are reached, record the number of compaction cycles experienced by the pavement maintenance material specimens. S4. Based on the standard axle load cycle, the number of compaction cycles under the service termination condition is converted into service time; S5. Based on the service time and the temperature range of the test, draw a scatter plot of test temperature-service time for the road maintenance pavement material specimens, and use the least squares method to fit a linear regression prediction equation for serviceability. S6. Define and determine the ultimate service limit, temperature variability A, and ultimate service point t based on the service performance linear regression curve. 70 The effective service volume S evaluation index value was determined, and the high-temperature service performance of relevant road maintenance paving materials was analyzed and evaluated. The conversion of the number of compaction cycles under service termination conditions into service time based on the standard axle load cycle is as follows: Draw a table of test temperature and maximum number of compaction cycles for the maintenance pavement material specimens, record the test data of the number of compaction cycles at different test temperatures, and convert the number of compaction cycles at different test temperatures into service time according to the conversion relationship. The conversion formula is as follows: Service life = Number of compaction cycles / (3600 * load cycle); The definition and determination of the ultimate service limit, temperature change rate A, and ultimate service point t are based on the serviceability linear regression curve. 70 The effective service volume S evaluation index value was determined, and the high-temperature service performance of relevant road maintenance paving materials was analyzed and evaluated, specifically: The ultimate service limit is defined as the dynamic stability of the pavement material specimen under different test temperatures being less than 1000 cycles / mm, or the appearance of ruts 2mm to 5mm deep on the surface of the pavement material, or the service time corresponding to the bonding of the binder in the pavement material to the contact surface of the load wheel being fitted into a corresponding function curve. The temperature change rate A is defined as the slope of the extreme service regression function curve; The extreme service point t 70 Defined as the function value corresponding to the ultimate service limit when the test temperature of the road maintenance pavement material specimen is 70℃; The effective service product S is defined as the limit value of the integral of the limit service boundary regression function curve over the temperature range [40, 70], and the calculation formula is as follows: ； Where (Ax+b) is the serviceability linear regression prediction equation; A is the slope of the line, i.e., the temperature change rate; and b is the intercept of the line.

2. The evaluation method according to claim 1, characterized in that, Step S1, which involves molding asphalt mixture specimens of different sizes according to the design mix proportion, specifically includes: The gradation types of the asphalt mixture specimens include dense gradation, semi-open gradation, and open gradation; The asphalt mixture specimens are 30cm×30cm×5cm, 60cm×60cm×10cm, and 90cm×90cm×15cm in size. The preparation method of the asphalt mixture specimen is as follows: weigh coarse and fine aggregates and mineral powder according to the design gradation, place them in a clean container, and keep them warm in a 190℃ oven for later use; then weigh asphalt according to the mix proportion, and select the heating temperature according to the asphalt type for heating and heat preservation; transfer the pre-mixed coarse and fine aggregates to a mixing pot, then add hot asphalt, adjust the mixing blades to insert into the mixture for mixing, and finally pour in hot mineral powder and continue mixing until the mixture is evenly mixed; apply a layer of release agent to the inner wall of the vibratory compaction mold, pour the evenly mixed modified asphalt mixture evenly into the compaction mold in a clockwise direction from the edge to the center, set the compaction temperature, and compact the specimen.

3. The evaluation method according to claim 2, characterized in that, The binder is selected from base asphalt or modified asphalt, the aggregate is selected from basalt or diabase aggregate, and the mineral powder is selected from limestone powder; the release agent is selected from dimethyl silicone oil emulsion or PETS release agent or zinc stearate emulsion; the vibratory compaction mold is selected from martensitic steel, ferritic steel or austenitic steel.

4. The evaluation method according to claim 1, characterized in that, Step S2 involves evenly spreading the road maintenance paving material to be tested on the surface of a precast asphalt mixture specimen, compacting it using a roller roller, storing it at a constant temperature, and marking the roller roller direction on the specimen surface after the specimen has developed strength. Specifically: A layer of 1-3 cm thick or a unit paving rate of 0.5 kg / m² is laid on the surface of the prepared asphalt mixture specimen. 2 -1.2 kg / m 2 The road maintenance paving material was formed using a standard axle load roller and then placed in a ventilated place to dry for 48 hours. After the strength was fully developed, the rolling mold was removed and the rolling direction was marked with a white marker.

5. The evaluation method according to claim 1, characterized in that, Step S3 involves placing the prepared pavement maintenance specimens into pre-selected compaction equipment for dynamic compaction. Once the predetermined service termination conditions are met, the number of compaction cycles experienced by the pavement maintenance material specimens is recorded. Specifically: Place the prepared pavement maintenance material specimens into the rectangular clamps of the metal base of the test trough according to the rolling direction, and fix them with screws. Then, install the deformation measurement sensors according to the horizontal position indicated by the track. Use a crane to lift the rolling instrument and equipment into the temperature-controlled chamber, seal all air pipes, bottom and opening of the temperature-controlled chamber, and turn on the heating system to control the test environment temperature, so that the pavement maintenance material specimens are preheated and kept at the test temperature for 3-6 hours. Set the loading speed, load cycle, and loading pressure index of the compaction equipment, and accelerate the rolling of the pavement material specimens. When the test reaches the service termination condition, the accelerated rolling test is ended, and the corresponding number of rolling times is recorded. The service termination conditions are: the dynamic stability of the pavement material specimen is less than 1000 times / mm, or the surface of the pavement material has ruts 2mm to 5mm deep, or the binder in the pavement material is obviously adhered to the contact surface of the load wheel. The compaction equipment includes any one of the following: MMLS3 accelerated loading tester, ALF large full-scale accelerated loading device, HVS heavy-duty vehicle simulator, or MLS mobile load simulator. The heating system is selected from a hot air circulation heating system, an infrared heater, or a combination of infrared and hot air heaters. The environmental temperature control chamber is a constant temperature chamber constructed from a small environmental temperature control box or a canvas insulated cover or insulated material. The roller temperature values ​​are selected as 40℃, 50℃, 60℃, and 70℃, the loading pressure is set to 0.6~0.8Mpa, and the unidirectional loading speed of the compaction instrument is 6~9km / h.

6. The evaluation method according to claim 1, characterized in that, Step S5 describes plotting a scatter plot of test temperature versus service time for road maintenance pavement material specimens based on service time and the tested temperature range, and then using the least squares method to fit a linear regression prediction equation for serviceability, specifically: A scatter plot of test temperature-service time was plotted using mathematical analysis software for the maintenance paving material specimens. Based on the least squares calculation principle and the linear equation y=Ax+b, the scatter plot was fitted to form the optimal serviceability linear regression prediction curve. The mathematical analysis software can be any one of Excel, Matlab, Mathematica, and SPSS.

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