Aggregate and asphalt interface self-healing evaluation method and system

Abstract

The invention discloses an aggregate and asphalt interface self-healing evaluation method and system, and the method comprises the steps: respectively manufacturing limestone, granite and basalt aggregate test pieces, constructing a dynamic shear rheological test platform, testing the self-healing properties of asphalt interfaces with different lithology by using a dynamic shear rheometer, and evaluating the self-healing properties of the asphalt interfaces in a fatigue-intermittent-fatigue load mode. Parameters such as dynamic shear modulus and loading times are measured at intermittent time, and evaluation is performed by using self-healing indexes, so that not only can the influence of different lithologic aggregates on the asphalt interface interaction be judged, but also the self-healing capability of asphalt under different adhesion conditions, stress states, temperatures and damage conditions can be accurately evaluated, and the evaluation accuracy is improved. The optimal self-healing temperature and adaptive aggregate are obtained; in addition, the aggregate test piece can be used for evaluating the rheological properties of different types of asphalt and aggregate, and provides a basis for screening the optimal asphalt mixture under different traffic volumes and vehicle-mounted environments.

Description

Technical Field

[0001] The present invention relates to the technical field of road engineering, and in particular to a method and system for evaluating the self-healing property of an aggregate and asphalt interface. Background Art

[0002] In recent years, with the rapid development of my country's road traffic industry, various forms of damage have occurred to a considerable extent on the road surface under the increasing traffic pressure; during its service life, the road not only has to withstand the repeated effects of pulling, pressing and shearing of vehicle loads, but also is affected by changes in ambient temperature; under the coupling effect of the above two, the asphalt pavement structure is easily damaged by cracking, which greatly reduces the service life of the asphalt pavement and seriously affects driving safety.

[0003] Asphalt is the main material of asphalt pavement. It has strong healing ability due to its diffusion flow ability. Asphalt mixture used for paving pavement also has self-healing ability, and the self-healing ability of asphalt mixture is closely related to the self-healing property of asphalt. There are two common types of self-healing mechanisms in asphalt concrete, namely adhesion healing and cohesive healing; cohesive healing is the healing process of microcracks in asphalt, while adhesion healing is a healing mechanism that occurs when the adhesive-aggregate interface is debonded.

[0004] In recent years, domestic and foreign scholars have conducted a lot of research on the self-healing properties of asphalt, and verified it through tensile tests, dynamic shear rheology, and atomic force microscopy; for example, CN107422034B (an asphalt-aggregate interface fatigue test method based on ultrasonic method, published on 2020-03-31), CN114563284A (an asphalt-aggregate interface damage and self-healing effect evaluation method, published on 2022-05-31), however, these evaluation methods are to infer the self-healing properties of asphalt through macroscopic and microscopic methods, such as obtaining asphalt- The maximum bonding force of the aggregate interface unifies the interface bonding force and fatigue characteristics, and studies and analyzes their internal relationship on the basis of obtaining the maximum interface bonding force, or measures the contact angles between distilled water, n-heptane, glycerol with known surface energy and asphalt and aggregate, calculates the surface energy of asphalt and aggregate, and then calculates the Gibbs free energy of asphalt, water, and aggregate to determine the degree to which the asphalt mixture is susceptible to water damage, measures the surface energy parameters of asphalt and aggregate after heating and self-repair by repair agent, and evaluates the self-repair effect. The effect of aggregate-asphalt interface interaction on the self-healing property of asphalt specimens is not considered, and the self-healing property of aggregate-asphalt adhesion interface is ignored.

[0005] Therefore, there is an urgent need for an evaluation method for the self-healing performance of asphalt interfaces based on different lithologies. Summary of the invention

[0006] Purpose of the invention: In order to overcome the above shortcomings, the purpose of the present invention is to provide a method for evaluating the self-healing property of the aggregate and asphalt interface, which can better evaluate the influence of different lithologies on the self-healing property of the asphalt interface, and use a dynamic shear rheometer to perform a time scanning test on the asphalt mixture to obtain the complex shear modulus of the asphalt mixture. -Time t curve diagram, based on which the self-healing property of aggregate-asphalt is evaluated; and the self-healing performance of asphalt mixture under different temperatures and fatigue conditions is further calculated, which is of great significance for extending and improving the fatigue life of asphalt mixture.

[0007] In order to solve the above technical problems, the present invention provides a method for evaluating the self-healing property of the aggregate and asphalt interface, comprising: Step S1: preparing a first aggregate specimen and a second aggregate specimen; Step S2: installing the first aggregate specimen and the second aggregate specimen in a dynamic shear rheometer respectively, and placing the center points of the first aggregate specimen and the second aggregate specimen on the same center extension line; Step S3: preheating the first aggregate specimen and the second aggregate specimen to a preset temperature and placing an asphalt sample between the first aggregate specimen and the second aggregate specimen, thereby pressing a target film thickness and forming an asphalt mixture with the first aggregate specimen and the second aggregate specimen, and placing the mixture for a first preset time; Step S4: evaluating the self-healing performance of the asphalt-aggregate interface of the asphalt mixture according to the dynamic shear modulus-load action times and dynamic shear modulus-time curves generated by scanning the asphalt mixture with a dynamic shear rheometer and in combination with the self-healing index.

[0008] As a preferred embodiment of the present application, in step S1, the method further comprises the following steps: Step S11: using a plurality of rocks of different lithology to prepare a first aggregate specimen and a second aggregate specimen, and polishing the first aggregate specimen and the second aggregate specimen into a mirror surface; Step S12: cutting the first aggregate specimen and the second aggregate specimen to a preset thickness and making the cut first aggregate specimen and the second aggregate specimen into cylindrical specimens.

[0009] As a preferred embodiment of the present application, in step S2, the method further comprises the following steps: Step S21: fixing the first connection base and the second connection base to the first clamp and the second clamp of the dynamic shear rheometer respectively; Step S22: The first aggregate piece is fixedly connected to the first connection base by applying epoxy resin to form a first component, and the second aggregate piece is fixedly connected to the second connection base by applying epoxy resin to form a second component; Step S23: leaving the first component and the second component to stand for a second preset time for curing; Step S24: adjusting the first component and the second component after solidification to be coaxial and installing the first component and the second component into a dynamic shear rheometer.

[0010] As a preferred embodiment of the present application, in step S3, the method further comprises the following steps: Step S31: performing preset calibration on the dynamic shear rheometer; Step S32: adjusting the first component and the second component to a first temperature value by a dynamic shear rheometer; Step S33: placing the asphalt sample on the second component and using the first component to extrude the asphalt sample to a preset thickness; Step S34: After the preset extrusion time, the temperature of the first component and the second component is adjusted to a second temperature value, the asphalt sample is trimmed and shaped, and left to stand for a first preset time.

[0011] As a preferred embodiment of the present application, the asphalt sample is a cylinder, and the first bottom diameter and the second bottom diameter of the asphalt sample are equal.

[0012] As a preferred method of the present application, in step S4, when preparing the asphalt sample, the base asphalt is placed in an oven, baked into a fluid state at a preset temperature, and then taken out and poured into a silicone mold to form an asphalt sample; wherein the asphalt sample is a cylinder, and the bottom diameter of the asphalt sample is equal to the bottom diameter of the first aggregate specimen and the second aggregate specimen, respectively.

[0013] As a preferred embodiment of the present application, in step S4, the method further comprises the following steps: Step S41: performing time scanning tests on asphalt samples at different temperatures respectively to obtain complex shear modulus-time curves of asphalt mixtures at different temperatures; Step S42: for each target temperature, the relationship between the initial modulus and time before and after placement is obtained, and the self-healing index at the temperature is obtained according to calculation; Step S43: judging the self-healing performance of the asphalt-aggregate interface according to the self-healing index.

[0014] As a preferred embodiment of the present application, limestone, granite and basalt are used to prepare the first aggregate specimen and the second aggregate specimen.

[0015] As a preferred embodiment of the present invention, the method further includes the following method: The effects of different lithologic aggregates on the self-healing properties of asphalt interfaces were evaluated based on the degree of recovery of the complex shear modulus before and after placement; The self-healing of the asphalt specimens was evaluated by combining the complex shear modulus and time: in, As a self-healing indicator, is the initial dynamic shear modulus of asphalt after first loading, is the dynamic shear modulus when the first loading stops, is the initial dynamic shear modulus of asphalt after loading after healing, and t is the healing curing time; Dynamic shear modulus of asphalt after healing Reduce to Loading time, 2 is the dynamic shear modulus of asphalt before healing Reduce to Loading time.

[0016] The present application also provides an aggregate and asphalt interface self-healing evaluation system for executing the evaluation method, comprising: A dynamic shear rheometer, used to measure the self-healing performance of an asphalt mixture, comprising a first clamp and a second clamp; A connection assembly, comprising a first connection base and a second connection base, wherein the first sample is installed in the first fixture through the first connection base, and the second sample is installed in the second fixture through the second connection base; A control unit comprising: A pre-measurement module, used for preheating the first aggregate specimen and the second aggregate specimen to a preset temperature and placing an asphalt sample between the first aggregate specimen and the second aggregate specimen, thereby pressing a target film thickness and forming an asphalt mixture with the first aggregate specimen and the second aggregate specimen, and placing the mixture for a first preset time; The self-healing measurement module is used to evaluate the self-healing performance of the asphalt-aggregate interface of the asphalt mixture based on the dynamic shear modulus-load number and dynamic shear modulus-time curve generated by scanning the asphalt mixture with a dynamic shear rheometer and combined with the self-healing index.

[0017] The above technical solution of the present application has the following advantages compared with the prior art: 1. Complex shear modulus obtained by dynamic shear rheometer -Time t curve chart can accurately determine the self-healing time of aggregate and asphalt. It is applicable to asphalt mixtures under different temperatures and damage conditions, providing more accurate self-healing evaluation.

[0018] 2. It can determine the optimal self-healing temperature under different temperature conditions, especially for the evaluation of the self-healing effect under high temperature conditions in summer, which provides a basis for the study of the influence of temperature on the self-healing property of asphalt pavement and helps to predict the performance of asphalt pavement in actual use.

[0019] 3. It can effectively evaluate the impact of different ambient temperatures on the self-healing ability of pavement cracks, provide guidance for optimizing pavement durability, and then accurately evaluate the differences in the self-healing performance of asphalt interfaces with different rock aggregates, optimize the selection of aggregates and asphalt, and improve the overall fatigue resistance and durability of asphalt pavements. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0021] Figure 1 It is a flow chart of a method for evaluating the self-healing properties of the aggregate and asphalt interface provided by an embodiment of the present invention.

[0022] Figure 2 It is a schematic diagram of an asphalt mixture provided by an embodiment of the present invention installed in a dynamic shear rheometer.

[0023] Figure 3 It is a schematic diagram of the aggregate-asphalt-aggregate interlayer provided in an embodiment of the present invention.

[0024] Figure 4 It is a schematic diagram of the self-healing performance of three types of aggregates under the conditions of a temperature of 25° C. and damage degrees of 20%, 40%, and 60% provided by an embodiment of the present invention.

[0025] Figure 5 It is a schematic diagram of the self-healing performance of the aggregate at different temperatures under the conditions of a damage degree of 20% and an interval time of 60 minutes provided by an embodiment of the present invention.

[0026] Figure 6 It is a schematic diagram of fatigue-intermittent-fatigue load loading provided by an embodiment of the present invention.

[0027] Figure 7 is the complex shear modulus of the asphalt mixture provided by the embodiment of the present invention - Schematic diagram of the time t curve.

[0028] Figure 8 Schematic diagram of the root mean square roughness of three aggregates provided in an embodiment of the present invention.

[0029] Fig. 9It is a schematic diagram of the arithmetic mean heights of three types of aggregates provided in an embodiment of the present invention.

[0030] Fig.10 It is a schematic diagram of the self-healing index HI-time t of the three aggregates provided in the embodiment of the present invention at a temperature of 25° C. and a damage degree of 20%.

[0031] Description of the Figures in the Specification: 11. First clamp, 12. Second clamp, 21. First connecting base, 22. Second connecting base, 31. First aggregate specimen, 32. Second aggregate specimen, 41. First component, 42. Second component, 50. Asphalt specimen, 61. Bolt and nut connection of first connecting base, 62. Bolt and nut connection of second connecting base. DETAILED DESCRIPTION

[0032] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0033] refer to Figure 1 As shown, in some embodiments, the method for evaluating the self-healing property of the aggregate and asphalt interface involves the following steps: Step S1: preparing aggregate specimens, wherein the aggregate specimens include a first aggregate specimen 31 and a second aggregate specimen 32 that are completely identical.

[0034] Specifically, when preparing the first aggregate specimen 31 and the second aggregate specimen 32, firstly, the required aggregate plate is provided, and the aggregate plate is preliminarily polished by a grinder until the surface is smooth. Then, the aggregate plate is polished by a polishing device to ensure that the surface reaches a mirror effect to eliminate any surface roughness and ensure accuracy in subsequent tests.

[0035] In some embodiments of the present application, the aggregate plate is prepared using three different rock types: granite, limestone, and basalt.

[0036] Next, use a cutting machine to cut the polished aggregate plate. When cutting, ensure that the aggregate plate has a uniform thickness and a flat edge. Fix the cut aggregate plate on the coring machine to ensure that it is firmly fixed to prevent deviation during drilling. Perform drilling operations on the aggregate plate. During drilling, the drill bit should be kept at a vertical angle to avoid angle deviation affecting the shape accuracy of the specimen. For example, the reference thickness of the aggregate plate after cutting in this application is 2 mm, and the bottom diameter of the cylindrical aggregate specimen is 8 mm. The thickness and bottom diameter can be set and adjusted by the operator according to actual needs. This is an example.

[0037] After the preparation is completed, the first aggregate specimen 31 and the second aggregate specimen 32 are numbered and stored so as to be distinguished in subsequent experimental operations.

[0038] Step S2: Install the first aggregate specimen 31 and the second aggregate specimen 32 in the dynamic shear rheometer 100, and perform position fine-tuning in the zero calibration mode to locate the center points of the first aggregate specimen 31 and the second aggregate specimen 32 on the same center extension line.

[0039] Specifically, in step S2, the method comprises the following steps: Step S21: The first connection base 21 and the second connection base 22 are fixedly connected to the first clamp 11 and the second clamp 12 of the dynamic shear rheometer 100 respectively.

[0040] Specifically, refer to Figure 2 As shown, the first connecting base 21 and the second connecting base 22 are respectively installed in the first clamp 11 and the second clamp 12 of the dynamic shear rheometer 100, and then the first connecting base 21 and the second connecting base 22 are respectively fixed in the first clamp 11 and the second clamp 12 by fasteners; illustratively, the first connecting base 21 and the second connecting base 22 are completely identical cylindrical structures, which are adjusted to maintain coaxiality after installation, thereby ensuring consistency and accuracy of measurement.

[0041] Step S22: The first aggregate piece is fixedly connected to the first connection base 21 by applying epoxy resin to form a first component 41, and the second aggregate piece is fixedly connected to the second connection base 22 by applying epoxy resin to form a second component 42.

[0042] Specifically, when the dynamic shear rheometer 100 is in the zero correction mode, the aggregate specimen is installed on the connection base. The specific installation process is to evenly apply an appropriate amount of epoxy resin on the bottom surface of the first aggregate specimen 31, and align and connect it with the first connection base 21 to ensure coaxial alignment to form a first component 41; similarly, epoxy resin is applied to the bottom surface of the second aggregate specimen 32, and it is aligned and connected with the second connection base 22 to ensure coaxial alignment to form a second component 42. During alignment, the position is fine-tuned by setting the zero gap to ensure that the aggregate specimen is concentrically and coaxially set with the connection base, ensuring that the aggregate specimen will not produce errors due to eccentricity in subsequent tests.

[0043] In actual operation, it is preferred to use a connection base with the same diameter as the bottom surface of the aggregate specimen, that is, the bottom surface diameters of the first connection base 21 and the second connection base 22 are respectively equal to the bottom surface diameters of the first aggregate specimen 31 and the second aggregate specimen 32. This design can ensure that the base and the specimen are fully aligned and reduce test errors. Furthermore, the bottom surface diameter of the connection base can also be slightly larger than the bottom surface diameter of the aggregate specimen to ensure the stability of the connection.

[0044] Step S23: leaving the first component 41 and the second component 42 to stand for a time set by the operator to solidify.

[0045] Among them, the static curing time is set by the operator according to actual needs. In the actual implementation process, after the epoxy resin is initially hardened, the first component 41 and the second component 42 are taken out of the dynamic shear rheometer 100 and placed on a horizontal work surface. Keep it still for 24 hours until the epoxy resin is completely cured. During the curing process, avoid any external force interference to ensure the integrity and firmness of the epoxy resin connection.

[0046] Step S24 : adjusting the first component 41 and the second component 42 after solidification to be coaxial and installing the first component 41 and the second component 42 into the dynamic shear rheometer 100 .

[0047] Specifically, after the epoxy resin is completely cured, the connected first component 41 and the second component 42 are reinstalled into the first clamp 11 and the second clamp 12 of the dynamic shear rheometer 100, and the first component 41 and the second component 42 are re-fine-tuned to be coaxial with the first clamp 11 and the second clamp 12 respectively to reduce the test error.

[0048] Step S3: preheating the first aggregate specimen 31 and the second aggregate specimen 32 to a preset temperature and placing an asphalt sample between the first aggregate specimen 31 and the second aggregate specimen 32, thereby pressing the target film thickness and forming an asphalt mixture with the first aggregate specimen 31 and the second aggregate specimen 32, and placing it for a first preset time.

[0049] Specifically, first, the dynamic shear rheometer 100 is fully calibrated, including inertia calibration, motor calibration and zero calibration, to ensure the accuracy of the instrument during the test and avoid affecting the test results due to equipment errors.

[0050] After the calibration is completed, the installed first aggregate specimen 31 and the second aggregate specimen 32 are heated by the heating device provided in the dynamic shear rheometer 100. The heating temperature is set according to the high temperature grade of the asphalt. In this embodiment, No. 70 base asphalt is used and the selected heating temperature is 45°C to ensure uniform surface temperature of the aggregate.

[0051] The pre-prepared asphalt specimen 50 is placed on the surface of the second aggregate specimen 32; in the specific operation, firstly, the No. 70 base asphalt is placed in an oven and heated to a fluid state at 150°C, and then the fluidized asphalt is poured into a silicone mold and cooled to form a cylindrical asphalt specimen 50; to ensure the consistency of the test, the bottom diameters D1 and D2 of the asphalt specimen 50 are respectively the same as the bottom diameters of the aggregate specimens.

[0052] After the asphalt test piece 50 is placed on the second aggregate test piece 32, the first aggregate test piece 31 is adjusted to squeeze the asphalt test piece 50 downwards for preliminary shaping, and then scraped to the desired scraping film thickness; then, the first aggregate test piece 31 is further adjusted to squeeze the asphalt test piece 50 to reach a preset target thickness; in this embodiment, the target thickness reference is 2 mm. In this process, the first aggregate test piece 31, the second aggregate test piece 32 and the asphalt test piece 50 are in close contact to form an asphalt mixture.

[0053] The asphalt mixture after forming needs to be cooled to the set test temperature. After closing the hatch of the environmental chamber, the mixture is placed at the test temperature for curing for 15 minutes. The test temperature selected in this embodiment is 25°C, but according to different test conditions, the temperature can be selected from 25°C, 35°C, 45°C or 55°C. Under medium temperature (25°C to 45°C), an aggregate specimen with a diameter of 8 mm is used for testing; under high temperature (55°C), an aggregate specimen with a diameter of 25 mm is used instead. In this experiment, 25°C is used as the test temperature for subsequent dynamic shear rheology testing.

[0054] Therefore, reference Figure 3 Schematic diagram of forming aggregate-asphalt-aggregate interlayer.

[0055] Step S4: evaluating the self-healing performance of the asphalt-aggregate interface of the asphalt mixture according to the dynamic shear modulus-load action times and dynamic shear modulus-time curves generated by scanning the asphalt mixture by the dynamic shear rheometer 100 and combining with the self-healing index.

[0056] Specifically, before conducting a time sweep test, it is first necessary to perform a stress or strain scan on the asphalt mixture using a dynamic shear rheometer 100 to determine appropriate strain and stress application parameters and provide accurate experimental conditions for subsequent time sweep tests to ensure the reliability and repeatability of the test data.

[0057] After determining the appropriate strain and stress parameters, the dynamic shear rheometer 100 is used to perform a time scan test on the asphalt mixture. In this embodiment, the strain is controlled to be 6% and the frequency is set to 10 Hz. Under this condition, the complex shear modulus of the asphalt mixture is Conduct time scan experiments, record and plot −t curve diagram, reflecting the trend of complex shear modulus of different aggregate-asphalt mixtures changing with time.

[0058] After the test, according to The self-healing index of the aggregate-asphalt interface is calculated by the −t curve graph. The self-healing index can be calculated by the self-healing index formula, which specifically reflects the self-healing performance of the asphalt-aggregate interface under different lithology aggregates. This embodiment can evaluate the influence of aggregates on the self-healing of the asphalt interface by comparing the self-healing performance of different aggregates and asphalt.

[0059] The obtained self-healing index is combined with the damage degree to draw a self-healing index-damage degree curve. Through this curve, the self-healing performance of different aggregate-asphalt interfaces under the same damage state can be intuitively judged; for example, refer to Figure 4 As shown in the figure, by evaluating three aggregates (limestone, basalt, and granite) with damage degrees of 20%, 40%, and 60% at 25°C, it was found that the self-healing performance of the limestone-asphalt interface was the best, followed by basalt, and granite was relatively poor.

[0060] Under different temperature conditions, the self-healing performance of aggregate-asphalt interface is different; Figure 5 As shown in the figure, under the medium temperature conditions of 25℃, the damage degree of 20% and the intermittent time of 60min, the self-healing performance of the limestone-asphalt interface is better than that of the granite and basalt interfaces. As the temperature increases, the self-healing performance of the basalt and granite interfaces gradually becomes better than that of the limestone interface. This is related to the mineral composition and surface roughness of the aggregate. The strong polar minerals such as CaCO3 in the limestone improve their adhesion with asphalt through chemical adsorption at medium temperature, showing better self-healing properties.

[0061] Under high temperature conditions, as hot asphalt flows into the pores and textures on the aggregate surface, the contact area with the aggregate surface increases and the adhesion is enhanced, making the self-healing performance of the basalt and granite interface surpass that of limestone under high temperature conditions. This indicates that the mineral composition and surface characteristics of different rock types have a significant effect on the self-healing performance of the aggregate-asphalt interface at different temperatures.

[0062] Therefore, this application prepared three aggregate specimens of limestone, granite and basalt, constructed a dynamic shear rheology test platform, and used a dynamic shear rheometer to test the self-healing properties of asphalt interfaces with different rock types. According to the fatigue-intermittent-fatigue loading mode (reference Figure 6As shown in the figure, the dynamic shear modulus and the number of load actions and other parameters can be measured at intervals, and the asphalt self-healing index can be used for evaluation to determine the influence of the self-healing property of asphalt under different lithology conditions. The dynamic shear platform constructed by the present invention can not only determine the influence of aggregates of different lithology on the aggregate-asphalt interface interaction, but also accurately determine the self-healing property of asphalt under different adhesion conditions and the self-healing ability under different stress states, temperatures and different damage states, so as to obtain the best self-healing temperature under the influence of different lithology and the best-suited aggregate under different temperature conditions. In addition, the aggregate specimens used in this application can be applied to the rheology of different types of asphalt and aggregate specimens of different lithology, and can determine the self-healing ability of asphalt mixture under different damage states, and can screen the optimal asphalt mixture for different traffic volumes and vehicle-mounted environments.

[0063] In some embodiments, the self-healing property of the aggregate-asphalt interface can be evaluated by the degree of damage. To quantify the degree of interface damage, the calculation formula is: ;in: is the complex shear modulus after load damage, is the initial complex shear modulus.

[0064] In some embodiments, the mineral component is Figure 7 As shown by Figure 7 It can be seen that the mineral composition of the three aggregates is significantly different. The mineral composition of limestone is mainly calcite, which has strong adsorption properties, which helps to enhance the adhesion of asphalt on the interface and improve its self-healing properties. The mineral composition of aggregates can significantly affect the bonding ability of the interface with asphalt, thereby affecting its self-healing properties at different temperatures.

[0065] In some embodiments, the aggregate surface roughness can be measured by the arithmetic mean height and RMS roughness Other indicators are used to characterize, refer to Figure 8 and Fig. 9 As shown in the figure, aggregates with higher roughness, such as granite and basalt, have larger surface areas, and the bonding area with asphalt increases, which improves the total bonding force between the two. In comparison, limestone has a lower roughness, but its strong polar mineral components enhance the self-healing property of the interface. Under high temperature conditions, the liquid phase of asphalt is conducive to infiltration into the pores and microcracks on the surface of the aggregate. After cooling, the asphalt forms a gelled structure in the pores, producing a wedging and anchoring effect, thereby further enhancing the bonding force and self-healing ability of the aggregate-asphalt interface. This mechanism is particularly suitable for high temperature environments and can enhance the overall fatigue resistance of the interface.

[0066] In summary, the present invention provides a method for evaluating the self-healing property of the aggregate and asphalt interface, using a dynamic shear rheometer 100 to perform a time scanning test on an asphalt mixture to obtain the complex shear modulus of the asphalt mixture. -Time t curve diagram, the self-healing performance of aggregate and asphalt is evaluated according to the curve diagram, the curve diagram obtained by the aggregate and asphalt self-healing evaluation method provided by the present invention can accurately judge the self-healing time of aggregate and asphalt, and can also obtain the self-healing property of asphalt mixture under different temperature conditions and different damage states, and can judge the optimal self-healing temperature of different asphalt mixtures, which is of great significance for studying and improving the anti-fatigue performance of asphalt mixtures.

[0067] As shown in the reference figure, in some embodiments, it also relates to an aggregate and asphalt interface self-healing property evaluation system for executing the above-mentioned aggregate and asphalt interface self-healing property evaluation method, comprising: A dynamic shear rheometer 100, used for measuring the self-healing performance of an asphalt mixture, comprises a first clamp 11 and a second clamp 12; A connection assembly, comprising a first connection base 21 and a second connection base 22, wherein the first sample is installed in the first fixture 11 through the first connection base 21, and the second sample is installed in the second fixture 12 through the second connection base 22; A control unit comprising: A pre-measurement module is used to preheat the first aggregate specimen 31 and the second aggregate specimen 32 to a preset temperature and place an asphalt sample between the first aggregate specimen 31 and the second aggregate specimen 32, thereby pressing a target film thickness and forming an asphalt mixture with the first aggregate specimen 31 and the second aggregate specimen 32, and placing the mixture for a first preset time; The self-healing measurement module is used to evaluate the self-healing performance of the asphalt-aggregate interface of the asphalt mixture based on the dynamic shear modulus-load number and dynamic shear modulus-time curve generated by scanning the asphalt mixture by the dynamic shear rheometer 100 and combining it with the self-healing index.

[0068] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0069] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for evaluating the self-healing property of aggregate and asphalt interface, characterized in that: The following steps are involved: Step S1: preparing a first aggregate specimen and a second aggregate specimen; Step S2: installing the first aggregate specimen and the second aggregate specimen in a dynamic shear rheometer respectively, and placing the center points of the first aggregate specimen and the second aggregate specimen on the same center extension line; Step S3: preheating the first aggregate specimen and the second aggregate specimen to a preset temperature and placing an asphalt sample between the first aggregate specimen and the second aggregate specimen, thereby pressing a target film thickness and forming an asphalt mixture with the first aggregate specimen and the second aggregate specimen, and placing the mixture for a first preset time; Step S4: evaluating the self-healing performance of the asphalt-aggregate interface of the asphalt mixture according to the dynamic shear modulus-load action times and dynamic shear modulus-time curves generated by scanning the asphalt mixture with a dynamic shear rheometer and in combination with the self-healing index.

2. A method for evaluating the self-healing property of aggregate and asphalt interface according to claim 1, characterized in that: In step S1, the method further comprises the following steps: Step S11: using a plurality of rocks of different lithology to prepare a first aggregate specimen and a second aggregate specimen, and polishing the first aggregate specimen and the second aggregate specimen into a mirror surface; Step S12: cutting the first aggregate specimen and the second aggregate specimen to a preset thickness and making the cut first aggregate specimen and the second aggregate specimen into cylindrical specimens.

3. A method for evaluating the self-healing property of aggregate and asphalt interface according to claim 1 or 2, characterized in that: In step S2, the method further comprises the following steps: Step S21: fixing the first connection base and the second connection base to the first clamp and the second clamp of the dynamic shear rheometer respectively; Step S22: The first aggregate piece is fixedly connected to the first connection base by applying epoxy resin to form a first component, and the second aggregate piece is fixedly connected to the second connection base by applying epoxy resin to form a second component; Step S23: leaving the first component and the second component to stand for a second preset time for curing; Step S24: adjusting the first component and the second component after solidification to be coaxial and installing the first component and the second component into a dynamic shear rheometer.

4. A method for evaluating the self-healing property of aggregate and asphalt interface according to claim 3, characterized in that: In step S3, the method further comprises the following steps: Step S31: performing preset calibration on the dynamic shear rheometer; Step S32: adjusting the first component and the second component to a first temperature value by a dynamic shear rheometer; Step S33: placing the asphalt sample on the second component and using the first component to extrude the asphalt sample to a preset thickness; Step S34: After the preset extrusion time, the temperature of the first component and the second component is adjusted to a second temperature value, the asphalt sample is trimmed and shaped, and left to stand for a first preset time.

5. A method for evaluating the self-healing property of aggregate and asphalt interface according to claim 4, characterized in that: The asphalt sample is a cylinder, and the first bottom diameter and the second bottom diameter of the asphalt sample are equal.

6. A method for evaluating the self-healing property of aggregate and asphalt interface according to claim 4, characterized in that: In step S4, when preparing the asphalt sample, the base asphalt is placed in an oven, baked into a fluid state at a preset temperature, and then taken out and poured into a silicone mold to form an asphalt sample; wherein the asphalt sample is a cylinder, and the bottom diameter of the asphalt sample is equal to the bottom diameter of the first aggregate specimen and the second aggregate specimen, respectively.

7. The method for evaluating the self-healing property of the aggregate and asphalt interface according to claim 1, characterized in that: In step S4, the method further comprises the following steps: Step S41: performing time scanning tests on asphalt samples at different temperatures respectively to obtain complex shear modulus-time curves of asphalt mixtures at different temperatures; Step S42: for each target temperature, the relationship between the initial modulus and time before and after placement is obtained, and the self-healing index at the temperature is obtained according to calculation; Step S43: judging the self-healing performance of the asphalt-aggregate interface according to the self-healing index.

8. The method for evaluating the self-healing property of the aggregate and asphalt interface according to claim 2, characterized in that: Limestone, granite and basalt are used to prepare the first aggregate specimens and the second aggregate specimens.

9. A method for evaluating the self-healing property of aggregate and asphalt interface according to claim 8, characterized in that: The method also includes the following method: The effects of different lithologic aggregates on the self-healing properties of asphalt interfaces were evaluated based on the degree of recovery of the complex shear modulus before and after placement; The self-healing of the asphalt specimens was evaluated by combining the complex shear modulus and time: in, As a self-healing indicator, is the initial dynamic shear modulus of asphalt after first loading, is the dynamic shear modulus when the first loading stops, is the initial dynamic shear modulus of asphalt after loading after healing, and t is the healing curing time; Dynamic shear modulus of asphalt after healing Reduce to Loading time, 2 is the dynamic shear modulus of asphalt before healing Reduce to Loading time.

10. A system for evaluating the self-healing property of the aggregate-asphalt interface for executing the evaluation method according to any one of claims 1 to 9, characterized in that: include: A dynamic shear rheometer, used to measure the self-healing performance of an asphalt mixture, comprising a first clamp and a second clamp; A connection assembly, comprising a first connection base and a second connection base, wherein the first sample is installed in the first fixture through the first connection base, and the second sample is installed in the second fixture through the second connection base; A control unit comprising: A pre-measurement module, used for preheating the first aggregate specimen and the second aggregate specimen to a preset temperature and placing an asphalt sample between the first aggregate specimen and the second aggregate specimen, thereby pressing a target film thickness and forming an asphalt mixture with the first aggregate specimen and the second aggregate specimen, and placing the mixture for a first preset time; The self-healing measurement module is used to evaluate the self-healing performance of the asphalt-aggregate interface of the asphalt mixture based on the dynamic shear modulus-load number and dynamic shear modulus-time curve generated by scanning the asphalt mixture with a dynamic shear rheometer and combined with the self-healing index.

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