Method for analyzing compatibility of modified asphalt

Abstract

The invention discloses a modified asphalt compatibility analysis method which comprises the following steps: constructing an initial molecular model which comprises matrix asphalt and a modifier model; performing structure optimization on the initial molecular model, and constructing a modified asphalt unit cell model based on the initial molecular model after the structure optimization; performing NVT ensemble simulation on the modified asphalt unit cell model to obtain a molecular dynamics trajectory file; calculating key parameters of a phase field model based on the molecular dynamics trajectory file, wherein the key parameters comprise a migration coefficient and an interaction parameter; constructing a phase field model based on the key parameters; and carrying out transient research on the phase field model to obtain compatibility data of the modified asphalt changing along with time. According to the technical scheme, the phase change of the modified asphalt can be accurately tracked through modeling, energy minimization and mechanism analysis.

Description

Technical Field

[0001] The invention belongs to the technical field of material mixing compatibility characterization, and in particular relates to a modified asphalt compatibility analysis method. Background Art

[0002] In recent years, the transportation industry has developed rapidly, and the number of cars has been increasing. At the same time, due to the influence of the complex natural environment, the traditional paving binder matrix asphalt has poor road performance due to temperature sensitivity and other problems, which easily causes road rutting, cracks and other diseases. The cross-linking effect of polymers and asphalt can make the modified asphalt have excellent road performance, so polymers are widely used in asphalt modification. However, modified asphalt is prone to phase separation during storage, transportation and long-term use, that is, the polymer phase separates from the asphalt phase. When the modifier and asphalt have poor compatibility, the two phases are severely separated, which directly leads to the inability of polymer molecules to be well dispersed in the cross-linked network of the polymer, and the effect of improving the performance of asphalt cannot be achieved. Therefore, it is very important to study the storage stability between asphalt and polymer.

[0003] Traditionally, the storage stability of polymer modified asphalt is mainly evaluated by rheology, segregation experiments and microscopic observation experiments. However, the environment of modified asphalt is changeable during its preparation, and the experimental process is complicated and time-consuming, so it is impossible to accurately and quantitatively analyze the factors affecting the storage stability of the prepared modified asphalt. Some researchers have studied the influencing factors of asphalt compatibility from a microscopic perspective by studying molecular dynamics. This method avoids the cumbersome on-site experimental process and quantitatively or qualitatively analyzes the effect of a certain parameter of modified asphalt on its storage stability. Although this method deeply reveals the microscopic mechanism of the material, molecular dynamics simulation can usually only cover the time scale of nanoseconds to microseconds, while many actual physical and chemical processes (such as aging, changes in rheological properties, etc.) may take longer to appear. Phase field theory can make up for this shortcoming, simulate and construct the phase changes of polymer modified asphalt from a mesoscopic perspective, and fully reproduce the phase separation process of modified asphalt. However, previous studies always estimated phase field parameters through experimental results and could not construct an accurate phase field model. Therefore, current experimental methods are still difficult to accurately capture the phase changes of modified asphalt, and it is urgent to develop more accurate mesoscopic-scale modified asphalt compatibility characterization methods to provide theoretical guidance for the characterization methods of polymer solution compatibility. Summary of the invention

[0004] The purpose of the present invention is to provide a method for analyzing the compatibility of modified asphalt to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above object, the present invention provides a method for analyzing the compatibility of modified asphalt, comprising:

[0006] Constructing an initial molecular model, wherein the initial molecular model includes a matrix asphalt and a modifier model;

[0007] Structural optimization is performed on the initial molecular model, and a modified asphalt crystal cell model is constructed based on the structurally optimized initial molecular model;

[0008] Performing NVT ensemble simulation on the modified asphalt unit cell model to obtain a molecular dynamics trajectory file;

[0009] Calculating key parameters of the phase field model based on the molecular dynamics trajectory file, wherein the key parameters include a mobility coefficient and an interaction parameter;

[0010] constructing a phase field model based on the key parameters;

[0011] A transient study is conducted on the phase field model to obtain the compatibility data of the modified asphalt that varies with time.

[0012] Optionally, the constructing of the initial molecular model specifically includes:

[0013] Based on the preset periodic boundary conditions, the preset initial density of the shaping unit cell and the preset target density, the initial molecular models of the matrix asphalt and the modifier were constructed in combination with the Material Studio molecular dynamics software.

[0014] Optionally, the structural optimization of the initial molecular model specifically includes:

[0015] The initial molecular model is subjected to geometric optimization and annealing treatment to obtain a structurally optimized initial molecular model.

[0016] Optionally, the modified asphalt unit cell model is constructed based on the initial molecular model after structural optimization, specifically including:

[0017] The structure-optimized matrix asphalt and modifier models were placed into an amorphous unit cell and the periodic boundary conditions were maintained to obtain the unit cell model of the modified asphalt.

[0018] Optionally, the NVT ensemble simulation of the modified asphalt unit cell model specifically includes:

[0019] The modified asphalt model is geometrically optimized, and an NVT ensemble simulation is performed at a preset temperature to obtain a molecular dynamics trajectory file.

[0020] Optionally, the key parameters of the phase field model are calculated based on the molecular dynamics trajectory file, specifically including:

[0021] Analyze the cohesive energy density, mean square displacement and solubility parameters of the molecular dynamics trajectory file based on the Forcite module;

[0022] The cohesive energy density, mean square displacement and solubility parameter are converted into coefficients to obtain the key parameters.

[0023] Optionally, constructing a phase field model based on the key parameters specifically includes:

[0024] A geometric model is established in COMSOL Multiphysics software, random variables are added to the geometric model as initial values ​​of the phase field model to obtain an initial phase field model, and the key parameters are introduced into the initial phase field model to construct a free energy function and a phase field model.

[0025] Optionally, the transient study of the phase field model specifically includes:

[0026] The phase field model is divided into extremely fine grids, and a transient study is performed on the phase field model after the extremely fine grid division based on a preset time step and a preset tolerance to obtain the compatibility data of the modified asphalt that changes with time.

[0027] The technical effects of the present invention are:

[0028] In molecular dynamics, the present invention finds parameters that can be used for the phase field model of modified asphalt phase separation through modeling, energy minimization and mechanism analysis, accurately tracks the phase changes of modified asphalt, and the phase field model coupled with molecular dynamics parameters realizes the transition from estimating simulation parameters from experimental results to accurately predicting simulation results using simulation parameters. This innovative method is more efficient and accurate than the existing modified asphalt compatibility experimental method. The phase field model coupled with molecular dynamics parameters can more comprehensively and accurately simulate the behavior and characteristics of materials by integrating information at the microscopic and macroscopic scales, thereby enhancing the depth and breadth of research. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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 will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0031] Figure 1 1 is a schematic diagram of the compatibility analysis process of modified asphalt provided in an embodiment of the present invention;

[0032] Figure 2It is the molecular model of 50#SBS modified asphalt established in the embodiment of the present invention;

[0033] Figure 3 These are the results of the fluorescence microscope experiment and phase field simulation of the 50#SBS polymer modified asphalt in the embodiments of the present invention. DETAILED DESCRIPTION

[0034] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0035] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0036] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those of ordinary skill in the art generally understood by the present invention. Although the present invention describes only preferred methods, any method similar or equivalent to that described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0037] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present application description and examples are exemplary only.

[0038] The words “include,” “including,” “have,” “contain,” etc. used in this article are open-ended terms, meaning including but not limited to.

[0039] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0040] Embodiment 1

[0041] like Figure 1 - Figure 3 As shown, this embodiment provides a modified asphalt compatibility analysis method, including:

[0042] Construct an initial molecular model, which includes a matrix asphalt and a modifier model; perform structural optimization on the initial molecular model, and construct a modified asphalt crystal cell model based on the structurally optimized initial molecular model; perform NVT ensemble simulation on the modified asphalt crystal cell model to obtain a molecular dynamics trajectory file; calculate key parameters of a phase field model based on the molecular dynamics trajectory file, the key parameters include a migration coefficient and an interaction parameter; construct a phase field model based on the key parameters; perform a transient study on the phase field model to obtain compatibility data of the modified asphalt that changes with time.

[0043] This embodiment relates to a method for evaluating the compatibility of modified asphalt based on molecular dynamics and phase field method, comprising the following steps:

[0044] Step 1: Based on Material Studio molecular dynamics software, the molecular models of matrix asphalt and modifier were established. The boundary conditions were set as periodic boundary conditions and the initial density of amorphous unit cell was 0.1 g / cm 3 , target density is 1.0g / cm 3 .

[0045] Step 2: After the model is established, the model is geometrically optimized and annealed to minimize the model energy and obtain a stable molecular model. The Smart algorithm is selected in the geometry optimization module with 20,000 iterations. The initial temperature is 298K and the temperature is increased to 500K in 10 steps, and 5 cycles are loaded.

[0046] Step 3, placing the matrix asphalt model and modifier model obtained after structural optimization into an amorphous unit cell, and using periodic boundary conditions to obtain a unit cell model of modified asphalt; wherein the periodic boundary conditions of the amorphous unit cell are the same as those in step 1.

[0047] Step 4, after geometric optimization and annealing of the modified asphalt model, the NVT ensemble is used to generate a molecular dynamics trajectory file; among them, the model of the modified asphalt is slightly larger than the matrix asphalt model, the maximum number of iterations is set to 30,000 times, the annealing step is the same as step 2, the NVT ensemble is performed at the required temperature with a time step of 1fs, a total step of 1000ps, and 5000 steps are output per frame.

[0048] Step 5: Use the Cohesive Energy Density and Mean Square Displacement functions of the Forcite module to analyze the trajectory file obtained above, specifically:

[0049] The cohesive energy density is obtained by analyzing the Cohesive Energy Density function. The cohesive energy density is:

[0050]

[0051] E coh =- <E inter >= <E intra >- <E total >=CED v +CED e (2)

[0052] In formula (1), Ecoh is the cohesive force, and V is the molar volume of the system;

[0053] Formula (2) E inter is the intermolecular energy, E intra is the intramolecular energy, E total is the system energy. v is the van der Waals cohesive energy density CED e is the electrostatic cohesive energy density.

[0054] Preferably, in step 5, the mean square displacement is obtained by the Mean Square Displacement function analysis, and the diffusion coefficient is:

[0055]

[0056] In formula (3), D is the diffusion coefficient and MSD is the mean square displacement.

[0057] Preferably, in step 5, the solubility parameter is:

[0058]

[0059] Wherein δ in formula (4) is the solubility parameter.

[0060] Step 6: Convert the parameters obtained by the Forcite module analysis into key parameters of the phase field model:

[0061] The key parameters of the phase field model are the migration coefficient and the interaction parameter. The migration coefficient can be converted by the diffusion coefficient, and the interaction parameter can be converted by the solubility parameter:

[0062]

[0063] The migration coefficient of formula (5) is M, where V m is the volume, c A and c B are the polymer and asphalt system concentrations, respectively;

[0064] Formula (6) i-j is the interaction parameter, V iis the molar volume of the solvent in the system, δ i and δ j Represents the solubility parameters of the solvent and solute.

[0065] Step 7, establishing a geometric model based on COMSOL Multiphysics numerical simulation software; the geometric model is a rectangle, and the size of the rectangle is the same as the size of the fluorescence microscope image: 1.414*1.06.

[0066] Step 8, add multi-physics coupling interface: add phase field physics to simulate the phase separation process of polymer modified asphalt, set parameter properties and use random variables, initial values, etc. to constrain;

[0067] The free energy function and phase field model constructed in the phase field physics field are:

[0068]

[0069] In formula (7), R is the universal gas constant, T is the Kelvin temperature, s is the swelling coefficient, φ is the order parameter, and k is the gradient energy coefficient.

[0070] M and χ are the key parameters of the phase field model, which are obtained by molecular dynamics in step 6.

[0071] Step 9, perform extremely fine meshing on the geometric model;

[0072] Step 10, conduct a transient study on the model, adjust the output time step and relative tolerance in the transient settings according to the solution requirements, and adjust the pairing tolerance and time step configuration of the solver;

[0073] Step 11, post-process the calculation results, add a drawing group to display the volume fraction of the polymer phase and the asphalt phase, the velocity field and other views, and compare and verify with the results of the fluorescence microscopy experiment and the asphalt hot storage experiment;

[0074] In molecular dynamics, this embodiment finds parameters that can be used for the phase field model of modified asphalt phase separation through modeling, energy minimization and mechanism analysis, and accurately tracks the phase changes of modified asphalt. The phase field model coupled with molecular dynamics parameters realizes the transition from estimating simulation parameters from experimental results to accurately predicting simulation results using simulation parameters. This innovative method is more efficient and accurate than the existing modified asphalt compatibility experimental method. The phase field model coupled with molecular dynamics parameters can more comprehensively and accurately simulate the behavior and characteristics of materials by integrating information at the micro and macro scales, thereby enhancing the depth and breadth of research.

[0075] Specific algorithm examples of this embodiment include:

[0076] Example 1:

[0077] Step 1: Based on Material Studio software, a model of No. 50 matrix asphalt (asphaltene: 8.07wt%, colloid: 28.02wt%, aromatic fraction: 44.66wt%, saturated fraction: 16.35wt%) and SBS modifier was established. The boundary conditions were set as periodic boundary conditions. In order to avoid the entanglement or high overlap of molecular chains, the amorphous unit cell was constructed with an initial density of 0.1g / cm 3 , target density is 1.0g / cm 3 .

[0078] Step 2: The constructed model first uses the geometry optimization of the Forcite module, selects the Smart algorithm, and iterates 20,000 times, followed by annealing, starting from the initial temperature of 298K, heating up to 500K in 10 steps, and then cooling to room temperature. Each step performs a molecular dynamics simulation of NPT and stays for 20ps. After annealing, the energy of the system tends to be stable, and the local unreasonable structure generated in the model is eliminated.

[0079] Step 3: In the Amorphous Cell module, the 50-base asphalt model and the SBS modifier model obtained after annealing are placed in a 3D image with an initial density of 0.1 g / cm 3 , target density is 1.0g / cm 3 In the amorphous unit cell, periodic boundary conditions were used to obtain the unit cell model of SBS modified asphalt.

[0080] Step 4, perform geometric optimization on SBS modified asphalt. Since the model of SBS modified asphalt is slightly larger than the matrix asphalt model, set the maximum number of iterations to 30,000, followed by annealing. The annealing steps are the same as step 2. Finally, at a temperature of 436K, a time step of 1fs and a total step of 1000ps are used, and an NVT ensemble of 5000 steps is output per frame to generate the molecular dynamics trajectory file of SBS modified asphalt.

[0081] Step 5: The cohesive energy density and mean square displacement obtained in the molecular dynamics trajectory file are converted into the key parameters of the phase field model through formulas (1) to (6): the migration coefficient and the interaction parameter. The interaction parameter is 3.036, and the migration coefficients of 50# asphalt and SBS are 1.6*10 -16 m 5 ·J -1 ·s -1 and 5.09*10 -18 m 5 ·J -1 ·s -1 .

[0082] Step 6, build a 1.414*1.06 geometric model based on COMSOL Multiphysics software, and add random variables with 2 variables, an average value of 0.0323, and a range of 0.005 as the initial values ​​of the SBS modified asphalt phase field model.

[0083] Step 7, add the phase field physics field, introduce the mobility coefficient No. 2 interaction parameter obtained by molecular dynamics into the phase field, and construct the free energy function (Formula 7) and the phase field model (Formula 8).

[0084] Step 8: Divide the geometric model into extremely fine grids.

[0085] Step 9: Perform a transient study on the model. The time unit is s, the initial time is 0s, the step size is 100s, and the stop time is 10800s. In order to make the model more accurate, the relative tolerance is 0.0001 and the absolute tolerance is 0.01.

[0086] Step 10, after outputting the phase field model of 50#SBS modified asphalt, study the compatibility of 50#SBS modified asphalt over time, compare it with the fluorescence microscope image, and verify the accuracy of the phase field model.

[0087] Example 2:

[0088] Step 1: Based on Material Studio software, a model of No. 70 matrix asphalt (asphaltene: 7.96wt%, colloid: 29.51wt%, aromatic fraction: 44.47wt%, saturated fraction: 15.15wt%) and SBS modifier was established. The boundary conditions were set as periodic boundary conditions. In order to avoid the entanglement or high overlap of molecular chains, the amorphous unit cell was constructed with an initial density of 0.1g / cm 3 , target density is 1.0g / cm 3 .

[0089] Step 2: The constructed model first uses the geometry optimization of the Forcite module, selects the Smart algorithm, and iterates 20,000 times, followed by annealing, starting from the initial temperature of 298K, heating up to 500K in 10 steps, and then cooling to room temperature. Each step performs a molecular dynamics simulation of NPT and stays for 20ps. After annealing, the energy of the system tends to be stable, and the local unreasonable structure generated in the model is eliminated.

[0090] Step 3: In the Amorphous Cell module, the annealed No. 70 base asphalt model and the SBS modifier model are placed in a 3D model with an initial density of 0.1 g / cm 3 , target density is 1.0g / cm 3In the amorphous unit cell, periodic boundary conditions were used to obtain the unit cell model of SBS modified asphalt.

[0091] Step 4, perform geometric optimization on SBS modified asphalt. Since the model of SBS modified asphalt is slightly larger than the matrix asphalt model, set the maximum number of iterations to 30,000, followed by annealing. The annealing steps are the same as step 2. Finally, at a temperature of 436K, a time step of 1fs and a total step of 1000ps are used, and an NVT ensemble of 5000 steps is output per frame to generate the molecular dynamics trajectory file of SBS modified asphalt.

[0092] Step 5: The cohesive energy density and mean square displacement obtained in the molecular dynamics trajectory file are converted into the key parameters of the phase field model through formula (1)-formula (6): migration coefficient and interaction parameter. The interaction parameter is 2.768, and the migration coefficients of 70# asphalt and SBS are 1.64*10 -16 m 5 ·J -1 ·s -1 and 5.31*10 -18 m 5 ·J -1 ·s -1 .

[0093] Step 6, build a 1.414*1.06 geometric model based on COMSOL Multiphysics software, and add random variables with 2 variables, an average value of 0.0323, and a range of 0.005 as the initial values ​​of the SBS modified asphalt phase field model.

[0094] Step 7, add the phase field physics field, introduce the mobility coefficient No. 2 interaction parameter obtained by molecular dynamics into the phase field, and construct the free energy function (Formula 7) and the phase field model (Formula 8).

[0095] Step 8: Divide the geometric model into extremely fine grids.

[0096] Step 9: Perform a transient study on the model. The time unit is s, the initial time is 0s, the step size is 100s, and the stop time is 10800s. In order to make the model more accurate, the relative tolerance is 0.0001 and the absolute tolerance is 0.01.

[0097] Step 10, after outputting the 70#SBS modified asphalt phase field model, the compatibility of 70#SBS modified asphalt over time is studied and compared with the fluorescence microscope image to verify the accuracy of the phase field model.

[0098] Example 3:

[0099] Step 1: Based on Material Studio software, a model of No. 110 matrix asphalt (asphaltene: 8.05wt%, colloid: 31.62wt%, aromatic fraction: 42.58wt%, saturated fraction: 17.74wt%) and SBS modifier was established. The boundary conditions were set as periodic boundary conditions. In order to avoid the entanglement or high overlap of molecular chains, the amorphous unit cell was constructed with an initial density of 0.1g / cm 3 , target density is 1.0g / cm 3 .

[0100] Step 2: The constructed model first uses the geometry optimization of the Forcite module, selects the Smart algorithm, and iterates 20,000 times, followed by annealing, starting from the initial temperature of 298K, heating up to 500K in 10 steps, and then cooling to room temperature. Each step performs a molecular dynamics simulation of NPT and stays for 20ps. After annealing, the energy of the system tends to be stable, and the local unreasonable structure generated in the model is eliminated.

[0101] Step 3: In the Amorphous Cell module, the 110 base asphalt model and the SBS modifier model obtained after annealing are placed in a 3D model with an initial density of 0.1 g / cm 3 , target density is 1.0g / cm 3 In the amorphous unit cell, periodic boundary conditions were used to obtain the unit cell model of SBS modified asphalt.

[0102] Step 4, perform geometric optimization on SBS modified asphalt. Since the model of SBS modified asphalt is slightly larger than the matrix asphalt model, set the maximum number of iterations to 30,000, followed by annealing. The annealing steps are the same as step 2. Finally, at a temperature of 436K, a time step of 1fs and a total step of 1000ps are used, and an NVT ensemble of 5000 steps is output per frame to generate the molecular dynamics trajectory file of SBS modified asphalt.

[0103] Step 5: The cohesive energy density and mean square displacement obtained in the molecular dynamics trajectory file are converted into the key parameters of the phase field model through formula (1)-formula (6): migration coefficient and interaction parameter. The interaction parameter is 3.036, and the migration coefficients of 110# asphalt and SBS are 1.85*10 -16 m 5 ·J -1 ·s -1 and 5.88*10 -18 m 5 ·J -1 ·s -1 .

[0104] Step 6, build a 1.414*1.06 geometric model based on COMSOL Multiphysics software, and add random variables with 2 variables, an average value of 0.0323, and a range of 0.005 as the initial values ​​of the SBS modified asphalt phase field model.

[0105] Step 7, add the phase field physics field, introduce the mobility coefficient No. 2 interaction parameter obtained by molecular dynamics into the phase field, and construct the free energy function (Formula 7) and the phase field model (Formula 8).

[0106] Step 8: Divide the geometric model into extremely fine grids.

[0107] Step 9: Perform a transient study on the model. The time unit is s, the initial time is 0s, the step size is 100s, and the stop time is 10800s. In order to make the model more accurate, the relative tolerance is 0.0001 and the absolute tolerance is 0.01.

[0108] Step 10, after outputting the phase field model of 110#SBS modified asphalt, study the compatibility of 110#SBS modified asphalt over time, compare it with the fluorescence microscope image, and verify the accuracy of the phase field model.

[0109] The evaluation method proposed in this embodiment is not limited to the compatibility of modified asphalt materials. It fills the current technical gap in establishing and tracking the evolution of the microscopic and mesoscopic phases of modified asphalt over time. It has high computational efficiency while ensuring computational accuracy, significantly reduces the time and economic costs of the modified asphalt compatibility evaluation, and provides theoretical guidance for the design and application of modified asphalt materials.

[0110] The above is only a preferred specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for analyzing the compatibility of modified asphalt, characterized in that: include: Constructing an initial molecular model, wherein the initial molecular model includes a matrix asphalt and a modifier model; Structural optimization is performed on the initial molecular model, and a modified asphalt crystal cell model is constructed based on the structurally optimized initial molecular model; Performing NVT ensemble simulation on the modified asphalt unit cell model to obtain a molecular dynamics trajectory file; Calculating key parameters of the phase field model based on the molecular dynamics trajectory file, wherein the key parameters include a mobility coefficient and an interaction parameter; constructing a phase field model based on the key parameters; A transient study is conducted on the phase field model to obtain the compatibility data of the modified asphalt that varies with time.

2. A modified asphalt compatibility analysis method according to claim 1, characterized in that: The constructing of the initial molecular model specifically comprises: Based on the preset periodic boundary conditions, the preset initial density of the shaping unit cell and the preset target density, the initial molecular models of the matrix asphalt and the modifier are constructed in combination with the MaterialStudio molecular dynamics software.

3. A modified asphalt compatibility analysis method according to claim 1, characterized in that: The structural optimization of the initial molecular model specifically includes: The initial molecular model is subjected to geometric optimization and annealing treatment to obtain a structurally optimized initial molecular model.

4. A modified asphalt compatibility analysis method according to claim 1, characterized in that: The modified asphalt crystal cell model is constructed based on the initial molecular model after structural optimization, specifically including: The structure-optimized matrix asphalt and modifier models were placed into an amorphous unit cell and the periodic boundary conditions were maintained to obtain the unit cell model of the modified asphalt.

5. A modified asphalt compatibility analysis method according to claim 1, characterized in that: The NVT ensemble simulation of the modified asphalt unit cell model specifically includes: The modified asphalt model is geometrically optimized, and an NVT ensemble simulation is performed at a preset temperature to obtain a molecular dynamics trajectory file.

6. A modified asphalt compatibility analysis method according to claim 1, characterized in that: The key parameters of the phase field model calculated based on the molecular dynamics trajectory file specifically include: Analyze the cohesive energy density, mean square displacement and solubility parameters of the molecular dynamics trajectory file based on the Forcite module; The cohesive energy density, mean square displacement and solubility parameter are converted into coefficients to obtain the key parameters.

7. A modified asphalt compatibility analysis method according to claim 1, characterized in that: The phase field model is constructed based on the key parameters, specifically comprising: A geometric model is established in COMSOL Multiphysics software, random variables are added to the geometric model as initial values ​​of the phase field model to obtain an initial phase field model, and the key parameters are introduced into the initial phase field model to construct a free energy function and a phase field model.

8. A modified asphalt compatibility analysis method according to claim 1, characterized in that: The transient study of the phase field model specifically includes: The phase field model is divided into extremely fine grids, and a transient study is performed on the phase field model after the extremely fine grid division based on a preset time step and a preset tolerance to obtain the compatibility data of the modified asphalt that changes with time.

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