Molecular simulation method and device for interaction behavior of vulcanized rubber powder and asphalt

Abstract

The invention provides a molecular simulation method and device for interaction behaviors of vulcanized rubber powder and asphalt, and relates to the technical field of molecular simulation, and the method comprises the following steps: respectively constructing a rubber powder molecular model and an asphalt molecular model through molecular simulation software; establishing a rubber powder modified asphalt system model according to the rubber powder molecular model and the asphalt molecular model; distributing molecular force fields to the rubber powder molecular model, the asphalt molecular model and the rubber powder modified asphalt system model; performing energy minimization processing and relaxation operation on the rubber powder modified asphalt system model, and calculating thermodynamic parameters and particle motion trails of the rubber powder modified asphalt system model; and evaluating the interaction effect of the vulcanized rubber powder and the asphalt according to the thermodynamic parameters and the particle motion trail of the rubber powder modified asphalt system model. According to the molecular simulation method, the interaction between the vulcanized rubber powder and the asphalt is systematically explained from the molecular level.

Description

Technical Field

[0001] This application relates to the field of molecular simulation technology, and in particular to a molecular simulation method and apparatus for the interaction behavior of vulcanized rubber powder and asphalt. Background Technology

[0002] Adding rubber powder obtained from the grinding of waste tires to asphalt pavements not only consumes a large amount of waste tires but also improves the overall performance of the asphalt pavement, including high and low temperature performance, crack resistance, and noise reduction. During the production of rubber tires, vulcanizing crosslinking agents are added to enhance the strength and durability of the rubber material. However, even after physical crushing, waste rubber powder still contains a large number of vulcanization bonds (SS bonds, CS bonds). The presence of these vulcanization bonds results in poor compatibility between the rubber powder and asphalt. To obtain rubber asphalt with good stability, higher heating temperatures and longer times are needed during the preparation process to break these vulcanization bonds. To overcome this drawback, pre-desulfurizing the vulcanized rubber powder can significantly shorten the rubber asphalt preparation time and improve its storage stability. Considering the performance of vulcanized rubber powder and rubber asphalt, the pretreatment method for vulcanized rubber powder is to break the vulcanization cross-linking bonds while maintaining the integrity of the rubber powder backbone. The bond energy of the CC bond is 347 kJ / mol, the CS bond is 259 kJ / mol, and the SS bond is 213 kJ / mol. However, in practice, it is difficult to achieve precise degradation of the vulcanization cross-linking bonds, and the degree of degradation of vulcanized rubber powder is a major factor affecting the performance of rubber asphalt. Existing macroscopic and microscopic experiments are insufficient to accurately characterize the impact of the desulfurization degree of vulcanized rubber powder on asphalt, and there is a lack of molecular explanations regarding the interaction between rubber powder and asphalt with different desulfurization degrees.

[0003] To overcome the limitations of macroscopic and microscopic testing, molecular dynamics (MD) simulations can supplement experimental results at the nanoscale. Currently, MD simulations are widely used in asphalt material research, revealing the interactions between asphalt and many modifiers such as SBS, polyurethane, and epoxy resin. However, existing molecular simulations of rubber powder and asphalt simplify the rubber powder to a fully desulfurized state, failing to consider the influence of vulcanization crosslinking bonds and the desulfurization process on asphalt properties, and thus cannot systematically explain the interaction between vulcanized rubber powder and asphalt at the molecular level. Summary of the Invention

[0004] In view of this, this application proposes a molecular simulation method and apparatus for the interaction behavior of vulcanized rubber powder and asphalt.

[0005] In a first aspect, this application provides a molecular simulation method for the interaction behavior of vulcanized rubber powder and asphalt, including:

[0006] Molecular models of rubber powder and asphalt were constructed using molecular simulation software.

[0007] A model of the rubber powder modified asphalt system was established based on the aforementioned rubber powder molecular model and the aforementioned asphalt molecular model.

[0008] Assign molecular force fields to the rubber powder molecular model, the asphalt molecular model, and the rubber powder modified asphalt system model;

[0009] Energy minimization and relaxation operations were performed on the rubber powder modified asphalt system model, and the thermodynamic parameters and particle trajectories of the rubber powder modified asphalt system model were calculated.

[0010] The interaction between vulcanized rubber powder and asphalt was evaluated based on the thermodynamic parameters and particle trajectories of the rubber powder modified asphalt system model.

[0011] In one embodiment, establishing a rubber-modified asphalt system model based on the rubber powder molecular model and the asphalt molecular model includes:

[0012] The vulcanization crosslinking bonds are introduced into the rubber powder molecular model molecule to form a vulcanized rubber powder model, and the vulcanized rubber powder model is subjected to graded desulfurization treatment to obtain a first desulfurized rubber powder model and a second desulfurized rubber powder model.

[0013] Based on the vulcanized rubber powder model, the first desulfurized rubber powder model, the second desulfurized rubber powder model, and the asphalt molecule model, layered structures are constructed and mixed and assembled to obtain dry rubber asphalt models and wet rubber asphalt models.

[0014] In one embodiment, the step of introducing vulcanization crosslinks into the rubber powder molecular model molecule to form a vulcanized rubber powder model includes:

[0015] During the modeling process, the CH bonds in the three molecular structures of the adhesive powder molecular model are randomly broken, and sulfur is introduced in proportions of 2% to 6%. Sulfur atoms are used to connect the broken bonds to form CS bonds, SS bonds and SSS bonds.

[0016] In one embodiment, the step of performing graded desulfurization treatment on the vulcanized rubber powder model to obtain a first desulfurized rubber powder model and a second desulfurized rubber powder model includes:

[0017] Select all the vulcanization crosslinking bonds in the vulcanized rubber powder model, break all the SS bonds and SSS bonds, and break a small number of CS bonds and C=C bonds to obtain the first desulfurized rubber powder model.

[0018] Based on the first desulfurized rubber powder model, the remaining CS bonds and some C=C bonds in the first desulfurized rubber powder model are broken to obtain the second desulfurized rubber powder model.

[0019] In one embodiment, the asphalt molecular model is a twelve-component molecular model, including four components: asphaltenes, resins, saturates, and aromatics.

[0020] In one embodiment, the energy minimization process includes geometry optimization and annealing calculations; the relaxation operation includes dynamic calculations under the NVT ensemble and the NPT ensemble.

[0021] In one embodiment, the molecular force field is a COMPASSII force field.

[0022] In one embodiment, the thermodynamic parameters include: the cohesive energy density of the rubber powder molecular model and the asphalt molecular model, the free volume and occupied volume of the wet rubber asphalt model, and the particle trajectory of the wet rubber asphalt model is the motion path of the dry rubber asphalt model as it changes over time.

[0023] In one embodiment, evaluating the interaction effect between vulcanized rubber powder and asphalt based on the thermodynamic parameters and particle trajectories of the rubber powder modified asphalt system model includes:

[0024] The cohesive energy density of the rubber powder molecular model and the asphalt molecular model is converted into a solubility parameter, and the compatibility is determined based on the solubility difference between the rubber powder molecular model and the asphalt molecular model.

[0025] The free volume fraction of the wet-process rubber asphalt model is calculated based on the free volume and occupied volume of the wet-process rubber asphalt model. The free volume fraction is used to characterize the influence of rubber powder on the free volume of asphalt.

[0026] Energy parameters of rubber molecules and asphalt molecules are extracted from the energy of the wet rubber asphalt model and the dry rubber asphalt model, respectively. The bonding energy between rubber and asphalt in the corresponding rubber asphalt model is calculated based on the total energy of the wet rubber asphalt model, the total energy of the dry rubber asphalt model, the total energy of rubber molecules, and the total energy of asphalt molecules.

[0027] The motion path of rubber molecules over time is obtained from the particle motion trajectory of the dry rubber asphalt model, and the diffusion coefficient of rubber molecules in asphalt is calculated based on the motion path of rubber molecules over time.

[0028] Secondly, this application also provides a molecular simulation device for the interaction behavior of vulcanized rubber powder and asphalt, comprising:

[0029] The first construction module is used to construct molecular models of rubber powder and asphalt using molecular simulation software.

[0030] The second construction module is used to establish a rubber powder modified asphalt system model based on the rubber powder molecular model and the asphalt molecular model.

[0031] The force field allocation module is used to allocate molecular force fields to the rubber powder molecular model, the asphalt molecular model, and the rubber powder modified asphalt system model;

[0032] The computation module is used to perform energy minimization and relaxation operations on the rubber powder modified asphalt system model, and to calculate the thermodynamic parameters and particle trajectories of the rubber powder modified asphalt system model.

[0033] The evaluation module is used to evaluate the interaction effect between vulcanized rubber powder and asphalt based on the thermodynamic parameters and particle motion trajectories of the rubber powder modified asphalt system model.

[0034] The molecular simulation method for the interaction behavior between vulcanized rubber powder and asphalt proposed in this application has the following advantages over related technologies:

[0035] 1. The molecular simulation method of this application constructs molecular models of rubber powder and asphalt using molecular simulation software, respectively, which establishes a basic framework that closely matches the actual material structure for subsequent analysis, avoids simulation deviations caused by model distortion, and ensures the reliability of subsequent research. Then, a rubber powder modified asphalt system model is established based on the two basic models, successfully extending the single molecular model to the modified system existing in actual engineering, realizing the precise connection between the simulation scenario and actual application, and filling the gap of being unable to reflect the interaction of the system when only simulating a single substance.

[0036] 2. Molecular force fields were assigned to the rubber powder molecular model, asphalt molecular model, and rubber powder modified asphalt system model, providing a scientific basis for the accurate calculation of intermolecular interactions and ensuring the accuracy of subsequent energy calculations and kinetic simulations. Furthermore, by performing energy minimization and relaxation operations on the rubber powder modified asphalt system model, unreasonable structures in the model were effectively eliminated, allowing the system to reach a state of thermodynamic equilibrium. This enabled the accurate calculation of thermodynamic parameters and particle trajectories, providing quantitative data support for the evaluation of interaction effects and avoiding the one-sidedness of qualitative analysis.

[0037] 3. Evaluating the interaction between vulcanized rubber powder and asphalt based on the obtained thermodynamic parameters and particle motion trajectories can reveal the intrinsic mechanism of their interaction at the molecular level. This not only makes up for the shortcomings of existing macroscopic and microscopic experiments that cannot explain the mechanism of action in essence, but also provides an intuitive and reliable reference for the scientific selection of vulcanized rubber powder in asphalt pavement construction. At the same time, it provides molecular-level theoretical guidance for the optimization and upgrading of rubber asphalt modification technology, and promotes the efficiency and rationalization of waste rubber powder in the application of asphalt pavement. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a flowchart illustrating a molecular simulation method for the interaction behavior between vulcanized rubber powder and asphalt in one embodiment of this application.

[0040] Figure 2 This is a schematic diagram of the structure of three adhesive powder molecular models in one embodiment of this application;

[0041] Figure 3 This is a schematic diagram of the structure of an asphalt molecular model in one embodiment of this application;

[0042] Figure 4 This is a schematic diagram of the structure of a dry rubber asphalt model in one embodiment of this application;

[0043] Figure 5 This is a schematic diagram of the structure of a wet rubber asphalt model in one embodiment of this application;

[0044] Figure 6 This is a flowchart illustrating step S105 in one embodiment of this application;

[0045] Figure 7 This is a schematic diagram illustrating the difference in solubility between three types of adhesive powder molecules and asphalt in one embodiment of this application;

[0046] Figure 8 This is a schematic diagram of the free volume fraction of wet-process rubber asphalt in one embodiment of this application;

[0047] Figure 9 This is a schematic diagram illustrating the bonding energy between rubber powder and asphalt in a dry rubber asphalt model and a wet rubber asphalt model in one embodiment of this application.

[0048] Figure 10 This is a schematic diagram of the diffusion coefficient of rubber powder in a dry rubber asphalt system in one embodiment of this application;

[0049] Figure 11 This is a schematic diagram of the molecular simulation device for the interaction behavior of vulcanized rubber powder and asphalt in one embodiment of this application. Detailed Implementation

[0050] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0051] In some embodiments, such as Figure 1 As shown, this application provides a molecular simulation method for the interaction behavior of vulcanized rubber powder and asphalt, including the following steps S101 to S105.

[0052] S101: Molecular models of rubber powder and asphalt were constructed using molecular simulation software.

[0053] The rubber powder is composed of three types of molecules: natural rubber, butadiene rubber, and styrene-butadiene rubber, in a ratio of approximately 1:1:1. Natural rubber is composed of cis-1,4-isoprene as a monomer, butadiene rubber is composed of 1,4-butadiene as a monomer, and styrene-butadiene rubber is composed of styrene, cis-1,4-butadiene, and trans-1,4-butadiene. Based on the composition of the rubber molecules, monomers of cis-1,4-isoprene, 1,4-butadiene, styrene, cis-1,4-butadiene, and trans-1,4-butadiene are constructed. Repeating units of cis-1,4-isoprene are defined to construct natural rubber molecular chains; repeating units of 1,4-butadiene are defined to construct butadiene rubber molecular chains; repeating units of styrene, cis-1,4-butadiene, and trans-1,4-butadiene are defined to construct styrene-butadiene rubber molecular chains in a ratio of 3:1:6.

[0054] like Figure 2 As shown, the asphalt molecular model is a twelve-component model, including four components: asphaltenes, resins, saturated components, and aromatic components. The proportions of these four components in the asphalt molecular model can be determined by gel permeation chromatography (GPC).

[0055] Asphaltene and resin molecules are the main components that provide the viscosity and strength of asphalt, and are composed of macromolecular aromatic structures; saturated and aromatic components are lightweight components, and micelles formed by asphaltene and resin are dispersed in saturated and aromatic components.

[0056] The contents of the four components of 70# base asphalt were determined by gel permeation chromatography (GPC). The experimental and simulated values ​​of the contents of the four components are shown in Table 1.

[0057] Table 1 shows the content of the four components of asphalt.

[0058] The molecular information of the twelve components of asphalt is shown in Table 2.

[0059] Table 2 shows the asphalt molecules used in the simulation.

[0060] For example, the asphalt molecular model was constructed and balanced using the same method as the rubber powder molecular model. Twelve asphalt molecules were added in proportion to 0.1 g / cm³. 3 In the simulation chamber, after 10,000 steps of geometry optimization, 300 ps of NVT kinetic simulation (298 K), 5 cycles of annealing (500,000 steps, temperature 200 K ~ 600 K), and 500 ps of NPT kinetic simulation (298 K, pressure 1.0 e), the simulation was successfully completed. -4 (GPa). Finally, a fully balanced asphalt molecular model can be obtained. Molecular models of rubber powder and asphalt at different temperatures were constructed using the same method.

[0061] S102: Establish a model for the rubber powder modified asphalt system based on the molecular model of rubber powder and the molecular model of asphalt.

[0062] It is understandable that introducing vulcanization crosslinks into the rubber powder molecular model can yield a vulcanized rubber powder model with properties consistent with those of real vulcanized rubber powder. Subsequently, based on this vulcanized rubber powder model, staged desulfurization treatment can be performed to obtain partially desulfurized and fully desulfurized rubber powder models.

[0063] S103: Assign molecular force fields to the rubber powder molecular model, asphalt molecular model, and rubber powder modified asphalt system model.

[0064] The molecular force field can be the COMPASS II force field, which is widely used to describe the interactions between organic compounds and has strong universality and high accuracy. It should be noted that the COMPASS II force field is a widely validated general-purpose molecular force field with high adaptability to complex systems such as organic compounds, polymers, and sulfur-containing compounds. It can accurately describe the stretching, bending, and torsional effects of carbon-carbon bonds, carbon-hydrogen bonds, and vulcanization crosslinking bonds (CS bonds, SS bonds, etc.) of natural rubber, butadiene rubber, and styrene-butadiene rubber in rubber powder molecules. Simultaneously, it can accurately characterize the molecular structure characteristics and interactions of the four components in asphalt molecules: asphaltenes, resins, saturated components, and aromatic components. It is particularly suitable for simulating multi-component, multi-bonded composite systems such as rubber powder and asphalt in this application. Its advantage lies in balancing computational accuracy and efficiency, both reproducing key interactions such as van der Waals and electrostatic interactions between real molecules and avoiding energy calculation deviations or simulation result distortions caused by insufficient force field adaptability.

[0065] It is understandable that assigning molecular force fields to the rubber powder molecular model, asphalt molecular model, and rubber powder modified asphalt system model aims to provide a unified and scientific set of rules for describing the physicochemical interactions of these models. The essence of molecular simulation is to deduce the energy changes and motion states of a system by calculating the interactions between molecules, such as attraction, repulsion, bond stretching and bending. The molecular force field is the mathematical framework that defines these interactions; without force field assignment, subsequent energy calculations, dynamic relaxation, and parameter extraction cannot be performed. Unifying the force field assignment to the three types of models (rubber powder, asphalt, and modified system) ensures that all three models use consistent calculation standards in subsequent energy minimization and relaxation operations, eliminating parameter conflicts between different force fields.

[0066] S104: Perform energy minimization and relaxation operations on the rubber powder modified asphalt system model, and calculate the thermodynamic parameters and particle trajectories of the rubber powder modified asphalt system model.

[0067] The energy minimization process includes geometric optimization and annealing calculations; the relaxation operation includes dynamic calculations under the NVT ensemble and the NPT ensemble.

[0068] Geometric optimization of the rubber-modified asphalt system model can eliminate unreasonable structures. Van der Waals interactions can be calculated using the atom-based method with a cutoff radius set to 1.55 nm. Electrostatic interactions are calculated using the PPPM method with an accuracy set to 1.0 e. -4 kcal / mol. The energy can be minimized using the SMART method, reaching energy convergence after 10,000 iterations.

[0069] After geometric optimization, the rubber powder modified asphalt system model was kinetically balanced under an isothermal and isovolume NVT ensemble for a time of 300 ps and a time step of 1 fs. A Nose controller was used to control the temperature at around 298 K to obtain the model in equilibrium stage 1.

[0070] Annealing simulation is performed on the equilibrium stage 1 model to minimize energy globally. The initial temperature can be set to 200K, the intermediate temperature can be set to 600K, and the temperature cycle can be set to 5 times. An isothermal-isobaric NPT ensemble fully scaled simulation system is used, with each temperature cycle having 100,000 steps, for a total of 500,000 annealing simulation steps, to obtain the equilibrium stage 2 model.

[0071] The model in equilibrium phase 2 is then used again for dynamic calculations using the NPT ensemble, with the temperature set to 298 K and the pressure to 1.0 e. -4GPa, with temperature and pressure controlled by Nose and Andersen controllers respectively. After 500 ps of volume compression, the final equilibrium model was obtained for subsequent thermodynamic parameter calculations.

[0072] It should be noted that the energy minimization processing and relaxation operation settings described above are an example provided in this application, and the relevant parameters can be adjusted as needed.

[0073] S105: Evaluate the interaction effect between vulcanized rubber powder and asphalt based on the thermodynamic parameters and particle motion trajectories of the rubber powder modified asphalt system model.

[0074] In applications, the solubility of rubber powder and asphalt can be calculated based on thermodynamic parameters. Compatibility can be analyzed based on the solubility difference between the two; a smaller solubility difference indicates better compatibility. The diffusion behavior of rubber powder in the asphalt system can be analyzed based on the particle trajectories of the rubber powder-modified asphalt system model, i.e., the diffusion of rubber molecules in the rubber-asphalt system. A larger diffusion coefficient indicates faster diffusion of rubber molecules, making it easier for them to penetrate the asphalt and form a mutually integrated system. The free volume fraction of the corresponding model can also be calculated based on the thermodynamic parameters of the rubber powder-modified asphalt system model, and the anti-aging effect can be evaluated based on the free volume fraction. Furthermore, the binding energy between asphalt and rubber molecules in the corresponding model can be calculated based on the thermodynamic parameters of the rubber powder-modified asphalt system model, and the degree of bonding between different types of rubber and asphalt can be determined through the binding energy.

[0075] The aforementioned molecular simulation method constructs molecular models of rubber powder and asphalt using molecular simulation software, establishing a basic framework that closely matches the actual material structure for subsequent analysis. This avoids simulation bias caused by model distortion and ensures the reliability of subsequent research. Next, a rubber powder-modified asphalt system model is established based on these two basic models, successfully extending the single molecular model to modified systems existing in actual engineering. This achieves precise alignment between the simulation scenario and practical application, filling the gap in simulating only single substances and failing to reflect system interactions. Assigning molecular force fields to the rubber powder molecular model, asphalt molecular model, and rubber powder-modified asphalt system model provides a scientific basis for accurate calculation of intermolecular interactions, ensuring the accuracy of subsequent energy calculations and kinetic simulations. Furthermore, by performing energy minimization and relaxation operations on the rubber powder-modified asphalt system model, unreasonable structures in the model are effectively eliminated, bringing the system to thermodynamic equilibrium. This allows for accurate calculation of thermodynamic parameters and particle trajectories, providing quantitative data support for evaluating interaction effects and avoiding the limitations of qualitative analysis. Evaluating the interaction between vulcanized rubber powder and asphalt based on the obtained thermodynamic parameters and particle motion trajectories can reveal the intrinsic mechanism of their interaction at the molecular level. This not only makes up for the shortcomings of existing macro- and micro-scale experiments that cannot fundamentally explain the mechanism of action, but also provides an intuitive and reliable reference for the scientific selection of vulcanized rubber powder in asphalt pavement construction. At the same time, it provides molecular-level theoretical guidance for the optimization and upgrading of rubber asphalt modification technology, and promotes the efficiency and rationalization of waste rubber powder in asphalt pavement applications.

[0076] In some embodiments, step S102, establishing a rubber-modified asphalt system model based on the rubber powder molecular model and the asphalt molecular model, includes: introducing vulcanization crosslinking bonds into the rubber powder molecular model molecules to form a vulcanized rubber powder model, and performing graded desulfurization treatment on the vulcanized rubber powder model to obtain a first desulfurized rubber powder model and a second desulfurized rubber powder model; constructing layered structures and performing mixed assembly based on the vulcanized rubber powder model, the first desulfurized rubber powder model, the second desulfurized rubber powder model, and the asphalt molecular model to obtain a dry-process rubber asphalt model and a wet-process rubber asphalt model, respectively. The rubber powder structures of the vulcanized rubber powder model, the first desulfurized rubber powder model, and the second desulfurized rubber powder model can be found in [reference needed]. Figure 3 The structure of the dry-process rubber asphalt model can be found in [reference needed]. Figure 4 The structure of the wet-process rubber asphalt model can be found in [reference]. Figure 5 .

[0077] There are three types of rubber powder molecular models. Introducing vulcanization crosslinking bonds into these three molecular models can form a vulcanized rubber powder model. Different degrees of desulfurization treatment on the vulcanized rubber powder model can create a first desulfurized rubber powder model and a second desulfurized rubber powder model. For example, the constructed rubber model and asphalt molecular model are assembled into a layered structure using the Build layer module, and then subjected to 10,000 steps of geometric optimization and 300ps of NVT kinetic simulation (298K) to obtain an equilibrium dry-process rubber-asphalt model. Again, for example, the vulcanized rubber powder model, the first desulfurized rubber powder model, the second desulfurized rubber powder model, and the asphalt molecular model are combined in proportions at 0.1g / cm³. 3 In the simulation chamber, the mass of the rubber powder was 10% of the mass of the asphalt. After the initial model was built, it underwent 20,000 steps of geometric optimization, followed by 300ps of NVT (298K) kinetic calculations, 5 annealing cycles (500,000 steps, temperature 200K~600K), and 500ps of NPT kinetic calculations (298K, pressure 1.0e). -4 (GPa) can yield a stable wet-process rubber asphalt model.

[0078] For the basic rubber powder molecular model composed of natural rubber, butadiene rubber, and styrene-butadiene rubber in proportion, a vulcanized rubber powder model is formed by introducing vulcanization cross-linking bonds. This model accurately simulates the vulcanization structure remaining in actual waste rubber powder due to the addition of vulcanization cross-linking agents during tire production. Finally, a vulcanized rubber powder model with the same molecular characteristics as real vulcanized rubber powder is obtained, filling the gap in existing simulations that ignore the vulcanization nature of rubber powder.

[0079] Subsequently, based on the vulcanized rubber powder model, graded desulfurization treatment was performed, achieving accurate restoration of the molecular structure of rubber powder with different desulfurization degrees, providing gradient model samples for subsequent comparative analysis. Finally, the vulcanized rubber powder model and the desulfurized rubber powder model were combined with the asphalt molecular model to construct a layered structure corresponding to the dry modification scenario in actual engineering. A mixed system was constructed by mixing and assembling the models in proportion to correspond to the actual wet modification scenario, resulting in dry rubber asphalt models and wet rubber asphalt models. This ensures a high degree of adaptability between the simulation scenario and engineering application, and also comprehensively reveals the influence of desulfurization degree and modification method on the interaction between rubber powder and asphalt through multi-model comparison.

[0080] In some embodiments, the vulcanization crosslinking bonds are introduced into the rubber powder molecular model molecules to form a vulcanized rubber powder model, including the steps of randomly breaking the CH bonds in the three molecular structures of the rubber powder molecular model during the modeling process, introducing 2% to 6% sulfur, and using sulfur atoms to connect the broken bonds to form CS bonds, SS bonds and SSS bonds.

[0081] It is understandable that the CH bonds in natural rubber, butadiene rubber, and styrene-butadiene rubber are randomly broken, and sulfur atoms are connected to exposed carbon atoms to form CS bonds, SS bonds, and SSS bonds, thus completing the vulcanization process of rubber molecules. The ratio of the three types of vulcanization crosslinking bonds can be 5:3:2. Vulcanization crosslinking bonds can not only form crosslinks between different molecular chains, but also form self-crosslinks on the same molecular chain, resulting in a vulcanized rubber powder model.

[0082] For the three basic molecular structures of natural rubber, butadiene rubber, and styrene-butadiene rubber in the rubber powder molecular model, a random CH bond breaking method is used to simulate the activation of active sites in rubber molecules during vulcanization. This is because in actual tire production, vulcanizing crosslinking agents cause the CH bonds on the rubber molecular chains to break, forming active free radicals that provide attachment sites for sulfur atoms. The random breaking method can restore the randomness of the distribution of active sites in the real vulcanization process, avoiding idealization deviations in the model structure. Subsequently, the proportion of sulfur introduced is strictly controlled within 2% to 6%, a range that closely matches the sulfur content of actual waste tire rubber powder, ensuring that the sulfur content characteristics of the model are consistent with waste rubber powder in actual engineering. Next, by connecting the broken CH bonds with sulfur atoms, three types of vulcanization crosslinking bonds—CS bonds, SS bonds, and SSS bonds—are directionally formed, successfully restoring the complex molecular structure of vulcanized rubber powder formed by the vulcanization process. This solves the problem of simplified rubber powder structure in existing simulations and provides a structurally realistic and parameter-controllable benchmark model for subsequent staged desulfurization treatment and the interaction analysis of rubber powder with asphalt at different desulfurization levels, ensuring that subsequent simulation results accurately reflect the performance of actual rubber powder.

[0083] In some embodiments, the vulcanized rubber powder model is subjected to graded desulfurization treatment to obtain a first desulfurized rubber powder model and a second desulfurized rubber powder model, including: selecting all vulcanization crosslinking bonds in the vulcanized rubber powder model, breaking all SS bonds and SSS bonds, and breaking a small portion of CS bonds and C=C bonds to obtain a first desulfurized rubber powder model; based on the first desulfurized rubber powder model, breaking the remaining CS bonds and some C=C bonds in the first desulfurized rubber powder model to obtain a second desulfurized rubber powder model.

[0084] It is understandable that, because the bond energies of SS bonds (bond energy 213 kJ / mol) and SSS bonds are much lower than those of CS bonds (bond energy 259 kJ / mol), they will preferentially break during desulfurization. Simultaneously, only a small portion of CS bonds and C=C bonds will break. This simulates the characteristic of "preferentially breaking weak bonds and retaining some strong cross-linking bonds" in partial desulfurization processes, while avoiding over-desulfurization. The result is a first desulfurized rubber powder model with a relatively low degree of desulfurization, corresponding to actual lightly desulfurized products. Subsequently, based on the first desulfurized rubber powder model, all remaining CS bonds and some C=C bonds are further broken. At this point, the vulcanization cross-linking bonds in the vulcanized rubber powder are almost completely broken, retaining only the rubber molecule's main chain structure. This achieves molecular-level reduction for deep desulfurization, resulting in a second desulfurized rubber powder model with complete desulfurization, corresponding to actual deep desulfurized products.

[0085] In some embodiments, the thermodynamic parameters include: the cohesive energy density of the rubber powder molecular model and the asphalt molecular model, the free volume and occupied volume of the wet rubber asphalt model, the energy of the wet rubber asphalt model and the dry rubber asphalt model, and the particle trajectory is the motion path of the dry rubber asphalt model as it changes over time.

[0086] In some embodiments, such as Figure 6 As shown, in step S105, the interaction effect between vulcanized rubber powder and asphalt is evaluated based on the thermodynamic parameters and particle motion trajectories of the rubber powder modified asphalt system model, including the following steps S601 to S604.

[0087] S601: Convert the cohesive energy density of the rubber powder molecular model and the asphalt molecular model into solubility parameters, and determine the compatibility based on the solubility difference between the rubber powder molecular model and the asphalt molecular model.

[0088] The cohesive energy density of the models at different temperatures was calculated, and the solubility parameter was calculated according to the following formula:

[0089]

[0090] In the formula, δ is the solubility parameter; CED is the cohesive energy density; E coh ν is the intermolecular cohesive energy; V is the molar volume.

[0091] refer to Figure 7The solubility differences between vulcanized rubber powder, first desulfurized rubber powder, and second desulfurized rubber powder and asphalt at different temperatures are shown. As temperature increases, the solubility difference between rubber molecules and asphalt molecules gradually decreases. The solubility difference between the three rubber powders and asphalt is ranked as follows: vulcanized rubber powder > first desulfurized rubber powder > second desulfurized rubber powder. At 298K, the solubility difference of the first desulfurized rubber powder is 42% lower than that of the vulcanized rubber powder, and the solubility difference of the second desulfurized rubber powder is 40% lower than that of the first desulfurized rubber powder. This suggests that rubber powder with a higher degree of desulfurization has better compatibility with asphalt. This also indicates that in practical engineering applications, rubber asphalt prepared using desulfurized rubber powder has better storage stability, and rubber powder with a high degree of desulfurization is less likely to separate from asphalt.

[0092] S602: Calculate the free volume fraction of the wet-process rubber asphalt model based on the free volume and occupied volume of the wet-process rubber asphalt model. The free volume fraction is used to characterize the influence of rubber powder on the free volume of asphalt.

[0093] The free volume fraction of wet-process rubber asphalt was calculated using the Connolly Surface method. Atom probes were set to 0 nm and 0.155 nm to obtain the free volume and occupied volume of wet-process rubber asphalt, respectively. The free volume fraction of different wet-process rubber asphalts was then calculated using the following formula:

[0094]

[0095] In the formula V f V represents the free volume fraction; V represents the total volume; and V0 represents the occupied volume. A larger free volume fraction indicates a larger space for molecular diffusion, and the average distance and diffusion rate of molecular diffusion increase accordingly.

[0096] Figure 8 The free volume fraction of wet-process rubber asphalt was shown when the atomic radii were 0 nm and 0.155 nm. 0.155 nm represents the predominant size of oxygen atoms. The free volume fraction was highest at a detection radius of 0 nm, and decreased significantly at 0.155 nm. Regardless of the detection radius, the free volume fraction was highest in the vulcanized rubber powder asphalt system, and the free volume fractions of the two types of desulfurized rubber powder asphalt were similar. This indicates that the vulcanized rubber powder asphalt has more molecular diffusion space, while the first and second desulfurized rubber powders are more tightly bound to the asphalt, resulting in less free space for molecular diffusion.

[0097] On the other hand, 0.155 nm is the size of an oxygen atom. The higher the free volume fraction in vulcanized rubber powder asphalt, the easier it is for oxygen atoms to penetrate into the system during oxidation, leading to easier oxidation. Therefore, in practical engineering, to improve the anti-aging effect of rubber asphalt, desulfurized rubber powder should be used as much as possible to reduce the penetration and diffusion of oxygen atoms inside the rubber asphalt.

[0098] S603: Extract the energy parameters of rubber molecules and asphalt molecules from the energy of the wet rubber asphalt model and the dry rubber asphalt model respectively. Calculate the bonding energy between rubber and asphalt in the corresponding rubber asphalt model based on the total energy of the wet rubber asphalt model, the total energy of the dry rubber asphalt model, the total energy of rubber molecules, and the total energy of asphalt molecules.

[0099] Specifically, the Energy module (the energy calculation module in the molecular simulation software) was used to calculate the energy of either the dry-process or wet-process rubber asphalt model. Rubber molecules were removed from the rubber asphalt model, and the Energy module was used to calculate the energy of the asphalt molecules. Similarly, after removing asphalt molecules from the rubber asphalt model, the Energy module was used to calculate the energy of the rubber molecules. The binding energy between asphalt and rubber molecules was calculated to characterize the degree of bonding between different types of rubber and asphalt.

[0100] Based on the constructed dry-process rubber-asphalt model and wet-process rubber model, the bonding energy between rubber and asphalt is calculated using the bonding energy calculation formula. The formula for calculating the bonding energy is:

[0101]

[0102] In the formula E r-a E represents the bonding energy between rubber and asphalt. total E represents the total energy of the dry-process rubber asphalt model or the wet-process rubber model. r and E a These represent the energies of rubber molecules and asphalt molecules, respectively. A positive binding energy indicates mutual repulsion, while a negative binding energy indicates mutual attraction. The larger the absolute value of the binding energy, the stronger the repulsion / attraction effect.

[0103] Figure 9The results show the calculated bonding energy between rubber and asphalt in dry-process and wet-process rubber asphalt. Regardless of whether it's vulcanized or desulfurized rubber powder, the bonding energy between rubber and asphalt is higher in the wet-process rubber asphalt system. This indicates that the rubber powder mixes more evenly with asphalt under wet modification, resulting in better asphalt modification. Furthermore, regardless of whether it's dry or wet modification, the bonding energy between vulcanized rubber powder and asphalt is the lowest, significantly lower than the other two types of desulfurized rubber powder, indicating that vulcanized rubber powder has the worst asphalt modification effect. The main reason is that desulfurization breaks the sulfur crosslinking bonds of the crosslinked rubber molecules, allowing the rubber molecular chains to more easily penetrate into the asphalt system, expanding the contact between rubber and asphalt molecules, thereby increasing the bonding energy. Comparing the results of the first and second desulfurized rubber powders, it was found that the binding energy between the two rubber powders and asphalt was not significantly different under dry modification conditions. However, under wet modification conditions, the binding energy between the second desulfurized rubber powder and asphalt was much greater than that between the first desulfurized rubber powder and asphalt. This indicates that the rubber powder under fully desulfurized conditions is more suitable for wet modification, thus fully leveraging its modification effect.

[0104] S604: Obtain the motion path of rubber molecules over time from the particle motion trajectory of the dry rubber asphalt model, and calculate the diffusion coefficient of rubber molecules in asphalt based on the motion path of rubber molecules over time.

[0105] In applications, the diffusion coefficient is used to measure the diffusion of rubber molecules in a dry-process rubber asphalt system. A higher diffusion coefficient indicates faster diffusion of rubber molecules, making it easier for them to penetrate the asphalt and form a cohesive system. Based on the motion trajectory of the dry-process rubber asphalt model, the movement path of rubber molecules over time can be obtained. Mean square displacement curves are plotted based on these paths, and the diffusion coefficient of the rubber powder is calculated by fitting the curve, thus analyzing the diffusion behavior of the rubber powder in the asphalt system. The formula for calculating the diffusion coefficient is:

[0106]

[0107] In the formula, D is the diffusion coefficient; N is the number of calculated particles; t is the simulation time; r j (t) and r j (0) represents the particle positions at time t and the initial time, respectively. That is, molecular diffusion simulation is performed using set parameters to obtain the particle positions at the initial and final times, and the diffusion coefficient of each type of rubber powder in asphalt is determined based on the set parameters and the particle positions at the initial and final times. The set parameters include the number of particles to be calculated and the simulation time.

[0108] By taking the equilibrium period in the dry rubber asphalt model, the mean square displacement as a function of time is obtained, and then the diffusion coefficient is calculated. (Reference) Figure 10The figure shows the diffusion coefficients of rubber molecules in a dry-process rubber asphalt system. At 298K, the diffusion coefficients of the three rubber powders are ranked as follows: vulcanized rubber powder < first desulfurized rubber powder < second desulfurized rubber powder. The diffusion coefficients of the first and second desulfurized rubber powders are close, but the first and second desulfurized rubber powders are twice that of the vulcanized rubber powder. This indicates that during the dry modification process, the diffusion effect of vulcanized rubber powder on asphalt is poor, and desulfurized rubber powder has difficulty entering the asphalt system to exert its modifying effect, while desulfurized rubber powder penetrates into the asphalt more easily. This suggests that in actual asphalt pavement construction, within the short mixing time of asphalt, aggregate, and rubber powder, the modifying effect of vulcanized rubber powder on asphalt is very limited. Vulcanized rubber powder mainly exhibits independent granular form, and the interfacial bonding effect between vulcanized rubber powder and asphalt is poor. Desulfurized rubber powder, on the other hand, can mix better with asphalt in a short time, transferring some of the rubber powder properties to the asphalt, thus modifying the asphalt, and the bonding effect between desulfurized rubber powder and asphalt is better.

[0109] Based on the above, the thermodynamic analysis results of the interaction between different desulfurization degrees and asphalt in this embodiment are as follows:

[0110] Adding vulcanization crosslinks to rubber molecules can improve the mechanical properties of rubber, but it also reduces the interaction between rubber molecules and asphalt to some extent. The solubility difference between vulcanized rubber powder and asphalt is the largest, resulting in poor compatibility. However, after desulfurization treatment, the solubility difference between desulfurized rubber powder and asphalt decreases, improving their compatibility. This provides an explanation for the desulfurization pretreatment of vulcanized rubber powder in practical engineering. In dry-modified rubber-asphalt systems, the diffusion coefficient of vulcanized rubber powder is much smaller than that of two desulfurized rubber powders with different desulfurization levels, indicating that the modification effect of vulcanized rubber powder on asphalt is very limited within a limited construction time, and desulfurized rubber powder can penetrate into the asphalt more easily. In wet-modified rubber-asphalt systems, vulcanized rubber powder asphalt has the largest free volume fraction, resulting in larger internal voids and making it more susceptible to oxidation and aging. Desulfurized rubber powder asphalt has a relatively smaller free volume fraction, resulting in better system stability. The bonding energy between rubber powder and asphalt in wet-process rubber asphalt is greater than that in dry-process rubber asphalt. Furthermore, the bonding energy of both types of desulfurized rubber powder is significantly greater than that of vulcanized rubber powder, and the bonding energy of the second desulfurized rubber powder in wet-process rubber asphalt is much greater than that of the first. This indicates that the bonding effect between asphalt and desulfurized rubber powder is optimal, and the higher the degree of desulfurization, the better the bonding effect. This provides a basis for using desulfurized rubber powder in the actual construction of rubber asphalt pavements.

[0111] In summary, this application establishes models of rubber powder and asphalt with different degrees of desulfurization, and by calculating solubility parameters, diffusion coefficients, free volume fractions, and binding energy, reveals the interaction between rubber powder and asphalt with different degrees of vulcanization at the molecular level. This provides a mechanistic explanation for macroscopic and microscopic experiments and a reference for actual rubber asphalt pavement construction.

[0112] In some embodiments, please refer to Figure 11 This application provides a molecular simulation device 110 for the interaction behavior of vulcanized rubber powder and asphalt, including: a first building module 111, a second building module 112, a force field distribution module 113, a calculation module 114 and an evaluation module 115.

[0113] The first building module 111 is used to build molecular models of rubber powder and asphalt respectively using molecular simulation software.

[0114] The second building module 112 is used to establish a model of the rubber powder modified asphalt system based on the rubber powder molecular model and the asphalt molecular model.

[0115] The force field assignment module 113 is used to assign molecular force fields to the rubber powder molecular model, the asphalt molecular model, and the rubber powder modified asphalt system model.

[0116] The computation module 114 is used to perform energy minimization and relaxation operations on the rubber powder modified asphalt system model, and to calculate the thermodynamic parameters and particle trajectories of the rubber powder modified asphalt system model.

[0117] Evaluation module 115 is used to evaluate the interaction effect between vulcanized rubber powder and asphalt based on the thermodynamic parameters and particle motion trajectories of the rubber powder modified asphalt system model.

[0118] It should be noted that the molecular simulation device 110 for the interaction behavior of vulcanized rubber powder and asphalt provided in this application embodiment and the molecular simulation method for the interaction behavior of vulcanized rubber powder and asphalt provided in this application embodiment are based on the same inventive concept. Therefore, the specific implementation of this embodiment can refer to the implementation of the aforementioned molecular simulation method for the interaction behavior of vulcanized rubber powder and asphalt, and the repeated parts will not be described again.

[0119] In some embodiments, an electronic device provided in this application includes a processor and a memory; the memory stores a computer program, wherein the computer program, when executed by the processor, implements the above-described molecular simulation method for the interaction behavior of vulcanized rubber powder and asphalt.

[0120] Specifically, the processor may include, for example, a general-purpose microprocessor, an instruction set processor and / or an associated chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor may also include onboard memory for caching purposes. The processor may be a single processing unit or multiple processing units for performing different actions of the method flow according to embodiments of this application.

[0121] Memory can be any medium capable of containing, storing, transmitting, propagating, or transmitting instructions. For example, memory can include, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, instruments, or propagation media. Specific examples of memory include: magnetic storage devices such as magnetic tape or hard disk drives (HDDs); optical storage devices such as optical discs (CD-ROMs); and also random access memory (RAM) or flash memory; and / or wired / wireless communication links.

[0122] This application also provides a computer-readable medium storing a computer program that, when executed by a processor, implements the molecular simulation method for the interaction behavior of vulcanized rubber powder and asphalt described above. This computer-readable medium may be included in the device / apparatus / system described in the above embodiments; or it may exist independently and not assembled into that device / apparatus / system. The aforementioned computer-readable medium carries one or more programs, which, when executed, implement the method as described in the embodiments of this application.

[0123] According to embodiments of this application, a computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media can also be any computer-readable medium other than computer-readable storage media, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wireless, wired, optical fiber, radio frequency signals, etc., or any suitable combination thereof.

[0124] Those skilled in the art will understand that the features described in the various embodiments of this application can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this application. In particular, the features described in the various embodiments of this application can be combined and / or combined in various ways without departing from the spirit and teachings of this application. All such combinations and / or combinations fall within the scope of this application. Therefore, the scope of this application should not be limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A molecular simulation method for the interaction behavior of vulcanized rubber powder and asphalt, characterized in that, include: Molecular models of rubber powder and asphalt were constructed using molecular simulation software. A model of the rubber powder modified asphalt system was established based on the aforementioned rubber powder molecular model and the aforementioned asphalt molecular model. Assign molecular force fields to the rubber powder molecular model, the asphalt molecular model, and the rubber powder modified asphalt system model; Energy minimization and relaxation operations were performed on the rubber powder modified asphalt system model, and the thermodynamic parameters and particle trajectories of the rubber powder modified asphalt system model were calculated. The interaction between vulcanized rubber powder and asphalt was evaluated based on the thermodynamic parameters and particle trajectories of the rubber powder modified asphalt system model.

2. The molecular simulation method for the interaction behavior of vulcanized rubber powder and asphalt as described in claim 1, characterized in that, The step of establishing a rubber-modified asphalt system model based on the rubber powder molecular model and the asphalt molecular model includes: The vulcanization crosslinking bonds are introduced into the rubber powder molecular model molecule to form a vulcanized rubber powder model, and the vulcanized rubber powder model is subjected to graded desulfurization treatment to obtain a first desulfurized rubber powder model and a second desulfurized rubber powder model. Based on the vulcanized rubber powder model, the first desulfurized rubber powder model, the second desulfurized rubber powder model, and the asphalt molecule model, layered structures are constructed and mixed and assembled to obtain dry rubber asphalt models and wet rubber asphalt models.

3. The molecular simulation method for the interaction behavior of vulcanized rubber powder and asphalt as described in claim 2, characterized in that, The step of introducing vulcanization crosslinks into the rubber powder molecular model molecule to form a vulcanized rubber powder model includes: During the modeling process, the CH bonds in the three molecular structures of the adhesive powder molecular model are randomly broken, and sulfur is introduced in proportions of 2% to 6%. Sulfur atoms are used to connect the broken bonds to form CS bonds, SS bonds and SSS bonds.

4. The molecular simulation method for the interaction behavior of vulcanized rubber powder and asphalt as described in claim 3, characterized in that, The step of performing graded desulfurization treatment on the vulcanized rubber powder model to obtain a first desulfurized rubber powder model and a second desulfurized rubber powder model includes: Select all the vulcanization crosslinking bonds in the vulcanized rubber powder model, break all the SS bonds and SSS bonds, and break a small number of CS bonds and C=C bonds to obtain the first desulfurized rubber powder model. Based on the first desulfurized rubber powder model, the remaining CS bonds and some C=C bonds in the first desulfurized rubber powder model are broken to obtain the second desulfurized rubber powder model.

5. The molecular simulation method for the interaction behavior of vulcanized rubber powder and asphalt as described in claim 1, characterized in that, The asphalt molecular model is a twelve-component molecular model, including four components: asphaltenes, resins, saturated components, and aromatic components.

6. The molecular simulation method for the interaction behavior of vulcanized rubber powder and asphalt as described in claim 1, characterized in that, The energy minimization process includes geometric optimization and annealing calculations; the relaxation operation includes dynamic calculations under the NVT ensemble and the NPT ensemble.

7. The molecular simulation method for the interaction behavior of vulcanized rubber powder and asphalt as described in claim 1, characterized in that, The molecular force field is a COMPASS II force field.

8. The molecular simulation method for the interaction behavior of vulcanized rubber powder and asphalt as described in claim 2, characterized in that, The thermodynamic parameters include: the cohesive energy density of the rubber powder molecular model and the asphalt molecular model, the free volume and occupied volume of the wet rubber asphalt model, the energy of the wet rubber asphalt model and the dry rubber asphalt model, and the particle trajectory is the motion path of the dry rubber asphalt model as it changes over time.

9. The molecular simulation method for the interaction behavior of vulcanized rubber powder and asphalt as described in claim 8, characterized in that, The evaluation of the interaction between vulcanized rubber powder and asphalt based on the thermodynamic parameters and particle trajectories of the rubber powder modified asphalt system model includes: The cohesive energy density of the rubber powder molecular model and the asphalt molecular model is converted into a solubility parameter, and the compatibility is determined based on the solubility difference between the rubber powder molecular model and the asphalt molecular model. The free volume fraction of the wet-process rubber asphalt model is calculated based on the free volume and occupied volume of the wet-process rubber asphalt model. The free volume fraction is used to characterize the influence of rubber powder on the free volume of asphalt. Energy parameters of rubber molecules and asphalt molecules are extracted from the energy of the wet rubber asphalt model and the dry rubber asphalt model, respectively. The bonding energy between rubber and asphalt in the corresponding rubber asphalt model is calculated based on the total energy of the wet rubber asphalt model, the total energy of the dry rubber asphalt model, the total energy of rubber molecules, and the total energy of asphalt molecules. The motion path of rubber molecules over time is obtained from the particle motion trajectory of the dry rubber asphalt model, and the diffusion coefficient of rubber molecules in asphalt is calculated based on the motion path of rubber molecules over time.

10. A molecular simulation device for the interaction behavior of vulcanized rubber powder and asphalt, characterized in that, include: The first construction module is used to construct molecular models of rubber powder and asphalt using molecular simulation software. The second construction module is used to establish a rubber powder modified asphalt system model based on the rubber powder molecular model and the asphalt molecular model. The force field allocation module is used to allocate molecular force fields to the rubber powder molecular model, the asphalt molecular model, and the rubber powder modified asphalt system model. The computation module is used to perform energy minimization and relaxation operations on the rubber powder modified asphalt system model, and to calculate the thermodynamic parameters and particle trajectories of the rubber powder modified asphalt system model. The evaluation module is used to evaluate the interaction effect between vulcanized rubber powder and asphalt based on the thermodynamic parameters and particle motion trajectories of the rubber powder modified asphalt system model.

Images