A method and system for testing the stability of SBS-modified asphalt grafted with desulfurized rubber powder.

Abstract

This invention provides a method and system for testing the stability of SBS-modified asphalt grafted with desulfurized rubber powder, relating to the field of asphalt stability testing technology. The method includes: processing waste tire rubber powder to obtain desulfurized waste tire rubber powder; preparing asphalt samples based on the desulfurized waste tire rubber powder; constructing a multi-level model of SBS-modified asphalt grafted with desulfurized rubber powder based on the asphalt samples; determining the crosslinking density of the rubber in the asphalt samples through crosslinking density tests based on the multi-level model; performing dynamic shear rheological tests on the asphalt samples to obtain the complex modulus and phase angle at multiple temperature points and multiple frequencies; determining the crosslinking stability coefficient based on the crosslinking density, complex modulus, and phase angle; and determining the stability of the SBS-modified asphalt grafted with desulfurized rubber powder based on the crosslinking stability coefficient. According to this invention, the stability of asphalt can be detected based on the crosslinking density, improving the accuracy of asphalt stability testing.

Description

Technical Field

[0001] This invention relates to the field of asphalt stability testing technology, and in particular to a method and system for testing the stability of SBS-modified asphalt grafted with desulfurized rubber powder. Background Technology

[0002] Current technologies use the ratio of tensile residual energy during freeze-thaw cycles and real-time monitoring of physical data to test asphalt stability, but do not consider the impact of crosslinking density on asphalt stability. In other words, it is impossible to test the stability of asphalt based on crosslinking density.

[0003] The information disclosed in the background section of this application is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0004] This invention provides a method and system for testing the stability of SBS-modified asphalt grafted with desulfurized rubber powder, which can solve the technical problem that related technologies cannot detect the stability of asphalt based on the crosslinking density.

[0005] According to a first aspect of the present invention, a method for testing the stability of SBS-modified asphalt grafted with desulfurized rubber powder is provided, comprising: processing waste tire rubber powder to obtain waste tire desulfurized rubber powder; preparing an asphalt sample based on the waste tire desulfurized rubber powder, wherein the asphalt sample is SBS-modified asphalt grafted with desulfurized rubber powder; constructing a multilevel model of the SBS-modified asphalt grafted with desulfurized rubber powder based on the asphalt sample; determining the crosslinking density of the rubber in the asphalt sample by a crosslinking density test based on the multilevel model; performing a dynamic shear rheological test on the asphalt sample to obtain the complex modulus and phase angle at multiple temperature points and multiple frequencies; determining a crosslinking stability coefficient based on the crosslinking density, the complex modulus, and the phase angle; and determining the stability of the SBS-modified asphalt grafted with desulfurized rubber powder based on the crosslinking stability coefficient.

[0006] Furthermore, based on the asphalt sample, a multi-level model of desulfurized rubber powder grafted SBS modified asphalt is constructed, including: using molecular dynamics simulation to construct a molecular dynamics model of desulfurized rubber powder grafted SBS, asphalt, and admixtures in the asphalt sample, and performing quantum mechanical calculations; based on the molecular dynamics model and the quantum mechanical calculations, a multi-level model of desulfurized rubber powder grafted SBS modified asphalt is constructed.

[0007] Furthermore, based on the multi-level model, the crosslinking density of rubber in the asphalt sample is determined by a crosslinking density test, including: obtaining a first mass of a preset rubber disc pressed into a two-roll mill according to the multi-level model; swelling the preset rubber disc in toluene and then removing it to obtain a second mass and a second density of the swollen preset rubber disc; obtaining the volume and density of toluene; and determining the crosslinking density of rubber in the asphalt sample based on the first mass, the second mass, the second density, the volume and density of toluene.

[0008] Further, the crosslinking density of rubber in the asphalt sample is determined based on the first mass, the second mass, the second density, the toluene volume, and the toluene density, including: according to the formula: , Determine the crosslinking density of rubber per unit volume in the e-th asphalt sample. ,in, For the first quality, For the second mass, For the second density, The density of toluene, The volume fraction of rubber in the pre-defined rubber disc is set for swelling. These are polymer-solvent interaction parameters. This represents the volume of toluene.

[0009] Further, determining the crosslinking stability coefficient based on the crosslinking density, the complex modulus, and the phase angle includes: obtaining a first maximum value, a first minimum value, and a first average value of the complex modulus of the asphalt sample at multiple temperature points and multiple frequencies based on the complex modulus; obtaining a second maximum value, a second minimum value, and a second average value of the phase angle of the asphalt sample at multiple temperature points and multiple frequencies based on the phase angle; obtaining the loss factor change rate based on the first maximum value, the first minimum value, and the first average value; obtaining the frequency sensitivity index based on the second maximum value, the second minimum value, and the second average value; and determining the crosslinking stability coefficient based on the crosslinking density, the loss factor change rate, and the frequency sensitivity index.

[0010] Further, the crosslinking stability coefficient is determined based on the crosslinking density, the loss factor change rate, and the frequency sensitivity index, including: according to the formula: Determine the crosslinking stability coefficient of the e-th asphalt sample ,in, Let be the crosslinking density of rubber per unit volume in the e-th asphalt sample. To set the crosslinking density per unit volume of rubber, Let be the rate of change of the loss factor for the e-th asphalt sample. Let be the frequency sensitivity index of the e-th asphalt sample.

[0011] Further, based on the crosslinking stability coefficient, the stability of the SBS-modified asphalt grafted with desulfurized rubber powder is determined, including: if the crosslinking stability coefficient is greater than a preset crosslinking stability coefficient, the stability of the SBS-modified asphalt grafted with desulfurized rubber powder is determined to be good; if the crosslinking stability coefficient is less than or equal to the preset crosslinking stability coefficient, the stability of the SBS-modified asphalt grafted with desulfurized rubber powder is determined to be poor.

[0012] According to a second aspect of the present invention, a stability testing system for desulfurized rubber powder grafted with SBS modified asphalt is provided, comprising: a waste tire desulfurized rubber powder module for processing waste tire rubber powder to obtain waste tire desulfurized rubber powder; an asphalt sample module for preparing an asphalt sample based on the waste tire desulfurized rubber powder, wherein the asphalt sample is desulfurized rubber powder grafted with SBS modified asphalt; a multi-level model construction module for constructing a multi-level model of desulfurized rubber powder grafted with SBS modified asphalt based on the asphalt sample; a crosslinking density module for determining the crosslinking density of rubber in the asphalt sample through a crosslinking density test based on the multi-level model; a complex modulus and phase angle module for performing dynamic shear rheological tests on the asphalt sample to obtain the complex modulus and phase angle at multiple temperature points and multiple frequencies; a crosslinking stability coefficient module for determining the crosslinking stability coefficient based on the crosslinking density, the complex modulus, and the phase angle; and a stability status module for determining the stability status of the desulfurized rubber powder grafted with SBS modified asphalt based on the crosslinking stability coefficient.

[0013] Technical Effects: According to this invention, by constructing a multi-level model, the behavior of SBS-modified asphalt grafted with desulfurized rubber powder can be analyzed in depth from multiple levels, including microscopic, mesoscopic, and macroscopic. This helps to comprehensively understand the structure-performance relationship of the asphalt at different scales. Furthermore, by conducting crosslinking density tests, the crosslinking density of the rubber in the asphalt sample can be determined to optimize the asphalt performance. The complex modulus and phase angle obtained from dynamic shear rheological testing can reflect the viscoelastic properties of the asphalt at different temperatures and frequencies. The stability of the asphalt can be detected based on the crosslinking density, improving the accuracy of asphalt stability testing. When determining the crosslinking density of the rubber in the asphalt sample, the physical and chemical changes of the rubber during the swelling process, as well as the interaction between the rubber and the solvent, can be used to determine the crosslinking density. Crosslinking density is a key indicator for evaluating the performance of rubber materials, reflecting the number and tightness of crosslinks between rubber molecular chains. When determining the crosslinking stability coefficient, it can be determined through crosslinking density, loss factor change rate, and frequency sensitivity index. This allows for accurate assessment of the ability of the tightness of the internal rubber network structure of the asphalt material to resist the effects of temperature and frequency changes during actual use, thus understanding the performance stability and reliability of the asphalt material.

[0014] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Other features and aspects of the invention will become clearer from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0016] Figure 1 An exemplary flowchart of a method for testing the stability of SBS-modified asphalt grafted with desulfurized rubber powder according to an embodiment of the present invention is shown.

[0017] Figure 2 An exemplary flowchart illustrates a multi-level model for constructing desulfurized rubber powder grafted SBS modified asphalt according to an embodiment of the present invention;

[0018] Figure 3 A flowchart for calculating crosslinking density according to an embodiment of the present invention is shown as an example;

[0019] Figure 4 A flowchart for calculating the crosslinking stability coefficient according to an embodiment of the present invention is shown as an example;

[0020] Figure 5 A flowchart for determining a steady state according to an embodiment of the present invention is illustrated by way of example;

[0021] Figure 6 A block diagram of a stability testing system for desulfurized rubber powder grafted with SBS modified asphalt according to an embodiment of the present invention is shown as an example. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0024] Figure 1 An exemplary flowchart illustrates a method for testing the stability of SBS-modified asphalt grafted with desulfurized rubber powder according to an embodiment of the present invention. The method includes: Step S1, processing waste tire rubber powder to obtain desulfurized waste tire rubber powder; Step S2, preparing an asphalt sample based on the desulfurized waste tire rubber powder, wherein the asphalt sample is SBS-modified asphalt grafted with desulfurized rubber powder; Step S3, constructing a multi-level model of SBS-modified asphalt grafted with desulfurized rubber powder based on the asphalt sample; Step S4, determining the crosslinking density of the rubber in the asphalt sample through a crosslinking density test based on the multi-level model; Step S5, performing a dynamic shear rheological test on the asphalt sample to obtain the complex modulus and phase angle at multiple temperature points and multiple frequencies; Step S6, determining the crosslinking stability coefficient based on the crosslinking density, the complex modulus, and the phase angle; Step S7, determining the stability of the SBS-modified asphalt grafted with desulfurized rubber powder based on the crosslinking stability coefficient.

[0025] The stability testing method for SBS-modified asphalt grafted with desulfurized rubber powder according to embodiments of the present invention, by constructing a multi-level model, allows for in-depth analysis of the behavior of SBS-modified asphalt grafted with desulfurized rubber powder at multiple levels, from microscopic to macroscopic. This helps to comprehensively understand the structure-property relationship of the asphalt at different scales. Furthermore, by conducting crosslinking density tests, the crosslinking density of the rubber in the asphalt sample can be determined to optimize the asphalt's performance. The complex modulus and phase angle obtained from dynamic shear rheological testing can reflect the viscoelastic properties of the asphalt at different temperatures and frequencies. The stability of the asphalt can be detected based on the crosslinking density, improving the accuracy of asphalt stability testing.

[0026] According to an embodiment of the present invention, in step S1, waste tire rubber powder is first placed in an oven for drying. The oven temperature is set to 60°C until the rubber powder is completely dried and the moisture is removed (the quality of the rubber powder is constant). The rubber powder is then desulfurized using a microwave device. Finally, a desulfurization aid is used to treat the surface of the desulfurized rubber powder to obtain desulfurized waste tire rubber powder.

[0027] According to one embodiment of the present invention, in step S2, desulfurized rubber powder with C=O and S=O polar ester groups is grafted onto the PB segment of SBS using a living or controlled polymerization method via a thiol-olefin click reaction. Desulfurized rubber powder grafted with SBS modified asphalt with different degrees of polymerization is prepared by adjusting the temperature and screw speed using a screw extruder.

[0028] According to one embodiment of the present invention, in step S3, a multi-level model of desulfurized rubber powder grafted SBS modified asphalt is constructed based on the asphalt sample.

[0029] Figure 2A flowchart illustrating, exemplarily, describes a multi-level model for constructing desulfurized rubber powder grafted SBS modified bitumen according to an embodiment of the present invention.

[0030] According to an embodiment of the present invention, step S3 includes: step S31, using molecular dynamics simulation method to construct a molecular dynamics model of desulfurized rubber powder grafted SBS, asphalt and admixture in the asphalt sample, and performing quantum mechanical calculations; step S32, based on the molecular dynamics model and the quantum mechanical calculations, constructing a multi-level model of desulfurized rubber powder grafted SBS modified asphalt.

[0031] According to one embodiment of the present invention, firstly, by investigating and summarizing existing research results, typical molecules such as polymers and asphalt are screened. Based on the composite material fusion mechanism and chemical principles, desulfurized rubber powder grafted with SBS, asphalt, and admixture molecules are constructed to clarify the composition of the multi-component composite modified asphalt mixture model. Then, based on the characteristic indicators of asphalt components, the number of molecules in the mixture model is calculated, and molecular force fields and calculation parameters are allocated to construct a molecular dynamics model. Molecular dynamics, mesoscopic dynamics, radial distribution function, and other parameters, along with blending experiments, are used to analyze the mechanism of action in the dispersion and stabilization process of the copolymer. First-principles density functional theory is used to calculate the synergistic effect of the multi-component composite modified asphalt in the dispersion, swelling, and stabilization stages. Combined with calculations involving kinetics, thermodynamics, optical properties, transition state search, and competitive adsorption, the influence of surface modification methods on the microstructure of the multi-component composite modified asphalt is elucidated, revealing the synergistic effect of the multi-component composite system at the molecular and quantum mechanical levels. The parameter transfer methods from the molecular model to the coarse-grained model are studied for the copolymer, asphalt, admixture, and interface in the desulfurized rubber powder grafted with SBS and admixture multi-component composite modified asphalt. Considering the viscoelastic properties of rubber materials, the coarse-grained force fields of the copolymer and asphalt's all-atom model structure and mechanical properties are obtained using anti-Boltzmann iteration and mechanical correction. The coarse-grained force field of the admixture is obtained using strain energy conservation. The interface coarse-grained force field parameters are obtained using energy matching in copolymer pull-out simulations. The dispersion and entanglement network of desulfurized rubber powder-grafted SBS are quantitatively characterized by calculating the distribution characteristics, entanglement properties, and surface asphalt molecular chain adsorption of the SBS. The static mechanical properties (uniaxial tension) and dynamic mechanical properties (oscillatory shear) of the multi-component composite material are calculated. The relationship between the structure and dynamic and static mechanical properties of multi-component composite materials with different fractions / sizes of desulfurized rubber powder-grafted SBS is analyzed, and a coarse-grained model of desulfurized rubber powder-grafted SBS and admixture-modified multi-component composite asphalt is established. Therefore, the "micro-meta-macro" multi-level model constructed based on the above content is the multi-level model of SBS-modified asphalt grafted with desulfurized rubber powder. This model describes and analyzes asphalt samples from multiple levels, including microscopic (such as molecular structure, interaction between rubber particles and the asphalt matrix), mesoscopic (such as dispersion state of rubber particles, phase interface characteristics), and macroscopic (such as overall mechanical properties, rheological properties). The multi-level model of SBS-modified asphalt grafted with desulfurized rubber powder provides a theoretical basis and directional guidance for the design of crosslinking density tests, data interpretation, and correlation analysis between crosslinking density and overall asphalt performance.

[0032] According to one embodiment of the present invention, in step S4, the crosslinking density of rubber in the asphalt sample is determined by crosslinking density test based on the multi-level model.

[0033] Figure 3 A flowchart for calculating crosslinking density according to an embodiment of the present invention is shown as an example.

[0034] According to an embodiment of the present invention, step S4 includes: step S41, obtaining a first mass of a preset rubber disc pressed into a two-roll mill according to the multi-level model; step S42, swelling the preset rubber disc in toluene and then removing it to obtain a second mass and a second density of the swollen preset rubber disc; step S43, obtaining the volume and density of toluene; and step S44, determining the crosslinking density of the rubber in the asphalt sample based on the first mass, the second mass, the second density, the volume and density of toluene.

[0035] According to one embodiment of the present invention, acetone was used as a solvent to perform Soxhlet extraction on rubber in an asphalt sample at 60°C for 24 hours. The residue was first pressed into 0.2 mm sheets using a two-roll mill. Then, pre-set rubber discs with a diameter of 12 mm were cut with a cutter, weighed, and recorded as the first mass. These discs were then placed in toluene and swollen at room temperature for 72 hours. After swelling, the pre-set rubber discs were removed, and the small amount of residual solvent on the surface of the discs was wiped off with filter paper. The discs were then quickly weighed and recorded as the second mass. Rubber particles can absorb lightweight components in asphalt, forming an elastic network and reducing flow deformation at high temperatures. The cross-linking density of the rubber in the asphalt sample reflects the tightness of the internal network structure of the rubber.

[0036] According to an embodiment of the present invention, determining the crosslinking density of rubber in an asphalt sample based on the first mass, the second mass, the second density, the volume of toluene, and the density of toluene includes: determining the crosslinking density of rubber per unit volume in the e-th asphalt sample according to formulas (1) and (2). ,

[0037] (1),

[0038] (2),

[0039] in, For the first quality, For the second mass, For the second density, The density of toluene, The volume fraction of rubber in the pre-defined rubber disc is set for swelling. These are polymer-solvent interaction parameters. This represents the volume of toluene.

[0040] According to an embodiment of the present invention, in formula (1), The result of multiplying the second mass by the ratio of the second density to the toluene density represents the equivalent volume of the absorbed toluene mass at the density of the swollen rubber. The sum of the first mass and the equivalent volume converted from the mass of absorbed toluene to the density of the swollen rubber represents the equivalent total volume with reference to the density of the swollen rubber. The ratio between the first mass and the equivalent total volume referenced to the density of the swollen rubber represents the volume fraction of rubber in the pre-swollen rubber disc. In formula (2), due to the interaction between rubber molecules and solvent molecules, this interaction alters the swelling behavior of the rubber and is related to the polymer-solvent interaction parameter (e.g., 0.44). The product of the polymer-solvent interaction parameter and the square of the volume fraction of rubber in the pre-swollen rubber disc represents the effect of the polymer-solvent interaction on the swelling system. This term, derived from thermodynamic theory, relates to the free energy of rubber swelling and reflects the change in free energy caused by volume changes during the swelling process. This comprehensively reflects the change in mixing free energy when the rubber phase and solvent phase are mixed during the rubber swelling process. As a correction factor related to the volume fraction of rubber, it takes into account the volume change characteristics of rubber during the swelling process due to the presence of cross-linked structures, and further corrects the calculation results of cross-linking density. This means combining the volume factor of the solvent with the extension and constraint factors of the rubber molecular chains. Let be the crosslinking density of rubber per unit volume in the e-th asphalt sample, representing the tightness of the internal network structure of the rubber. The higher the crosslinking density, the tighter the internal network structure of the rubber, meaning that the rubber exhibits higher strength and elasticity.

[0041] In this way, the crosslinking density of rubber in an asphalt sample can be determined by observing the physical and chemical changes of rubber during the swelling process, as well as the interaction between rubber and solvent. Crosslinking density is a key indicator for evaluating the performance of rubber materials, reflecting the number and tightness of crosslinks between rubber molecular chains.

[0042] According to one embodiment of the present invention, in step S5, a dynamic shear rheometer is activated to perform tests based on different shear frequencies (5000 r / min, 5500 r / min, 6000 r / min) and different temperature points (170℃, 180℃, 190℃). During the test, the instrument automatically records data such as the complex modulus and phase angle at different frequencies. The complex modulus reflects the overall resistance to deformation of the asphalt sample under alternating shear, including the elastic and viscous components, while the phase angle represents the phase difference between stress and strain, reflecting the viscoelastic characteristics of asphalt.

[0043] According to one embodiment of the present invention, in step S6, the crosslinking stability coefficient is determined based on the crosslinking density, the complex modulus, and the phase angle.

[0044] Figure 4 A flowchart for calculating the crosslinking stability coefficient according to an embodiment of the present invention is shown as an example.

[0045] According to an embodiment of the present invention, step S6 includes: step S61, obtaining a first maximum value, a first minimum value, and a first average value of the complex modulus of the asphalt sample at multiple temperature points and multiple frequencies based on the complex modulus; step S62, obtaining a second maximum value, a second minimum value, and a second average value of the phase angle of the asphalt sample at multiple temperature points and multiple frequencies based on the phase angle; step S63, obtaining the loss factor change rate based on the first maximum value, the first minimum value, and the first average value; step S64, obtaining the frequency sensitivity index based on the second maximum value, the second minimum value, and the second average value; and step S65, determining the crosslinking stability coefficient based on the crosslinking density, the loss factor change rate, and the frequency sensitivity index.

[0046] According to one embodiment of the present invention, the rate of change of the loss factor can be determined according to the formula... We obtained, among which, Let be the rate of change of the loss factor for the e-th asphalt sample. The first maximum value of the e-th asphalt sample. This is the first minimum value of the e-th asphalt sample. This is the first average value of the e-th asphalt sample, used to measure the relative change of the loss factor within the test range. It reflects the fluctuation of the viscous components of the asphalt material during frequency scanning; the smaller the fluctuation, the better. The smaller the value, the more stable the material. The frequency sensitivity index can be calculated using the formula... We obtained, among which, Let e ​​be the frequency sensitivity index of the e-th asphalt sample. The second maximum value of the e-th asphalt sample. This is the second minimum value of the e-th asphalt sample. The second average value of the e-th asphalt sample is used to measure the relative change of the index within the test range, reflecting the sensitivity of the asphalt material to frequency changes. The lower the sensitivity, the smaller F, the closer the material is to an ideal elastomer, and the better its stability. The crosslinking stability coefficient is used to comprehensively evaluate the stability of the asphalt crosslinking structure.

[0047] According to one embodiment of the present invention, determining the crosslinking stability coefficient based on the crosslinking density, the loss factor change rate, and the frequency sensitivity index includes: determining the crosslinking stability coefficient of the e-th asphalt sample according to formula (3). ,

[0048] (3),

[0049] in, Let be the crosslinking density of rubber per unit volume in the e-th asphalt sample. To set the crosslinking density per unit volume of rubber, Let be the rate of change of the loss factor for the e-th asphalt sample. Let be the frequency sensitivity index of the e-th asphalt sample.

[0050] According to one embodiment of the present invention, in formula (3), The crosslinking density of rubber per unit volume in the e-th asphalt sample is compared with the crosslinking density of rubber per unit volume of a preset value (e.g., 10⁻). 4 mol / cm 3 The higher the ratio of the crosslinking density to the internal network structure of the rubber, the greater the stability of the asphalt sample. The result is the change rate of the loss factor of the e-th asphalt sample plus 1. The smaller this result is, the smaller the fluctuation of the viscous component of the asphalt material during the frequency scanning process, and the greater the stability of the asphalt sample. The result is the frequency sensitivity index of the e-th asphalt sample plus 1. The smaller the result, the lower the sensitivity of the asphalt material to frequency changes, the closer the asphalt sample is to an ideal elastic body, and the greater the stability of the asphalt sample. for and The larger the reciprocal of the product, the greater the stability of the asphalt sample. and Multiplying these values ​​yields the crosslinking stability coefficient of the e-th asphalt sample. The larger this crosslinking stability coefficient, the greater the stability of the asphalt sample.

[0051] In this way, the crosslinking stability coefficient can be determined by crosslinking density, loss factor change rate, and frequency sensitivity index. This allows for accurate assessment of the tightness of the internal rubber network structure of asphalt materials and their ability to resist the effects of temperature and frequency changes during actual use, thus understanding the performance stability and reliability of asphalt materials.

[0052] According to one embodiment of the present invention, in step S7, the stability of the desulfurized rubber powder grafted with SBS modified asphalt is determined based on the crosslinking stability coefficient.

[0053] Figure 5 A flowchart for determining a steady state according to an embodiment of the present invention is shown as an example.

[0054] According to one embodiment of the present invention, step S7 includes: step S71, if the crosslinking stability coefficient is greater than the preset crosslinking stability coefficient, then it is determined that the stability of the desulfurized rubber powder grafted with SBS modified asphalt is good; step S72, if the crosslinking stability coefficient is less than or equal to the preset crosslinking stability coefficient, then it is determined that the stability of the desulfurized rubber powder grafted with SBS modified asphalt is poor.

[0055] According to one embodiment of the present invention, if the crosslinking stability coefficient is greater than the preset crosslinking stability coefficient (e.g., 0.9), it is determined that the desulfurized rubber powder grafted SBS modified asphalt has good stability, that is, the modified asphalt can better resist the effects of external factors such as temperature changes and traffic loads, and maintain the stability of its physical and chemical properties; otherwise, it is determined that the desulfurized rubber powder grafted SBS modified asphalt has poor stability.

[0056] The stability testing method for SBS-modified asphalt grafted with desulfurized rubber powder according to embodiments of the present invention, by constructing a multi-level model, allows for in-depth analysis of the behavior of SBS-modified asphalt grafted with desulfurized rubber powder at multiple levels, from microscopic to macroscopic, contributing to a comprehensive understanding of the structure-performance relationship of the asphalt at different scales. This allows for the determination of the crosslinking density of rubber in the asphalt sample through crosslinking density testing, thereby optimizing the asphalt performance. The complex modulus and phase angle obtained from dynamic shear rheology testing can reflect the viscoelastic properties of asphalt at different temperatures and frequencies. The stability of asphalt can be detected based on the crosslinking density, improving the accuracy of asphalt stability testing. When determining the crosslinking density of rubber in the asphalt sample, the physical and chemical changes of rubber during the swelling process, as well as the interaction between rubber and solvent, can be used to determine the crosslinking density. Crosslinking density is a key indicator for evaluating the performance of rubber materials, reflecting the number and tightness of crosslinks between rubber molecular chains. The crosslinking stability coefficient can be determined through crosslinking density, loss factor change rate, and frequency sensitivity index. It can accurately assess the tightness of the internal network structure of asphalt materials and their ability to resist the effects of temperature and frequency changes during actual use, and understand the performance stability and reliability of asphalt materials.

[0057] Figure 6An exemplary block diagram of a stability testing system for SBS-modified asphalt grafted with desulfurized rubber powder according to an embodiment of the present invention is shown. The system includes: a waste tire desulfurized rubber powder module for processing waste tire rubber powder to obtain waste tire desulfurized rubber powder; an asphalt sample module for preparing asphalt samples based on the waste tire desulfurized rubber powder, wherein the asphalt sample is SBS-modified asphalt grafted with desulfurized rubber powder; a multi-level model construction module for constructing a multi-level model of the SBS-modified asphalt grafted with desulfurized rubber powder based on the asphalt sample; a crosslinking density module for determining the crosslinking density of rubber in the asphalt sample through a crosslinking density test based on the multi-level model; a complex modulus and phase angle module for performing dynamic shear rheological tests on the asphalt sample to obtain the complex modulus and phase angle at multiple temperature points and multiple frequencies; a crosslinking stability coefficient module for determining the crosslinking stability coefficient based on the crosslinking density, the complex modulus, and the phase angle; and a stability status module for determining the stability status of the SBS-modified asphalt grafted with desulfurized rubber powder based on the crosslinking stability coefficient.

[0058] This invention can be a method, apparatus, system, and / or computer program product. The computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for performing various aspects of the invention.

[0059] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments, and any variations or modifications may be made to the implementation of the present invention without departing from the stated principles.

Claims

1. A method for testing the stability of SBS-modified asphalt grafted with desulfurized rubber powder, characterized in that, include: Waste tire rubber powder is processed to obtain desulfurized waste tire rubber powder. Asphalt samples were prepared based on the desulfurized rubber powder from waste tires, wherein the asphalt samples were SBS-modified asphalt grafted with desulfurized rubber powder. A multi-level model of the SBS-modified asphalt grafted with desulfurized rubber powder was constructed based on the asphalt samples. The crosslinking density of the rubber in the asphalt samples was determined through a crosslinking density test based on the multi-level model. Dynamic shear rheological tests were performed on the asphalt samples to obtain the complex modulus and phase angle at multiple temperature points and frequencies. The crosslinking stability coefficient was determined based on the crosslinking density, the complex modulus, and the phase angle. The desulfurization... The stability of SBS-modified asphalt grafted with rubber powder; determining the crosslinking stability coefficient based on the crosslinking density, the complex modulus, and the phase angle, including: obtaining the first maximum value, the first minimum value, and the first average value of the complex modulus of the asphalt sample at multiple temperature points and multiple frequencies based on the complex modulus; obtaining the second maximum value, the second minimum value, and the second average value of the phase angle of the asphalt sample at multiple temperature points and multiple frequencies based on the phase angle; obtaining the loss factor change rate based on the first maximum value, the first minimum value, and the first average value, including: according to the formula: Obtain the rate of change of the loss factor for the e-th asphalt sample, where, The first maximum value of the e-th asphalt sample. This is the first minimum value of the e-th asphalt sample. Let the first average value be the value of the e-th asphalt sample; based on the second maximum value, the second minimum value, and the second average value, obtain the frequency sensitivity index, including: according to the formula: The frequency sensitivity index of the e-th asphalt sample is obtained, where, The second maximum value of the e-th asphalt sample. This is the second minimum value of the e-th asphalt sample. The second average value of the e-th asphalt sample; the crosslinking stability coefficient is determined based on the crosslinking density, the rate of change of the loss factor, and the frequency sensitivity index, including: according to the formula: Determine the crosslinking stability coefficient of the e-th asphalt sample ,in, Let be the crosslinking density of rubber per unit volume in the e-th asphalt sample. To set the crosslinking density per unit volume of rubber, Let be the rate of change of the loss factor for the e-th asphalt sample. Let be the frequency sensitivity index of the e-th asphalt sample.

2. The method for testing the stability of SBS-modified asphalt grafted with desulfurized rubber powder according to claim 1, characterized in that, Based on the asphalt sample, a multi-level model of SBS-modified asphalt grafted with desulfurized rubber powder was constructed, including: using molecular dynamics simulation to construct a molecular dynamics model of SBS-grafted with desulfurized rubber powder, asphalt, and admixtures in the asphalt sample, and performing quantum mechanical calculations; based on the molecular dynamics model and the quantum mechanical calculations, a multi-level model of SBS-modified asphalt grafted with desulfurized rubber powder was constructed.

3. The method for testing the stability of SBS-modified asphalt grafted with desulfurized rubber powder according to claim 1, characterized in that, According to the multi-level model, the crosslinking density of rubber in the asphalt sample is determined by crosslinking density test, including: obtaining the first mass of a preset rubber disc pressed into a two-roll mill according to the multi-level model; swelling the preset rubber disc in toluene and then removing it to obtain the second mass and second density of the swollen preset rubber disc; obtaining the volume and density of toluene; and determining the crosslinking density of rubber in the asphalt sample based on the first mass, the second mass, the second density, the volume and density of toluene. Specifically, acetone is used as a solvent for Soxhlet extraction of rubber in the asphalt sample at 60°C for 24 hours. The residue is first pressed into a 0.2 mm sheet using a two-roll mill, and then preset rubber discs with a diameter of 12 mm are cut using a cutter, weighed and recorded as the first mass. These discs are then soaked in toluene at room temperature for 72 hours, and the preset rubber discs are removed. A small amount of residual solvent on the surface of the discs is wiped off with filter paper, and the discs are quickly weighed and recorded as the second mass.

4. The method for testing the stability of SBS-modified asphalt grafted with desulfurized rubber powder according to claim 3, characterized in that, The crosslinking density of rubber in the asphalt sample is determined based on the first mass, the second mass, the second density, the toluene volume, and the toluene density, including: according to the formula: , Determine the crosslinking density of rubber per unit volume in the e-th asphalt sample. ,in, For the first quality, For the second mass, For the second density, The density of toluene, The volume fraction of rubber in the pre-defined rubber disc is set for swelling. These are polymer-solvent interaction parameters. This represents the volume of toluene.

5. The method for testing the stability of SBS-modified asphalt grafted with desulfurized rubber powder according to claim 1, characterized in that, The stability of SBS-modified asphalt grafted with desulfurized rubber powder is determined based on the crosslinking stability coefficient, including: if the crosslinking stability coefficient is greater than the preset crosslinking stability coefficient, the stability of SBS-modified asphalt grafted with desulfurized rubber powder is determined to be good; if the crosslinking stability coefficient is less than or equal to the preset crosslinking stability coefficient, the stability of SBS-modified asphalt grafted with desulfurized rubber powder is determined to be poor.

6. A stability testing system for SBS-modified asphalt grafted with desulfurized rubber powder, used to perform the stability testing method for SBS-modified asphalt grafted with desulfurized rubber powder as described in any one of claims 1-5, characterized in that, include: The waste tire desulfurization rubber powder module is used to process waste tire rubber powder to obtain waste tire desulfurization rubber powder. asphalt The system includes the following modules: a sample module for preparing asphalt samples based on the desulfurized rubber powder from waste tires, wherein the asphalt samples are SBS-modified asphalt grafted with desulfurized rubber powder; a multi-level model construction module for constructing a multi-level model of the SBS-modified asphalt grafted with desulfurized rubber powder based on the asphalt samples; a crosslinking density module for determining the crosslinking density of the rubber in the asphalt samples through crosslinking density tests based on the multi-level model; a complex modulus and phase angle module for performing dynamic shear rheological tests on the asphalt samples to obtain the complex modulus and phase angle at multiple temperature points and multiple frequencies; a crosslinking stability coefficient module for determining the crosslinking stability coefficient based on the crosslinking density, the complex modulus, and the phase angle; and a stability status module for determining the stability status of the SBS-modified asphalt grafted with desulfurized rubber powder based on the crosslinking stability coefficient.

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