CN-121999922-A - Foam rubber asphalt formula determination method

Abstract

The invention discloses a foam rubber asphalt formula determining method which comprises the steps of S1, constructing a molecular model of a foam rubber asphalt composite system, S2, carrying out molecular dynamics simulation on the molecular model to obtain a balanced stable structure configuration, S3, calculating shear modulus, interfacial adhesion work and fracture energy of the foam rubber asphalt system under different rubber doping amounts, foaming medium doping amounts and temperature conditions based on the stable structure configuration, and S4, carrying out multi-objective optimization by taking the shear modulus, the interfacial adhesion work and the fracture energy as performance indexes, and determining the combination of the temperature, the foaming medium doping amount and the rubber doping amount of the optimal formula of the foam rubber asphalt. According to the method, the combination of the foaming temperature, the mixing amount of the foaming medium and the mixing amount of the rubber is determined through molecular modeling and a multi-objective optimization algorithm, so that the performance prediction and the parameter optimization of the foam rubber asphalt are realized.

Inventors

• CHEN ZHIZHONG
• GUO XIAOFENG
• CHU FUJUN
• HAN YANFEI
• ZHAO PENGFEI
• XU HAILONG
• LI FENG
• SONG LONGLONG
• WANG SUFEI
• LU JIABAO
• CAI NING
• HU DONGLIANG
• YANG FAN
• ZHOU JINFA
• ZHAO JUN
• ZHANG ZHIQIANG
• ZHANG JIUPENG
• Segirahu
• CHEN XUAN
• YANG LIHONG

Assignees

• 内蒙古交工养护工程技术有限责任公司
• 长安大学

Dates

Publication Date

20260508

Application Date

20251224

Claims (10)

1. 1. A method for determining a foam rubber asphalt formulation, comprising: S1, constructing a molecular model of a foam rubber asphalt composite system; s2, performing molecular dynamics simulation on the molecular model to obtain a balanced stable structure configuration; s3, calculating shear modulus, interfacial adhesion work and fracture energy of the foamed rubber asphalt system under the conditions of different rubber doping amounts, foaming medium doping amounts and temperatures based on the stable structure configuration; s4, performing multi-objective optimization by taking the shear modulus, the interfacial adhesion work and the fracture energy as performance indexes, and determining the combination of the temperature, the foaming medium doping amount and the rubber doping amount of the optimal formula of the foam rubber asphalt.
2. 2. The method for determining the foam rubber asphalt formula according to claim 1, wherein the constructing the molecular model of the foam rubber asphalt composite system comprises the following steps: s11, separating components of the matrix asphalt to obtain asphaltene, colloid, aromatic components and saturated components, analyzing and determining element composition and functional group distribution of each component, and constructing a representative molecular structure or molecular model of each component; S12, carrying out directional modification on the waste rubber powder, and determining a representative molecular structure or a molecular model of the modified rubber powder; S13, establishing an initial molecular model of the foam rubber asphalt composite system according to the representative molecular structure or molecular model of each component of the matrix asphalt, the representative molecular structure or molecular model of the modified rubber powder and the proportion of a foaming medium, and performing geometric optimization and energy minimization treatment.
3. 3. The method for determining a foam rubber asphalt formulation according to claim 2, wherein in step S11, the method for separating the components of the matrix asphalt comprises solvent extraction and chromatography, and the elemental composition and functional group distribution of each component are determined by infrared spectroscopy, nuclear magnetic resonance, mass spectrometry and elemental analysis, and the molecular formula is modified according to the result of the elemental analysis.
4. 4. The method according to claim 2, wherein in step S12, the directional modification comprises oxidation, cleavage, and grafting.
5. 5. The method for determining a foam rubber asphalt formula according to claim 2, wherein in step S13, geometric optimization and energy minimization are performed on an initial molecular model of the foam rubber asphalt system by using a COMPASS II force field, and an energy fluctuation range of the foam rubber asphalt system is not more than 2% of an initial total energy, so as to obtain an initial stable structure, wherein the initial molecular model of the foam rubber asphalt system is an amorphous state or an interface composite system.
6. 6. A method of determining a foamed rubber asphalt formulation according to claim 2, wherein the foaming medium comprises one or more of water, a low boiling point organic solvent.
7. 7. The method for determining a foam rubber asphalt formulation according to claim 1, wherein the molecular dynamics simulation is performed on the molecular model to obtain a balanced stable structural configuration, and the method comprises the steps of: And (3) carrying out molecular dynamics simulation under the regular ensemble conditions of NVT and NPT, wherein the adopted force field is a COMPASS II force field, the integral step length is 1 femto second, the total simulation time is not less than 500 pico seconds, and the system density and the energy are balanced to obtain a stable structural configuration which can be used for performance calculation.
8. 8. The method of claim 1, wherein in step S3, calculating the shear modulus, interfacial adhesion work, and energy of rupture of the foamed rubber asphalt system comprises: Applying small shear strain to the stable structure configuration, recording a linear section of a stress-strain curve, and calculating a system shear modulus; Constructing an interface model of the foam rubber asphalt and mineral aggregates, and calculating an energy difference to obtain an interface adhesion work; And carrying out uniaxial tension molecular dynamics simulation on the foam rubber asphalt system, and calculating the area under a stress-strain curve to obtain the fracture energy.
9. 9. The method for determining a foamed rubber asphalt formulation according to claim 1, wherein in step S4, the multi-objective optimization comprises: And normalizing the shear modulus, the interfacial adhesion work and the fracture energy serving as performance indexes, inputting a non-dominant sorting genetic algorithm to generate a pareto optimal solution set, calculating the comprehensive closeness of each scheme in the pareto optimal solution set by using an approximate ideal solution sorting method, and selecting the scheme with the highest closeness as the combination of the temperature, the foaming medium doping amount and the rubber doping amount of the foam rubber asphalt optimal formula.
10. 10. The method for determining the foam rubber asphalt formulation according to claim 9, wherein the weights of the shear modulus, the interfacial adhesion work and the breaking energy in calculating the integrated closeness are determined by using a TOPSIS algorithm modified by an entropy weight method.

Description

Foam rubber asphalt formula determination method Technical Field The invention belongs to the technical field of road engineering materials and calculation simulation, and particularly relates to a foam rubber asphalt formula determination method. Background The foam rubber asphalt is a modified material prepared by introducing waste rubber powder into matrix asphalt and through an instantaneous foaming process, has good high-temperature stability, low-temperature crack resistance and water stability, and has great potential in road pavement structure application. The addition of the rubber powder can obviously improve the viscoelastic property of asphalt and improve the durability of the material, but the compatibility between the rubber powder and the asphalt is poor, the dispersibility of the rubber powder particles in the asphalt is poor, and the modification effect and the subsequent foaming property are easy to be unstable. The traditional modification method relies on experience or a large number of experiments to determine the optimal blending amount and process conditions, and has the advantages of long period, high cost and poor repeatability. In recent years, molecular dynamics simulation provides a new technical path for asphalt material research, and microstructure evolution, intermolecular interaction and performance response of materials can be simulated by constructing a molecular layer model. However, the existing researches focus on the simulation evaluation of single performance (such as high-temperature performance or low-temperature performance) and lack the systematic optimization of the multi-performance indexes of the foamed rubber asphalt. In addition, the traditional material performance evaluation method such as the analytic hierarchy process has the problems of strong subjectivity, poor result stability and the like in the weight distribution in parameter optimization, and is difficult to meet the scientific decision requirement of a multi-factor coupling system. Therefore, a method for determining the optimal proportion of the foam rubber asphalt by an advanced multi-objective optimization algorithm based on a molecular scale model and comprehensively considering a plurality of performance indexes is needed, so that the scientificity and the efficiency of the design of the rubber foam asphalt material are improved. Disclosure of Invention The invention aims to solve the technical problem of providing a foam rubber asphalt formula determination method aiming at the defects of the prior art, and the method realizes the performance prediction and parameter optimization of the foam rubber asphalt by determining the combination of foaming temperature, foaming medium mixing amount and rubber mixing amount through a molecular modeling and multi-objective optimization algorithm. The invention adopts the technical proposal for solving the problems that: A method for determining a foam rubber asphalt formulation, comprising: S1, constructing a molecular model of a foam rubber asphalt composite system; s2, performing molecular dynamics simulation on the molecular model to obtain a balanced stable structure configuration; s3, calculating shear modulus, interfacial adhesion work and fracture energy of the foamed rubber asphalt system under the conditions of different rubber doping amounts, foaming medium doping amounts and temperatures based on the stable structure configuration; s4, performing multi-objective optimization by taking the shear modulus, the interfacial adhesion work and the fracture energy as performance indexes, and determining the combination of the temperature, the foaming medium doping amount and the rubber doping amount of the optimal formula of the foam rubber asphalt. In the scheme, the construction of the molecular model of the foam rubber asphalt composite system comprises the following steps: S11, separating components of the matrix asphalt to obtain asphaltene, colloid, aromatic components and saturated components, analyzing and determining element composition, functional group distribution and relative molecular mass of each component, constructing a representative molecular structure or molecular model of each component, and calculating the quantity proportion of each component; S12, carrying out directional modification on the waste rubber powder to determine a representative molecular structure or a molecular model of the modified rubber powder, wherein the modification aims have the dual purposes of firstly matching the specific functional groups with key chemical characteristics (such as aromatic ring structures) of asphalt aromatic components in the chemical structure, secondly adjusting the chain segment length and the polymerization degree of the rubber molecules in the physical conformation through controllable degradation or grafting so as to be close to the molecular size distribution of the asphalt aromatic component model, and forming a uniform and sta