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With the aim of studying the anti-rutting performance of Thiopave modified asphalt mixture applied to the upper layer of pavement, the strain-hardening creep model in ABAQUS finite element software was used to analyze the rutting under the condition of introducing temperature field. Compared with the calculation results of the rutting of ordinary asphalt pavement, it is found that Thiopave can improve the temperature sensitivity of asphalt mixture. With the increase of temperature, the rutting change of Thiopave modified asphalt pavement is smaller than that of ordinary asphalt. Thiopave also has a certain degree of improvement in the fatigue resistance of asphalt pavements, which can be applied to sections with high traffic volume in high temperature areas.

Due to the warming of the climate, the heavy load of vehicles has caused the rut damage of asphalt pavement more and more serious. It is especially important to find a road material with excellent performance against rutting. Yang Xiwu, Das et al. [

Calculating the rutting by the use of ABAQUS finite element software, it is assumed that the materials of each layer are uniform and isotropic, the asphalt surface layer conforms to the viscoelastic constitutive relation, and the other layers all satisfy Hooke’s law [

The strain-hardening creep model in ABAQUS finite element is adopted to analyse rutting calculation. The constitutive equation [

ε • c r = ( A q [ ( m + 1 ) ε ¯ c r ] m ) 1 m + 1 (1)

where ε • c r is uniaxial equivalent creep strain rate; ε ¯ cr is uniaxial equivalent creep strain; q is stress, MPa A, n, m are Model parameters, determined by indoor material creep test generally, A, n > 0, −1 < m ≤ 0.

It’s assumed that the material parameters of soil foundation, lime soil and cement stabilized macadam base remain constant under different temperature. Anti-pressure rebound test and creep test were performed to determine the elastic and creep parameters of asphalt mixture [

The left and right sides of the model are set to zero displacement in the X direction, and the bottom boundary of model is fixed, as shown in

In this study, the effect of repeated loading of asphalt pavement rutting is simplified to a loading step to reduce the time of finite element analysis calculation, the calculation formula is as shown in Equation (2).

t = 0.36 NP n w p B v (2)

where t is Wheel load cumulative action time; N is times of wheel load; P is Vehicle axle weight; n_{w} is number of rounds of the axle; p is tire ground pressure; B is tire ground width; v is traffic speed. The load parameters can be obtained according to formula (2), as shown in

Affected by the natural environment, the temperature of the road surface fluctuates greatly, while the deep sub-grade fluctuates slightly, it can be considered

Material | Temperature (˚C) | Material Elastic Parameters | Creep Parameter | |||
---|---|---|---|---|---|---|

Compressive Resilience modulus/E (MPa) | Poisson’s Ratio/μ | A | n | m | ||

Thiopave modified asphalt AC-13 grade | 20 | 1180 | 0.25 | 2.235E−11 | 0.905 | −0.723 |

30 | 985 | 0.30 | 9.877E−10 | 0.816 | −0.658 | |

40 | 824 | 0.35 | 9.653E−09 | 0.698 | −0.634 | |

50 | 778 | 0.40 | 8.558E−07 | 0.349 | −0.586 | |

60 | 769 | 0.45 | 9.564E−06 | 0.251 | −0.559 | |

AC-20 Grade | 20 | 910 | 0.25 | 4.580E−11 | 0.944 | −0.596 |

30 | 752 | 0.30 | 2.461E−09 | 0.796 | −0.585 | |

40 | 600 | 0.35 | 3.673E−08 | 0.773 | −0.570 | |

50 | 440 | 0.40 | 4.802E−06 | 0.595 | −0.532 | |

60 | 380 | 0.45 | 7.778E−05 | 0.384 | −0.441 | |

Sup-25 grade | 20 | 1031 | 0.25 | 4.590E−11 | 0.922 | −0.581 |

30 | 900 | 0.30 | 3.461E−09 | 0.859 | −0.576 | |

40 | 710 | 0.35 | 1.956E−08 | 0.830 | −0.562 | |

50 | 500 | 0.40 | 1.200E−06 | 0.322 | −0.522 | |

60 | 390 | 0.45 | 3.755E−05 | 0.210 | −0.418 | |

Cement Stabilized Gravel | - | 1200 | 0.20 | - | - | - |

Lime soil | - | 300 | 0.30 | - | - | - |

Soil matrix | - | 45 | 0.35 | - | - | - |

parameter | AC Sup | CTB | LS | SG |
---|---|---|---|---|

Thermal conductivity K (J/(m・h・˚C)) | 4680 | 5616 | 5148 | 5616 |

Density ρ (kg/m^{3}) | 2300 | 2200 | 2100 | 1800 |

Heat capacity/C (J/(kg・˚C)) | 924.9 | 911.7 | 942.9 | 1040.0 |

Solar radiation absorption rate α_{s} | 0.90 | |||

Road Reflectance/ε | 0.81 | |||

Absolute zero value/TZ (˚C) | −273 | |||

Stefan-Boltzmann constant σ/J/(h・m^{2}・K^{4}) | 2.041 × 10^{−4} |

that the temperature value remain constant [

Tire Grounding Width/(cm) | 18.6 | Driving Speed (km/h) | 80 |
---|---|---|---|

Axle Load (KN) | 100 | Tire Grounding length (cm) | 19.2 |

Ground Pressure (MPa) | 0.7 | Single Loading Time (s) | 0.008641 |

Cumulative Standard Axle Load (Million times) | 50 | Total Loading Time (s) | 4320 |

the atmosphere, and the heat convection [

The influence of temperature on asphalt mixture cannot be ignored. The increase of temperature will cause a rapid reduction of dynamic stiffness modulus of asphalt mixture in a short time. Accordingly, the ability of resistance to rutting deformation of pavement reduces, and the deformation expands gradually which will eventually lead to the damage of pavement. The permanent deformation under high temperature of asphalt mixture is main reason for rutting. The rutting usually occurs in summer when the temperature is higher than 25˚C - 30˚C. Road surface temperature fluctuates most with the increase of atmospheric temperature.

It can be seen from

As is shown in

Load is one of the crucial factors of the rutting deformation of asphalt pavement. The more overloaded vehicles, the more severe the deformation of the rutting is. Keep the thickness and the corresponding material of each layer constant, analyzing the rutting caused by different tire pressures under the condition at

500,000 times of the axle load and the atmospheric temperature was 30˚C. The results are shown in

From

It can be seen from

It can be seen from

With the increase of the times of loading, the upheaval on both sides of the wheel track gradually increases. When the cyclic load reaches 1,000,000 times, the deflection and elevation of the Thiopave modified asphalt pavement are both smaller than that of ordinary asphalt pavement. And the amplitude of variation is also smaller than that of ordinary asphalt pavement.

a) The rutting deformation of Thiopave modified asphalt pavement increases with the increase of temperature and tire pressure, while the deformation of rutting is smaller than that of ordinary asphalt pavement.

b) In the early stage of cyclic loading, the rutting deformation of Thiopave modified asphalt pavement grew slowly and was relatively close to that of ordinary asphalt pavement. As the times of loading increases to 1,000,000 times gradually, the rutting of ordinary asphalt pavement reaches 12 mm, which is much larger than the that of Thiopave modified asphalt pavement 4.8 mm. It can be concluded that the fatigue resistance of Thiopave modified asphalt pavement is better than that of ordinary asphalt pavement. Therefore, it is recommended to use the Thiopave modified asphalt pavement on the road with large traffic volume to effectively reduce the road surface damage caused by rutting.

The authors declare no conflicts of interest regarding the publication of this paper.

Wang, X.S., Wang, J.J. and Qiu, Y.J. (2019) Finite Element Analysis of Thiopave Modified Asphalt Pavement. World Journal of Engineering and Technology, 7, 48-57. https://doi.org/10.4236/wjet.2019.72B006