Micromechanical modeling of asphalt concrete fracture using a user-defined three-dimensional discrete element method
来源期刊：中南大学学报(英文版)2012年第12期
论文作者：CHEN Jun(陈俊) WANG Lin-bing(汪林兵) HUANG Xiao-ming(黄晓明)
文章页码：3595 - 3602
Key words：asphalt concrete; fracture behavior; micromechanics; discrete element method; three-dimensional simulation
Abstract: A user-defined micromechanical model was developed to investigate the fracture mechanism of asphalt concrete (AC) using the discrete element method (DEM). A three-dimensional (3D) AC beam was built using the “Fish” language provided by PFC3D and was employed to simulate the three-point bending beam test at two temperature levels: -10 °C and 15 °C. The AC beam was modeled with the consideration of the microstructural features of asphalt mixtures. Uniaxial complex modulus test and indirect tensile strength test were conducted to obtain material input parameters for numerical modeling. The 3D predictions were validated using laboratory experimental measurements of AC beams prepared by the same mixture design. Effects of mastic stiffness, cohesive and adhesive strength on AC fracture behavior were investigated using the DEM model. The results show that the 3D DEM fracture model can accurately predict the fracture patterns of asphalt concrete. The ratio of stress at interfaces to the stress in mastics increases as the mastic stiffness decreases; however, the increase in the cohesive strength or adhesive strength shows no significant influence on the tensile strength.
CHEN Jun(陈俊)1, WANG Lin-bing(汪林兵)2, HUANG Xiao-ming(黄晓明)3
(1. College of Civil and Transportation Engineering, Hohai University, Nanjing 210098, China
2. Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University,
Blacksburg 24061, USA;
3. School of Transportation, Southeast University, Nanjing 210096, China)
Abstract:A user-defined micromechanical model was developed to investigate the fracture mechanism of asphalt concrete (AC) using the discrete element method (DEM). A three-dimensional (3D) AC beam was built using the “Fish” language provided by PFC3D and was employed to simulate the three-point bending beam test at two temperature levels: -10 °C and 15 °C. The AC beam was modeled with the consideration of the microstructural features of asphalt mixtures. Uniaxial complex modulus test and indirect tensile strength test were conducted to obtain material input parameters for numerical modeling. The 3D predictions were validated using laboratory experimental measurements of AC beams prepared by the same mixture design. Effects of mastic stiffness, cohesive and adhesive strength on AC fracture behavior were investigated using the DEM model. The results show that the 3D DEM fracture model can accurately predict the fracture patterns of asphalt concrete. The ratio of stress at interfaces to the stress in mastics increases as the mastic stiffness decreases; however, the increase in the cohesive strength or adhesive strength shows no significant influence on the tensile strength.
Key words:asphalt concrete; fracture behavior; micromechanics; discrete element method; three-dimensional simulation
