集料均匀性对沥青混合料低温劈裂强度影响数值研究

NUMERICAL SIMULATION OF AGGREGATE UNIFORMITY INFLUENCE ON LOW TEMPERATURE SPLITTING STRENGTH OF ASPHALT MIXTURES

为了数值研究集料均匀性对沥青混合料低温劈裂强度影响,基于粘聚带模型和三维离散元法,建立沥青混合料低温劈裂试验三维微观力学模型,通过在模型不同方向上加载,模拟集料均匀性对沥青混合料低温劈裂强度影响,并对模拟强度加以试验验证。研究结果表明,基于三维离散元法,可以模拟沥青混合料低温劈裂试验;集料分布状态的不均匀造成沥青混合料低温劈裂强度呈现各向异性;集料均匀性对沥青混合料低温劈裂强度影响不大,其间相关性不明显,但与低温劈裂强度变异性间相关性却很显著。

This paper aims to investigate the influence of aggregate uniformity on the low temperature splitting strength （LTSS） of asphalt mixtures by numerical simulation method. A mieromeehanieal model for the splitting test for asphalt mixtures at low temperature was established by using a cohesive zone model （CZM） and a three-dimensional （3D） discrete element method （DEM）. The influence of aggregate uniformity on the LTSS was simulated by loading in different directions of this model. Simulation strengths were verified by laboratory splitting tests. The results show that the LTSS of asphalt mixtures can be simulated well using CZM and 3D DEM. The LTSS exhibits anisotropy that is caused by aggregate distribution non-uniformity. The influence of aggregate uniformity on the LTSS is insignificant and there is no obvious correlation between them. However, the correlation between aggregate uniformity and the variation in the LTSS is significant.