基于虚拟劈裂试验研究影响沥青混合料低温抗裂性能的因素

摘要:

使用X-ray CT扫描粗集料,在PFC3D中重建颗粒,按照集料级配设计随机生成各档集料,构建沥青砂浆相并结合空隙相的实际分布,在重力作用和伺服机制控制下生成沥青混合料虚拟试件,随后设置合适的接触模型以及微观参数,进行虚拟劈裂试验,对影响混合料低温性能的因素进行分析。结果表明：本研究使用虚拟劈裂试验研究沥青混合料的低温抗裂性能是可行的；增大沥青砂浆间以及集料与沥青砂浆间的粘结强度可以提升沥青混合料的低温抗裂性能；增大集料体积分数、空隙率会减弱沥青混合料的低温抗裂性能；集料摩擦系数与沥青混合料的低温抗裂性能无明显相关性。

Abstract:

Use X-ray CT to scan coarse aggregates, reconstruct particles in PFC3D, randomly generate aggregates in various grades according to the aggregate gradation design, construct asphalt mortar phase and combine the actual distribution of void phases, and generate under the control of gravity and servo mechanism Asphalt mixture virtual specimens, and then set the appropriate contact model and micro parameters, perform virtual splitting test, and analyze the factors that affect the mixture"s low-temperature performance. The results show that it is feasible to use virtual splitting test to study the low-temperature anti-cracking performance of asphalt mixture in this study; increasing the bonding strength between asphalt mortar and between aggregate and asphalt mortar can improve the low-temperature anti-cracking performance of asphalt mixture; Increasing the aggregate volume fraction and porosity will weaken the low-temperature anti-cracking performance of the asphalt mixture; there is no obvious correlation between the friction coefficient of the aggregate and the low-temperature anti-cracking performance of the asphalt mixture.