2D Mesoscale cracking simulation of partially saturated asphalt based on moisture diffusion and a cohesive zone model
2D Mesoscale cracking simulation of partially saturated asphalt based on moisture diffusion and a cohesive zone model
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DOI：
10.1080/10298436.2023.2242557
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发表时间：
2023-08
影响因子：
3.8
通讯作者：
Linglin Li;J. Wu;N. Thom;D. Hargreaves;G. Airey;Jusheng Zhu;Ahmed Abed;Mujib Rahman;Zhen Zhang
中科院分区：
文献类型：
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作者：
Linglin Li;J. Wu;N. Thom;D. Hargreaves;G. Airey;Jusheng Zhu;Ahmed Abed;Mujib Rahman;Zhen Zhang
摘要本文的主要目的是开发一个结合水分扩散和粘性区模型的组合模型，解决各向异性和加载速率相关的部分饱和沥青开裂。利用X射线CT扫描，获取沥青的横截面切片，通过Matlab和AutoCAD将其转换为矢量图像，形成数字化沥青试样。沥青中的水分浓度，经过不同的浸泡时间，量化菲克定律。在5°C数字间接拉伸强度试验（DITST）过程中，采用水分扩散和断裂的顺序耦合模型研究了浸泡时间、各向异性和加载速率对沥青开裂性能的影响。研究结果表明，部分饱和沥青中的水分演变过程中，通过两个或三个阶段：近零增长（仅适用于远离初始水分沥青界面的位置），快速增长，和高原。DITST的峰值载荷、刚度和断裂功随浸泡时间呈指数下降，主要是在前四周内。各向异性导致不同的DITST结果时，不同的加载方向。湿损伤降低抗裂性在所有方向上，而增加加载速率增强它。断裂刚度和强度表现出可比的影响开裂性能在特定的加载速率。
ABSTRACT The primary objective of this paper was to develop a combined model that incorporates moisture diffusion and a cohesive zone model, addressing anisotropic and loading-rate dependent cracking within partially saturated asphalt. Utilising X-ray CT scan, cross-sectional slices of asphalt were acquired and converted into vector images through Matlab and AutoCAD, forming a digital asphalt sample. Moisture concentration in the asphalt, after different immersion durations, was quantified by Fick's law. A sequentially coupled model of moisture diffusion and fracture investigated the effect of immersion duration, anisotropy, and loading rate on cracking performance of the asphalt during a digital indirect tensile strength test (DITST) at 5°C. Findings revealed that moisture evolution in partially saturated asphalt proceeds through two or three stages: near-zero growth (only applicable for locations far from the initial moisture-asphalt interface), rapid growth, and a plateau. Peak load, stiffness, and fracture work in DITST exponentially reduced with immersion duration, predominantly within the first four weeks. Anisotropy led to differential DITST results when varying loading direction. Moisture damage decreased crack resistance across all directions, while increasing loading rate enhanced it. Fracture stiffness and strength exhibited comparable impacts on cracking performance at a specific loading rate.