Using random heterogeneous DEM model to simulate the SCB fracture behavior of asphalt concrete. (10th March 2020)

• Record Type: Journal Article
• Authors: Xue, Bin; Pei, Jianzhong; Zhou, Bochao; Zhang, Jiupeng; Li, Rui; Guo, Fucheng
• Is Part Of: Construction & building materials. Volume 236(2020)
• Publication Date: 2020-03-10
• Subjects: Asphalt concrete -- Fracture -- Discrete element method -- Algorithmic technique -- Heterogeneous; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2019.117580
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: A heterogeneous fracture simulation approach is proposed. Asphalt concrete model has a random aggregate structure. Bilinear cohesive fracture model is adopted as the constitutive law. Contact force and crack evolution are studied. Abstract: A heterogeneous fracture simulation approach based on algorithmic technique and discrete element method (DEM) was developed in this paper for simulating the fracture behavior of asphalt concrete under semi-circular bending (SCB) test. Asphalt concretes were modeled as heterogeneous materials with random aggregate structures and asphalt mastic by a novel algorithm. A bilinear cohesive fracture model was used as the constitutive law for modeling crack initiation and propagation. The simulation approach was verified by experimental results of asphalt concretes with different nominal maximum aggregate sizes (NMAS) at different temperatures. Moreover, the contact force and crack evolution were analyzed to study the failure mechanism of SCB specimen. Lastly, a parametric analysis was performed to investigate the effect of aggregate strength on the fracture behavior of asphalt concrete. Results showed that simulation results agreed well with the experimental results at different test conditions. NMAS, temperature and aggregate strength had significant influences on the hardening and softening behavior as well as crack propagation paths. The fracture failure mechanism of SCB specimen was mainly attributed to the tension force. The random heterogeneous fracture simulation approach has significant potential to aid in understanding the fracture mechanism of asphalt concrete, and reduce the required number of expensive and time-consuming experimental tests.