On the low temperature mixed mode fracture analysis of asphalt binder – Theories and experiments

• Published in: Engineering fracture mechanics Vol. 186; pp. 181 - 194
• Main Author: Mirsayar, M.M.
• Format: Journal Article
• Language: English
• Published: New York Elsevier Ltd 01.12.2017; Elsevier BV
• Subjects: Asphalt; Asphalt binder; Crack propagation; Criteria; Deformation mechanisms; Experiments; Flux density; Fracture criteria; Fracture mechanics; Fracture toughness; Fractures; Low temperature; Low temperature physics; Mixed mode crack propagation; Propagation modes; Strain; Stresses; Fracture criteria; Experiments; Asphalt binder; Mixed mode crack propagation; Low temperature
• ISSN: 0013-7944; 1873-7315
• DOI: 10.1016/j.engfracmech.2017.10.010

[Display omitted] •Experimental and theoretical study of low temperature fracture of asphalt binder.•Exploring low temperature mixed mode crack propagation mechanism in asphalt binder.•Proposing two new laboratory specimens for mixed mode fracture testing of asphalt.•Examining different fracture criteria to study crack propagation in asphalt. Brittle fracture of asphalt binder is studied in this paper at low temperatures and under mixed mode crack tip deformation. A set of fracture tests are conducted by two new laboratory specimens made of a type of asphalt binder. The suggested specimens can provide pure mode I (opening), mixed mode I/II, and pure mode II (sliding) crack propagation conditions. The crack propagation angles and fracture toughness values were measured from experiments under pure mode I, pure mode II and mixed mode I/II conditions. The experimental results were then evaluated using different fracture criteria: strain energy density (SED), maximum tangential stress (MTS), and maximum tangential strain (MTSN). The role of the first non-singular term of the elastic stress and strain field (generally called T-term) on the predictions provided by each criterion is discussed. It was found that both specimens are significantly affected by the T-term, and adding T-term significantly improves the predictions provided by each criterion. It was shown that for the mixed mode conditions, the strain-based criteria provide better predictions for the fracture toughness than stress-based and energy-based criteria. The results of this paper will help researchers to understand the mechanism of mixed mode crack propagation in asphalt binders, and as a result in pavement structures, at low temperatures.