Essential and Plastic Works of Ductile Fracture in Asphalt Binders

Abstract

Currently, no satisfactory asphalt binder test method exists that can relate properties measured in the laboratory to fatigue performance in service. The loss modulus of the binder, G*sinδ, as proposed by the Strategic Highway Research Program, is a rheological parameter that measures the energy dissipated within the homogeneous binder at low strains under dynamic conditions. A number of publications have reported that this binder parameter provides little correlation with the susceptibility of the asphalt concrete to fracture at high strains in the nonlinear regime under simulated in-service conditions. The essential work of the fracture method, an energy-based testing approach used for the fracture characterization of ductile materials, was explored. Given that asphalt is a ductile material at ambient temperatures, it is only reasonable to assume that the essential work of fracture method yields valuable information with likely use in fatigue performance ranking. The binders investigated showed a wide range of essential and plastic works of fracture at ambient temperature and a single rate of loading. Although only six binders were evaluated, their works of fracture were contrasted with other properties.

Advanced analytical techniques in fatigue and rutting related characterisations of modified bitumen: Literature review

“…These damaging conditions are normally accompanied by high strain levels and yielding in binder films in the nonlinear viscoelastic range. In response to that, researchers at Queen's University proposed the double-edged notched tension (DENT) test which is based on the concept of essential work of fracture (EWF) of materials in a ductile state [39]. The binder ranking based on this method showed a strong correlation with observed fatigue cracking in the accelerated loading facility (ALF) and exactly the same ranking as the push-pull asphalt mix fatigue test [18,19].…”

“…Andriescu et al [39] successfully applied this test on bituminous binders. They found that no correlation exists between fracture properties and the SHRP fatigue parameter.…”

“…11 (c), is the total specific work of fracture (J/m 2 ), is the ligament length (m), is the sample thickness (m), β is a geometrical constant which depends on the shape of the plastic zone, is the specific essential work of fracture (J/m 2 ), and is the specific plastic work of fracture (J/m 3 ) [39,54].…”

“…It is believed that the main drawback of the SHRP fatigue parameter is the neglect of the damaging circumstances that would take place in the pavement during the fracture process [17,39]. These damaging conditions are normally accompanied by high strain levels and yielding in binder films in the nonlinear viscoelastic range.…”

New simplified approach for obtaining a reliable plateau value in fatigue analysis of bituminous materials

“…However, the fatigue life of hot-mix asphalt (HMA) has been recognized to be highly sensitive to the properties of the binder and fatigue cracking normally initiates and propagates within the binder, binder-filler mastic or at the bitumen-aggregate interface. A large number of research groups have attempted to identify testing procedures and fundamental parameters that can accurately reflect the contribution of the binders' properties on the fatigue resistance of asphalt mixtures and subsequent pavement performance [2][3][4][5][6][7][8][9][10][11]. In this regard, time sweep repeated cyclic loading tests, adopted in this study, have been successfully used to evaluate the fatigue properties of binders [3,5,12].…”