Investigation of Indirect Tensile Fatigue Testing of Warm Mix Asphalt

Fatigue cracking is one of the major distresses that affects the performance of asphalt pavements. Such fatigue cracks appear along the wheel paths and are due to many factors including binder stiffness, traffic loading magnitude and applications, as well as environmental conditions. Taking into consideration the increased emphasis on the use of warm mix asphalt (WMA) technologies, it is necessary to investigate the fatigue life of WMA mixtures since they are less susceptible to aging. Different fatigue testing methods exist to test the HMA specimens and amongst them, the indirect tensile loading type, specified in the European specification, EN 12697-24: 2012, Annex E, was utilized in this study. Two types of WMA technologies namely, chemical additive based (Advera®) and organic additive based (Sasobit®) were benchmarked with HMA in this investigation. Cylindrical shaped Marshall specimens were fabricated and tested in the indirect tensile fatigue tests to determine their fatigue life. The research results were analyzed and discussed. Our results indicated that, except for the case of 5%Advera® at 150kPa and 2Hz, the addition of both WMA additives not only reduced the mixing and compaction temperatures, but also showed better fatigue resistance of WMA when compared with conventional HMA.補正完