ABSTRACT
In recent years, there is growing awareness of environmental issue such as global warming and climate change. This kind of problem becomes more pronounce, where asphalt surfaces are exposed extremely higher temperature and heavy rain during summer time. In addition, it is desirable for asphalt paving industry to accelerate recycling technology, in terms of sustainability. Therefore, there is still room for discussion about the durability of asphalt mixtures under harsh conditions, in terms of temperature and moisture sensitivity. In order to tackle this challenging issue, both warm-mix asphalt (WMA) mixture and reclaimed asphalt pavement (RAP) with WMA are assessed using the saturation aging tensile stiffness (SATS) test, then those mechanical properties are examined through laboratory experiments. This paper assesses the durability of both WMA mixture and reclaimed asphalt pavements with WMA, looking at the two factors: stiffness and fatigue, then the following conclusions are being drawn through laboratory experiments. With regard to stiffness modulus, the Indirect Tensile Stiffness Modulus (ITSM) results show that RAP-WMA mixtures tend to show increase in stiffness modulus with SATS conditioning. In terms of the retained stiffness, the RAP-WMA mixture did not indicate a reduction in retained stiffness whilst the WMA mixture demonstrated a significant drop in stiffness with the SATS conditioning. In addition, the Indirect Tensile Fatigue Tests (ITFT) demonstrated that the WMA mixture with SATS conditioning showed a large initial strain resulting in a shorter fatigue life, whereas the RAP-WMA mixtures indicated a longer fatigue life than the WMA mixture with SATS conditioning. Finally, failure pattern analysis reveals that RAP-WMA mixtures show difference in fatigue patterns among the two RAP-WMA mixtures. This might be related to the effect in rejuvenators on fatigue properties.
