Influence of Moisture Damage on Fatigue of Warm Mix and Hot Mix Asphalt Mixture

Quantification of the fatigue life of warm mix asphalt (WMA) is challenging due to various factors such as the extent of aging and moisture susceptibility, to mention a few. Hydrated lime as an antistripping material can enhance the fatigue life of moisture conditioned WMA mixture; however, due to the filler effect of lime, the fatigue life can be reduced. In this investigation, samples of hot mix asphalt (HMA) and WMA with and without hydrated lime were subjected to fatigue testing using four-point bending at three strain levels (400, 600, and 800 microstrain) for unconditioned and moisture damaged conditions. The collected data was analyzed appealing to various post-processing methods, and it was seen that the beneficial effect of warm mix additives or hydrated lime was seen at lower strain level (400 microstrain) and not at higher strain levels (600 and 800 microstrain) based on the evolution of flexural stiffness and energy dissipation.