Detecting the Role of Fly Ash Additive in Enhancing the Fatigue Life of Asphalt Concrete

Enhancing the fatigue life of asphalt concrete by implication of coal fly ash additive was investigated in this work.Asphalt concrete mixtures have been prepared with optimum binder requirements; additional mixtures were also prepared with ±0.5 % binder above and below the optimum.Coal fly ash was implicated into the asphalt cement binder in the wet process.The mixtures were compacted using laboratory roller compaction into a slab mold.Beam specimens were obtained from the prepared slab samples and tested for fatigue life at 20 ℃ with the aid of dynamic bending beam test and three constant strain levels of (750, 400, and 250) microstrain.Specimens were subjected to the long term ageing process before conducting the dynamic test.It was observed that implication of coal fly ash in the asphalt concrete exhibit longer fatigue life regardless of the implemented constant strain level.It was concluded that the coal fly ash exhibit negative influence on the fatigue life of asphalt concrete after ageing as compared with the control mixture.