ABSTRACT
The main criteria used in measuring pavement construction effectiveness are sustainability issues related to economic savings and energy and emission reduction. The potential effect of using fly ash in an asphalt binder is the efficient use of existing materials through rework or structural change to ensure that the material’s properties are improved, promoting a longer lifespan and enhanced sustainability. The effects of fly ash from five different sources and lime were analyzed for rutting, fatigue cracking, and low-temperature cracking resistance. Two binder grades commonly used in North Dakota were tested: PG 58-28 and PG 64-28. An initial 3%-6% fly ash content by binder weight was evaluated by increasing the fly ash in 1% increments based on literature reviews and laboratory experiments. The effect of fly ash used as a mineral filler on low-temperature cracking resistance for two projects was also investigated. Using 5% fly ash by binder weight resulted in better rutting, fatigue cracking, and low-temperature cracking resistance compared to the control for PG 58-28. Fly ash from Coal Creek Station (CCS) and Ottertail (OTR) resulted in better fatigue cracking and low-temperature cracking resistance than other fly ash materials and lime compared to PG 58-28. An optimum dosage of fly ash can be a sustainable material to replace some asphalt binders used in asphalt pavements.
