Performance characteristics of different mineral filler in asphalt concrete mixtures

With the increase of traffic load in Canada, asphalt mixtures are required to sustain heavier loads and withstand the harsh Canadian winter. This requires careful design and material selection. This study evaluates the performance of different types of mineral filler in asphalt pavements. Five 19mm Superpave mixes were tested with four types of mineral filler namely fly ash (Class C and Class F). Blast Furnace Slag and General Use Portland cement along with a control mix with limestone dust. The results showed that, Class C fly ash generated the most economical mix by reducing 0.3% asphalt content of total mix. The indirect tensile strength (ITS) and tensile strength ration (TSR) test results were used to evaluate the effects of different fillers for water susceptibility. Both types of fly ashes have excellent results on Tensile Strength Ratio (TSR) which increase resistance to water susceptibility. These mixes have a very positive effect on stripping resistance. Improvements in binder properties were shown after short and long term aging which was attributable to the reduction of oxidation and aging effect. Binder with fly ash has the best rutting and fatigue resistance out of all tested binder samples.