Effect of Filler Type on the Durability of Asphalt Concrete Mixes

Abstract

Mineral filler is the finest fraction of aggregate (smaller than 75 gm) used in the production of asphalt paving mixed. It is essential for producing a mixture that is dense, cohesive, durable, and resistant to water penetration. In spite of the fact that filler is very small proportion of the total aggregates in the mix, due to its rather high affinity for asphalt, the changes in the type of the filler can cause the paving mixture to perform satisfactorily during the design life or deteriorate rapidly under the effect of traffic and environmental impact. The objective of this study is to investigate the effect of mineral filler types (three types, limestone dust, Portland cement and hydrated lime) in the durability of asphalt concrete mixture. To achieve the objective of this study, Marshall mix design method was utilized to produce asphalt concrete mixes at their optimum asphalt content. The mixes were, then, tested to investigate their durability properties including moisture damage and fatigue characteristics. The results indicated that the mixes prepared with hydrated lime have superior resistance to moisture damage in comparison with Portland cement and lime stone dust. On the other hand, the mixes prepared with Portland cement type of filler showed better resistance to the fatigue failure of asphalt concrete pavement.