Effect of Filler on Volumetric Properties and Film Thickness of Asphalt Mixtures

Mineral filler is the finest fraction of aggregate used in concrete asphalt that can fill the void with effective interface in the mixture. It is essential for producing a mixture which is dense, cohesive, durable and resistance to the water penetration. Small change in the amount or the properties of the filler can cause the paving mixture to appear excessively dry or rich and film thickness can be a good parameter to predict concrete asphalt stability. It is generally believed that an asphalt paving mixture should have an adequate asphalt film thickness around the aggregate particles to ensure reasonable durability (resistance to aging) of the mixture. This study focuses on comparing volumetric properties and film thickness of the asphalt concrete using different fillers with a view to the geometry, physical and chemical properties. The fillers are limestone mineral and portland cement that used in two different specific surfacein the construction of Marshal test specimens. The range of the changes depends on the filler interaction with bitumen. Volumetric properties were investigated in the study are density, VFB, VTM, VMA. Other properties are Marshall stability, flow, optimum binder and film thickness. Results show that kind, content and filler properties have different effects on the volumetric properties and film thickness.