Evaluation of Sawdust Ash as a Sustainable Mineral Filler in Asphalt Mixture

This study focuses on the incorporation of waste and/or by-product materials (Sawdust ash) in the construction industry such as the production of hot asphalt concrete mixture to provide valuable advantages from the environmental and economic perspective. Accordingly, the mixture of the biomasses was used as a replacement for the conventional mineral filler in hot asphalt mixture in 5%, 10%,15%, 20% and 25% The mechanical properties were assessed by conducting a Marshal stability test. The Marshall test showed an increase in stability from 7.1 at 5%(control) to 9.4 at 10% which meets the standard requirement for stability of the FMW while the flow results decreased from 3.1 at 5%(control) to 3.0 at 10% indicating that reduction in flow means an increase in the elasticity of the asphalt wearing course. Tests on aggregate and bitumen were carried out which included aggregate crushing value, aggregate impact value, elongation, flakiness, specific gravity, Los Angeles abrasion test, penetration test, extraction, compaction and extrusion, and marshal stability and flow test at 5% and 10% met the requirement of the FMW. While the 15%,20%, and 25% didn’t meet the requirement of the FMW. The experimental results have shown a significant improvement in the mechanical properties and a substantial upgrade in durability of the production mixtures with Sawdust Ash of 5% and 10% in comparison with the control mixture at 5% and as a result, the mixing of the waste materials can be incorporated in place of the conventional mineral filler in Asphalt mixture particularly in places where the wastes are abundant.