Use of waste cooking oil, tire rubber powder and palm oil fuel ash in partial replacement of bitumen

Bitumen is a heavy hydrocarbon sourced from petroleum refineries as by-product which is widely used as binder for flexible pavement. Bitumen is non-hazardous at room temperature but when heated to 165-200 °C to coat all the aggregates it generates hazardous fume which is severely detrimental to health. Consequences such as environmental degradation, depleting petroleum reserves and price spiking, led researchers to explore alternative sources of obtaining binder for flexible pavement. This research focused on the effect of adding waste cooking oil, tire rubber powder and palm oil fuel ash to reduce the percentage of bitumen in the mixture where palm oil fuel ash was applied as additive. These three modifiers are sourced from waste materials, easily available in the market and cheap in price. This method of recycling these waste materials solves the issue of littering and can ensure a cleaner environment. Laboratory investigations based on AASHTO and ASTM standard were performed to check physical and rheological properties of modified binders. Results were compared with neat bitumen as control sample to assess the feasibility of new mixture to be used in industrial scale. Outcome from this research shows that up to 15% replacement of bitumen is possible and this could produce equal or better performance in terms of stability, flow and rutting resistance. This work contributes directly to the field of transportation and highway in development of alternative binder for flexible pavement by introducing improved modified binder compositions using waste materials.