Blended waste utilization in road construction: physical characteristics of bitumen modified with waste cooking oil and high-density polyethylene

The use of bio-oils in the production of asphalt binders has found application mostly in cold climates, and not in hot climates due to the rutting problems associated with bio-oil modified binders. The reality of a harsh and changing climate faced by today’s world necessitates an enhancement of the temperature susceptibility of these binders. This is the focus of this research. In this research, high-density polyethylene (HDPE) is combined with waste cooking oil (WCO) to develop an asphalt binder with improved properties. The results obtained showed that when 7.5% HDPE was added to the binder with 15% replacement of the base bitumen with WCO (B85-WCO15), a 54.7% increase in softening point and 9.3% decrease in penetration were obtained. It was found that higher percentages of WCO can be used for bitumen modification if HDPE is used as a stabilizer. The increased specific gravity obtained from the addition of HDPE provides further evidence that HDPE can be used to stabilize WCO modified binder. The penetration index values indicate that HDPE can be used to reduce the temperature susceptibility of the bio-oil modified binder. The results obtained from this research suggest that waste oils and waste HDPE can be blended in asphalt mixes to deliver asphalt pavements with improved performance.