Conventional physical and microwave properties of bitumen modified with waste cooking oil (WCO)

Abstract

Bitumen is a rheological, viscoelastic, thermoplastic and extremely complex material that has hydrocarbons as its predominant molecules with slight traces of others. Bitumen is semi solid at room temperature, liquid at high temperature and solid at very low temperature. Due to its complexity, till date complete understanding of its properties have not been fully known. Various techniques/methods have been developed by many researchers in order to study the behavior of this complex material. This research is aimed at developing another method of determining the properties of bitumen using microwave technology by way of examining the performance of bitumen PG 76 and PEN 60 – 70 modified with Waste Cooking Oil (WCO) using the conventional tests, dielectric constant (DC) and loss factor (LF). The modification was done by replacing neat bitumen with WCO at 0%, 1.5%, 3.0% and 4.5% by weight of the neat bitumen. The conventional tests conducted were penetration, softening point and viscosity, all in accordance with ASTM standards. The DC measurement was carried out at 2.45 GHz (ISM Band) while the LF was measured at 500 MHz frequencies. The results of the conventional tests showed that increasing the percentage of WCO has effect on the bitumen binders by increasing their penetration values and at the same time decreasing their softening point and viscosity. Also based on the DC value, the performance of PG 76 bitumen binder reduced with the increment in the WCO percentage. However, the results of the LF for two modified bitumen binders were illogical. Comparatively, it is the conclusion of this study that, the modified PG 76 bitumen binder will perform better than the modified PEN 60 – 70 bitumen. The result further reveals that the modified binders can only be used in temperate regions.