Rheological properties of modified binder incorporating coconut char

Abstract

Coconut char derive from coconut shell is a waste product that is anticipated to be potential alternative for modified binder. Coconut char has great potential to be used as the base material for modifier because it is safe to use. In this study the coconut char was used as additive in asphalt modified binders. This paper presents the rheological properties of modified bitumen incorporating coconut char. Rheology can be defined as the fundamental measurements associated with the flow and deformation characteristics of bitumen, evaluation of the flow and permanent deformation of time-temperature dependent materials, such as bitumen, that are stressed through the application of force. The modified bitumen was tested under different aging conditions using Rotational Viscometer (RV), Rolling Thin Film Oven (RTFO) and Dynamic Shear Rheometer (DSR). Coconut char was blended with 5, 10, 15, 20 and 25% by weight of the penetration grade 80/100. DSR was employed to measure the rutting resistance, the G*/sin at temperature 46–76 °C. Based on the findings, it is shown that the increase in coconut char percentage can effectively give highest G*/sin and affect the rutting performance under ageing condition. It also found that modified bitumen samples enhanced the rheological properties of the bitumen in terms of fatigue cracking and rutting.