Experimental Studies on Bio-bitumen Produced Using Charcoal from Coconut Shell Waste

Rutting and fatigue cracking are the two main distresses in flexible pavement which affect the serviceability and durability of the pavement. Although bitumen is only 5–6% by weight of mixture, it has 40% effect on the performance during service life. With the increase in percentage of overloaded commercial vehicles, premature rutting in the bituminous mixtures has been observed very often on pavements. In order to stiffen the bitumen, several methodologies have been adopted in the past, and still research is being carried out in various other aspects to produce bitumen with superior permanent deformation resistance. On the other hand, tropical countries such as Indonesia, India, Philippines, and Srilanka being one of the largest producers of coconut in the world also produce burnt coconut shell (CS) waste, which creates environmental concern regarding disposal due to large percentage of carbon. In this study, charcoal powder from the CS waste was used to modify VG30 bitumen at 1, 2, 3, and 4% (by wt. of bitumen), and investigate its permanent deformation characteristics. The basic properties of bitumen such as penetration value, softening point, and penetration index were determined to understand the consistency of the bitumen. Further, dynamic shear rheometer was used to determine complex modulus and phase angle. The permanent deformation resistance of bitumen was studied using multiple stress creep-recovery (MSCR) test to quantify creep compliance, %recovery, and stress sensitivity. The results indicated that at 2% addition, desired bitumen properties were maximized and control binder was rendered less stress sensitive after modification.