Use of raw sugarcane molasses as a partial replacement of asphalt binder: An experimental investigation

Bio-bitumen is becoming 'talk in the air' within the pavement community due to its sustainable advantages. While it is not easy to replace the conventional bitumen, which is one of the oldest engineering material, increasing environmental concerns and oil crisis demands at least partial, if not complete, replacement of bitumen. In this study, raw sugarcane molasses (SM), a by-product obtained from the sugarcane industry, was used as a partial replacement of asphalt binder. Several tests on binders and mixtures were carried out to assess its suitability for asphalt pavement. The optimum dosage of SM was found to be 25% by weight of bitumen. VG30 modified with 25% SM had rutting and fatigue performance similar to, or improved, compared to the control binder. Irrespective of the aggregate source, SM modified mixes showed satisfactory performance in terms of moisture resistance, fatigue resistance, and accumulation of permanent deformation. Statistical analysis showed that there is no significant impact of binder type (VG30 and 25SM) on the performance of asphalt mixtures. Therefore, 25% molasses can be successfully used to partially replace the conventional bitumen, which in addition to being a sustainable technology, will reduce the cost of binder in the mix by approximately 21%.