UV Aging Resistance of Modified Bitumen: Comparison of SBS and Biochar

Abstract

The importance of road pavement durability must not be underestimated, as it impacts road safety, reduces maintenance costs and environmental impacts. The constant exposure of wearing courses to atmospheric agents such as UV-rays or rain, and traffic-induced stresses, contribute to accelerated wear and deterioration. The aging behaviour of the binder used plays a crucial role in the pavement’s durability during its service life. The objective of this study is to investigate the potential of alternative additives to effectively compete with conventional polymers in enhancing resistance to UV aging. For this purpose, the effect of two different additives (one natural and one synthetic) on the durability of bitumen was studied. Biochar was chosen as the natural additive and SBS as the synthetic. Two aging methods, thermal and UVB ageing, were implemented to understand which additive would lead to the formulation of a binder that would not only perform better from a mechanical perspective but would also be more durable. The experimental results obtained suggest that biochar has a positive anti-aging effect, though lower than that offered by virgin SBS polymer, and that, for selected applications, it could represent a cost-effective alternative.