Sustainability of bitumen use in highways Available to Purchase

Crude oil is a finite resource, and bitumen, as part of the oil refining process, shares its common future. In 1973 predictions were that oil resources would be entirely depleted in 30 years’ time. We have now reached that deadline. This paper examines the current oil reserves position, and considers the continued use of bitumen in highway maintenance and construction, from the stance that sustainability means ‘acting today with tomorrow in mind’. Proven oil reserves and production ratios are examined to determine the future availability of oil and—more specifically—bitumen, in both the short and long term. The factors affecting bitumen availability, such as competition from other hydrocarbon uses and manufacturing implications, are discussed and expressed in terms of sustainability. The source of suitable bitumen crude is examined and explained in terms of the overall refining barrel. The misapprehension that bitumen is a ‘waste product at the end of the refining process’ is exposed. The features of bitumen that mark it as a unique petroleum product are highlighted, and the impact of oil sand deposits on the future supply of bitumen is assessed. Enhanced binder performance through polymer modification, hardened grade and emulsification/foaming techniques has facilitated more sustainable highway construction and maintenance procedures. The relationship between the binder and composite materials is examined in terms of sustainability and environmental performance. The case is made for incorporation of sustainability criteria within code and procurement procedures, in terms both of binder specification and of the maintenance and construction techniques employed.