Comparing bio-binders, rubberised asphalts, and traditional pavement technologies

Nowadays pavement technologies must comply with sustainability requirements, including global warming, energy consumption, and quietness. On the one hand, global warming is the most important category of impacts analysed as it is primarily associated with climate change and with intrinsic effects on human health, weather, and natural habitats. The emission of greenhouse gases (GHGs), is essentially related to fuel combustion during construction and transportation operations, but also during the materials production processes. On the other hand, traffic noise is a major concern, being related to premature mortality and years lived with disability. The road industry is focused on developing solutions able to face these issues and in the last years, the use of crumb rubber from end-of-life tyres and the use of binders combined with renewable natural resources (bio-binders) have gained momentum. Despite this, many uncertainties arise when comparing different solutions and this calls for specific comparisons in terms of life cycle assessment (LCA). Based on the above, the objectives of the study described in this paper have been confined to i) comparing rubberized and bio-asphalts, and traditional pavement technologies from a broader perspective, including LCA-based criteria; ii) setting up a method to compare innovative (e.g. green) and traditional pavement technologies; iii) detecting, discussing, and promoting competitive equilibria among pavement technologies. Six different alternative solutions were studied including two reference scenarios (traditional dense-graded and porous asphalt concrete), a solution with the use of crumb rubber, and a solution with a bio-binder.