Environmental impacts of hot, warm and half warm recycled bituminous mixtures
- Carretera Magazine No. 228 - January / April 2020
Jorge ORTIZ RIPOLL
ARNÓ
Xavier CRISÉN GRAU
ARNÓ
Adriana MARTINEZ REGUERO
Universidad Politécnica de Cataluña
Rodrigo MIRÓ RECASENS
Universidad Politécnica de Cataluña
ABSTRACT
For some years, reducing bituminous mix temperatures has been a common trend among asphalt producers because it is a very effective way to reduce energy consumption and atmospheric emissions of asphalt plants, along with other reasons. However, the energy demand of bituminous mixtures production is not only related to mix temperature, but also to the specific production technology, materials and designs used to achieve the temperature reduction. In bituminous mixtures containing Reclaimed Asphalt Pavement (RAP), the usability of aged bitumen in turn depends on the production temperature, being more effective in hot bituminous mixes that in other ones. Therefore, it is not a trivial task to relate environmental impact of bituminous mixtures to production temperatures and RAP content, especially from a life cycle perspective.
On the other hand, an increasing number of public administrations are trying to encourage the production of low temperature mixes by including specific technologies in their specifications or on the criteria used in selection procedure, perhaps invading areas of decision that should belong to producers. This circumstance also justifies the opportunity to review the typical, and generally oversimplified, relationships used to defend low temperatures production and high RAP contents, from an environmental point of view. In any case, it seems that public incentives to promote the energetic efficiency and environmental gains should not be aimed to any particular bituminous mix production technology. According to the findings of this study, to specify by performance, including environmental performances, is a better way to progress towards efficiency and sustainability.
KEYWORDS
Half-warm, Warm, Asphalt mixes, Energetic demand, Heavy fuel, Emissions.
