Asfalto ecológico: uma análise sobre a viabilidade da sua utilização como substituto do asfalto convencional

Abstract

The production of petroleum asphalt cement (PAC) has a great importance for the development of the Brazilian economy, since road transport has been privileged since the 50's. Another fundamental product for transport services is the tire. PAC and tire are associated with supply chains that generate significant environmental impacts. PAC is made up of bitumen, a compound generated from the petroleum distillation process; its production requires a large amount of energy, which is obtained from fossil fuel burning – generating polluting gases emission. Regarding tires, the stages that have the greatest environmental impacts involve the disposal at its end-of-life. In view of this scenery, emerges the ecological asphalt, a modified PAC containing 20% by mass of ground waste tires, which improves the pavement’s quality, reduces the amount of bitumen needed to manufacture the same volume of PAC and guarantees a more environmentally friendly destination to tire wastes. This work presents a life cycle assessment (LCA) of tire production with different destinations, CAP production and ecological asphalt production; all product systems were compared using the environmental model Environmental Footprint (Mid-point indicator) and indicators (climate change, freshwater ecotoxicity, carcinogenic and non-carcinogenic human toxicity, fossil fuel consumption and water consumption) were calculated to verify the best scenarios from an environmental point of view. It was found that ecological asphalt generated the lowest environmental impacts, except for the water footprint. This was mainly observed by the decreased use of bitumen, which is the main cause of the environmental impacts studied. The higher water consumption in the ecological asphalt life cycle was due to the mechanical recycling for obtaining ground rubber tires, a step that uses a large amount of energy from hydroelectric plants