Life cycle energy and carbon analysis of a road-safety barrier produced using recycled tire rubber

Increasing end-of-life material recovery and its application in new products is essential to reduce resource consumption. This paper assesses the cradle-to-gate life cycle energy and carbon dioxide (CO2) emissions of a new road safety barrier product to be installed around guardrails’ poles. To analyze​ the potential life cycle benefit of incorporating recycled materials, a base case product A, produced with conventional virgin synthetic rubber and polypropylene (PP), was compared with two equivalent alternatives under study: B (using recycled end-of-life tire rubber granulate (TRG) and PP), and C (using TRG and recycled polypropylene). The results show that the incorporation of recycled TRG has a positive effect in primary energy and carbon emissions. Product B presents less 38% CO2 emissions and 47% non-renewable primary energy than product A. The combination of TRG and recycled polypropylene (C), presents even more benefits: less 69% CO2 and 86% non-renewable primary energy than A. Supply chain processes and material production have much higher impacts than the product manufacturing (e.g. product molding only represents 5% of the primary energy of product A). To conclude, recycled materials incorporation should be strongly encouraged since it has a great potential to reduce current carbon emissions and primary energy of products.