The Environmental Impact of Carbon Emissions and Carbon Dioxide Capture by a Reinforced Concrete Road Structure during Its Life Cycle

This is a case study assessing the environmental impact of GHG emissions from the construction of a reinforced concrete structure. Studies of concrete carbonation focus on concerns about the reduction in pH that causes corrosion of reinforcement. The study aims to show that the CO2 capture by exposed concrete structures is very small during their service life, but quite significant at the end of their life if the concrete is crushed and recycled, showing the importance of this action within the context of the circular economy. We estimated the emissions from the production of the main materials used. We calculated the CO2 capture during the service life and the subsequent recycling in aggregates associated with carbon credits from scrap steel. A device was used to measure carbon levels for three years and produced a 100-year estimate. The results showed a minimal CO2 capture during the service life compared to the respective emissions. However, there is a significant CO2 capture when considering the circular economy involved in the recycling process. CO2 captured by concrete and steel recycling accounts for 40% of emissions, contributing to the achievement of United Nations Sustainable Development Goals No. 8, 12 and 13.