A research team led by Professor Ippei Maruyama, Project Researcher Daiki Sawa, and Project Assistant Professor Naho Yamashita from the Graduate School of Engineering at the University of Tokyo; Associate Professor Ichiro Daigo from the Research Center for Advanced Science and Technology at the University of Tokyo; and Professor Hiroki Tanigawa from the Graduate School of Environmental Studies at Nagoya University has calculated the total amount of CO2 emitted during the production of architectural and civil engineering concrete structures in Japan. They also quantified the total amount of CO2 fixed through carbonation reactions during the service life of these structures, considering factors such as the lifespan, shape, finishing materials, and post-demolition measures of the buildings and infrastructures.
Their findings revealed that a total of 1.4 million tons of CO2 have been fixed in concrete structures to date. Approximately 14% of the CO2 emitted during the cement production process—specifically during the extraction of calcium from limestone—has been re-fixed as calcium carbonate during the service life of the concrete structures.
The predictive method developed through this study is expected to clarify how to evaluate CO2 uptake as the concrete sector moves toward carbon neutrality in the future, providing valuable insights for strategic planning. Additionally, the team plans to collaborate with research groups from other countries to expand similar activities across Asia.
Figure Cumulative CO2 uptake by concrete structures in Japan
Papers
Journal: Journal of Cleaner Production
Title: CO2 uptake estimation in Japan's cement lifecycle
Authors: Daiki Sawa, Naho Yamashita, Hiroki Tanikawa, Ichiro Daigo, Ippei Maruyama*
DOI: 10.1016/j.jclepro.2024.144542