Contribution to sustainable seismic design of reinforced concrete members through embodied CO_2 emissions optimization

摘要

The embodied CO2 emissions of reinforced concrete (RC) structures can be significantly reduced by structural optimization that maximizes structural efficiency. Previous studies dealing with design of RC structures for minimum CO2 emissions do not address seismic design provisions. This is the case despite the fact that in many countries around the world, including most of the top 10 countries in CO2 emissions from cement production, RC structures have to be designed against earthquake hazard. To fill a part of this gap, this study, using exhaustive search, examines optimum designs of RC beam and column members for minimum embodied CO2 emissions according to Eurocode-8 for all ductility classes and compares them with optimum designs based on material cost. It is shown that seismic designs for minimum CO2 footprint lead to less CO2 emissions but are more expensive than minimum cost designs. Their differences strongly depend on the assumed values of the environmental impact of reinforcing steel and concrete materials. Furthermore, it is concluded that seismic design for high ductility classes can drive to significant reductions in embodied CO2 emissions.