Dome Construction Experiment at EXPO 2025 Utilizing Carbon Negative Concrete Technology

Concrete is a challenging material for achieving a low-carbon society because of the large amount of CO₂ emissions during cement production. Technologies have been developed to separate, recover and reuse CO₂ as a resource. We adopted the following two types of environmentally friendly concrete to reduce CO₂ emissions in the construction of the Expo dome: ECM (Energy CO₂ Minimum) concrete and CO₂-SUICOM (CO₂ Storage Utilization for Infrastructure by Concrete Materials). ECM concrete contains high content granulated blast furnace slag (GGBS) to reduce CO₂ emissions by reducing cement content 1). CO₂-SUICOM can achieve negative CCO₂ emissions by absorbing CO₂ into γ-C2S contained as an admixture through carbonation curing 2). Previously, the curing required a special curing chamber in a factory. Thus, CO₂-SUICOM application was limited to precast components. The aim of this study is to develop a method for carbonation curing of CO₂-SUICOM on-site and to evaluate the CO₂ emission reduction effects of environmentally friendly concrete.