Development of a new ecological concrete with CO2 emissions below zero

A new ecological concrete has been developed which utilizes CO2 emitted from a power plant and which can achieve CO2 emission levels below zero. This ecological concrete is named CO2-SUICOM (CO2 Storage under Infrastructure by Concrete Materials). This concrete is based on two typical features. One is using a special additive (the dicalcium silicate γ phase: γ-2CaO⋅SiO2) and coal-ash instead of cement. These materials have very low level of CO2 emissions, and γ-2CaO⋅SiO2 hardens concrete by reaction with CO2. The other feature of this concrete is that CO2 in the exhaust gas of a power plant can be captured. After this concrete is manufactured, it is set in a chamber. Exhaust gas is drawn into the chamber, and CO2 included in the exhaust gas is captured in the concrete. A method of evaluating the amount of CO2 in concrete was developed, which involved analyzing concentrations of CO2 using an inorganic carbon analyzing device. In this method it is important to use samples of a particular size. The method was used to confirm that amounts of CO2 emitted during preparation of the concrete were below zero.