Japanese construction contractor Taisei Corporation announced on February 16th that it has developed carbon negative concrete that significantly reduces the emission of carbon dioxide during the production process by using blast furnace slag and other materials instead of cement. Adding calcium carbonate in concrete also results in a reduction in the amount of CO2 emission.

"T-eConcrete/Carbon-Recycle" is an improved version of the company's existing environmentally friendly concrete "T-eConcrete," which does not use cement in its production. It can absorb CO2 through calcium carbonate produced from recovered CO2. One cubic meter of concrete can fix 70 to 170 kg of CO2. Due to the CO2 fixation inside the concrete material and the use of blast furnace slag, an industrial by-product, the CO2 balance during the manufacturing process can be minus 55 to minus 5 kg per cubic meter.

　Since the recovered CO2 is not directly absorbed into the concrete during production, corrosion of the reinforcing steel inside the concrete is prevented, and the durability of reinforced concrete structures is sustained. It can be manufactured using normal equipment at ready-mixed concrete plants. The strength and fluidity, which is a measure of workability, are equivalent to those of ordinary concrete, and can be constructed in the same way as conventional concrete.(2021/02/17)