Efforts to decarbonize are also accelerating in the construction industry.
For concrete, which is widely used in buildings, the raw materials and manufacturing process are being reviewed, and technology is being developed to reduce carbon dioxide emissions.
Concrete is made by mixing powdered cement with sand and water, but Taisei Corporation, a major general contractor, uses calcium carbonate instead of cement, which emits a lot of carbon dioxide during the manufacturing process. Developed the technology.
Calcium carbonate, the raw material, is made by blowing carbon dioxide contained in factory exhaust gas into an aqueous solution of calcium.
This way, up to 170 kilograms of carbon dioxide per cubic meter of concrete can be contained inside.
If carbon dioxide is directly absorbed, the internal reinforcing bars are easily corroded and the places where it can be used are limited, but this technology has solved this problem by converting carbon dioxide to calcium carbonate.
After establishing a more efficient manufacturing method, he wanted to order manufacturing from a concrete manufacturer and put it into practical use, and Eiji Owaki, the team leader of Taisei Corporation Technology Center, said, "From the materials used to the finished structure, the entire construction I want to actively reduce emissions. "
In addition, Kajima Construction Co., Ltd., a major general contractor, is using concrete that directly absorbs carbon dioxide during the manufacturing process for curbs on roads and bollards in parking lots, and is considering the development of concrete that will prevent deterioration of reinforcing bars in the future. I will.
Research is underway in the cement industry to reduce carbon dioxide emissions during the manufacturing process, and efforts to decarbonize are accelerating in the construction industry as well.