Most of our modern infrastructure and architecture is bad on concrete, and the production of cement used in concrete is one of the biggest causes of worldwide carbon dioxide emissions. This constitutes a serious issue that must be addressed, especially with the current state of our Planet Earth. In this effort, Nendo displays a specimen of a greener and cleaner way to construct and build with its Block-Wall House. The Block-Wall House is partially built using a new concrete that captures carbon dioxide instead of emitting it!
Designer: Nendo & Kajima Corporation
Tucked away in Japan’s Nagano Prefecture, the Block-Wall House is located next to a rural road. The house features a lot of glazing, to offer privacy against pedestrians and passing vehicles. The home is equipped with an angled screen which lets residents look out but makes it quite difficult for a passerby to glance inside. This screen is made using 2000 blocks which have been arranged in parallel rows to form five walls, with a length of 360 feet. This screen is made from the aforementioned sustainable and novel concrete!
This newly developed concrete is made by the Kajima Corporation in collaboration with the Chugoku Electric Power Co, Denka, and Landes Co. The concrete is named CO2-SUICOM, and for its production, a special cement mixture is placed in a curing chamber, and carbon dioxide is pumped into the chamber for absorption. This absorbed CO2 gets stuck inside the concrete and is not released. It is as strong as regular concrete!
“Generally, concrete hardens through a chemical reaction between cement and water,” explains Kajima Corporation. “But with CO2-SUICOM, over half the cement is replaced with a material we call γ-C2S. Instead of reacting with water, γ-C2S reacts with the CO2 in the air to harden. After mixing the materials needed to create CO2-SUICOM, the concrete can be placed in a location with high CO2 levels so it can capture the CO2 and harden, trapping the gas inside. For example, a thermal power plant or other facility that produces carbon-heavy exhaust gases can redirect the gases into a carbon sequestration chamber, where concrete products made with CO2-SUICOM can be placed to capture the CO2 in the gases.”
Currently, the price of producing CO2-SIUCOM concrete is about three times higher than usual concrete in Japan. Hence, work is being done to bring down the price, and Kajima Corporation believes that the concrete will become more economical in the future.
