1. Home
  2. News Release
  3. Development of “CUCO - Precast Concrete for Construction” that reduces, fixes, and absorbs CO2, and reduces emissions in the production process by more than 80 percent

Development of “CUCO - Precast Concrete for Construction” that reduces, fixes, and absorbs CO2, and reduces emissions in the production process by more than 80 percent－First application as a foundation material for the event hall building at Osaka-Kansai Expo to be held in 2025－

October 19, 2023

As part of the NEDO*1 Green Innovation Fund Project titled "Development of Concrete and Other Manufacturing Technologies Using CO2" (hereinafter referred to as the "Project"), Takenaka Corporation (President: Masato Sasaki), in collaboration with Kajima Corporation (President: Hiromasa Amano) and DENKA Corporation (President: Toshio Imai), is managing the CUCO consortium to implement this project. The consortium is developing carbon-negative concrete*2 that emits virtually zero or less CO2 during the production process.

Through this project, we have now developed "CUCO - Precast Materials for Construction" (hereinafter referred to as "developed materials"), which is a type of concrete that reduces, fixes, and absorbs CO2. Compared to conventional concrete, these developed materials can reduce CO2 emissions by over 80 percent during the production stage.

There are four variations of the developed materials, each featuring different combinations of the technologies that reduce, fix, and absorb CO2. All of these materials will be applied as foundation components for the Pavilion World Messe Event Hall Building (a temporary structure*3) at the 2025 Japan International Exposition (Osaka-Kansai Expo). This marks the first time these materials will be utilized in an actual building. After the Expo, the Event Hall Building will be dismantled, but the developed materials will remain in use as a foundation to test the resource recycling technology. Additionally, we will investigate how the properties of the concrete, such as strength and durability, change over the long term when used in a real-world environment.

  • *1NEDO: New Energy and Industrial Technology Development Organization
  • *2Carbon-negative concrete: Concrete that reduces, fixes, or absorbs more CO2 than the amount of CO2 emitted during manufacture.
  • *3Temporary buildings: Buildings constructed to last only for a short period, such as for an exposition. Structural performance is equivalent to that of a permanent structure.
Foundation members of the Event Hall Building of Osaka-Kansai Expo where the developed materials were applied
Foundation members of the Event Hall Building of Osaka-Kansai Expo where the developed materials were applied

Outline of the Developed Materials

The concrete we developed incorporates various technologies designed to reduce, fix, and absorb CO2. The three main technologies implemented are:

  1. 1.Technology to Reduce CO2 Emissions
    This technology cuts CO2 emissions by approximately 60 percent by utilizing ECM*4 cement, which incorporates blast furnace slag fine powder known for its low CO2 emissions, in place of conventional cement.
  2. 2.Technology to Fix CO2
    This technology stores CO2 by fixing it into the calcium content of concrete demolition debris, which is then used as aggregate or filler in the new concrete (referred to as CCU material*5).
  3. 3.Technology to Absorb CO2
    This technology enables the absorption and fixation of CO2 after concrete hardening. It involves mixing cement with LEAF, a special admixture that enhances the capacity to absorb CO2 and effectively densify the hardened body.

In this application, four types of developed concrete are utilized, which include combinations of technologies (1 and 2 with different CCU materials), (1 and 3), and (1, 2, and 3).

  • *4ECM: Abbreviation for Energy and CO2 Minimum, a cement in which about 60 percent of conventional cement is replaced by blast furnace slag fine powder, an industrial by-product, to reduce energy consumption and CO2 emissions during cement production.
  • *5CCU materials: CCU stands for carbon capture and utilization, which in this technology refers to materials for concrete produced by utilizing (fixing) CO2 as a resource.

Reference URL： https://www.takenaka.co.jp/news/2022/01/04/

Reference URL：CUCO website https://www.cuco-2030.jp/english/

Future Development

CUCO will work with NEDO to develop and improve CO2 reduction, fixation, and absorption technologies to achieve carbon negativity, thereby contributing to the transition to a decarbonized society.