What's New

Tokyo, Japan - February 06, 2025 -The BFCCU^*1 Study Group (consisting of thirteen companies: Penta-Ocean Construction Co., Ltd. [organizer], Asunaro Aoki Construction Co., Ltd., Asanuma Corporation, Hazama Ando Corporation, Okumura Corporation, Kumagai Gumi Co., Ltd., Konoike Construction Co., Ltd., Tekken Corporation, Tokyu Construction, Tokyo Techno Corporation, Toyo Construction Co., Ltd, Haseko Corporation and Yahagi Construction Co., Ltd.) hereby announces that we newly developed CELBIC-RA, an environmentally friendly concrete that exhibits "low-carbon features" and "resource recycling effect", by adding recycled aggregate generated from demolition wastes and other materials, to CELBIC^*2, a green concrete.

CELBIC-RA (Consideration for Environmental Load using Blast furnace slag In Concrete-Recycled Aggregate) is an environmentally friendly concrete made from standard CELBIC (mixed with granulated blast furnace slag as 70% of the binder) and recycled aggregate, a CCU material in which carbon dioxide (CO₂) is fixed during fabrication and storage processes. Compared to an ordinary concrete mix, CELBIC-RA achieves up to 70% CO₂ reduction. The recycled aggregate is manufactured mainly from demolition wastes and other materials, and contains cement paste, which chemically reacts with CO₂, allowing it to fix CO₂ during the fabrication and storing processes. Recycled aggregate of classes M and L are commonly used for producing CELBIC-RA because of their relatively higher content in cement paste for fixing CO₂. The BFCCU Study Group validated production and quality control methods for CELBIC-RA by empirical machine testing and demonstrated its efficacy as structural concrete.

^*1 BFCCU:Blast Furnace slag + Carbon dioxide Capture and Utilization
^*2 CELBIC: a green concrete that reduces carbon dioxide emissions from concrete materials by approximately 9 to 63% while maintaining the required quality for concrete structures

Features

1. Environmentally friendly concrete
CELBIC-RA is an environmentally friendly concrete that falls under the "Resource Recycling Grade 3" and "Low Carbon Grade 3" of the environmental performance ratings in the Japanese Architectural Standard Specifications for Reinforced Concrete Work JASS 5 (Architectural Institute of Japan), for its large content of granulated blast furnace slag and recycled aggregate.

2. Improved CO₂ reduction effect
CELBIC-RA, achieving a 70% reduction in the use of Portland cement and utilizing recycled aggregate that fixes atmospheric CO₂, reduces CO₂ emissions from concrete materials by approximately up to 70 %^*3.
^*3 test calculation results

3. Use of recycled aggregate classes M and L
CELBIC-RA uses recycled aggregate of classes M and L, which are manufactured by mechanical processing, including crashing and griding, instead of specialized processes such as heating. Consequently, it is possible to fix a large amount of CO₂ while reducing energy input during manufacturing process. As CELBIC-RA falls under the category of "Recycled Aggregate Concrete M" specified in JIS A 5022, it can be applied to building structures such as cast-in-place piles and foundations.

The member companies of the BFCCU Study Group are working to reduce CO₂ emissions throughout the supply chains and to make effective use of resources. Together, we will strive to promote the commercial and widespread use of CELBIC-RA, an environmentally friendly concrete, at actual sites, and to contribute to the realization of a circular economy and carbon neutrality by 2050.