Japanese construction industry predicts that it will experience a lack of labor due to their aging residents linked with the diminishing number of children, and sustenance and restoration expenses will grow due to aging infrastructure. To overcome and answer such obstacles and problems, Kengo Kuma developed a carbon fiber composite material with various characteristics of being durable, lightweight, strong, and non-corrosive. This thermoplastic carbon fiber composite is termed as CABKOMA. The thermoplastic resin is utilized as the matrix resin which can transform itself with heat even after it is hardened and fixed. 

An earthquake-resistant building constructed with the world's lightest anti-seismic reinforcement revealed by Kengo Kuma - Sheet1
Cabkoma ©www.komatsumatere.co.jp

“The material is unusual. It’s something that we dreamed of but was unable to realize until now. We believe that this flexible anti-seismic reinforcement is quite an accomplishment”, says world-famous Japanese architect Kengo Kuma. 

An earthquake-resistant building constructed with the world's lightest anti-seismic reinforcement revealed by Kengo Kuma - Sheet2
Cabkoma strand rod ©www.komatsumatere.co.jp
An earthquake-resistant building constructed with the world's lightest anti-seismic reinforcement revealed by Kengo Kuma - Sheet3
Abkoma strand rod and steel rod comparison ©www.komatsumatere.co.jp

CABKOMA is sustainable, light in weight, and has very high tensile strength. It is rust free and is extremely durable. CABKOMA can change in dimension with the temperature and thermal deformation is possible. The strands are 5 times lighter than its steel equivalent, indicating that a 6th of the weight is expected to have the same tensile strength as steel cables. The strands are so light in weight that 160 meters of that weigh 12 kgs while still preserving the power equivalent of a metal cable that is five times more in weight. The CABKOMA strand rod is a carbon fiber composite material made of a carbon-fiber core and the outer layer is enveloped with inorganic fiber, into which thermoplastic resin is impregnated. 

An earthquake-resistant building constructed with the world's lightest anti-seismic reinforcement revealed by Kengo Kuma - Sheet4
Cabkoma strand rod ©www.komatsumatere.co.jp

In Nomi city, Japan, architect Kengo Kuma has refurbished an office building identified as the world’s first earthquake-resistant construction reinforced by carbon fiber. Rising three-stories high, the structure called ‘fa-bo’ operates as a workspace, exhibition, and research space for the Japanese fabric manufacturing company of Komatsu Seiren. Established in an effective earthquake zone, the client needed a structure and a framework that would be capable of withstanding tsunamis and earthquakes. Carrying that necessity in mind, Kuma chose to restore and refurbish the client’s prior office building by fastening carbon fibers on the external facade, to strengthen and increase the building against the natural calamities. Equipped with minimalistic concrete, fa-bo is durable and firm enough to bear harsh weather conditions, earthquakes, and floods. The building also highlights a showroom with displays and workshops that are accessible to visitors interested and engaged in fabric crafting. On top of fa-bo is a rooftop garden with a magnificent view of Mt. Haku. 

An earthquake-resistant building constructed with the world's lightest anti-seismic reinforcement revealed by Kengo Kuma - Sheet5
Fabo ©www.archdaily.com
An earthquake-resistant building constructed with the world's lightest anti-seismic reinforcement revealed by Kengo Kuma - Sheet6
Cabkoma strand rod interior ©interestingengineering.com

From distant, these carbon fiber rods lightly cover around and across the whole building almost like a translucent and thin cloak. The outcome is an airy, organic, and structural façade that has a fabric-like aesthetic while still extending the strength and durability to withstand ground movement through an earthquake crisis. Using computer technology, the location of each of these bars were fully assessed before its fabrication to react to the horizontal seismic force and motion from north to south, and east to west. Overall, Kuma has turned an ordinary office section into an artistic building linked to its program; visually and functionally. The rods designed, together act as seismic supports and in turn, opens up opportunities for further earthquake reinforcement tactics and approaches in architecture. The material’s high tensile force and elasticity make the rods ten times more powerful than iron. “This is the very first time that this material was used as a means of reinforcement against earthquakes”, says Kuma. The gaps left between the rods demarcate building entrances.

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Cabkoma strand rod roof ©inhabitat.com
An earthquake-resistant building constructed with the world's lightest anti-seismic reinforcement revealed by Kengo Kuma - Sheet8
Cabkoma interior fabric ©inhabitat.com

The lightweight carbon fiber composites can also be seen in the interior, which highlights white draped fabrics that imitate the sculptural facade. The green roof is covered with another Komatsu Seiren produce called Greenbiz, permeable, and porous ceramic boards made from waste material in carbon fiber generation.

The material’s capacity to grasp complicated shapes offers architects, engineers, and makers a level of design versatility not typically found with other competing materials. Kuma also believes the rod will “change things” and has the potential to generate an influential revolution in the realm of architecture.

Author

Shraddha Erandole, an architect by profession and curious by nature. A firm believer in architecture and research, when combined with design thinking, it helps in strengthening our society and has a positive effect. If not reading, you will always find her sipping coffee and capturing the sky.