fib Deputy President and Presidium member，Incoming President from 2021，Executive Vice President and Chief Technology Officer of Sumitomo Mitsui Construction,
Akio Kasuga is an executive vice president and CTO of Sumitomo Mitsui Construction. He received his diploma and doctoral degree in civil engineering from Kyushu University in 1980 and 1997. He has designed more than 200 bridges and has experienced projects of R&D and construction sites. He is deputy president of fib from 2019 to 2020, incoming President from 2021. And also he is a head of delegates of Japan National Member Group and a board member of Japan Prestressed Concrete Institute.
Keynote Lecture Title:
A Challenge to Non-metallic Bridges
The first non-metallic bridge was built in 1990 in Tochigi, Japan. AFRP shear reinforcement and prestressing tendons were used instead of steel. However, the cost of this prototype non-metallic bridge was 2.5 times compared with usual prestressed concrete bridges. And our R&D of non-metallic bridge was suspended. In 2010, West Nippon Expressway Company announced the joint research project regarding non-metallic bridge. Then their most important requirement was 1.5 times initial cost of the structure. Usually the life cycle cost of bridges is 2 to 3 times compared with initial cost. Therefore, 1.5 times initial cost and no maintenance cost are acceptable for the bridge owner.
At that time, Sumitomo Mitsui Construction has experiences of non-metallic bridges and our joint research was started in 2010. In order to suppress the cost of new structure, fiber reinforced concrete, butterfly web and AFRP internal and external tendons were used. In 2015, the temporary bridge was built in Nagasaki to collect data of the bridge. And in 2019, the highway bridge in Tokushima will be constructed. In order to realize the non-metallic bridge, many leading edge technologies since 1990 are gathered. Nom-metallic bridges can regain its extreme high durability because they eliminate the factor of deterioration, steel reinforcements.