Mitsubishi Plastics Infratec Co., Ltd., Takenaka Corporation, Constec Engi, Co., Sanko Techno Co., Ltd., Bond Engineering Co., Ltd. and Konishi Co., Ltd. have developed the “CFRP Anchoring Method”, a new method to reinforce columns and beams of buildings using carbon fiber sheets, CFRP rods and CFRP corrugated plates*. Having obtained certification and registration from the General Building Research Corporation of Japan, the Companies will start full-scale sales of the new method.

Renovation and reinforcement of roads, bridges and other infrastructure that were constructed during Japan’s high economic growth period are now drawing attention. It is also known that buildings completed before the 1981 amendments to the Building Standard Act do not meet the current quake-resistance standards. Those buildings have been reinforced by a method whereby lightweight, high　performance carbon fiber sheets are strengthened to columns and beams. However, columns are in many cases attached to the wall, preventing carbon fiber sheets from entirely wrapping the columns. In such cases, slits are made on the wall to enable the columns to be wrapped, or holes are bored on the wall where steel anchors are embedded and secured by metallic tighteners. These methods must be done with heavy equipment, requiring additional work.

The newly developed CFRP Anchoring Method is a strengthening method using carbon fiber sheets, whereby CFRP rods are embedded in holes bored on the wall and secured by CFRP corrugated plates. It was considered difficult to execute this method as it requires holes to be bored accurately on the side wall. This problem was solved with a newly developed special drill. Features of the new method are as follows:
 - It uses CFRP, which is lighter than metallic materials, requiring no heavy machinery.
 - Steel is not used, realizing rust-free, highly-durable reinforcement.
 - Required work is only to bond CFRP rods and corrugated plates that were fabricated at a plant directly to carbon fiber sheets wrapped around the columns, resulting in reduced work at the site, the shortened work period and the stabilized quality.
 - Equal strengthening effect is obtained in a short work period in case of both columns attached to the wall and stand-alone columns.

Work under this method will be carried out by Takenaka, Constec Engi, Sanko Techno and Bond Engineering using materials to be provided by Mitsubishi Plastics Infratec and Konishi.

The need for methods to reinforce buildings with insufficient quake resistance is expected to grow further to respond to earthquake disasters. The Companies will facilitate widespread dissemination of the CFRP Anchoring Method, which protects precious lives and property from disasters, to contribute to the creation of a safe and secure society.

* Carbon-fiber-reinforced plastics that are made at a plant by combining epoxy resin and carbon fiber and processed into rod-shape or corrugated-shape.

 

Product photo

Carbon fiber sheet CFRP corrugated plate and CFRP rod

 

Work photo

 

 

 

 

Corporate outline

Mitsubishi Plastics Infratec Co., Ltd．
Head office: 1-2-2 Nihonbashihongokucho, Chuo-ku, Tokyo
Representative: Masato Sasaki, President
Capital:  400 million yen (Mitsubishi Plastics 100%)
Line of business: Manufacturing and sales of synthetic resin products (house building plastics pipe, building materials and equipment, house and building materials, construction materials, waterproofing/strengthening/functional materials, and plastic plates)

Takenaka Corporation
Head office: 4-1-13 Hommachi, Chuo-ku, Osaka City, Osaka
Representative: Toichi Takenaka, President
Capital:  50 billion yen
Line of business: Contract, design and supervision of construction work and civil engineering work

Constec Engi, Co.
Head office: 2-3-14 Tokiwa-Cho, Chuo-Ku, Osaka City, Osaka
Representative: Yonezo Nakano, President
Capital:  96 million yen
Line of business: Investigation/diagnosis, repair/retrofitting work and seismic diagnosis/seismic retrofitting work of concrete buildings, asbestos treatment and dioxin removal work

Sanko Techno Co., Ltd.  
Head office: Life Garden Nagareyama Otakanomori, 6-183-1 Higashi Hatsuishi, Nagareyama City, Chiba
Representative: Hideto Horage, President
Capital:  768 million yen
Line of business: Planning & development, manufacturing, sales, construction and import/export of construction materials (post-installation anchors, drill bits, industrial fasteners, etc.), composites, waterproofing materials and measuring instrument

Bond Engineering Co., Ltd.  
Head office: 4-6-25 Tsurumi, Tsurumi-ku, Osaka City, Osaka
Representative: Shiro Nakaya, President
Capital:  100 million yen
Line of business: Investigation, design, quantity survey and construction of repair, reinforcement and renovation work for concrete buildings, steel structure and special civil engineering work  

Konishi Co., Ltd. 
Head office: 1-7-1 Doshomachi, Chuo-ku, Osaka City, Osaka
Representative: Tomoo Omaru, President
Capital:  4,603 million yen
Line of business: Manufacturing and sale of synthetic adhesive, sealing materials and resins (“Bond”), flooring wax, cleaning substance and plastics mold release agent (“Bond Wax”) and industrial tape (“Bond Tape”)

 

For further information please contact:
Public Relations and Investor Relations office,
Mitsubishi Chemical Holdings Corporation.
TEL: +81-3-6748-7140