CHAPTER 1

INTRODUCTION

For over 10 years now, the Japanese have pioneered the use of advanced fibers and polymer composites, initially within Japan itself, and more recently in Europe, Asia and the United States. Although the economic competitiveness of individual products may be unknown or questionable, each application provides a unique advantage because of the intrinsic properties of composites. Listing the reasons behind the rapid development and growth of these activities in Japan can shed light on why such advances have not taken place in the United States at the same rate, despite efforts (although isolated in most cases until recently) in similar areas.

A shortage of skilled labor combined with an aging workforce. This presents a special challenge to Japanese construction firms in retaining their global position. Simplified construction methods resulting from the use of lighter materials that are easier to handle and that can be largely prefabricated are major drivers pushing the use of composites in Japan.

Societal preoccupation with neatness and aesthetics. The potential to have cleaner work sites - while simultaneously increasing the capability to integrate form and function with aesthetics - makes the use of composites and advanced materials specially attractive to the Japanese.

The predominance of a marine environment. Japan's major urban metropolis and industrial centers are all within a marine environment that makes the corrosion of steel a constant problem. The deterioration of steel and degradation of wooden structures provides a strong impetus for the use of corrosion- and degradation-resistant materials.

Growth in population and the corresponding increased demand on transportation and related infrastructure. The infrastructure in Japan has been overwhelmed by unforeseen usage levels. In addition to previous poor design and construction practices that resulted in accelerated deterioration, a lack of large spaces for expansion has led to the search for innovative solutions on land and in reclaiming habitable areas from the sea.

Earthquake and seismic activity. The need for lighter construction materials and more seismic resistant structures in Japan has placed a high emphasis on the use of new and advanced materials that can both decrease dead weight and absorb shock and vibration through tailored microstructures. The objectives are similar for the retrofit/rehabilitation/strengthening of pre-existing structures to make them seismic resistant, or to repair damage caused due to seismic activity.

Close link between materials suppliers and construction industry. A major barrier to the acceptance of composites by the construction industry in the United States is the absence of a relationship between materials suppliers and the construction industry at levels higher than that of salesman and potential customer. The keiretsu structure has forged strong business links between these groups in Japan. Each sector has the potential to use the other to demonstrate capabilities or as quick and ready resource centers.

Research and development laboratories in the civil construction area. Large construction companies in the United States have virtually no R&D centers, whereas there are as many as 15 such centers in Japan, funded by and managed by individual companies. The search for new and improved materials begins within the company, increasing its relevance and acceptance.

Willingness for pre-competitive collaboration. Japanese materials suppliers are more amenable to collaboration at both the pre-competitive and competitive stages to facilitate demonstrations and increase market penetration. Collaboration often takes place through associations and "clubs," as well as through the sharing of technology, in order to facilitate market growth.

Tax incentives. Japanese companies have been given significant tax breaks for the use of internal funds for research and development, especially for demonstration projects.

Codes and regulations. A significant cause for differences between U.S. and Japanese procedures is that the Japanese construction industry is far less curtailed by codes and regulations than is the case in the United States. In Japan, the industry has more flexibility to experiment with new materials and structural forms. This should not be taken to mean that Japanese companies are any less responsible or liable than their U.S. counterparts. Japanese companies are individually responsible for the structures they build; however, it is much easier for them to build without completely qualifying the materials of construction as long as the viability of the materials has been proven. The time taken to get a project through the bureaucracy is also often much less, although this is sometimes countered by the need for overall concurrence. There also appears to be a much stronger direct link between the Ministry of Construction and composites companies than in the United States, which may be an artifact of Japan's industrial structure.

Positioning and global competitiveness. Japanese construction companies and the materials industry were quick to realize that the reduction in defense spending would lead to enormous opportunities to apply composites in the infrastructure area. To gain a competitive edge, they began to commit their resources at an early date. The competitive position of Japanese construction companies in the international arena (especially in the Middle East) has also made it possible for them to initiate the use of new materials earlier in the commercial arena (such as the use of carbon reinforced concrete in the Al-Shaheed monument in Iraq by the Kajima Corp., and the use of carbon fiber sheet building strengthening in Korea by the Tonen Corp.).

The critical need to find a new use for carbon fiber. Although carbon fiber is produced worldwide, Japanese companies have been more aggressive in finding and developing new markets. Keiretsu relationships between materials suppliers and construction companies and the more advantageous regulatory environments referred to above no doubt are factors. This also may be due in part to the higher overall carbon fiber production capacities in Japan than in the United States. The Japanese composites industry expects the current ¥40 billion/year carbon fiber market to grow to ¥200 billion/year by the year 2000, primarily due to increased usage in building and infrastructure related products.

Willingness to establish demonstration sites. Materials suppliers in Japan appear to be more willing than their U.S. counterparts to use their own structures as demonstration sites for their products. (For example, Shimizu has used NEFMAC in its own buildings, and Mitsubishi Kasei and Tonen have used carbon fiber for rehabilitation projects.) This is partly due to codes, but material suppliers are ready to put forth major investment towards a long term goal, rather than focus on per quarter earnings (as in the United States). The predominant trend is for demonstrations aimed at the advancement of technology initiated by MITI and other government agencies, but funded by industry.

Based on the factors discussed above as well as socio-economic and cultural factors, the Japanese composites and construction industries appear to be poised to lead the world in the application of this new technology. Moreover, almost all the companies are also aggressively pursuing advancements in non-composite fields as well, both inside and outside the civil infrastructure arena. Nippon Steel even has competitive products in the same market niche (e.g. steel and carbon fiber-based cables).

The use of composites for civil infrastructure purposes encompasses a wide range of applications ranging from buildings and bridges, to pipelines, to offshore and marine structures.

Within this segment, advanced fibers and polymer matrix composites (PMCs) are used in a variety of forms including chopped fiber, continuous fiber, rod and bar type reinforcing elements, cables, grids, 3D reinforcing cages, and sheet type elements. A large variety of these forms are available commercially from an array of suppliers as is described in later sections of this report. A partial listing of reinforcing elements available in the Japanese market is given in Table 1.1. The list is not all inclusive. It is presented to showcase the wide range of products available already.

Table 1.1
Composite Elements Available Commercially

Constructor or Developer

Fabricator or Fiber Supplier

Fiber

Resin Type

Shape

Ohbayashi Corp.

Mitsubishi Kasei Corp.

Pitch-Based CF

Epoxy

Round Bar

Kajima Corp.

Arisawa

Pitch, PAN CF and AF

Epoxy

3D Fabric

 

Akzo

AF

Epoxy

Plate-like Rod

Shimizu Construction, Ltd.

Dainippon Glass Industries Co., Ltd.

GR and CF (PAN)

Vinylester

Lattice - 2D, 3D

Kumagai Gumi Co., Ltd.

Arisawa

CF (PAN) and GF

Epoxy, PPS

Rod, Spiral Hoop, and Stirrup

Taisei Corp.

Toho Rayon Co., Ltd.

CF (PAN)

Special Cement

Panels and Rods

Mitsui Construction Co., Ltd.

Toray and DuPont

AF and CF (PAN)

Epoxy

Braided Rod

Tokyo Rope Mfg. Co., Ltd.

Toho Rayon Co., Ltd.

CF (PAN)

Epoxy and BMI

Strand Rod (CFCC)

Sumitomo Construction Co., Ltd.

Teijin, Ltd.

AF

Vinylester

Round Bar

Okumura Gumi Co., Ltd.

Showa High-Polymer Co., Ltd.

CF (Pitch), AF, and GF

Vinylester

Spiral Rod

Takenaka Corp.

 

CF (PAN, Pitch) and AF

Epoxy

3D Elements

Mitsubishi Rayon Co., Ltd.

 

CF (PAN)

Epoxy

Rods

Toray Industry Inc.

 

CF (PAN)

Epoxy

Surface-Modified Rod and Stirrup

Nippon Steel Corp.

Kanebo, Ltd.

CF (Pitch) and AF

Epoxy

Mesh-like Element

  

CF (Pitch)

Epoxy

Strand

Kuraray Co., Ltd.

Kanebo, Ltd.

Vinylon (Polyvinyl Alcohol Fiber)

Epoxy

Surface-modified Rod and Braided Rod

Osaka Gas Co., Ltd.

Kanebo, Ltd.

CF (Pitch)

Epoxy

Braided Rod, Uni Rod, and Mesh-Like Element


CF = carbon fiber; GF = glass fiber; AF = aramid fiber; GR = graphite

In addition to the efforts being made by individual companies in developing markets for composites in civil engineering applications, there are strategic alliances between suppliers and large construction companies (e.g., Teijin, Ltd. and Sumitomo Construction Co., Ltd.) and "pre-competitive collaboration" through several different mechanisms. Some of the mechanisms include trade and professional associations, government initiated programs and government laboratories, and product-specific associations such as the Advanced Composite Cable (ACC) Club, the Carbon Fiber Repair and Reinforcement Research Association (CFRRA), and the Association of Aramid Reinforcement for Concrete Structures. The membership of these associations includes companies from the construction, materials, and design sectors. The associations serve as forums for standardization (akin to the Suppliers of Advanced Composite Materials Association - SACMA - in the United States) as well as forums for the joint promotion and demonstration of the technology. These associations will be described in more detail in sections on reinforcing elements and external reinforcement. Table 1.2 gives a listing of some of the professional associations that oversee research and set agendas, similar to the way in which organizations such as American Society of Civil Engineers (ASCE) function in the United States.

Table 1.2
Professional Organizations Involved in the Use of Composites in Civil Infrastructure

Association

Charge / Committee

Japan Society of Civil Engineering

Research committee on uses of fiber reinforced concrete and fiber composites

Japan Society of Construction

Research subcommittee for the development of composite applications

Japan Society of Steel Construction

Applications group for new materials for structural elements

Japan Ocean Industries Association

Research committee for the use of new materials in marine applications

Although Japanese companies appear to transfer concepts into demonstrations and applications directly and sometimes perhaps in a haphazard way, they do focus on the development of a detailed engineering base for some of the more promising application areas. They also conduct research to further the technology and its economic competitiveness. This process provides a paradigm in which a company or industry first develops a market, then goes back to further develop design data and fundamental knowledge, while simultaneously working on market penetration. It is not uncommon for individual companies and associations to have well-planned and structured development programs spanning 4 to 5 years, with secure funding for the entire period at a consistently high level, and without the constant fear of the project being terminated early due to changes in priorities.

The emphasis in this study is on two main areas: (a) the use of composite reinforcing elements in concrete, as replacements for conventional steel cable/tendon type reinforcement, and (b) the use of composites for the rehabilitation and retrofit of aging and deteriorating concrete structures or for structural elements that need to be brought up to code. In each of these categories, a number of different applications will be discussed to provide an overall picture of ongoing and completed activities. A short description of the use of chopped carbon fibers in concrete is also included.


Published: October 1998; WTEC Hyper-Librarian