Before beginning a brief description of Japanese activities in the civil engineering area, it is worthwhile to list the reasons behind the rapid development and growth of this area in Japan, where despite efforts by U.S. companies such as DuPont, Hercules and Dow over the past decade, very little real advance (in terms of market penetration) has been seen in the U.S.
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 can be largely prefabricated, are major drivers pushing the use of composites.
The potential of having cleaner work sites while simultaneously increasing the capability of integrating form and function with aesthetics makes the use of composites and advanced materials attractive.
Japan's major urban and industrial centers are all within a marine environment that makes corrosion of steel a constant problem. The constant deterioration of steel and even wooden structures provides a strong impetus for the use of corrosion- and degradation-resistant materials.
Infrastructure in Japan has been overwhelmed by a level of usage not foreseen. In addition to previous poor design and construction practices that resulted in accelerated deterioration, lack of large spaces for expansion has led to the search for innovative solutions.
The need for lighter construction materials and more seismic resistant structures has placed high emphasis on the use of new and advanced materials that can not only decrease dead weight but can also absorb the shock and vibration through tailored microstructures. Similar objectives are seen for retrofit/rehabilitation/strengthening of pre-existing structures that have to be retrofitted to make them seismic resistant, or to repair damage caused by seismic activity.
A major barrier to the acceptance of composites by the construction industry in the U.S. is the lack of connection between the materials suppliers and construction industry at a level higher than salesman/potential customer. The keiretsu structure has already forged strong business links between these groups in Japan, whereby each has the potential for using the other as a demonstration of capabilities or as a quick and ready resource center.
Whereas large construction companies in the U.S. have no R&D centers, there are as many as 15 such centers in Japan -- funded and managed by individual companies. Thus the search for and the development of new and improved materials begins with the company rather than from the outside, thereby increasing its acceptance.
A significant difference between procedures in the U.S. and Japan is that the construction industry is far less curtailed by codes and regulations in Japan than it is in the U.S. The flexibility afforded to them in experimenting with new materials and structural forms is higher. This in no way should be taken to mean that they are any less responsible or liable than their U.S. counterparts; rather, Japanese companies feel 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 viability has been proven. The time taken to get through the bureaucracy is also often much less.
Japanese construction companies and the materials industry were quick to realize that the reduction in defense spending would lead to enormous opportunities for application of composites in the infrastructure area, and began to commit their resources at an early date, so as to gain a competitive edge. 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 (such as the use of carbon fiber reinforced concrete in the Al-Shaheed monument in Iraq by Kajima Corporation).
Although carbon fiber is produced worldwide, Japanese companies have been more aggressive not only in finding new markets, but also in trying to develop them (the use of the keiretsu and more advantageous code regulations no doubt are factors as well). This may in part be due to the higher overall carbon fiber production capacities in Japan as compared with those in the U.S.
Materials suppliers in Japan appear to be more willing to use their own structures as demonstration sites for their products (Shimizu through the use of NEFMAC in their building, Mitsubishi Kasei and Tonen Corporation through the use of carbon fiber for rehabilitation, etc.) than their U.S. counterparts. Part of this is no doubt due to codes, but a large part is in essence their willingness to make major investments towards long term goals, rather than being tied to quarterly earnings (as in the U.S.).
This chapter discusses the use of advanced composites in Japan in grid-type structures. Other uses, including short and continuous fiber, cable-typed elements, 3-D and grid structures, and applications in retrofit and rehabilitation will be covered in future publications by this author. This was found to be the best way to maintain the original focus of this study, which was composites in general and not just civil infrastructure applications. The development of the civil engineering market will also be discussed. It should, however, be noted that the cost-competitiveness of the products compared to traditional construction material is based on claims that the panel did not attempt to check, and hence should be treated with a degree of caution. However, it is clear that the Japanese are far ahead of the U.S. in the development (and in the capturing) of this new market and are steadily increasing their lead.
Rather than present a detailed list of the motivation and background for the use of composites in infrastructure, the interested reader is referred to Karbhari (1993) and Ballinger (1992). In the context of this report, we discuss pertinent developments in the area of grid-type structures.