Large Volume, High-Performance Applications of Fibers in Civil Engineering VICTOR C. LI ACE-MRL, Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan 48109 Received 8 November acce Nouem ber 2000 ABSTRACT: This article presents an overview of fiber applications in cementitious composites. The socio-economic considerations surrounding materials development in civil engineering in general, and fiber reinforced cementitious materials in particular appliations are fibers are used in these applications, are documented. An attempt is made to extract common denominators among the widely varied applications. The R&D and industrial trends of applying fibers in enhancing structural performance are depicted. An actual case study involving a tunnel lining constructed in Japan is given to illustrate how a newly proposed structural design guideline takes into account the load carrying con- tribution of fibers. Composite properties related to structural performance are de cribed for a number of FRCs targeted for use in load carrying structural members Structural applications of FRCs are currently under rapid development. In coming years, it is envisioned that the ultra-high performance FRC, with ductility matching that of metals, will be commercially exploited in various applications. Highlights of such a material are presented in this article. Finally, conclusions on market trends are drawn, and favorable fiber characteristics for structural applications are provided o 2002 John Wiley Sons, Inc. J Appl Polym Sci 83: 660-686, 2002 Key words: FRC, ECC; fiber; composites; structure INTRODUCTION Fibers are generally used in one of two forms short staple randomly dispersed in the cement The use of fibers to reinforce a brittle material can tious matrix of a bulk structure, or continuous be traced back to egyptian times when straws or mesh used in thin sheets. In recent years, some horsehair were added to mud bricks. Straw mats attempts to weave synthetic fibers into three-di- serving as reinforcements were also found in mensional reinforcements have been made In ad- early Chinese and Japanese housing construc- dition, fiber-reinforced plastic rods are currentl tion. The modern development of steel fiber rein- entering the market as replacement of steel bar forced concrete may have begun around the early reinforcements. Beyond cementitious matrix, fi- 1960s, preceded by a number of patents. Poly- ber-reinforced plastics are finding increasing use meric fibers came into commercial use in the late in the civil engineering industry. However, this 970s, glass fibers experienced widespread use in article will focus only on the material with the the 1980s, and carbon fiber attracted much atten- currently largest consumption of fiber--randomly che early 1990s oriented fiber-reinforced cementitious matrix (ce- ment, mortar, and concrete) materials (hereafter Contract grant sponsor: National Science Foundation. breviated as FRCs). Based on industrial sources, the amount of fibers used worldwide at Joumal of Applied Polymer Science, Val. 83, 660-686(2002) o 2002 John wiley Sons, Inc. present is estimated at 300, 000 tons per year, andLarge Volume, High-Performance Applications of Fibers in Civil Engineering VICTOR C. LI ACE-MRL, Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan 48109 Received 8 November 2000; accepted 18 November 2000 Published online 15 November 2001; DOI 10.1002/app. 2263 ABSTRACT: This article presents an overview of fiber applications in cementitious composites. The socio-economic considerations surrounding materials development in civil engineering in general, and fiber reinforced cementitious materials in particular, are described. Current FRC appliations are summarized, and the where, how, and why fibers are used in these applications, are documented. An attempt is made to extract common denominators among the widely varied applications. The R&D and industrial trends of applying fibers in enhancing structural performance are depicted. An actual case study involving a tunnel lining constructed in Japan is given to illustrate how a newly proposed structural design guideline takes into account the load carrying con￾tribution of fibers. Composite properties related to structural performance are de￾scribed for a number of FRCs targeted for use in load carrying structural members. Structural applications of FRCs are currently under rapid development. In coming years, it is envisioned that the ultra-high performance FRC, with ductility matching that of metals, will be commercially exploited in various applications. Highlights of such a material are presented in this article. Finally, conclusions on market trends are drawn, and favorable fiber characteristics for structural applications are provided. © 2002 John Wiley & Sons, Inc. J Appl Polym Sci 83: 660–686, 2002 Key words: FRC; ECC; fiber; composites; structure INTRODUCTION The use of fibers to reinforce a brittle material can be traced back to Egyptian times when straws or horsehair were added to mud bricks. Straw mats serving as reinforcements were also found in early Chinese and Japanese housing construc￾tion. The modern development of steel fiber rein￾forced concrete may have begun around the early 1960s, preceded by a number of patents.1 Poly￾meric fibers came into commercial use in the late 1970s, glass fibers experienced widespread use in the 1980s, and carbon fiber attracted much atten￾tion in the early 1990s. Fibers are generally used in one of two forms— short staple randomly dispersed in the cementi￾tious matrix of a bulk structure, or continuous mesh used in thin sheets. In recent years, some attempts to weave synthetic fibers into three-di￾mensional reinforcements have been made. In ad￾dition, fiber-reinforced plastic rods are currently entering the market as replacement of steel bar reinforcements. Beyond cementitious matrix, fi- ber-reinforced plastics are finding increasing use in the civil engineering industry. However, this article will focus only on the material with the currently largest consumption of fiber—randomly oriented fiber-reinforced cementitious matrix (ce￾ment, mortar, and concrete) materials (hereafter abbreviated as FRCs). Based on industrial sources, the amount of fibers used worldwide at present is estimated at 300,000 tons per year, and Contract grant sponsor: National Science Foundation. Journal of Applied Polymer Science, Vol. 83, 660–686 (2002) © 2002 John Wiley & Sons, Inc. 660