ABSTRACT
Since its introduction into the marketplace in the late 1960s, the use of fibre reinforced concrete has increased steadily. As of 2001, approximately 80 million m3 of FRC were produced annually, with the principal applications being slabs on grade (60%), fibre shotcrete (25%), precast members (5%), with the remainder of the production distributed amongst a number of other specialty products and structural forms. Unfortunately, at the time of writing (2005), fibres are still very little used in truly structural applications, despite their obvious effectiveness under seismic and other forms of dynamic loading, their ability to control crack widths, and so on. This is largely because most structural design codes for concrete, such as ACI 318, Building Code Requirements for Structural Concrete, are based primarily on concrete strength as the principal design criterion; they do not consider toughness. That is, they are concerned primarily with the peak loads that a structure might withstand, rather than the 'post-peak' behaviour. However, it is precisely in this post-peak region that the fibres become most effective. Thus, there would need to be significant changes in our design philosophy, and of course in the codes themselves, for fibres to be used properly either in conjunction with conventional steel reinforcement or alone.
