ABSTRACT
Fibers have been used to reinforce brittle materials from time immemorial, dating back to the Egyptian and Babylonian eras, if not earlier. Straws were used to reinforce sun-baked bricks and mud-hut walls, horse hair was used to reinforce plaster, and asbestos fibers have been used to reinforce Portland cement mortars. Research in the late 1950s and early 1960s by Romualdi and Batson (1963) and Romualdi and Mandel (1964) on closely spaced random fibers, primarily steel fibers, heralded the era of using the fiber composite concretes we know today. In addition, Shah and Rangan (1971), Swamy (1975), and several other researchers in the United States, United Kingdom, Japan, and Russia embarked on extensive investigations in this area, exploring other fibers in addition to steel. By the 1960s, steel-fiber concrete began to be used in pavements, in particular. Other developments using bundled fiberglass as the main composite reinforcement in concrete beams and slabs were introduced by Nawy et al. (1971) and Nawy and Neuwerth (1977), as discussed in Section 22.8 of this chapter. From the 1970s to the present, the use of steel fibers has been well established as a complementary reinforcement to increase cracking resistance, flexural and shear strength, and impact resistance of reinforced concrete elements both in situ cast and precast.
