Thin-section fiber reinforced concrete is portland cement concrete or mortar reinforced with dispersed, randomly oriented discrete fibers. Fibers can be metal (low carbon or stainless), mineral (glass or asbestos), synthetic organic (carbon, cellulose, or polymeric), or natural organic (sisal). Fiber lengths can range from 1/8 inch to 2-1/2 inches. Furthermore, many existing thin fiber-cement composites on the market today comprise a blend of different fiber types. By ACI's definition, ferrocement is portland cement mortar reinforced by the number of very closely spaced layers of continuous fiber networks or meshes. Ferrocement can be manufactured with any of the fiber types mentioned above, even though its name might imply steel wire meshes. ACI the many thin-section fiber-cement building products available the world or under development. SP-124 contains papers presented at symposiums in Atlanta, Feb. 1989 and in San Diego, Nov. 1989.