Concrete is considered a brittle material because it has a low tensile strength and a low tensile strain before fracture. These shortcomings are generally overcome by reinforcing the concrete. Normally the reinforcement consists of continuous deformed steel bars or prestressing tendons. Recently, there has been an increasing interest in several types of microreinforcement as alternatives.
The current development has centered around two types of microreinforcement: small diameter, short lengths of randomly distributed discontinuous fibers (to produce fiber-reinforced concrete); and, small diameter continuous wire mesh (to make ferrocement). Fibers can be metallic (steel), mineral (asbestos or glass) or natural or synthetic organic (polypropylene, aramid or sisal). They can be incorporated in concrete by premixing, by shotcreting or by spraying. New types of fibers, new methods of fabrication and different types of applications are continuously being developed.
This article contains descriptions of properties and applications of concrete made with asbestos, glass, steel, and organic fibers.