Flexural behavior of sisal fiber reinforced concrete beams

The world today is faced with major housing and transportation crises. Steel, wood and concrete are the major economical and available construction materials. Wood is not used extensively in the tropics due to its susceptibility to termite damage. Cement is the most expensive ingredient in concrete. Minerals required to make cement are present on our earth in almost limitless quantities and are geographically widely distributed.; The last two decades have seen a rapid growth in the use of high strength concrete. The use of high strength concrete permits structural elements with smaller cross-sections. Larger spans are feasible in bridges resulting from the reduced dead loads. High strength concrete is more brittle than the previously used normal strength concrete, making it a prime candidate for fiber reinforcement.; The art of reinforcing clay with straw in the manufacture of bricks can be traced back to biblical times. Steel, polypropylene, glass and natural fibers continue to be tested for structural applications. Natural fibers can be cheaply extracted from a variety of plants that grow in various geographical regions. Some natural fibers have been used in non structural cement mortar composites. The dwindling material resources and meager economic resources in most of the third world, and the threat from natural disasters like earthquake effects on buildings and bridges, call for an investigation of the feasibility of using natural fibers in high strength concrete.; The suitability of using a natural fiber (sisal) to reinforce high strength concrete for structural purposes was investigated. The compression and tension behavior of high strength concrete reinforced with sisal fibers were compared with the behavior of high strength concrete without fiber reinforcement and with high strength concrete reinforced with either steel or polypropylene fibers. Flexural behavior was investigated by comparing results from beams reinforced as follows. (1) Conventional reinforced concrete, (2) conventional reinforced concrete with sisal fibers, (3) conventional reinforced concrete with steel fibers and (4) conventional reinforced concrete with polypropylene fibers.; Sisal fibers showed an inferior performance compared to steel and polypropylene fibers when used in high strength concrete.