In recent years , considerable amount of work has been conducted on the use of different types of fibers in concrete , because of the beneficial effect of fiber on the properties of concrete.There are different types of fibers commercially available , which are generally classified with respect to geometry and also the production process of fibers , therefore , fiber reinforced concrete can have inconsistent properties.During the past two decades , cellulose fibers have been widely used in concrete industry and some effort has been devoted to extend fibers application in Iran.however , further studies need to be undertaken on this issue.Due to the important of strength parameters in concrete , structure , this study , investigates the mechanical properties of cellulose fiber consist of viscose , Lifiran , Typha , Milkweed and Hemp reinforced concrete.cellulose fibers used in one weight fraction (1%).every cellulose fiber types were treated with sodium silicate , air dried and mixed with water , sandstorm,stone clay and cement.The bending and compression properties and density were determined after 7 days of hydration.results of this composites compared to the untreated fiber-cement composites and neat concrete.The results of this study indicate that the aqueous chemical treatment of cellulose fiber enhanced compressive strength and bending strength of milkweed fiber and lifitan fiber and reduce compressive strength and bending strength of typha fiber.compressive strength and density decreased for all fiber types and chemical treatment compared to the neat cement controls bending strength improved with hemp fiber and decreased with lifiran fiber and milkweed fiber.
