ABSTRACT
I. INTRODUCTION Plain unreinforced cementitious materials are characterized by low tensile strengths and low tensile strain capacities; that is, they are brittle materials. They thus require reinforcement before they can be used extensively as construction materials. Historically this reinforcement has been in the form of continuous reinforcing bars that could be placed in the structure at appropriate locations to withstand the imposed tensile and shear stresses. Fibers, on the other hand, are generally short and discontinuous and are randomly distributed throughout the cementitious matrix. They may not be as efficient as reinforcing bars in transmitting the tensile stresses. However, as they tend to be more closely spaced than conventional reinforcing bars, they are better at controlling cracking. It is important to recognize that, in general, fiber reinforcement is not a substitute for conventional reinforcement. Fibers and steel bars have different roles to play in modern concrete technology, and there are many applications in which both fibers and continuous reinforcing bars should be used [1,2].
