High performance macro synthetic fiber reinforced concrete

Öztürk, Çağrı
Since concrete is a brittle construction material, it has the tendency to fail in a brittle manner after the occurance of the first crack when it is subjected to a certain amount of load. Therefore, this property of concrete makes almost impossible for it to be used in load carrying structural elements without reinforcement. This reinforcement is usually utilized by a structural steel reinforcement such as rebar and wire mesh. The structural steel reinforcements compensate the low resistance against the tensile strength of the plain concrete by taking over the tensile stresses under different loading conditions. Nowadays, in addition to steel reinforcement randomly dispersed small sized fibers can also be utilized to improve the mechanical properties such as toughness of concrete. The aim of this study is to determine the toughness of high performance macrosynthetic fibers. In order to obtain high performance, fiber dosages up to 2.7% was utilized with a highly viscous matrix. The toughness parameters were investigated by two different panel test methods which are; i) ASTM C1550: Standard Test Method for Flexural Toughness of Fiber Reinforced Concrete, and ii) EFNARC Square Panel Test Method. As a result of the thesis study, it was found out that, with increasing fiber dosage, the energy absorption capacity of concrete improved significantly. Moreover, based on the energy absorption capacities obtained from the round and square specimens, an equation with good reliability was derived to describe the relation between the two test methods.