Investigating the effect of glass fiber on the toughness of fiber reinforced concrete

Fiber reinforced concrete (FRC) has been used widely due to its advantages over plain concrete such as high energy absorption, post cracking behavior, flexural and impact strengths, arresting shrinkage crack. Toughness is the amount of energy that a concrete can withstand by impact forces before rupturing. Toughness is obtained from the area under the force - deflection curve in flexural and compressive test and is characterized by a coefficient called the toughness ratio. In this study, the effect of 3 percentage of glass fiber (1,2 and 3%) with two different size of 3 and 6 millimeter on flexural and compressive toughness of FRC were investigated. The flexural and compressive toughness were carried out in accordance with the JSCE-SF4. The results indicate that by increasing the length of glass fiber, there is no significant change in the amount of flexural toughness. Mixtures with 3% glass fibers has the highest flexural toughness and mixtures with 2% glass fibers has the lowest flexural toughness. Among mixtures with the same length, the mixture with the higher percentage of glass fiber had the highest compressive toughness.