Investigating Flexural Performance of Fiber-Reinforced Concrete with Different Combinations of Macro-Synthetic Fibers

Concrete, as one of the most widely used building materials, has brittle behavior. Concrete pavement design factor is the 28-day concrete flexural strength. Adding fibers to concrete is effective on the ductility behavior, impact resistance, energy absorption, crack resistance, abrasion resistance, and tensile strength of the concrete and prevents crack expansion. For this purpose, a laboratory research was conducted to investigate the effect of different combinations of macro-synthetic fibers on the flexural strength of fiber-reinforced concrete, including flexural strength, average residual strength and flexural toughness. In this study, concrete specimens were constructed according to ASTM C1609, ASTM C1399 and ASTM C79 standards and were evaluated with four different macro-synthetic polymer fibers. Results of the experiments showed that adding fibers to concrete joints, the flexural strength increased by 3.31-16.96 percent. Also, the flexural toughness and average residual strength increased by addition of the fibers. Meanwhile, due to the soft break of regular concrete, flexural toughness and average residual strength could not be computed.