Stress-strain Analysis of Concrete Reinforced with Metal and Polymer Fibers

Fiber Reinforced Concrete (FRC) is mainly used in the construction of airports, highways, bridge decks, and industrial floors. Properties such as tensile strength, flexural strength, fatigue strength, impact strength, crack reduction, and energy absorption are substantially improved with the use of FRC. In this research, the behavior of the modulus of rupture and compressive strength of different samples of FRC are analyzed. Several mixtures with different percentages (0.25%, 0.50%, 0.75%, 1.00%, and 1.50%) of four commercial types of fibers or polymers are considered: (1) corrugated steel fiber, (2) steel fiber with hooks at the ends, (3) drawn synthetic fiber, and (4) corrugated synthetic fiber. Based on the results of this research, there is not a significant evidence of an increase in strength of FRC; even with higher fiber ratios. In fact, there was a decrease in the workability and the slump of the FRC samples, which were even zero for FRC samples with contents of fiber or polymer greater than 1%. In addition, it is demonstrated that the fiber with the best performance is the steel fiber with hooks at the ends. Finally, it is found that the performance of the fibers in the FRC samples depends on several factors as the size of the aggregates, complete particle size analysis, fine/coarse aggregate ratio, and concrete slump.