Investigating the Effect of Various Fibers on Plasticity and Compressive Strength of Concrete Samples

The addition of fibers helps to increase the performance of concrete in terms of resistance and flexibility. Different types of fibers that have different mechanical properties may change the behavior of concrete. Fiber-reinforced concrete with varied combinations of fibers (steel, macro synthetic, and polypropylene fibers) in 1% volume is investigated in this research. Concrete samples were fabricated from a combination of two types of fibers with different percentages to measure the compressive strength with the approach of determining the optimal ratio of fibers. The results showed that the hybrid samples containing steel fibers provide higher compressive strength compared to the samples containing macro synthetic and polypropylene fibers. Macro synthetic and polypropylene fibers in concrete samples have played a significant role in increasing the flexibility and efficiency of concrete, as well as significantly reducing cracking and increasing durability and toughness. In these hybrid models, coherence is preserved in the event of failure. The combination of polypropylene fibers with both steel and macro synthetic fibers significantly reduces the compressive strength of concrete samples. In concrete samples with hybrid fibers, samples with a combination of macro synthetic and steel fibers had higher compressive strength than samples with a combination of steel and polypropylene fibers.