Performance evaluation of hybrid fiber-reinforced concrete incorporating carbon and polypropylene fibers

Abstract

Concrete cracks easily because it’s brittle. To fix that, engineers have been mixing fibers into it for years. In this work, we tested three options: concrete with carbon fibers, with polypropylene fibers, and with both combined. We cast samples with different fiber amounts and tested them for compression, bending, and splitting tension. Adding fibers clearly helped. The concrete cracked less, absorbed more energy, and didn’t fail as suddenly compared to plain concrete. Load capacity and toughness also went up. The best results weren’t always from the hybrid mixes. A mix with 0.5% carbon fibers plus 0.4% polypropylene gave the highest flexural strength at 614 psi. But for splitting tensile strength, 0.5% polypropylene by itself won at 425 psi. So, the right fiber choice depends on what you need the concrete to do. Overall, fibers changed the concrete from brittle to ductile. That makes it tougher, more resilient, and better for demanding structural jobs.