Enhancing concrete performance with hybrid basalt-polypropylene fibers: experimental and numerical evaluation

This investigation assessed the effectiveness of basalt fiber (BF) and polypropylene fibers (PF) in M40 concrete by evaluating its mechanical strength and impact resistance. The concrete was mixed with separate additions of BF and PF and a hybrid combination of both, all in increments of 0.1%. The study found the optimum percentage of BF and PF was 0.2% by weight of concrete under compressive strength (CS), split tensile strength (STS), and flexural strength (FS). Moreover, at optimum percentage, it was found that BF and PF can potentially increase maximum CS by 5.10%, STS by 11.95%, and FS by 4.65% on 28 days of curing. However, including PF and BF in concrete decreases the flowability of the fresh concrete by 7.14% and 17.14%, respectively, at their optimum percentage. Also, experimental observations highlighted that the Modulus of elasticity and impact resistance of BF-added concrete are greater than that of PF-added concrete. Numerical simulations of impact tests with ANSYS software were validated by experimental results that considered the impact times and failure patterns. This study demonstrates that hybrid fiber-reinforced concrete while showing wider cracks, achieves superior impact resistance and more uniform damage distribution compared to plain concrete, which is prone to concentrated tensile failure.