Impact resistance, flexural and tensile properties of amorphous metallic fiber-reinforced cementitious composites according to fiber length

•We studied amorphous metallic fiber length effects (15/30 mm) on cementitious composite properties.•Flexural test, tensile test and high-velocity impact tests were conducted.•Amorphous metallic fibers with lengths of 30 mm exhibited optimal responses. In this study, we examined the effects of the lengths of amorphous metallic fibers on the flexural and tensile properties and the impact resistance of cementitious composites. Cementitious composites were fabricated following the addition of 1.0 or 2.0 vol% of amorphous metallic fibers (lengths of 15 or 30 mm). After the static flexural and tensile tests, high-velocity impact tests were conducted (impact velocities of 170 and 300 m/s) with a spherical projectile (diameter of 25 mm). Amorphous metallic fibers with lengths of 30 mm inhibited the propagation of fractures based on the absorption and distribution of stress until they fractured without being pulled out, which significantly improved the flexural and tensile properties of cementitious composites; this resulted in better inhibition of scabbing in fibers with lengths of 30 mm compared to fibers with lengths of 15 mm. Meanwhile, the amorphous metallic fibers with lengths of 15 mm were pulled out from the matrix owing to their relatively smaller bonding areas compared with the 30 mm fibers. This caused smaller improvements in flexural and tensile properties as well as impact resistance compared with the 30 mm fibers.