Mechanical behavior of twinning-induced plasticity (TWIP) steel fibre reinforced cementitious composite under impact loading

•The impact behaviours of TWIP steel fiber reinforced cementitious composite were investigated.•The effects of varying fiber types, impact heights, and impact times were discussed.•The fractal dimension was applied to quantify the damage degradation process. Twinning-induced plasticity (TWIP) steel fibre is a supermaterial known for its outstanding impact resistance. This paper, for the first time, applied TWIP steel fibre to increase the impact resistance of cementitious composites. The mechanical properties behaviours of TWIP steel fibre-reinforced cementitious composites (T-SFRCC) were investigated and compared with conventional SFRCC with normal steel fiber. The fractal theory was utilized to analyze the deterioration of damage in various SFRCCs subjected to impact loads, displaying TWIP steel fiber could prevent the cracks propagation and fewer fractal dimension compared with others. Results demonstrate that T-SFRCC has comparable compressive strength to SFRCC while exhibiting higher flexural strength. When subjected to impact loading, T-SFRCC demonstrates markedly improved energy absorption and impact toughness, such as better impact force and displacement. Specifically, the energy absorption capacity of T-SFRCC can exceed five times that of SFRCC with corrugated steel fiber, particularly evident when the drop height reaches 1200 mm. The influences of different fiber types and hammer drop methods on the impact resistance of SFRCCs were also discussed, which can provide reference for TWIP steel fiber in the field of cementitious composite materials.