Toughness, Reinforcing Mechanism, and Durability of Hybrid Steel Fiber Reinforced Sulfoaluminate Cement Composites

As a low-carbon ecological cement-based material, SAC (sulfoaluminate cement) has become research hotspot. This study developed SAC-based high-performance concrete material with good durability and high toughness. The mechanical properties of different scales MSF (macro steel fiber) mSF (micro reinforced sulfoaluminate composites were mainly studied, including their compressive strength, flexural toughness index, ratio, resistance to sulfate erosion was characterized. results show that adding HSF (hybrid fibers) can significantly improve concrete’s strength compared the Plain group. SSF1 (1% MSF) SSF2 (1.5% increased by 10.9%, 19.6%, HSF1 (0.1% mSF, 1.4% MSF), HSF2 (0.2% 1.3%MSF), HSF3 (0.3% 1.2% HSF4 (0.5% 1.0% 23.9%, 33.7%, 37.0%, 29.3%, respectively, while HSF1, HSF2, HSF3, groups 51.4%, 84.9%, 88.1%, 64.2%. Compared single fiber (SSF) group, group higher initial crack equivalent ratio. Hybrid fibers have synergistic effect when content is 0.2–0.3% 1.2–1.3%. mechanism multi-scale reinforcement hybrid-steel-fiber-enhanced researched. bridges macro-cracks, micro-cracks, these two fibers, through filling, bridging, anchoring, pulling off, out, composite materials. corrosion obtained. SO42− entered matrix reacted formed AFt, filling matrix’s pores. whole process similar self-healing concrete.