Steel Fiber Concrete Encased Steel (SFCES) beams were subjected to bending to investigate the effect of steel fibers on the behavior of Steel Reinforced Concrete beams with or without steel reinforcement. 18 SFCES beams reinforced with steel fibers, steel reinforcement, or both were cast. The parameters considered in the experiment were (a) the volume percentage of steel fiber (0%, 1%, and 2%), (b) the shear span to depth ratio(s/d = 2.5 and 3.5), (c) the stirrups spacing (180 mm and 360 mm), and (d) the presence or absence of longitudinal reinforcement (2Φ8+2Φ10).The cracking load, crack development, energy dissipation capacity, and ductility of the specimens were investigated. The results illustrate that the cracking load F_c, the total energy consumption, and the energy ductility increase with increasing steel fiber volume, and the average improvement with a steel fiber volume increase of 1% can reach 36.5%, 21.2%, and 28.67%, respectively. However, this strengthening effect of steel fibers was weakened due to the addition of steel reinforcement. The influence of the steel fiber volume and reinforcement configuration on each stage of energy consumption was mainly concentrated in the elastic (E₁) and failure stages (E₃). Finally, mathematical equations were proposed to predict the cracking load and crack width of the SFCES specimens, which were verified by comparing the predictions with the experiment results.

钢纤维混凝土包裹钢 (SFCES) 梁经受弯曲以研究钢纤维对带或不带钢筋的钢筋混凝土梁行为的影响。浇铸了 18 根钢纤维、钢筋或两者都加固的 SFCES 梁。实验中考虑的参数是（a）钢纤维的体积百分比（0%、1%和2%），（b）剪跨深度比（s/d = 2.5和3.5），（c）箍筋间距（180 mm 和360 mm），以及（d）纵向钢筋（2Φ8+2Φ10）的存在与否。研究了试件的开裂载荷、裂纹扩展、能量耗散能力和延性。结果表明，开裂载荷F _c，总能耗、能量延展性随着钢纤维用量的增加而增加，钢纤维用量每增加1%，平均提高分别可达36.5%、21.2%和28.67%。然而，由于加入了钢筋，钢纤维的这种强化作用减弱了。钢纤维体积和加固结构上的能量消耗的每个阶段的影响，主要集中在弹性（ë ₁）和故障级（ë ₃）。最后，提出了SFCES试件开裂载荷和裂纹宽度的数学方程，并通过与实验结果的对比验证。