In this research, the effect of using steel fiber and polypropylene on the behavior of the lightweight self-compacting concrete (LWSCC) beams have been studied. Seven beams have been cast with different parameters and compared. Two ratios of coarse aggregate replacement with light-weight aggregate expanded clay (LECA) have been considered partially and full replacement (50% and 100%) in this study based on previous study. Also, a 1% volumetric ratio fiber reinforcement has been added to investigate its effect on the flexural performance of LWSCC. A reduction in the ultimate load capacity and stiffness have been observed for LWSCC beams compared with the control beam by about 19% and 24.8% for partial and full LECA replacement, respectively. The steel fiber enhanced the performance of LWSCC beams in terms of cracking formation, crack width, ultimate capacity and allow the beams to have more ductile behavior. The ultimate load for fibrous LWSCC has been increased by about 11% and 12% for partial and full LECA replacement compared to beams without fibers. Beams with polypropylene and steel fibers exhibit similar behavior to the beams with steel fiber only in term of load-vertical displacement curves. However, the difference in the ultimate load capacity were 4% and 5% for the partial and full LECA replacement, respectively.

在这项研究中，研究了使用钢纤维和聚丙烯对轻质自密实混凝土 (LWSCC) 梁性能的影响。已经铸造了七根不同参数的梁并进行了比较。基于先前的研究，本研究中考虑了用轻质骨料膨胀粘土 (LECA) 替代粗骨料的两种比例，部分替代和完全替代（50% 和 100%）。此外，还添加了 1% 体积比纤维增强材料，以研究其对 LWSCC 弯曲性能的影响。与控制梁相比，部分和全部 LECA 更换的 LWSCC 梁的极限载荷能力和刚度分别降低了约 19% 和 24.8%。钢纤维增强了 LWSCC 梁在裂纹形成、裂纹宽度、极限承载力并允许梁具有更多的延展性。与没有纤维的梁相比，部分和全部 LECA 更换的纤维 LWSCC 的极限载荷增加了约 11% 和 12%。聚丙烯和钢纤维梁表现出与钢纤维梁相似的行为，仅在载荷-垂直位移曲线方面。然而，部分和全部 LECA 更换的极限负载能力差异分别为 4% 和 5%。