Reinforced beams with deteriorated concrete can be repaired by replacing the deteriorated part or the entire beam using new concrete. Either of the two scenarios is decided to be used based on the degree and distribution of deterioration along the beam. This paper compares the structural performance of composite and monolithic reinforced concrete beams which represents the two cases of partial and entire replacement of concrete, respectively. In total, 10 beams with dimensions of 3200×250×400 mm (L×W×D) were constructed. The reference monolithic beams were cast with either self-consolidating concrete (SCC) or fiber-reinforced self-consolidating concrete (FR-SCC). Composite beams were cast with conventional vibrated concrete (CVC) to a depth of 275 mm from the top then with either SCC or FR-SCC for the remaining third of the beam’s depth (125 mm) at the bottom. The composite beams were prepared to sim-ulate beams repaired in the tension zone after the removal of the deteriorated concrete. The test variables were fiber inclusion, fiber type, and beam type. One hybrid, one steel, and two polypropylene fiber types were employed in the FR-SCC. All fiber types were added at 0.5% by volume. The beams were simply supported and were loaded in four-point bending. Test findings indicate that both composite and monolithic beams exhibited similar cracking patterns at failure. However, the crack width of composite beams was lower due to enhanced fiber orientation along the tension zone and concrete confinement during the casting process. The structural performance of the beams was found to be mainly governed by mechanical characteristics of the fibers in the case of monolithic beams and mainly by the fiber length in the case of composite beams where fibers take preferential orientation during casting in the repair zone.

可以通过使用新混凝土更换损坏的部分或整个梁来修复混凝土损坏的钢筋梁。基于沿梁的劣化程度和分布来决定使用这两种情况中的任何一种。本文比较了分别代表部分和全部替换混凝土两种情况的组合和整体钢筋混凝土梁的结构性能。总共建造了10根尺寸为3200×250×400 mm（L×W×D）的梁。参考整体梁采用自密实混凝土 (SCC) 或纤维增强自密实混凝土 (FR-SCC) 浇筑。复合梁用传统的振动混凝土 (CVC) 浇筑到距离顶部 275 毫米的深度，然后在底部使用 SCC 或 FR-SCC 浇筑梁的剩余三分之一深度（125 毫米）。准备组合梁以模拟在拆除劣化混凝土后在受拉区修复的梁。测试变量是纤维夹杂物、纤维类型和光束类型。FR-SCC 中采用了一种混合纤维、一种钢和两种聚丙烯纤维类型。所有纤维类型的添加量为 0.5%（体积）。梁被简单地支撑并以四点弯曲加载。测试结果表明，复合梁和整体梁在失效时表现出相似的开裂模式。然而，由于在浇筑过程中沿受拉区的纤维取向增强和混凝土约束，复合梁的裂缝宽度较小。发现梁的结构性能在整体梁的情况下主要受纤维的机械特性控制，而在复合梁的情况下主要受纤维长度的控制，其中纤维在修复区铸造期间优先取向。