As the use time of concrete structures increases, defects such as concrete cracks, corrosion and exposure of steel bars gradually appear, resulting in additional repair of concrete structures to increase their durability and life. In this article, the effects of nano-modified polymer cement-based materials as repair material on the bending behavior of repaired concrete beams were studied. Based on the moment, deflection, strain, surface quality and cracking development monitor of repaired concrete beams, the bending behavior of repaired beams with polymer, nano-modified polymer and fibers was compared and the failure mechanism of the beams was analyzed. The results showed that the nano-modified polymer cement-based materials are helpful in improving the performance of repaired beams, manifested by the increase in the ultimate bending moment and the significant improvement in the quality of the interface between repair and matrix concrete. Compared with polymer cement-based materials, nano-modified polymer cement-based materials result in a 27% increase in ultimate bending moment of the repaired beam and a 58% increase in cracking moment, while reducing the total number of cracks by 23% and the average width of cracks by 17% in the repaired beam. This article demonstrated the availability of nanomaterials for improving the loading behavior of structural components with polymer-modified cement-based materials.

中文翻译：

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纳米改性聚合物水泥基材料对修复混凝土梁弯曲性能的影响

随着混凝土结构使用时间的增加，诸如混凝土裂缝，腐蚀和钢筋暴露等缺陷逐渐出现，导致对混凝土结构进行额外的修复以增加其耐久性和寿命。本文研究了纳米改性聚合物水泥基材料作为修补材料对修补后混凝土梁弯曲性能的影响。根据修补混凝土梁的弯矩，挠度，应变，表面质量和裂缝发展监测指标，比较了聚合物，纳米改性聚合物和纤维对修补梁的弯曲行为，并分析了其破坏机理。结果表明，纳米改性聚合物水泥基材料有助于改善修复梁的性能，其表现为极限弯矩的增加和修补混凝土与基体混凝土之间界面质量的显着改善。与聚合物水泥基材料相比，纳米改性的聚合物水泥基材料导致修复梁的极限弯曲力矩增加了27％，裂缝力矩增加了58％，同时使裂缝总数减少了23％，修复后的梁的平均裂缝宽度增加了17％。本文证明了纳米材料可用于改善聚合物改性水泥基材料的结构部件的加载行为。纳米改性的聚合物水泥基材料可使修复梁的极限弯曲力矩增加27％，裂缝力矩增加58％，同时将裂缝总数减少23％，将平均裂缝宽度减少17％在修复的光束中。本文证明了纳米材料可用于改善聚合物改性水泥基材料的结构部件的加载行为。纳米改性的聚合物水泥基材料可使修复梁的极限弯曲力矩增加27％，裂缝力矩增加58％，同时将裂缝总数减少23％，将平均裂缝宽度减少17％在修复的光束中。本文证明了纳米材料可用于改善聚合物改性水泥基材料的结构部件的加载行为。