预应力碳纤维加固钢筋混凝土梁方案讨论

Discussion on Method of Reinforced Concrete Beams Strengthened With Prestressed Carbon Fiber Reinforced Polymer

对5根长度为2.5m的钢筋混凝土梁进行分组试验,将相同条件下预应力加固梁与非预应力加固梁的工作性能进行了对比,并考虑了碳纤维布加固面积的变化对梁承载力的影响。试验发现,非预应力加固梁破坏形式为碳纤维布剥离破坏和受压区混凝土压碎破坏,而预应力加固梁都是碳纤维布拉断破坏;预应力加固提高了梁在使用阶段的工作性能以及梁的极限承载力。相比非预应力加固梁,预应力加固梁提高了钢筋屈服荷载并且有效地抑制了裂缝的出现和开展。

Five reinforced concrete beams of 2.5m lengths were tested. These beams were divided into five groups, considering the comparison of non-prestressed with prestressed carbon fiber reinforced polymer （CFRP） sheets and the different areas of CFRP. The non-prestressed beams failed by separation of the plate from the beam or concrete crush, while all of the prestressed beams failed by plate fracture. It was showed that beams prestressed with carbon fiber sheets combine the benefits of structural improvement in terms of serviceability and ultimate bearing capacity. Meanwhile, Prestressing produced significant increases in the load which causes yield of the internal steel over a non-prestressed specimen and effectively restricted the development of crack.