Prestressed concrete beams are widely used in construction, while they may be attacked by the corrosion medium during the service. Past research works show that coupled effect of high stress and corrosion can significantly deteriorate the performance of prestressed concrete structures. This article presents an experimental investigation on long-term behavior of prestressed concrete beams under the coupled effect of sustained load and corrosion. During the accelerated corrosion process, six prestressed concrete beams were subjected to different levels of sustained loads, and time-dependent prestress loss and concrete stains were recorded and analyzed. It is observed that the local corrosion (i.e. pitting corrosion) of the steel strands was significantly affected by the sustained load level, and the coupled effect led to more serious damage on the beams than individual sustained load or corrosion. Bending loads were finally applied to investigate the influence of corrosion on flexural capacities of these beams. It was found that the flexural capacities and failure mode of the beams were significantly influenced by corrosion. Meanwhile, the corrosion has more significant effect on tension strength of strands rather than bond strength.

中文翻译：

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持续荷载与腐蚀耦合作用下预应力混凝土梁长期性能试验研究

预应力混凝土梁在建筑中应用广泛，但在使用过程中可能会受到腐蚀介质的侵蚀。以往的研究表明，高应力和腐蚀的耦合作用会显着降低预应力混凝土结构的性能。本文对预应力混凝土梁在持续荷载和腐蚀的耦合作用下的长期行为进行了试验研究。在加速腐蚀过程中，六个预应力混凝土梁承受不同程度的持续荷载，并记录和分析随时间变化的预应力损失和混凝土污渍。观察到钢绞线的局部腐蚀（即点蚀）受持续载荷水平的显着影响，并且耦合效应导致梁的损坏比单独的持续载荷或腐蚀更严重。最后施加弯曲载荷来研究腐蚀对这些梁的抗弯能力的影响。结果表明，梁的抗弯能力和破坏模式受腐蚀的影响很大。同时，腐蚀对钢绞线的抗拉强度的影响比对粘结强度的影响更为显着。