This study presented an experimental investigation on the degradation of mechanical performance of reinforced concrete (RC) columns with the reinforcements corroded under sustained loads. A total of ten RC column specimens were tested. The effects of different levels of sustained load (0%, 30%, and 60% of the designed ultimate bearing capacity N u ) and reinforcement corrosion (0%, 5%, 10%, and 20%) on the failure modes, ultimate bearing capacity, and axial load–axial deformation relationship were analyzed. The results showed that the coupling adverse effects due to the reinforcement corrosion and sustained load considerably exacerbate the mechanical deterioration of RC columns and turn the failure mode into a much more brittle manner. Compared with the control specimen L-0-0, the ultimate bearing capacity of the specimen L-4-20 could be reduced as much as about 42%. Based on the test results, an improved model was proposed to estimate the ultimate bearing capacity of corroded RC columns, in which the effects of the corrosion of both longitudinal reinforcements and stirrups and the corrosion-induced spalling of concrete cover were taken into consideration. The close agreements between the analytical predictions and test results prove the applicability of the model.

中文翻译：

---

钢筋混凝土柱在持续荷载作用下腐蚀的机械退化

本研究对钢筋混凝土 (RC) 柱的力学性能退化进行了实验研究，其中钢筋在持续载荷下被腐蚀。总共测试了十个 RC 柱试样。不同水平持续荷载（设计极限承载力 N u 的 0%、30% 和 60%）和钢筋腐蚀（0%、5%、10% 和 20%）对破坏模式的影响，极限承载力、轴向载荷-轴向变形关系进行分析。结果表明，由于钢筋腐蚀和持续荷载引起的耦合不利影响大大加剧了钢筋混凝土柱的机械劣化，并使破坏模式变得更加脆弱。与对照试样 L-0-0 相比，试件 L-4-20 的极限承载力可降低约 42%。基于试验结果，提出了一种改进的模型来估计锈蚀钢筋混凝土柱的极限承载力，其中考虑了纵向钢筋和箍筋的腐蚀以及混凝土保护层腐蚀引起的剥落的影响。分析预测和测试结果之间的密切一致性证明了该模型的适用性。