Abstract Cracks in reinforced concrete structures accelerate the ingress of chlorides and therefore cause a higher risk for corrosion. In this research, autonomous healing of cracks by encapsulated polyurethane was investigated as a possible method to reduce reinforcement corrosion. Reinforced concrete beams were exposed weekly to a chloride solution and electrochemical parameters were measured to determine the influence of the self-healing mechanism on the corrosion process. The rebars were visually examined afterwards. For the cracked beams an active state of corrosion was detected within an exposure period of 10 weeks and clear pitting corrosion was observed on the rebars. Autonomous crack healing with low viscosity polyurethane could significantly reduce the corrosion in the propagation stage. For these specimens no visual damage to the rebars was detected. In conclusion, the application of self-healing concrete with a low viscosity polyurethane is able to enhance the durability of reinforced concrete structures in marine environments.

中文翻译：

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氯化物诱导聚氨酯包封自愈合混凝土的钢筋腐蚀行为

摘要 钢筋混凝土结构中的裂缝会加速氯化物的进入，从而导致更高的腐蚀风险。在这项研究中，研究了封装聚氨酯对裂缝的自主愈合，作为减少钢筋腐蚀的一种可能方法。钢筋混凝土梁每周暴露于氯化物溶液中，并测量电化学参数以确定自愈机制对腐蚀过程的影响。之后对钢筋进行目视检查。对于有裂纹的梁，在 10 周的暴露期内检测到腐蚀的活跃状态，并且在钢筋上观察到明显的点蚀。低粘度聚氨酯的自主裂纹愈合可以显着减少扩展阶段的腐蚀。对于这些试样，没有检测到钢筋的视觉损坏。总之，低粘度聚氨酯自修复混凝土的应用能够提高钢筋混凝土结构在海洋环境中的耐久性。