Abdulla Kurdo, Zhu Xiaoming, Su Meini
School of Engineering, Faculty of Engineering and Creative Technologies, University of Bolton, Deane Road, Bolton BL3 5AB, UK.
Department of Mechanical, Aerospace and Civil Engineering, University of Manchester, Manchester M13 9PL, UK.
Materials (Basel). 2022 Aug 3;15(15):5334. doi: 10.3390/ma15155334.
Fibric reinforced cementitious matrix (FRCM) composites have been used to improve the mechanical performance of reinforced concrete beams subjected to degradation in the past decades. Recently, dual-functional carbon fibres have been explored to provide both structural strengthening to RC beams and cathodic protection to reinforcement bars. This paper investigates the loading responses and structural behaviour of RC beams subjected to different levels of corrosion, protected by impressed current cathodic protection and structurally strengthened by external bonded FRCM. A numerical model is developed for the corroded RC beams under impressed current cathodic protection and structural strengthening by the FRCM composite. Upon validation against experimental results collected from the literature, the finite element model is then used for parametric study. A number of numerical results are generated to analyse the effects of key parameters, including the corrosion rate, degradation level of interfacial bonding properties due to anode acidification, and end anchorage, followed by detailed discussions. It is found that the significance of the corrosion of steel reinforcement bars significantly affects the load-carrying capacity of the beams. Increasing the corrosion rate from 0 to 40% reduces the load-carrying capacity of un-strengthened beams to 45% of the original capacity. Therefore, the cathodic protection provided by the C-FRCM plate is important to the reinforcement bars as it can avoid the cross-section area reduction of reinforcement bars and, thus, the main loading capacities of the beams. In this study, the degradation of the bonding properties at the interface of carbon fibre and the cementitious matrix due to anode acidification during impressed current cathodic protection is also considered. It is found that the bond strength of the C-FRCM plate has a slight effect on the load-carrying capacity of the beam. In addition, the application of end anchorage can significantly enhance both the load-carrying capacity and ductility of the beams. The rates of enhancement, if compared to the beams with no end anchorage, can reach up to 60%.
在过去几十年中，纤维增强水泥基复合材料（FRCM）已被用于改善遭受劣化的钢筋混凝土梁的力学性能。最近，人们探索了具有双重功能的碳纤维，可为钢筋混凝土梁提供结构加固以及对钢筋进行阴极保护。本文研究了在不同腐蚀程度下，通过外加电流阴极保护进行防护并由外部粘贴FRCM进行结构加固的钢筋混凝土梁的荷载响应和结构性能。针对外加电流阴极保护和FRCM复合材料结构加固作用下的锈蚀钢筋混凝土梁，建立了数值模型。在根据文献收集的实验结果进行验证后，该有限元模型被用于参数研究。生成了许多数值结果，以分析包括腐蚀速率、阳极酸化导致的界面粘结性能退化程度以及端部锚固等关键参数的影响，随后进行了详细讨论。研究发现，钢筋锈蚀的程度对梁的承载能力有显著影响。将腐蚀速率从0提高到40%，会使未加固梁的承载能力降低至原来的45%。因此，C-FRCM板提供的阴极保护对钢筋很重要，因为它可以避免钢筋截面积减小，从而避免梁的主要承载能力下降。在本研究中，还考虑了外加电流阴极保护期间阳极酸化导致的碳纤维与水泥基体界面粘结性能的退化。研究发现，C-FRCM板的粘结强度对梁的承载能力影响较小。此外，端部锚固的应用可显著提高梁的承载能力和延性。与没有端部锚固的梁相比，如果进行比较，增强率可达60%。
