Alkhateeb Mahmood Y, Hejazi Farzad
Department of Civil Engineering, University Putra Malaysia, Serdang 43400, Malaysia.
Department of Civil Engineering, School of Engineering, The University of the West of England, Bristol BS16 1QY, UK.
Materials (Basel). 2024 Jun 7;17(12):2794. doi: 10.3390/ma17122794.
The demand for strengthening reinforced concrete (RC) structures has increased considerably. Implementing carbon-fiber-reinforced polymer (CFRP) bars and concrete jacketing are the most effective techniques for RC beam retrofitting. Using the mechanical anchorage system (MAS) to attach CFRP bars to old concrete is highly recommended to avoid any debonding when it is applied to cyclic loads. However, the design of strengthening details is the most challenging issue because it involves many effective parameters. In this study, a design process for strengthening beams using CFRP bars with new MASs and concrete jacketing is proposed, and various design schemes are studied. The number of applied MASs and the thickness and grade of the concrete jacket were investigated through experimental testing and finite element (FE) simulations to define strengthening design details, such as the number and size of employed CFRP bars. Accordingly, an analytical technique was formulated to predict the performance of the strengthened beam in terms of the nominal ultimate load. The results demonstrated the high performance of the proposed system in preventing premature debonding. The proposed system enhances the beam capacity from 44 kN to 83 kN, representing an increase of more than 90%. In contrast, the conventional near-surface mounted (NSM) system exhibits a lower percentage increase at less than 37%. Both FE simulations and analytical approaches can be effectively employed to predict the behavior and capacity of the strengthened beam while considering various design parameters.
对加强钢筋混凝土（RC）结构的需求大幅增加。采用碳纤维增强聚合物（CFRP）筋和混凝土套箍是对RC梁进行加固的最有效技术。强烈建议使用机械锚固系统（MAS）将CFRP筋连接到旧混凝土上，以避免在承受循环荷载时出现任何脱粘现象。然而，加固细节的设计是最具挑战性的问题，因为它涉及许多有效参数。在本研究中，提出了一种使用带有新型MAS的CFRP筋和混凝土套箍对梁进行加固的设计流程，并研究了各种设计方案。通过试验测试和有限元（FE）模拟，研究了MAS的应用数量以及混凝土套箍的厚度和等级，以确定加固设计细节，如所使用的CFRP筋的数量和尺寸。据此，制定了一种分析技术，以根据名义极限荷载预测加固梁的性能。结果表明，所提出的系统在防止过早脱粘方面具有高性能。所提出的系统将梁的承载力从44 kN提高到83 kN，增幅超过90%。相比之下，传统的近表面粘贴（NSM）系统的增幅较低，不到37%。在考虑各种设计参数时，有限元模拟和分析方法都可以有效地用于预测加固梁的性能和承载力。
