Optimizing the Design of EB-FRP on RC Strengthening: Impact of Large-sized FRP Ties and Anchors

Abstract

Fiber-reinforced polymer (FRP) are a promising composite material for enhancing the performance and extending the service life of concrete structures. With its lightweight, excellent mechanical properties, and ease of installation, application of externally bonded fibre reinforced polymer (EB-FRP) systems have gained increasing attention in recent years. Despite the increasing interest, the current research primarily focuses on small-scaled FRP-strengthened concrete structures, characterized by a bond length of less than 250 mm and a thickness not exceeding 1 mm. Consequently, a more comprehensive understanding of the behaviour and performance of large-sized FRP systems is still required to optimize their design and utilization. This study investigates the debonding capacity of EB-FRP systems for tension strengthening of concrete structures using single-lap shear tests, exploring the influence of thicker and longer of FRP used. The study provides practical guidance for engineers and designers and highlights the importance of accurately predicting the upper bound for debonding force, and the limitations of current design codes. The results indicate that all variables, particularly thicker, then stiffer, FRP materials generally exhibit higher bond strength, and longer FRP ties contribute to increased post-debonding capacity. The study also found that current design codes may be unconservative ,and provides practical guidance for engineers and designers, and may lead to safer, more durable, and more sustainable structures.