12 - Durability of external fiber-reinforced polymer strengthening systems

Abstract

Publisher Summary Composites in construction offer many advantages such as higher strength, lighter weight, corrosion resistance, and design flexibility. Other factors that strengthen the case for using Fiber-Reinforced Polymer (FRP) composites in the rehabilitation and construction of structures are time and tailorability; strengthening techniques using FRP composites allow for cost-efficient retrofit options although in many cases the initial cost of FRP composites is higher than conventional materials. The alarming deterioration of the world's infrastructure and the susceptibility of steel to corrosion have caused engineers to seek out FRP composites as a retrofitting option, especially in structures like buildings, bridges, marine and water front constructions, and chemical plants. Although impressive inroads have been made into infrastructure applications, there are still barriers that need to be overcome to achieve the full potential of these materials in construction. Currently, the issue of most importance is durability. While a large number of experimental studies have demonstrated the effectiveness of externally FRP-strengthened Reinforced Concrete (RC) structures, important questions related to long-term behavior and durability still remain. When a concrete structure is strengthened with an externally bonded FRP fabric or pre-cured plate, the most critical aspect of its behavior is that the composite action in the system must be preserved during the designed service life of the structure. The durability performance of the parent material, including the interfacial bond between the FRP and the substrate, plays a very important role in the overall durability performance of a strengthened member.