PERFORMANCE-BASED STRUCTURAL FIRE RESISTANCE DESIGN OF FRP　STRENGTHENED CONCRETE

摘要

A considerable body of knowledge developed during the past three decades has clearly shown the benefits and effectiveness of using FRP materials for repair and reinforcement of steel, concrete, timber, and masonry structural elements in buildings. However, despite their numerous advantages over conventional materials and systems, their comparatively poor mechanical performance in fire has hindered their application in buildings. If left unprotected virtually all FRP materials will rapidly lose strength, stiffness, and bond integrity during a major building fire. A consequence of this rapid reduction in mechanical and bond properties, particularly when designers use the prescriptive approaches to structural fire resistance design which currently dominaje the construction industry, is that externally bonded FRP strengthening applications often require thick fire protection coatings - making FRP strengthening systems less attractive and more expensive. However, most prescriptive structural fire resistance requirements are based on definitions of structural fire resistance that were developed without structural strengthening or FRP systems in mind, and which are in many cases somewhat outdated based on available knowledge in the field fire safety science. This briefly paper summarizes current knowledge regarding the performance of FRP strengthening systems in fire and places this within the context of the state-of-the-art in performance-based structural fire engineering. The goal is to identify opportunities to use a performance-based design for fire framework, such as is currently given in the structural Eurocodes, to support fire-safe application of FRP strengthened structural elements in buildings.