8 - Hybrid fiber-reinforced polymer (FRP) composites for structural applications

Abstract

Fiber-reinforced polymer (FRP) has been a practical alternative construction material for replacing steel in the construction industry for several decades. However, some mechanical weaknesses of FRP are still unresolved, which limit the extensive use of this material in civil infrastructure. In order to mitigate the disadvantage of using FRP, the concept of hybridization is delivered here. The advantages of hybrid structural systems include the cost effectiveness and the ability to optimize the cross section based on material properties of each constituent material. In this chapter, two major applications of hybrid FRP composites are discussed: (1) the internal reinforcement in reinforced concrete (RC) structures, and (2) the cables in long-span cable-stayed bridges. In order to improve the flexural ductility of FRP-reinforced concrete (FRPRC) beam, the additional steel longitudinal reinforcement is proposed such that the hybrid FRPRC beams contain both FRP and steel reinforcement. In order to improve the vibrational problem in pure FRP cables used in bridge construction, an innovative hybrid FRP cable which can inherently incorporate a smart damper is proposed. The objective of this chapter is to deliver an up-to-date review of hybrid FRP composite structures, including both the industrial practice and the research in academia. The advantages of using hybrid FRP composites for construction will also be described with experimental support. It is hoped that the reader will appreciate the concept of hybridization, which leads to the efficient utilization of all constituent materials in a bonded system.