Understanding Fibre-Matrix Degradation of FRP Composites for Advanced Civil Engineering Applications: An Overview

Abstract

Common concretes use considerable amounts of fresh water and river sand, and their excessive use is already seriously implicating the environment. In this respect, seawater and sea sand concrete (SWSSC) is a very attractive alternative, since it addresses the increasing shortage of fresh water and dredging of river sand. A major concern with reinforced SWSSC is the severe corrosion of the steel reinforcements by seawater (that has a very high content of chloride which is very corrosive), thereby seriously impairing the strength of such concrete. Fibre reinforced polymer (FRP) can be a suitable alternative to replace steels as reinforcement. However, there has been little systematic work to understand the degradation kinetics and mechanisms of FRP in the chloride-containing alkaline SWSSC environment. This review first provides an overview of the degradation of FRP composites in normal concrete and chloride-containing alkaline SWSSC environments, and then presents an example of a recent study using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) that may provide a pathway to systematic experimental approach to understanding such degradation. The review also makes a comprehensive assessment of the influence of environment-assisted degradation on mechanical properties of FRPs.