Strength degradation behavior of glass fiber embedded in single fiber composite under hot water environment

Long-term durability of glass fiber reinforced plastics (GFRP) under water environment is strongly influenced by the strength degradation of its fiber reinforcement. Constant strain test in water, in which stress corrosion cracking (SCC) is initiated, was conducted for the single fiber composite (SFC) in order to investigate the strength degradation of E-glass fiber within the SFC. The strain applied to the glass fiber during the constant strain test was formulated by taking account of the fiber strain history, such as water absorption, thermal expansion, and the strain applied to the SFC. After the constant strain test, fragmentation test was conducted in order to estimate the residual strength of the embedded fiber. It was clarified that the degradation of the fiber strength progresses at higher applied strain and longer test time, moreover, the degradation of the fiber strength accelerated drastically at higher temperature.