Life prediction under sulfuric acid environment of FRP using X-ray analysis microscope

Fiber reinforced plastics (FRP) are widely applied to structures because of the better mechanical properties of lightweight, high strength and high corrosion resistance. Especially, FRP are used under water environments because they have much higher corrosion resistance than metals. Various immersion tests have been carried out in order to obtain corrosion resistance data of FRP. In those tests, water absorption quantity and degradation of glass fibers causing strength degradation are measured. However, the evaluation for material degradation process is not enough because domains and routes of water absorption are not clear. The characterization under the sulfuric acid environment is also important. So, the purpose of this study is to improve the reliability of FRP by applying a new evaluation technique. We proposed new evaluation methods for monitoring sulfur (S) element infiltration by applying X-ray analysis microscope, and investigated the degradation under sulfuric acid environment. The infiltration distance of S element causing the degradation was measured under various immersing conditions to carry out the life prediction on the relationship between the S element infiltration distance and the strength degradation.