| Pultruded FRP has recently been adopted as a structural material in construction. However, its long term durability is not yet thoroughly known and further study is required. Over a period of eleven years, the authors have carried out an exposure test in four locations, with climatic conditions ranging from subarctic to subtropical, for three types of pultruded CFRP plate having different layer systems. The specimens were evaluated using tensile tests in two directions (the pultruded direction and that at 90° to the pultruded direction) and in-plane shear tests. The tensile strength results in the pultruded direction showed no clear changes, but tensile strength in the 90° direction and in-plane shear strength showed a small reduction after eleven years. Specimens having a high ratio of uni-directional fiber content showed more marked reductions. The differences in exposure conditions showed no clear effect, even though the environmental differences between the test sites were large. The presence of a top coating was observed to confer a protective effect, especially with respect to in-plane shear strength, in contrast to the previous study of CFRP, in which no such effect was found. |
