Durability of Pultruded GFRP through Ten-Year Outdoor Exposure Test

Pultrusion is an easy molding method of fiber-reinforced polymer (FRP) to obtain a long composite material with a uniform cross-section at relatively low cost. In some cases, pultruded FRPs are now used in bridges and deck projects. Since the application of pultruded FRP as a structural material is increasing, a study on the durability of pultruded FRP under outdoor conditions is necessary in terms of safety. Some studies have shown that pultruded glass fiber-reinforced polymer (GFRP) exhibits a slight reduction in mechanical properties during outdoor exposure. Since pultruded GFRP consists of multi-layers, the change of mechanical properties in each layer is important to understand. In this study, an outdoor exposure test on pultruded GFRP for 10 years was conducted with three types of pultruded GFRP, which have different laminate systems, including surface-coated specimens of each type. Changes of strength and elastic modulus due to outdoor exposure were discussed with a focus on the contribution of each layer based on the rule of mixtures