| In the application of FRP as a structural material, appropriate resistance against the environmental actions of outdoor condition is required, and some previous studies reported that top coat painting has a good protective effect for pultruded GFRP. However the mechanism of protective effect of top coat paint on GFRP have not been studied well in the detail and further studies is still required. In this paper, the authors focused on the shield performance of top coat paint. Three type of pultruded GFRP plate with different laminate system was used in the test. Both painted and unpainted GFRP plates were tested under outdoor exposure test for maximum 10 years. The deterioration states of the retrieved specimens were tested with visual inspection and mechanical tests, and protective effect of top coat paint was confirmed. The shield performance againt water was tested by the immersion test using retrieved specimens from the exposure test. As the result, the water absorption curve of the coated specimens was different from the unpainted one and seems to have rather practical effect for the protection of GFRP. The shield performance againt light was also studied measuring the solar irradiation under some conditions. The solar irradiation of lower surface was 1/6.91 of the upper surface. Comparing this result with visual deterioration state, the upper surface was more deteriorated considering the total solar irradiation. The solar irradiation under top coat painting was also measured in this study, and the result of the light shield performance was 1/3 of without coating paint. |
