| The authors carried out outdoor exposure tests on pultruded GFRPs for six years in four places in Japan with different climates. Three types of pultruded FRPs with different laminate systems were tested. Changes of mechanical properties such as tensile, bending and in-plane shear were measured. The results showed that unpainted pultruded FRP showed a remarkable reduction in mechanical strength, and the retention ratio was about 0.7–0.8 of the initial values by the 6th year. Corresponding painted specimens showed small changes. This result shows that a top coating helps to prevent changes of mechanical properties of pultruded FRP. As regards the difference of the laminate systems, there were specimens whose roving layer ratio was low and showed small changes in some mechanical properties. No significant difference between exposure sites was observed in these tests. |
