Comparison of Normal and Accelerated Ageing of GRP Laminates Immersed in Seawater

摘要

Glass fibre reinforced plastic (GRP) materials for marine applications undergo losses to mechanical properties during ageing. This study examined a polyester, a phenolic and two vinylester GRP materials. Specimens were immersed in seawater, unloaded or loaded at a high service temperature of 30 deg C, or at 50 deg C as an accelerated ageing condition. Water uptake was monitored. After ageing to near saturation the losses in flexural strength ranged from 15 to 25% for the unloaded specimens. Loading in flexure at 20% of the strain to fail while ageing did not signlficantly affect the water uptake or losses to mechanical properties. Greater losses in mechanical properties from the 50 deg C immersion were accompanied by indications of abnormal degradation. The accelerated ageing condition therefore appears unsuitable for the assessment of these materials.