Prediction of long term performance for GRP pipes under sustained internal pressure

The long term performance of GRP pipes after 50 years was predicted from failure pressure and time to failure tested up to 10,000 h through sustained internal pressure test. GRP pipes made of glass chopped fibers, polyester resin, and sand were manufactured by continuous filament winding technique. Different pressure conditions were considered to 19 GRP pipes to induce damage at the specified time to failure. According to the results, the linear regression analysis was applicable to predict failure pressure of GRP pipes after 50 years as the correlation coefficient was 0.842 and the ratio of regression coefficient and its variance was 6.451. Based on the regression ratio between failure pressure for first 6 min and that of 50 years, the long term performance of GRP pipes after 50 years was degraded up to 57% of the initial performance.