Volume 26, Issue 6 (November 1998)
Creep Test of Cured-In-Place Pipe Material Under Tension, Compression, and Bending
Inexpensive and easily fabricated long-term creep test devices have been designed and built in order to identify the long-term creep behavior of cured-in-place pipe (CIPP) material under tension, compression, and bending. A special device for testing curved specimens has been designed, built, and evaluated. Loads were applied for 3000 h, and the deformations of CIPP specimens were recorded. Findley's equation, which has been successfully used to predict the creep behavior of plastics for more than 25 years, was used as a baseline for data analysis. The results from Findley's approach were compared with the results from the analyses by theoretical and log-fit methods. The comparison of the three approaches shows that the best estimation of 3000-h creep moduli can be obtained by using the log-fit method.