A Study of Water Absorption and Mechanical Properties of Glass Fiber/Polyester Composite Pipes — Effects of Specimen Geometry and Preparation

Abstract

Ring-shaped glass fiber/polyester composite specimens cut from composite pipes with various lengths and cut edge quality were immersed into deionized water, and their water absorption was noted regularly by registering their mass gain. Monotonic ring compression tests were performed to monitor the stiffness properties during the water absorption process. Effect of specimen length and cut edge sealing with the matrix material of the pipe on the water absorption process was analyzed. Water absorption curves were fitted to the experimental data with very high correlation coefficients. Specimen types with cut edge sealing were found to absorb significantly less water than the other types, and the absorbed water showed a nonlinear monotonic decreasing tendency with specimen length. Mechanical properties were found to be only slightly affected by moisture probably because of the small amount of absorbed water.