Bending Deformation Characteristics of Polyethylene Reinforced with Short Glass Fiber Pipe

Abstract

Agricultural pipelines in peat grounds are susceptible to disconnected joint dues, water leakage, and cuts in the pipes owing to pipe flattening or uneven settlement. An effective measure for such pipelines involves integrating joints by electrofusion even under uneven settlement and the use of polyethylene pipes with ground followability in the pipe longitudinal direction. Such pipes include those made of polyethylene reinforced with short glass fiber pipes (hereafter referred to as PE-GF pipes), which can be designed with smaller thickness as the rigidity along the pipe circumferential direction is higher than that of a polyethylene pipe, and have often been the object of application studies concerned with cost reduction. However, as the PE-GF pipes are reinforced with short glass fibers, their flexural performance limits must be ascertained for followability in the pipe longitudinal direction. Therefore, horizontal flexural testing was performed in this study under conditions where actual pipelines were arranged in the ground to confirm their deformation characteristics. Consequently, it was found that the allowable radius of curvature in the pipe longitudinal direction is 60D, where D is the outer diameter of the pipe.