EXPERIMENTAL STUDY ON REHABILITATION OF CORRODED PIPES

Corrosion is a severe problem that affects oil and gas pipelines all over the world. When combined with the complex loading combinations faced by buried pipelines, the effects of corrosion can be devastating. Corrosion decreases the burst pressure, longitudinal load-capacity, and lateral load-capacity of affected pipes. Much research has been conducted to address this problem, and many repair techniques have been developed, including the use of fibre-reinforced polymers (FRPs). Most of the research that has been conducted on the use of FRP composites to repair pipes is concerned with increasing the burst pressure. The purpose of this study is to use a relatively new fibre, basalt, to increase the bending capacity of corroded pipes. To this end, five full-scale lab experiments and finite element analysis was conducted. It was found that a composite made of basalt fabric can increase the ultimate load of a pipe in bending. However, only a pipe specimen with a corrosion depth of 20% of the wall thickness could fully recover the bending capacity to that of an uncorroded pipe through the use of basalt FRP (BFRP) composite. Analysis of different thicknesses of BFRP composites and different orientations of the fabric using finite element analysis software indicated that increasing the amount of BFRP layers only yields a marginal increase in strength when bending