Studying the effect of surface roughness on cathodic disbondment of composite laminates applied on gas pipe lines as a repair system

Repair and rehabilitation of gas transmission pipelines via traditional methods such as cut out, welding and steel sleeves, have a lot of problems and need shutting down the production. As a consequence, it is crucial to use composite laminates as a modern method for repair and rehabilitation of gas pipelines. This work is concerned with the determination of optimum surface roughness, prior to the application of composite laminates, via pull-off and lap-shear experiments. In order to ensure that during cathodic protection any disbondment will not occur for these protective laminates, the resistance of these laminates to cathodic disbondment was also investigated. According to the results, the optimum surface roughness was 60 micrometer and no disbondment was observed for the composite laminates.