Characterization of PVC joints' behaviour during variable loading laboratory tests

With the objective of defining parameters that can be used to assess the condition of PVC joints in the field, more than two-hundred destructive tests were done in the laboratory. Two diameters (110 mm and 315 mm) of new PVC double-sockets were tested. The occurrence of leakage during water pressure tests, intrusion during vacuum tests and characterization of joint stiffness during rotation were monitored. The results clearly demonstrate that leakage and intrusion do not occur for typical operational situations (angles below 10 degrees) if the rubber ring is in perfect condition. The joint's stiffness increases with the increase of inner-pipe pressure, diameter and with the level of insertion. Insertion plays the most relevant role. The results also show that the condition of a joint cannot only be defined by its angle, but that an extra parameter is necessary: the level of insertion.