Tiem Meijering, Jeannette Mulder, Günter Dreiling, Heinz Vogt
Papers # 2014 Chicago
In this study, it has been demonstrated that a 100 years service-lifetime for non-pressure sewage pipes, solid wall pipes and structured-wall pipes of PE and PP, can be expected provided some basic conditions are met. It has been demonstrated that the resistance to thermo-oxidative degradation of the applied materials is sufficient to assure an end-of-life time of at least 100 years. Provided that the allowable stresses at long term are met, brittle pipe failure is not likely to occur. The behavior of the solid wall and structured-wall pipes under constant deflection and strain conditions has been evaluated and relaxation tests have been carried out, showing that at long term the remaining stresses in the pipe do not exceed critical values. The composition of sewer water and the real sewer water temperature has no significant effect on the lifetime prediction. A series of excavation projects have been executed where the sewer pipes were already in service during up to a period of 38 years. From the test program it has been concluded that no reduction of pipe quality has been taken place and the prediction of a total service time of 100 years is apparent.