Márton Bredács, Andreas Frank, David Nitsche, Andreas Riha, Gerald Pinter
Papers # 2014 Chicago
Within this paper the property and lifetime profile of four small diameter PE water pipes for house supply, which were installed between 1968 and 1992 in Vienna and Graz, Austria, were studied. Based on thermo analytical and structure analytical test methods the materials show still expected values for PE even after more than 40 years in service. To predict residual pipe lifetimes regarding thermo-oxidative material aging a conventional Arrhenius concept was applied. After more than 1.5 years of conditioning the focused material properties showed significant changes depending on the aging temperature and aging time. The determined correlations were used to create master curves and Arrhenius plots to calculate activation energies and to predict failure times at an application relevant temperature of 15 °C. Based on the measured data all should reach or even clearly exceed the designed lifetime of 50 years.
The objective of this paper dedicated to the evaluation of the lifetime performance of small diameter pipes for house water supply, which have been in service for several decades. As all investigated pipes did not fail by SCG but were still intact after exhumation, the lifetime assessment was focused on long-term failure by thermo-oxidative material aging. In this context an ovenconditioning program up to approx. 1.5 years and a conventional Arrhenius concept were applied to predict residual pipe lifetimes.
