Restlebenszeitmodellierung von Polyethylen-Rohren auf Basis des Arrhenius-Konzepts

Translated title of the contribution: Lifetime prediction of polyethylene pipes based on the Arrhenius concept

Margarita Kaufmann

Research output: ThesisMaster's Thesis

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Abstract

This master thesis considers aging effects of polyethylene (PE) water pipelines and estimates the efficiency of stabilizers in the pipelines and further predicts their lifetime. Estimation and prediction are based on the Arrhenius concept. The lifetime of PE water pipelines should not be shorter than 50 years. The pipelines were dug out after a maximum usage of 44 years. To determine for how long the pipelines can still be used or if they should be replaced, aging effects were analyzed. Four methods were used for analyzing the aging processes. These are: a) aging in an oven to accelerate aging, b) dynamical Oxidation Induction Temperature (OIT) test for determination of the decrease of oxidation temperature (Tox), c) tensile test for analysis of elongation at break and d) Fourier Transform Infrared Spectroscopy (FT IR) for estimation of the carbonyl content. Further the efficiency of stabilizers in PE pipelines was calculated and their lifetime predicted. Both of these calculations are based on the Arrhenius concept and the time temperature shift principle. Additionally the activation energy for aging processes in PE pipelines was estimated and compared. The analysis of the results showed a decrease of Tox and elongation at break after aging in the oven. This allowed on the one hand modeling of the lifetime and on the other hand the estimation of the efficiency of stabilizers in the pipelines. The calculated results gave evidence that the pipelines even after many decades of use are in a very good condition and will reach the minimal lifetime of 50 years or in some cases even exceed it.
Translated title of the contributionLifetime prediction of polyethylene pipes based on the Arrhenius concept
Original languageGerman
QualificationDipl.-Ing.
Supervisors/Advisors
  • Pinter, Gerald Gerhard, Supervisor (internal)
  • Frank, Andreas, Co-Supervisor (external)
Award date18 Dec 2015
Publication statusPublished - 2015

Bibliographical note

embargoed until 16-11-2020

Keywords

  • Polyethylene
  • lifetime prediction
  • tensile test
  • dynamical OIT
  • FTIR

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