Impact of thermal-oxidative ageing on high-density polyethylene pipes: Analysis and prediction of service life

High-density polyethylene (HDPE) is increasingly used in the manufacture of culverts and drainage pipes because of its many advantages. The question of the longevity of HDPE pipes made from recycled resins compared with those made from virgin resins has aroused growing interest in the scientific community. Several recent studies have confirmed the high durability of HDPE, estimating its lifespan at over 100 years. However, external factors, such as environmental conditions and operating constraints, can influence this longevity. However, its oxidative thermal ageing is crucial to its durability. This study investigates the effects of thermo-oxidative ageing on the mechanical and physico- chemical properties of PE, highlighting the degradation mechanisms induced by prolonged exposure to high temperatures and oxygen. A method combining experimental tests and predictive modelling was developed to assess the lifetime of the materials. The Arrhenius model was used to estimate degradation kinetics and predict PE lifetime as a function of ageing conditions.