A review on the durability of PVC sewer pipes
Polyvinyl chloride (PVC) has become one of the dominant construction materials for sewer systems over the past decades, as a result of its reputed merits. However, since PVC sewer pipes have operated for decades in a hostile environment, concern over their longevity has been lately raised by sewer managers in the Netherlands. Towards that direction, the main factors and mechanisms that affect a PVC pipe’s lifetime are discussed in this article, along with the current lifetime prediction methods and their limitations. The review of relevant case studies indicates that material degradation, if any, occurs slowly. However, inspection (CCTV) data of three Dutch municipalities reveals that severe defects have already surfaced and degradation evolves at an unexpected fast rate. A main reason of this gap between literature and practice is the fact that comprehensive material testing of PVC sewer pipes is rarely found in the literature although it proves to be essential in order to trustfully assess the level of degradation and its origins.
Plastics are used for a wide range of commercial and industrial piping applications. The most known are polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), acrylonitrile–butadiene–styrene (ABS), polybutylene (PB) and glass–fibre-reinforced polyester (GRP or FRP). Concerning piping systems for drinking water supply, gas distribution and sewage disposal, PVC, PE and PP are the most popular polymer materials (PlasticsEurope, 2017). Especially for gravity sewer pipes, PVC has been extensively used over the past decades and has become the dominant construction material. Cost efficiency, ease of installation, range of available diameters (40–630 mm) and its reputed chemical resistance favour its wide acceptance by decision makers in urban drainage (Davidovski, 2016).