Etienne LAURENT, Pierre BELLOIR
Papers # 2012 Barcelona
With the increased urbanisation and the climate change perspectives, an integrated approach of storm water management is imperatively required. The creation of underground buffer reservoirs to temporarily store storm water using Polypropylene infiltration boxes is gaining in significance at a world-wide level. However technical requirements to ensure the structural integrity of the boxes over the intended lifetime have not yet been stipulated into standards, neither the base characteristics required to the raw material. The long term stress resistance of the materials could be established by performing pressure testing on pipe specimens according to ISO 9080 methodology. However a reliable estimate would require numerous testing over more than 1 year. An elegant alternative lies in performing creep experiments using the Stepped Isothermal Methodology. The method permits accessing to the long term strain deformation in no more than few testing days. Present work demonstrates the applicability of the methodology to Polypropylene raw materials. It evidences the significant differences of long term strength and deformation depending on the type of Polypropylene. It leads the way to the implementation of standardised criteria for the selection of Polypropylene materials for infiltration crates.