Tensile-Creep Behavior of Polypropylene Block Copolymer Resin for Non-pressure, Sanitary Corrugated Pipe for Drainage

The short-term tensile-creep behavior of polypropylene block copolymer and high density polyethylene resins in double and triple-wall corrugated pipes for water drainage and sanitation was investigated. The investigations were conducted at three stresses, with three temperatures at each stress, for a duration of 1,000 hours per EN ISO 899-1 Standard : Determination of creep behavior – Part 1 : Tensile Creep. The 50-year tensile creep at 500 psi and 23 ºC of each polymer was predicted using time-temperature superposition (TTS), in accordance with the Arrhenius equation. The findings demonstrated that polypropylene copolymer displayed higher creep modulus than high density polyethylene, and that creep compliance increased with increasing temperature; in addition, the creep deformation rate was at its highest early on in the test period, but decreased over time.