Bill Vanhoose, Jeff Biesenberger
Papers # 2010 Vancouver
While polypropylene (PP) has been widely used in corrugated sewer pipe production in Europe for the past 25+ years, high-density polyethylene (HDPE) remains the dominant material for corrugated sewer pipe production in North America. As such, both short term and long term material design properties have been established for pipe grade (HDPE) for use in American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factored Design (LRFD) Section 12 Design methodology. With the investigation into the use of PP in North America, came the need for long-term material design limits for use in the AASTHO strain based design. While short term material properties are readily available, long-term properties such as 100-year modulus of elasticity, 100-year ultimate tensile strength, and strain limit are less known and specifications for determination of material properties poorly defined. This paper describes test protocols established for material property determination including Stepped Isothermal Method (SIM) testing for modulus and ultimate tensile strength determination, evaluation of design stress for modulus predictions, and physical product compression stub testing for establishing design strain limits.
