Effects of temperature on material properties in spray and cured-in- place-pipe liners

Abstract

Temperature plays a vital role in estimating the long-term properties of spray and CIPP liners, which are examined for relining deteriorated water pipes. Temperature variation in pipelines should be known prior to installation of any polymer-based pipe or liner. This ensures that long-term properties can be assessed in the laboratory for known temperature fluctuations. This paper examines tensile testing at elevated temperatures conducted on a thermosetting spray liner and a thermosetting cured-in-place pipe (CIPP) liner. Temperature not only plasticises the polymer material making it more ductile, but can also reduce the tensile strength of non-reinforced polymer liners. Accelerated creep testing was also conducted as a comparison to traditional creep testing for both spray and CIPP liners. Long-term properties, such as creep modulus, may be able to be estimated based the stepped isothermal method (SIM). The use of SIM tests can approximate creep modulus and creep strain values and testing can be completed in less than a week compared with traditional creep tests that can take over 1 year to run.

Techniques