BENCH- AND FULL-SCALE TESTING OF CIP LINERS SUBJECTED TO ELEVATED TEMPERATURE

摘要

Consolidated Edison (Con Ed) of New York operates the New York City steam system, the largest commercial district heating system in the world, with more than 100 miles of transmission and distribution pipes serving Manhattan Island. Other heat district systems exist in San Francisco, Harrisburg, Minneapolis, Pittsburgh, San Diego, and Detroit, some dating back to 1903. The waste steam condensate is typically dumped into the local sewer system via steam traps. Rehabilitation of these aging sewer systems must take into consideration the possibility of failed steam traps, and the release of high temperature steam into the sewer system. This paper presents the findings of a 24-month experimental study performed to evaluate the performance of various resin materials when subjected to cyclic thermal loading (540 cycles intermittently changing between 90° and 212° F). The impact of long-term exposure to cyclic thermal loading on the mechanical strength of the various resin types was studied via standard ASTM tests (ASTM D638, ASTM D790), as well as by using Raman Spectroscopy, a technique used for studying the chemical composition and chemical bonds of materials, thus providing more fundamental understanding of the degradation of the resin materials at the molecular level.