In the fall of 2020, the City of Lancaster, PA undertook their first large scale geopolymer mortar pipe rehab project. This included Engleside rehab - 1377 LF of 9 to 10-ft diameter round concrete pipe and Culliton Park rehab - a 381 LF upstream section of 13ft x 9 ft brick arch for a total of 1,758 LF. A fully deteriorated liner design was done on the worst sections of Engleside to create a structurally-independent, corrosion-resistant, new pipe in the old pipe. A thinner geopolymer liner was used on the remainder of Engleside and on all of the Culliton Park arch as a partially-deteriorated design to create a structural enhancement and corrosion resistant liner.
Only the dry-weather flow had to be managed with an internal bypass. During wet-weather events, all bypass was turned off and construction work would stop to permit the full wet-weather flow through the pipe. The internal bypass substantially reduced the impact to the community and reduced the overall project cost.
Construction was completed early August 2021. This presentation will focus on the trenchless options considered, why the City of Lancaster selected geopolymer mortar, liner design methodology, QAQC, Internal bypass considerations, construction challenges and lessons learned.