Recently, the Delaware DOT completed their first large scale GeoSpray geopolymer mortar pipe rehabilitation project. This included work at 3 locations with pipes ranging from approximately 7’ x 10’ to 10’ x 17’ metal arches for a total of 608 LF: The geopolymer liner design assumed the existing pipes were fully deteriorated and utilized the distributed beam design method requiring an unreinforced geopolymer mortar liner ranging from 2.4” to 3.2” thick. This created a structurally independent, corrosion-resistant, new pipe inside the old pipe. The successful construction project was completed in cold weather conditions in February 2022 prior to an environmental deadline to be out of the stream by March 1. If DelDOT had to do three full bridge replacements, it would have taken 6-9 months minimum, and had a far greater public and environmental impact. Using accelerated bridge construction (ABC) by rehabilitation with geopolymer liner cut construction down to six weeks. This presentation will focus on the trenchless options considered, why DelDOT selected GeoSpray geopolymer mortar, liner design methodology, the H&H hydraulic analysis, specification development, QAQC testing, internal/external bypass considerations, construction challenges and lessons learned. It includes perspectives from the owner, design consultant, contractor and the material provider.