A Wisconsin Department of Transportation (WisDOT) project to reconstruct a portion of State Highway 164 in Racine County was completed in late 2013. A segment of the new roadway was constructed through a wetland area, where new twin 30-in. reinforced concrete pipe (RCP) storm water culverts crossed under the roadway for drainage. The roadway and subgrade had begun to settle above the culverts, causing the RCP culvert to move. This movement caused some of the pipe joints to separate, allowing subgrade material to migrate in from outside the pipe.
WisDOT and the general contractor looked for a trenchless solution to resolve the issue. They contacted a sewer rehabilitation contractor, Visu-Sewer Inc., located in Pewaukee, Wis. The representative recommended chemical grouting for the repair, but the first two joints on each end of the culverts were bolted together per WisDOT specifications and the bolts protruded into the pipe. These bolts could not be removed and prevented the grouting equipment from being pulled into the pipe.
Visu Sewer contacted Cretex Specialty Products—a manufacturer of manhole and pipe sealing products located Waukesha, Wis.—and inquired about the Cretex/HydraTite internal joint seal as a possible solution. The seals appeared to be the right solution and were submitted to WisDOT for approval. They were approved and chosen because they could be permanently installed at the defective joints without excavation and with easy man entry on the open-ended culverts.
A total of four (two in each RCP culvert) 30-in. double-wide Cretex/HydraTite joint seals were installed. To ensure no further settlement, the contractor also performed injection grouting to stabilize the soil around the outside of the joints.
