The Louisiana Department of Transportation & Design (LA DOTD) opened up a bid to reline an existing culvert which had severely deteriorated and was in need of either replacement or repair. The culvert was located directly under the highly-trafficked U.S. 68 in Jackson, Louisiana.
Ultimately, they decided to reline the host pipe with an asphalt coated ULTRA FLO® Pipe-Arch spiral rib pipe. The unique profile of the spiral rib pipe would provide a smooth interior capable of a Manning’s “n” of 0.012, equivalent to that of concrete pipe, while the exterior box ribs provide the structural strength. Adding to these inherent benefits, ULTRA FLO is also one of the most economical pipe reline solutions. The pipe arch shape was selected in order to maximize the area of opening versus a round pipe shape for the liner.
Upon the decision to proceed with use of spiral rib pipe arch, the local Contech Sales Engineer worked closely with the Contech engineering services and the Eunice, Louisiana manufacturing facility to prepare submittal drawings for approval by the contractor and the LA DOTD. The drawings showed the location of 2" diameter grout couplings, skid rails, hold down jacks, banding devices, and flotation calculations to insure proper installation of the reline pipe inside the host structure. The ability to position and hold the ULTRA FLO pipe arch centered within the host structure allowed for it to be grouted with flowable mortar completely encasing it. The flotation calculations and grout couplings allowed the contractor to stage grout the pipe with ease.