Fighting Corrosion to Preserve Historic Racetrack

HOBAS CC-GRP was the only material specified for the storm drainage improvement piping because of its resistance to corrosion, hydraulic capacity and the abrasion resistance. Detailed material specification also included specifics on the interior surface of the CC-GRP Pipe requiring a 50 percent elongation on the resin used. This was required to achieve the necessary abrasion resistance. Proof of prior performance of the pipe product was required. A five-year history and a list of 152,000 m of installed pipe were required with the submittal package. Since timing was critical the project specifications included a guaranteed pipe delivery time frame. HOBAS worked with the contractor and designer to provide installation recommendations for the tricky twin barrel installation submerged in flowable fill by direct bury. The 6.4 m trench width allowed for only a 61 cm clear space between pipes and a 46 cm clear space to the trench wall. The native soil material at the 3.6 m cover depth had a constrained modulus of only 4.8 MPa (Standard Penetration Test N = 2 blows per 30 cm minimum). To combat the properties of the poor native materials and to minimize settlement, a flowable fill was specified for the embedment material.