KHIT 78 Garrard Co. Pipe Inspection

The Garrard County US 27 Relocation project begins just north of the intersection between US 27 and Burdette Knob Road and extends north approximately 5.75 miles to the intersection of US 27 and KY 1845. Based on the contract plan set dated September 24, 2009 the project has approximately 20,000 linear feet of proposed culvert and storm sewer pipe. Approximately 14,200 linear feet of the proposed pipe crosses under pavement. The Kentucky Transportation Cabinet (KYTC) Division of Materials has stated that some of the Corrugated Metal Pipe (CMP) installed on the project did not meet the minimum corrugation depth specification and the asphalt coating on the CMP was severely cracked prior to installation. Additionally, the KYTC Division of Materials found instances of excess deflection and damage on the newly installed pipe. Based on this evidence the KYTC has requested that the Kentucky Transportation Center (KTC) inspect the newly installed culvert and storm sewer pipes that are under pavement on the Garrard County US 27 Relocation Project (item number 7-26.01) and monitor their condition under a long term study. The strength and service life of a CMP is dependent on many factors. Two of those factors are the corrugation depth and the asphalt coating. The depth of the corrugation is related to the amount of bending resistance a pipe can withstand. The protective coatings applied to the pipe are designed to provide protection against aggressive water and soil conditions. If either of these factors are compromised then a reduction in the material strength and service life may be realized or premature failure may occur.