Quarter 4, 2017

Concrete Pavement Progress www.acpa.org 12 Geotextile Fabric Drainage Layer Reduces New Construction Costs By Sheryl S. Jackson THE USE OF GEOTEXTILE FABRIC as an interlayer for an unbonded concrete overlay is not unusual, but a project inNorthCarolina is gaining positive attention for using the fabric as a drainage layer. Geotextile fabric was first used on a 5-mile sec- tion of the eastern loop of Greensboro’s new 44- mile long urban perimeter highway. The success of the application and the time- and cost-savings stemming from the innovative use of led to the use of the fabric for drainage as a design standard for the department. North Carolina’s first use of geotextiles in new pavement construction was in 2014, when the North Carolina DOT tested it on a weigh station project. Since then, the material has gained in popularity across the country. “The Greensboro Loop project was originally bid with permeable asphalt, but the contractor requested the design change through our value engineering process,” explains Christopher A. Peoples, P.E., statematerials engineer forNCDOT. “We feel comfortable adding this use of fabric in new concrete pavement construction to our design standards as a result of the combination of our experience with the weigh station and the construction process with the Loop project.” According to the value engineering change pro- posal approved by NCDOT, the design change to incorporate the geotextile drainage layer saved almost $556,000 in construction cost savings. The willingness to approve a design change speaks to the NCDOT’s open mindedness to NC GRE ENSBORO LOOP G R E E N S B O R O L O O P