Throughout 2005 and 2006, the U.S. Army Corps of Engineers (USACE) and the U.S. National Guard constructed a series of unpaved roads near the U.S. and Mexican border. The high, in-place cost of crushed, aggregate base (due to the far stockpile location from the project site) prevented a conventional solution to be constructed.
The project involved 9.4 miles of roadway along the border, directly south of Yuma, Ariz. The original design called for 10 in. of Arizona Department of Transportation (ADOT) Class 1 or 2 aggregate base course.
Tensar International provided a design recommendation to the USACE to utilize one layer of Tensar BX1100 Geogrid and 6 in. of ADOT-approved crushed, aggregate base course. The Corps chose to utilize Tensar Biaxial (BX) Geogrid to optimize the thickness of the unpaved road, and to save time and money.
The geosynthetic solution offered additional benefit through the ability of the installation crew to place and compact a single lift of aggregate rather than the specified two-lift operation for the 10-in. unreinforced section.
As was the case for the Arizona Border Patrol Roads, Tensar BX Geogrids allow owners, engineers and contractors to realize significant savings for unpaved roadways and working surfaces.