Alaska is known not only for its rugged beauty, but also for its rugged conditions. Severe winters, freeze-thaw cycles, wet climates and weak soils have all contributed to extreme cases of gravel road rutting, washboarding and failure in every region of the state.
In response, the Alaska DOT (AKDOT) has undertaken a "gravel-to-pave" program, focusing primarily on feeder routes throughout the state. A recent project near Homer features an installation of Tensar BX1200 Geogrids .
"Twelve miles of gravel roadways have rutted up to 12 in. Conditions were so severe that a high-strength fabric, installed just a year ago, had migrated to the surface," said Mark Lally, Tensar International Corp.'s northwest regional manager.
"Homer receives up to 3 ft of snow, and water seeps into the subgrade," said Newt Bingham, P.E., AKDOT central region materials engineer. "We selected geogrid to overcome thaw weakening of the subgrade and frost cracking of the pavement."
Installation of BX1200 Geogrid (185,000 sq yd provided by Polar Supply Co.) on top of a geotextile layer continued from August through late October 2006.
Quality Asphalt Paving completed installation of the geotextile along the narrow road with its hairpin curves.
