SEATTLE-Washington's infamous ``burning roads'' have been torn out and are undergoing repairs, using conventional methods this time around. Two roads which used tire chips as experimental roadbed material both began emitting smoke and oozing oil earlier this year-a situation that brought to a halt the use of tire chips in road construction in the state as well as other parts of the country.
In late April, work crews in Ilwaco, Wash., began removing about a million chipped tires-used to form the roadbed for a 150-foot stretch of Highway 100 lost to a 1994 mudslide. The roadbed was installed last October, but in January the buried chips began smoldering, eventually leaking oil into nearby Baker Bay at the mouth of the Columbia River.
Workers had to contend with occasional flare-ups during the uncovering and removal of the tire chips, according to Steve Gacke of the Washington Department of Transportation. The chips were hauled to a landfill and the oil byproduct was siphoned off and sent to a recycling plant, he said.
The DOT will repair the road with conventional rock-type fill, Mr. Gacke said. Meanwhile, the state has put a moratorium on the use of tire chips in road construction ``until a great deal of study is done,'' he said.
Meanwhile, a county road project outside Pomeroy, Wash., was undergoing deconstruction in May to remove 9,500 cubic yards of smoldering tire chips used to fill a 50-foot-deep ravine underneath the road a year ago.
Experts speculate that water from flooding and heavy rains started a chemical reaction-creating oxidation of the steel wire in the chips and generating heat in the pockets of air between the chips, possibly igniting them.