URBANA — A 24-year-old section of Windsor Road in Urbana is in such deteriorated shape that it needs to be torn up and rebuilt, according to Urbana's public works director.
The mile-plus, four-lane section of concrete pavement between Philo Road and Race Street suffers from alkali-silica reaction, or ASR, in which the concrete bond breaks down and flakes into fragments.
"The pavement has a cancer. It's terminal," said Bill Gray, Urbana's public works director. "It's not like you can remove a portion of it and save the rest of it. It's throughout the pavement. And it's a very unfortunate thing."
The cost to rebuild the section of Windsor Road will be well into the millions of dollars, Gray acknowledged.
"We have a multimillion-dollar problem," he said. "It's a big situation that we're going to have to address in the years ahead."
The cost of the project dwarfs all of the annual revenue Urbana gets from the state motor fuel tax — about $1 million — and from its own gas tax, now proposed to increase to 4 cents a gallon — about $700,000.
"It could take several years of revenue alone," he said.
City and county officials are looking at one way to reduce the cost and size of the project, putting that section of Windsor on a "diet" and trimming it to three lanes instead of the current four, Gray said. A report on the feasibility of such a move is expected from the Champaign-Urbana Urbanized Area Study later this summer.
"We're going to get the study done. We need to know that and then we'll need to have a consultant take a serious look at our options for replacing it," Gray said. "We've kicked around a variety of ideas, but they're all very costly."
The crumbling section of Windsor was built in 1988 and began showing signs of damage four or five years ago, Gray said.
"Usually a concrete pavement isn't going to totally fail like that," Gray said. "It's just a certain high content of chemicals in the concrete, along with moisture, along with freezing and thawing. The concrete bond is breaking down and the pavement is failing, so what happens is it's almost like you have a bunch of gravel strewn about the pavement. The pieces can be various sizes anywhere from a half-inch to several inches in diameter. And it becomes bigger and bigger if left unattended."
David Peshkin, vice president of Applied Pavement Technologies in Urbana, described ASR as "basically an unintended reaction between the ingredients in concrete which in the presence of water forms an expansive byproduct that breaks up the concrete from inside. When you have it you end up not having a lot of good alternatives for taking care of it."
Parts of Windsor Road in Champaign also have experienced pavement problems, said Roland White, Champaign's city engineer. About 30 to 40 percent of the section between First and Neil streets was torn up and replaced two years ago.
"It was never officially determined as (ASR), but we saw the same signs of distress and cracking," he said. Now the city is experiencing similar problems with fairly new concrete streets in a number of subdivisions, including Sawgrass, Ironwood West and Ashland Park, he said.
"It's something the whole industry is watching and is wary of," he said.
Gray said ASR is a problem that goes well beyond Champaign-Urbana.
"This is an issue in Minnesota and Colorado and multiple other states. It's not a new phenomenon for concrete," he said. "You really need to be aware of the raw materials used and their content. They need to be tested to make sure of their chemical content."
Kurt Smith, a program director with Applied Pavement Technology in Urbana, said that ASR is common throughout the United States, and not only in concrete pavement.
"At one time, it was thought to be just a problem in the western United States, but in the last 15 to 20 years it's been determined that every state in the country has some degree of ASR issues," Smith said.
It's also been discovered in dams, bridge abutments and retaining walls. It's also been found in some interstate highway projects, particularly in Nebraska and Colorado.
The Illinois Department of Transportation now tests individual components to be used in concrete pavement formulas, said Scott Lackey, a materials engineer at the Paris office of the agency, in order to reduce the likelihood of ASR.