
Edmonton is exploring new ways to fill an old problem.
Potholes sprout up every year, especially in the spring, when melting snow seeps into cracks and stretches the asphalt into bone-jarring gaps.
This spring, road crews have been patching potholes with a new material containing a secret ingredient that repels water and supposedly lasts longer than some of the material traditionally used.
The new material pushes water away so crews don’t have to soak up moisture or dig out debris beforehand, said Al Cepas, pavement management engineer with the city’s roadways maintenance branch. And while the traditional material, cold mix, doesn’t last more than a few weeks, the new mix is supposed to last years.
City crews using the new material patched potholes Wednesday morning along 88th Street. “These holes that have been filled today will last about three years,” Cepas said.
Road maintenance workers seem to prefer it already.
“They’d rather be using this than the cold mix,” said John Potter, supervisor of roadway maintenance for the northeast district. His workers found it easier to get a “nice finish” with it because it’s more malleable than the traditional mix.
Hot mix, a substance that lasts as long as five years, is used to fill potholes about 90 per cent of the time. The temporary cold mix is used in the spring, when the city is hit with a “pothole storm,” and there is not enough hot mix material or equipment to fill the holes, Cepas said.
Cold mix is also used by road workers on afternoon and evening shifts because the city’s asphalt plant shuts down at night, and new hot material isn’t available.
About a year and a half ago, two brothers from Florida arrived in Edmonton, offering the city free samples of the mix.
“We, of course, get a lot of people in the door claiming all sorts of fantastic things,” Cepas said. However, when the city tested the material in a few water-filled potholes in an industrial area, “lo and behold, they’re still holding a year and a half later.”
This year, the mix will be used to fill about 30,000 potholes. “This spring is really the test. Right now, it’s very promising, but we’ll have to wait and see,” Cepas said.
Although the city mixes the material at its own asphalt plant, the details of the secret ingredient are unknown, Cepas said. What he knows is that it’s no worse on the environment than the cold mix, contains a water-repelling ingredient, and so far, has filled wet potholes effectively.
Using the new material probably won’t save the city much money, but it might improve overall road conditions. Since crews shouldn’t have to return to the same holes to refill them, they will be freed up to fix holes they never had time to before, Cepas said.
The new mix costs 35 per cent more than the cold mix, which translates to about 70 cents more per pothole, pushing the total cost of filling an average hole to $8.70 from $8, Cepas said.
Edmonton isn’t the only city testing the new material. Calgary and Saskatoon are trying it out, too, said Christopher Hunt, president of the company that distributes the material.
Last fall, Yellowknife, N.W.T., switched to the new filler. Most cities in the United States, and places in Australia and New Zealand, are also using it, Hunt said.
Edmonton began testing another possible replacement for the cold mix last summer, when it laid down a soybean-based material in a southeast industrial area.
Although the last time Cepas checked on it, about a month and a half ago, it seemed to be “holding up,” he said it hasn’t been monitored too closely.
However, if the soybean product and the material used along 88th Street on Wednesday prove effective in the long run, they might both replace the cold mix.
“Ideally, we’d like to have more than one product to use. If the price of one product goes out to lunch, we’d like to have another product to substitute with,” Cepas said.
Although some extra-large potholes showed up this spring, including one just north of the Quesnell Bridge along Whitemud Drive which motorists were warned to drive around rather than through, Cepas said the number of complaints has been typical for the season.
Julius Madsan lives in the cul-de-sac off the section of 88th Street repaired Wednesday morning. “Last year it was disgusting,” he said, referring to the springtime potholes. When he learned the city was testing new filling material, he seemed pleased.
“I know some of the stuff they were using before didn’t last more than a couple of weeks. If it’s something that works, it’s a good idea.”
http://www.edmontonjournal.com/Road+workers+secret+formula+pothole+test/1455178/story.html
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