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What’s the best way to fix rough roads? County makes Maple Road a case study

What’s the best way to fix rough roads? County makes Maple Road a case study

Roads that cause teeth-gritting, shocks-and-alignment-killing frustration lie in every direction across Erie County. Patch and repaving trucks seem to return to them every spring like migrating birds.

“We patch it every year, and Mother Nature does its thing,” said county Public Works Commissioner John Loffredo. “It’s an irritation for the public, and it doesn’t do their vehicles any good.”

The county can’t afford to rebuild Maple Road, for instance, because that would cost $3 million to $4 million a mile. But it doesn’t want to patch the road every year either.

So what’s the best way to get repairs to last longer with the fewest dollars?

County officials hope to find the answer by turning the Maple Road into a giant, outdoor science lab.

The county recently agreed to spend roughly $150,000 to design and install eight different road-paving recipes on eight different sections of this east-west thoroughfare. The county will try different combinations of pavement removal and concrete/asphalt replacement to find out which holds up best in this unforgiving climate.

Maple Road is the busiest road Erie County owns, with 20,000 vehicles crisscrossing the five-lane artery each day. The road connects schools, hospitals, retail plazas and homes. Its poor condition has led one local resident to take extreme precautions.

Every year for the past seven years, Thad Boron has gone to his local home repair store, loaded up on asphalt crack filler, then set his alarm for 2 a.m. Under cover of darkness, he said, he would fill the latest crack in the street in front of his driveway, dragging filler across the entire width of Maple Road. He would rush back to the curb when headlights approached.

The Amherst homeowner said he preferred spending a little money fixing the road in front of his home than paying a lot of money fixing his car.

“I wasn’t going to back into a hole,” Boron said.

Road Building 101

Maple Road suffers more cracks than the average road because of the way it was originally built and later repaved.

It started out as a state-owned roadway in 1972, built with 9 inches of concrete over a stone base. Concrete has an advantage because it lasts four times longer than asphalt, settles evenly over rough surfaces and is generally more sturdy and impervious to damage.

“Makes sense, doesn’t it?” asked Loffredo, the public works commissioner. “Now the story turns bad.”

Building with concrete is more complicated. It takes longer to cure and is expensive to repair. It interacts badly with road salt, a necessity for winter road clearing. It also doesn’t stretch and contract as flexibly as asphalt, so builders must install expansion joints to keep the road from breaking.

Asphalt, meanwhile, is easier to pave with and repair. And it’s cheap. It doesn’t last as long as concrete, but repairs are relatively simple. When the state turned Maple Road over to the county, the local administrators decided to fix the deteriorated concrete surface by laying asphalt over it.

That’s not a problem – in Florida. But in this colder climate, the ground repeatedly swells and buckles as part of the region’s notorious freeze-thaw cycle. Last year’s record-setting cold, which froze the ground 4 feet deep, caused untold millions in road damage when the ground heaved upward as the thawing ground expanded during the spring.

That leads to cracks, which fill with water. The water refreezes and expands. The small cracks becomes bigger cracks, then potholes of growing size.

The problem is compounded on Maple Road because of all the built-in concrete expansion joints. The ground heaves and pushes the joints out of alignment, cracking the top asphalt layer year after year. Those cracks fill with water, and, well, you start to figure out why Maple Road resembles a dirty zebra, with thin stripes of black patching interrupting gray pavement every 60 feet or so.

One time, the cracks were so bad that Boron asked a deputy public works commissioner to visit his house. The deputy commissioner took a seat in the backyard while Boron set up two glasses of water on a window sill as a truck rolled over the asphalt crack in front of his house.

“Watch,” he said.

The water jiggled.

The experiment

This past week, Boron was the one doing the watching from his front lawn as supervisors and crews from Urban Engineers and Amherst Paving set out dozens of orange cones. They dug up and relaid the first four of eight test strips between North Forest and Hopkins roads, each one strategically placed at an existing expansion joint.

The goal is simple: If the county can’t afford to dig up and replace all of Maple Road, then maybe it can just reconstruct the expansion joint locations where the road surface is most prone to fail. The county just needs the right replacement formula.

If the county had the resources of the New York State Department of Transportation, then it could turn to the department’s Geotechnical Engineering and Materials bureaus. This is exactly the kind of engineering problem their staffers work on every day when it comes the construction and repair of the state’s 1,457 center-lane miles of roads in Western New York, said state DOT spokeswoman Susan Surdej.

But Erie County doesn’t employ such expertise, even though it owns more roads than any other county in the state – nearly 1,180 center-lane miles. Yet the county has about $10 million less than it needs to fix them all each year, Loffredo said.

Instead, it hires consultants. Urban Engineers recommended experimenting with eight different road repaving recipes for the single-lane, 6- to 8-foot-wide test strips. These repaving recipes are like lasagna recipes, except you substitute the layers of pasta, beef, ricotta and sauce for layers of concrete, asphalt, epoxy-coated steel rods and binders.

On Thursday, Charles Sickler, the county’s engineering director, donned his florescent yellow jacket and stood over a test strip that had just been poured with new concrete. That test strip and the one to his left required digging down to the bottom stone layer of the old roadway. The only difference was that the strip to his left was refilled with an asphalt base, while the one directly in front of him had 34 steel rods drilled into the surrounding concrete, then filled with an even stronger, faster-setting concrete.

The same formulas were applied to two other test strips on his right. But instead of digging up all 9 inches of old concrete roadway, paving crews just scraped off the top 3 inches.

Crews put plastic sheeting and black insulating blankets over the concrete-filled test strips to protect them from freezing before they could harden properly. Then they followed up with a sticky, black mesh overlay over all four test strips and a smoother, finishing layer of asphalt on top of everything.

Sickler motioned over to the right, where the shallower test strips had been dug. Repaving plans flapped in his hand.

“If that works as good as this, we’ll use that. It’s cheaper,” he said before pointing once more to the test strip directly in front of him. “This was a pain in the neck to do.”

Time will tell

A few weeks ago, Loffredo, the public works commissioner, sat before county legislators and asked them to rush approval of funding for the Maple Road test strips before below-freezing temperatures settled in for good.

On Thursday, it was clear the weather would cooperate.

The last four test strips to be installed this week will be like the first four, Loffredo said, except that thin fiberglass strands will be added to the top, finishing asphalt layer to see if that holds the road surface together longer.

It will take at least a year to see which test strip emerges as the most successful at preventing cracks on Maple Road. By next year, it’s likely some of the test strips can be ruled out as failures. But Sickler, the county’s engineering director, said it might take another year before a clear winner emerges – if a clear winner emerges.

The Maple Road test results can be applied to other similarly constructed roads. Loffredo said the county will likely experiment with other asphalt concoctions in the future since asphalt roads make up the vast majority of the county-owned network. Some pavement testing with asphalt additives and fibers was done on Hopkins Road in East Amherst last year.

Given the heavy costs associated with major road repair, local governments have an ongoing incentive to experiment with different paving techniques and ingredients to find the ideal balance between below-average costs and above-average results. Whether it’s crack filling, strip patching, micro paving, mill-and-overlay or full road reconstruction, the search is on to fix roads better, cheaper.

The one thing no one can afford is to commit taxpayer money to a costly repair that doesn’t work, Loffredo said.

“If we make the wrong decision,” he said, “in a year or two, we’re back to square one.”

Fuente de la noticia: http://www.buffalonews.com/city-region/erie-county/whats-the-best-way-to-fix-rough-roads-county-makes-maple-road-a-case-study-20151208

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