Source: Sherman Publications

Experimental road surface working well

by CJ Carnacchio

July 20, 2011

ADDISON TWP. – Motorists tooling along Lake George Rd. between Lakeville and Oakwood roads have probably noticed it’s a much more pleasant ride than it used to be.

That’s because last October this 3½-mile stretch of rural road was coated with a special test material that’s resulted in a harder, smoother surface.

“It’s been very successful,” said Addison Supervisor Bruce Pearson. “People have baked cookies and brought them in for me because the road is that good. I’m not kidding.”

Marketed as “Furnace Rock SF Blend,” the test material is a 50/50 blend of the natural aggregates (23A Natural Sand & Gravel) normally used by the Road Commission for Oakland County, plus steel furnace slag material, which is a nonmetallic by-product from either the conversion of iron to steel in a basic oxygen furnace or the melting of scrap to make steel in an electric arc furnace.

Pearson said a road commission representative indicated “this new material is equal to putting down crushed limestone.”

“It’s that good. It locks like cement,” the supervisor said. “It has a real high lime content in it and lime is one of the ingredients in cement. When you add water to the stuff, it actually binds together with the clay and makes a solid road.”

Steel furnace slag is environmentally acceptable and meets all of the Environmental Protection Agency’s risk assessment guidelines, according to the Dearborn-based Edward C. Levy Co., which produces Furnace Rock SF Blend.

Price-wise both Furnace Rock SF Blend and 23A gravel appear to cost about the same.

In a written statement, Levy indicated both materials are “competitively priced in the $4 (per) ton to $5 (per) ton range.”

Pearson said he was told both materials cost $4.75 per ton.

The test material used in Addison was donated by Levy.

“We’ve done a number of these types of deals with Levy over the last couple years,” said Craig Bryson, spokesman for the road commission. “It’s beneficial for everybody, obviously. We get free material. The community doesn’t have to pay for the material. And it gives Levy a chance to test out some material (in) a real world environment. Of course, if it works, they can then use that (data) to sell the material to other people. It’s a win-win situation.”

Pearson absolutely loves the stuff.

“Once it goes down, it’s like asphalt,” he said. “It’s held up all fall, all winter, all spring and now into the summer.”

Prior to the test material’s application, Lake George was a prime example of a bumpy, washboard road, according to Pearson.

“Our road was so bad,” the supervisor said. “I had so many complaints on it.”

Now, Lake George Rd. is so smooth, a new problem’s developed.

“I created another monster because now people are speeding on the road,” Pearson said. “Before you couldn’t (travel fast) because it was so bad. Now, I catch myself at 55 miles an hour. It’s just like driving on a paved road. I had to put the radar carts out there.”

The speed limit along that stretch is 55 mph, but people are going faster, Pearson noted.

As for the road commission’s opinion of Furnace Rock SF Blend, Bryson said “the jury’s just not in yet.”

“There’s some aspects of it we like (and) some aspects of it we’re a little bit concerned about. Generally, it’s provided a good surface.”

On the plus side, Bryson indicated “it seems to tighten down better than traditional gravel and maybe last a little longer.”

“The downside is that it seems to take a lot more brine to get to that point,” he said.

Brine is the liquid saltwater the commission sprays on its gravel roads to control the dust and harden the surface.

Bryson said it seems to take “about three times” as much brine to create a hard surface with the test material.

“It would seem to be an additional cost to get the better performance out of it,” he said.

According to Levy, Furnace Rock SF Blend has numerous benefits including reducing annual maintenance costs; allowing heavier loads on gravel roads without producing ruts; and recycling material from the steelmaking industry.

Pearson said he would like to place the Furnace Rock SF Blend on some other Addison roads. He mentioned Gilmore, Frick and Brewer (between Rochester and Townsend roads) as possibilities.

When asked if the road commission plans to use Furnace Rock SF Blend elsewhere in Addison, Bryson indicated future use is going to depend on cost and the outcome of this Lake George Rd. experiment.

“We want to give it a longer test period to see how it performs over at least the course of a full year,” he explained. “We put it down in late October, so we saw the winter performance. We haven’t yet really seen a full summer performance.”

Bryson noted the road commission is “always interested in trying new things.”

“We appreciate that Levy’s willing to work with us to test their new materials. Everybody benefits from the free material,” he said. “If we find something that’s cost effective and works better than what we’ve used in the past, everybody’s in favor of that.”