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A Better Set Of Building Blocks


The person that figures out a way to get rid of potholes here in the Midwest should win the Nobel Peace prize, or at the very least get a nomination. Those things are a nightmare. Right after winter, snow thaws, and next thing you know chunks of the rode the size of Pangaea begin to appear. How many times have you dodged one of these craters and/or the bits of road that have popped off? More times than you have finger and toes? Yeah, probably.

And that's where Dr. Nabil Grace comes into the picture. His research at Lawrence Tech University may be able to solve this pothole epidemic here in the Midwest. One of his many projects includes carbon fibers and how they could potentially replace some of the steel rebars in roads and bridges.

"Like it or not concrete cracks and we have a lot of cracks," he says. Grace is a distinguished professor at Lawrence Tech, chair of the Department of Civil Engineering, and director of the Center for Innovative Materials Research (CIMR).

A pothole exists because of corrosion in the steel rebars from winter road salt seeping into tiny cracks in the concrete. The salt attacks the steel resulting in corrosion that then creates internal pressure which pops out chunks of pavement. Grace wants to remove the source of the problem.

"For the last 22 year we've been researching materials that can replace steel," he says. "We have something that's about five times stronger than steel and at least four times [lighter]." No, it's not magic. It's carbon fibers.

"Carbon fiber is very thin like your hair," he said. "We take the fibers and blend it with special resin and can formulate different sizes to form steel beams. We cannot get away from concrete but we can use something that is less vulnerable to corrosion. It would solve a majority of our road problems." Well, except for traffic. Grace doesn't have a solution for that.

The same thing happens in highway bridges. The steel rebars corrode and break apart the concrete, which can rain debris onto roads below and weaken the concrete beams.

"There are 600,000 highway bridges in the united state, 12,000 in Michigan, and the federal high administration says that 25 percent needed to be replaced yesterday," he says. "And their major problem is the reinforcement steel."

In 2000 Lawrence Tech was awarded a contract to build two bridges, side by side, one conventional and one using carbon fibers, for the Bridge Street Bridge in Southfield. The two bridges lead traffic to an office park near Telegraph and Eight Mile over a tributary of the Rouge River.

Lawrence Tech had a five-year award to monitor the bridge that ended last year. They were just granted an additional ten years by the National Science Foundation. What they've found is that over a 100 year period the conventional bridge costs nearly three time more in maintenance –patching, replacement, treatment– than a carbon fiber bridge.

"We don't do research for the sake of research," Dr. Grace says. "We do research to deploy the results for the benefit of the tax payers, that's our goal."

So why doesn't every bridge and road have carbon fibers instead of steel? Well, they aren't exactly cheap. Carbon fibers are ten times the cost of steel and a carbon fiber bridge costs about 50 percent more than a conventional bridge. Grace says that it's sometimes hard to see the benefits of the long run when it's that much more upfront.

"People tend to think in terms of cost to build it and not the effect of filling a pothole every spring," he says.

But that doesn't mean people aren't willing or wanting to incorporate carbon fibers into their roads and bridges. LTU was awarded a contract to design a Bembrooke Avenue bridge by M-39 by the Michigan Department of Transportation and MDOT has also asked Grace to take a look at two bridges in Jackson to see what can be done. Additionally, Grace's lab was contacted by the Maine Department of Transportation wanting to incorporate carbon fibers in a cabled bridge.

Lawrence Tech's infrastructure research has produced five patents – three have been approved and two are on their way, he says. One includes a carbon fiber weaved wallpaper of sorts that wraps around the concrete beams, columns, or slabs making it four times stronger than steel.

"Civil engineering is very classic because a road is a road, bridges are bridges, pyramids are pyramids," he says. "It goes back to the ancient Egyptians, the Romans. But incidents like 9/11 and other attacks have changed our way of thinking about civil engineers. It's still traditional, still classical, but it has become a bed of innovation."

Just last year Lawrence Tech and Grace dedicated the Center for Innovative Materials Research, an $11 million facility funded by the United States Army. CIMR tests loading conditions. That means they can simulate traffic or test what one million pounds of force would mean to a full-scale section of a bridge. Grace says this will help them test and research for lighter and lighter materials for the army but can and will most definitely be applied to everyday infrastructure methods.

CIMR also has a simulated fire chamber, which the Discovery Channel came out, interviewed Grace, and video tapped for a program to run sometime this year. And CIMR will soon have something called an environmental chamber.

"The environmental chamber can simulate any type of environment," he says. "Very, very hot weather, freezing and thawing. And a few options that aren't available anywhere else in the county – blowing and freezing rain."

The fire chamber, in turn, can test conditions for heat of up to 2,200 degrees Fahrenheit and it's big enough for an entire Humvee. 

CIMR are military funded so Grace and his students in the civil engineering department are testing armored structures and materials under different loading conditions that can face a number simulated threats - for instance the steel in the World Trade Center attacks. The equipment in CIMR can pound a piece of the bridge to see how much damage it can take or a beam that is wrapped with the carbon fiber weave.

"Our research will go toward everyday use, to every day infrastructure, not just the military," he says. "We are solving problems that have a national interest. We're trying to improve the infrastructure of our state."

And then there's the stimulus money. Michigan is getting a big chunk to improve shovel-ready infrastructure projects. The bill includes $635 million for main state highways and bridges, while $212 million is going toward local road departments.

Great for Grace, right?

Well, the Bembrooke Bridge and the two in Jackson are kickbacks from the stimulus and MDOT has asked Lawrence Tech to work on (Bembrooke) and look into (the two Jackson bridges) a few projects. But, unfortunately, none of that money is going to research or experimental projects. And it all needs to be dedicated to projects within short period of time. That doesn't leave the university out of the picture, though.

Grace has worked closely with the National Science Foundation for the funding of a number of projects. In normal years one out of every 20 proposals submitted to the NSF is picked up. Now, with all the stimulus money going around, his program officer at the foundation told Grace that one out of every two proposals is getting pushed through. Grace says that after he heard that he went to the faculty and told them to get writing.

In the meantime, Grace will work with his students at CIMR, catching things on fire, smashing them to bits, freezing them (when the environmental chamber is operational next year), basically building things just to break them up again. Sounds like a frat party, right? No, it's Lawrence Tech's civil engineering department improving our infrastructure.


Terry Parris Jr. is the utility infielder for Metromode and its sister publications 
Concentrate
and Model D. His previous feature for Metromode was "Under 30 And Involved".

Photos:

Dr. Nabil Grace at LTU's Center for Innovative Materials Research Lab

Pothole

Bridge Model Testing at Lawrence Tech

Dr. Grace inside of heat chamber with LTU student

Final result of Bridge Model Testing at Lawrence Tech

All photographs by Detroit Photographer Marvin Shaouni Marvin Shaouni is the Managing Photographer for Metromode & Model D.



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