Drivers wearily tell the same joke every year. There are really just two seasons in Canada: winter and construction. As the first crocuses sprout, so does scaffolding on the nation’s bridges and interchanges. Lanes narrow. Delays proliferate. Tempers fray. Welcome to a spring, summer and fall of frustration.

As often as not, the culprit is concrete. Originally invented by the Romans, it’s immensely strong in what engineers call compression. In other words, it doesn’t crush easily, which makes it a great building material. But concrete in tension—stretched between two points—has only 10 percent of that strength. Put enough weight on the un-supported centre and concrete will break.

As early as the 1860s, engineers began addressing the problem by adding steel—which has a very high strength in tension—to concrete used in bridges and buildings. It’s a great solution, used to this day, but there’s a problem. When the concrete cracks—and it always does—water can get to the steel rods inside and rust them. And since rusted steel actually occupies more volume, the resulting force kicks the concrete apart from the inside. This causes more cracks, which… well, you get the idea. In the case of steel-reinforced concrete bridges, this internal battering means the structures will likely need to be “re-jacketed” every five to ten years. The external concrete must be jack hammered off down to the rusted steel, the steel cleaned or replaced, and a new layer of concrete applied. Result: expect delays.

Those delays could get shorter and less frequent, however, thanks to research by Dr. Amir Fam. Dr. Fam, a Canada Research Chair in civil engineering at Queen’s University, wants to break the re-jacketing cycle by removing steel from the equation altogether. Back in the early 90s, he began designing bridges that replaced traditional steel reinforcement with “tendons” of non-corroding carbon fibre and fibreglass. With no rust to wreak internal havoc, bridges built this way could last much longer before needing major maintenance.

Today, the technique is moving towards the mainstream, but Dr. Fam is continuing to think—quite literally—outside the box. Why not transfer all the reinforcement to the outside of bridge components by pouring concrete into forms made of the new materials and leaving them in place to provide the necessary structural strength? The forms—fabricated from ultra-tough fiberglass reinforced polymer—would serve the bonus function of repelling water. And there’s another advantage: the new approach lets builders avoid the costly and potentially hazardous work of removing traditional forms.

Dr. Fam’s leave-in-place technology is currently undergoing long-term assessment at a bridge site in Virginia. And it’s already in commercial use to create marine piles for industrial docks. How long until we see external forms on Canadian bridges and overpasses? Dr. Fam replies with a certain wry resignation familiar to many researchers. “In all honesty, the challenge is to get decision makers on board. We have to convince engineers who are used to more traditional methods—we have to convince them to try it.”

And when they do, construction season could get shorter. “No major maintenance for perhaps fifty years or more,” says Dr. Fam. “Isn’t that beautiful?”

Drivers everywhere can only agree.

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