Buckled roadway surprises motorists east of Hastings
A concrete slab on the north side of westbound M-43 in Hastings buckled so badly July 3, some surprised motorists found themselves airborne – and coming down pretty hard. (Photo by Tanett Hodge)
If the road rises up to meet you, watch out.
A semi-truck nearly overturned on a patch of buckled concrete on the north side of westbound M-43 in Hastings July 3.
After hitting this concrete, which resembled a ramp. of sorts, traveling at speeds of 50 mph, some vehicles became airborne – and then came down hard. Some of them hit the ground on one wheel.
The problem patch was quickly fixed, but not before a dozen or more motorists were unpleasantly surprised by it.
Why does concrete buckle?
Blame hot temperatures.
Barry County Road Commission Managing Director Brad Lamberg said these concrete slabs expand. Every material does. And, typically, there are joints between the rigid slabs – usually some sort of soft, springy rubber. But the soft joints can wear away or come out and, if they do, the void that's left will fill with sand and stones and other hard materials that don't easily accommodate the expansion of concrete.
With the heat of that day, those concrete slabs were all expanding, he said. Clearly, there was one joint that was the weakest.
“It's under the highest stress and it just finally pops,” Lamberg said.
To be technical about it, it's not just the heat, it's also because of what Lamberg called “the thermal expansion coefficient” of concrete.
Asphalt is much more flexible, he said.
But that's a whole other story.