Section of Highway 402 reopens after pavement buckled. How does extreme heat cause it?
Westbound lanes in a portion of Lambton County were closed since Sunday night
The westbound lanes of a section of Highway 402 in Lambton County have reopened after extreme heat buckled the pavement on Sunday. The temperature exceeded 30 C, minus the humidity, that day.
Ontario's Ministry of Transportation, which oversees the highway, said a pavement joint needed to be fixed.
The closure was between Oil Heritage Road and Mandaumin Road.
Pavement in a westbound curbside lane of County Road 22 in Lakeshore, west of Wallace Line, also needed repairs after it buckled, according to the County of Essex. A spokesperson for the county said that that while the damage occurred during the heat wave, they couldn't definitively say the high temperatures were the cause.
The road has since reopened.
Rigid material basically has nowhere to go, so it will buckle.- Mark Winterton, infrastructure engineer
Mark Winterton is an infrastructure engineer and now retired from the City of Windsor.
He said it's not uncommon to see incidents like this in our area this time of year when it really heats up.
"When concrete is poured, they put saw cuts into the concrete to allow for expansion. However, when it's extended periods of hot weather, the concrete will continue to expand, and that's because it's a rigid pavement … rigid material basically has nowhere to go, so it will buckle," Winterton told Afternoon Drive host Josiah Sinanan.
Winterton said that if concrete is poured in colder weather, roads become even more susceptible to cracking.
"Sometimes the expansion joints [are] filled with material — you know rocks and things — and sometimes … those joints don't function the way they're supposed to."
According to Winterton, buckling happens a lot on sidewalks and middle medians, but not as much on large concrete slabs.
"It's not beyond the realm of possibility, and certainly it can cause some safety hazards when it does happen."
When road concrete heats up, he said, either two slabs can come up, "tent up," or one can heave upward.
"You could get a sharp edge ... where you're hitting a bump that can go up several inches and that could cause the tires to blow out — or other safety hazards like that. It could be a fairly significant safety concern."
LISTEN | Infrastructure engineer talks about how heat can impact concrete:
Winterton said concrete is an excellent road material, particularly for heavy vehicles like trucks with lots of stopping and starting.
For lower-volume residential roads, crews normally use flexible pavement and asphalt pavement. Extreme heat can have negative effects there too, he said, making the surface prone to tire rutting.
"Where the tire path is, it will push the asphalt out on both sides. You'll have like a wavy surface … so that can be unsafe too … you could lose control if it's wet … cause skidding … it could freeze and cause slippery surfaces and, and hazardous surfaces that way."