Why do roads buckle in the summer heat?

YOUNGSTOWN, Ohio (WKBN) – Potholes frustrate drivers in the winter, but warm summer temperatures can cause another nuisance on the road.

The summer heat put a big bump in Youngstown Poland Road on Tuesday and impressed the neighbors.

“We started walking down the street, all of a sudden, it was there. It was like somebody set off a bomb underneath it. That’s how it looked, it buckled up that much,” Jeff Hartman said.

Physics explains how the 90-degree weather caused the warping in the road. The pavement is black, meaning it naturally gets hotter. Mahoning County Engineer Pat Ginnetti says heat causes materials to expand.

“You know, if you have a concrete road underneath asphalt, when the concrete slabs expand beyond their joints, they’re going to push and heave. Either at the joint or the weakest point.”

The older and drier a road gets, the more voids are created to trap gases that could pop the pavement.

“Depends on what’s underneath it. Concrete, certain types of gravel and slags are expansive. There’s gases within those voids that will expand that could cause that,” Ginnetti said.

An old brick road was beneath the pavement on Youngstown Poland Road.

Sealing a road may add moisture to allow expansion, which is one benefit of asphalt.

“Obviously, it’s rigid when you drive over it, but it’s going to expand and contract more forgivingly than concrete,” Ginnetti said.

Whether the road is concrete or asphalt, there’s no way to predict when it could buckle. Ginnetti says he is keeping his eye on certain roads and watching for bumps or cracks that pop up.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s