Watch out for buckling roads

With temperatures above 100 degrees in Mid-Missouri, the Missouri Highway Department Central District has asked motorists to watch for pavement "blow-ups."

The condition is created when extreme heat causes a pavement failure, usually at a joint of the pavement where a crack appears, allowing moisture to seep under the pavement. The crack weakens the pavement and excessive heat may cause the pavement to buckle and warp.

High-speed heavy truck traffic results in warped or broken pieces pavement on the roadway. It may result in a raised ridge, creating a bump or even dangerous broken pieces of pavement.

Purdue University research showed blow-ups are caused mainly by an increase in moisture and its accompanying expansion combined with the normal thermal expansion of the concrete.

Asphalt roads or streets usually are not affected.

"It's difficult to know when or where a pavement blow-up will occur when it gets this hot outside," said Central District Maintenance Engineer Mark Giessinger of the Missouri Department of Transportation (MoDOT).

"If anyone encounters a blow-up," Giessinger said, "use extra caution, slow down and give us a call to let us know where the problem is so we can get out there and take care of it."

Giessinger said the MoDOT crews are monitoring state routes for potential blow-ups and will make repairs as soon as they occur.