Crack & Seat

Overview
The purpose of cracking and seating concrete pavement prior to overlaying it is to minimize the occurrence and severity of reflection cracks in the overlay caused by slab action. This is done by cracking the concrete slabs to reduce their effective length and then seating the cracked slabs to reestablish subgrade support. It is either opened to traffic after cracking to accomplish seating, or a proof roller can be used.

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Benefits
Reflective cracking is caused by movement or faults in the concrete slab construction beneath that is reflected through the asphalt overlay. This can be caused by voids in the subbase, thermal expansion/contraction, rocking road slabs, or overload of the rigid pavement. Cracking and seating creates a flexible base underneath the new HMA surface, which reflective cracking minimizes.

After Cracking

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After Overlay

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More Information

Iowa State University – Rehabilitation of Concrete Pavements Using Crack & Seat