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Crews removing slabs of deteriorated pavement
from I-84 east of Boise

A massive 24-mile resurfacing and surface-treatment project began on I-84 east of Mountain Home early this month. The portion of work now under way involves crack sealing and slab replacement; but in the next few weeks, work will transition into a unique process.

Beginning late this month, crews will apply a methacrylate product to the pavement surface to help slow deterioration that eventually can lead to premature pavement failure because of ASR (Alkali Silica Reaction).

ASR is a process in which the aggregate reacts with the cement to form an expansive gel that breaks apart the concrete. Water accelerates the process. Although ITD has not used the process on a highway before, methacrylate has been used on Idaho’s bridges in the past to reduce corrosion and premature failure that is common when water is allowed to penetrate the surface and reach the rebar foundations.

ITD also is replacing sections of I-84 that are badly deteriorated. But it’s not your normal pothole repair. Crews cut and remove large slabs of the highway surface and pour new sections to extend the life of the highway.

Each of the slabs is approximately 18.4 tons, 13.5 feet wide, 15 feet long and 15 inches deep. They are lifted and removed with a heavy equipment.

Photos: Crews are removing slabs of deteriorated Interstate 84 as part of a project to replace deteriorated sections. Methacrylate coating also is being used to halt the corrosion before deterioration requires more drastic measures.