Whitetopping--the process of placing a thin concrete overlay directly on deteriorated asphalt parking areas--was demonstrated to a Michigan audience in the recent restoration of a section of the media/press parking section at the Pontiac Silverdome. Members of the Michigan Concrete Association (MCA) joined with members of the Associated Concrete Contractors of Michigan to provide funds, materials, and labor for the project.

Two paving lanes of 3 1/2-inch unreinforced concrete--each 16 feet wide and 264 feet long--were placed on the existing 6-inch asphalt, showing state-of-the-art construction designed to carry anticipated truck traffic for the next 20 years.

All placing, finishing, and curing were done in accordance with MCA's "Suggested Specifications for Parking Area Construction." The concrete mix was designed for 4000-psi compressive strength at 28 days, with 6.5 percent air content and a maximum 4-inch slump, for consolidation by vibratory screed. Curing compound application followed closely after the finishers.