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Virginia Department of Transportation workers take samples of the non-portland cement-based concrete for strength testing.
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Workers stand on the newly placed concrete only 30 minutes after they made the repairs.

There was a two-hour delay between the first and second slab replacements, as the second site required further preparation. The second repair site was 12x30 feet by 9 inches deep, requiring about 10 yards of concrete. Two mobile volumetric mix trucks arrived at 2 p.m. The gate settings were checked and the first truck was positioned for discharge. Ambient air temperature was 84° F with ground temperature near 94° F.

The temperature of the concrete off the shoot was 81° F. Crews consolidated the material with a 1-inch flex shaft vibrator and hand-screeded with a 2x4. The film was again sprayed onto the surface to assist in temperature control and finishing. The crew placed the first load of 7.5 yards in 18 minutes. The second truck was then positioned and another 2.5 yards were placed and finished. It took 39 minutes to place and finish the repair site.

Department of Transportation lab personnel took 2-inch cube samples, four autoclave bars, four slant shears, and two 4x8 cylinders for strength analysis.

Both slab replacements were reopened to traffic by the start of the evening commute, just hours after placement, alleviating traffic on this busy stretch of highway, not to mention commuter frustration as motorists hurried home to catch that movie.

Leo Kahl is vice president of marketing, and Doug Clasen is senior field engineeer at Ceratech. For more information, visit Ceratech atwww.ceratechinc.com.