Two roller-compacted concrete (RCC) paving projects in Tennessee reveal that an asphalt construction alternative doesn't automatically win the initial cost battle. On both projects, state officials were shown at the bid opening that RCC was the lower-cost alternative for initial construction.

For years, cement promotion groups have been touting RCC as a legitimate alternative to asphalt. The acceptance of RCC by DOT specifiers will soon convince more paving contractors to adopt this technique for private and commercial projects.

On Oct. 3, 1998, the Tennessee DOT (TnDOT) used approximately 270 cubic yards of RCC to build a 600-foot-long by 12-foot-wide lane on State Route 27 at the Signal Mountain Cement production facility in Chattanooga. The 2-, 3-, and 27-day compressive strength results were favorable.

Using this same design and placement method, TnDOT had an RCC access road paved at the Lookout Valley Industrial Park, also located in Chattanooga. This project started on a Saturday morning in March, and the road was opened to traffic the following afternoon. A detailed cost study confirmed that RCC was the lower-cost alternative. At the Savannah-Hardin County Industrial Park in Savannah, Tenn., TnDOT experimented with 3/4-inch monofilament polypropylene fibers and ran ASTM C 666 on an RCC pavement to determine whether there was any difference in the freeze/thaw resistance of RCC with and without fibers. There was a major difference, indicating that these fibers' prevention of early shrinkage cracking may help mitigate water infiltration into the concrete matrix and add freeze/thaw resistance to RCC.

The article includes a history of RCC and information about construction of the tallest RCC dam in the United States.