Pavement Preservation Journal, Spring, 2012
As shrinking state road budgets continue to favor pavement preservation techniques, an increasing number of states are choosing fine milling, or micro milling, to prepare asphalt pavements for surface treatments.
The cutter drum used for micro milling carries three to four times as many teeth as a conventional cutter, so the teeth are more closely spaced. The result is a finer surface texture on the pavement.
Micro milling is poised for rapid, nationwide growth over the next five years, said Jeff Rule Sr., of Roadtec Cutter Drums. Micro milling offers several advantages that conventional milling does not.
For one, a micro milled surface will not reflect upward into a thin overlay, as an aggressive, conventionally milled surface can do. For another benefit, micro milling is less expensive. The milling machine usually makes a shallow cut of 1 in. or less, so there is less recycled asphalt to haul away.
Rule says that states with specifications for micro milling include New York, Massachusetts, Rhode Island, Connecticut, Georgia, Alabama, Virginia, California, Indiana and South Carolina. “Tennessee is using micro milling now, and so is Georgia,” he said. “Alabama has a spec and has done some micro milling. Washington State is doing a lot of micro work.”