Lives of Mill-and-inlay Rehabilitation Strategies

The Kansas Department of Transportation and the Kansas Turnpike Authority routinely mill the surfaces of some asphalt concrete (AC) pavements before inlaying as part of the substantial maintenance program. In selecting this strategy, no "life" is assigned due to a lack of methodologies to estimate lives of such strategies. In this paper, the functional and structural lives of mill-and-inlay strategies were analyzed for seven different routes using Falling Weight Deflectometer test data and fatigue tests on AC beams sawn from the test sections. The results show that the "life" of a mill-and-inlay strategy is mostly controlled by serviceability. For high traffic pavements, an optimal mill-and-inlay depth based on fatigue can be found. Cost-effectiveness of this strategy is higher for pavements with high traffic volumes. The strategy did not appear to be susceptible to rutting nor did it appear to cause any damage to the existing pavement layers.