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On the football field, John Madden coached his team to Super Bowl success. In the new video, Smoother Roads Playbook, he introduces viewers to the Kansas Department of Transportation's (DOT) successful strategy for achieving smoother concrete pavements. Since implementing new smoothness specifications for concrete pavements 15 years ago, Kansas has gained national recognition for its innovative techniques and construction practices. The introduction of the pavement smoothness specification "was the single most important impact on concrete paving that I've seen in my career," says Mike Lackey, former State Transportation Engineer for Kansas DOT.
As explained by the video, which was jointly produced by Kansas DOT and the Federal Highway Administration (FHWA), smoothness has been promoted in Kansas not only by the new specifications but through an incentives program that compensates contractors for their extra efforts. This program and the smoothness specification in general have been well received by contractors. "The very fact that Kansas DOT has the smoothness incentive specification has raised the standard of paving in the State of Kansas, without a doubt," says Don Beuerlein, president of Koss Construction.
How have the DOT and contractors achieved these smoother pavements? The best practices advocated by Kansas and addressed in the video include making sure that the stringline, which is the primary guidance system for most paving equipment, is set precisely and protected from damage during paving. It should also be checked for proper grade and elevation before each paving operation. As the video noted, "the stringline has the greatest potential to affect smoothness." Another best practice is to maintain a consistent paving speed and avoid stopping or slowing the paver. To do this, contractors have to make sure they have an adequate supply of concrete delivered to paving sites and that delivery vehicles can move quickly and easily through a site and then back to the concrete plant. Contractors also strive for mix consistency and constantly monitor the concrete buildup in front of the paver to make sure that it doesn't get too high or low, as this can cause the concrete to swell or, conversely, a low spot to appear, resulting in a rougher pavement.
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