Micro Surfacing Controls Potholes

For the past few years, the Utah Department of Transportation (UDOT) was regularly patching and repairing a 9-mile section of I-80 that begins at the top of the Wasatch Mountain summit and extends to Salt Lake City. Although the open graded surface course (OGSC) that UDOT was using was designed to have very small voids so precipitation seeps through it and drains off the side of the road, this process did not work well in this area due to the frequent freeze-thaw cycles. Each winter, precipitation froze before getting the chance to drain and then created major potholes upon thawing. A microsurfacing treatment was tried as an alternative to the OGSC. Micro surfacing mixtures use four main ingredients, including a polymer-modified emulsion that produces a chemical reaction to force the moisture out and allows it to set in less than an hour. Although the microsurfacing treatment is usually laid over existing asphalt, in this project the treatment was put on top of a milled asphalt surface to provide a better bond. To ensure a smooth and long-lasting surface, the micro surfacing treatment was put down in two layers. The first layer was used as a scratch coat to smooth and level the milled road. The second coat was applied as the final driving finish to provide improved skid resistance and protection against the extreme weather conditions. The project presented many challenges, including restrictions on lane closures and the need to do all milling work at night. The close proximity of a watershed reservoir also meant that extra care had to be taken to prevent water contamination. In the first winter after application of the microsurfacing treatment, only seven potholes were observed in an area that had experienced over 700 potholes in each of the previous two years.

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  • English

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  • Accession Number: 01155377
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 21 2010 7:54AM