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  • Jul
    30

    Chip seals extend life of county roads

    Posted by: Public Works

    ​"We're, as a society, heavily invested in these roads," Don Newell says of the 1,118 miles of roadway for which Marion County is responsible.

    Newell manages the Operations Division for the county's Public Works Department, including overseeing the road maintenance conducted by county crews. The Engineering Division, headed by County Engineer Cindy Schmitt, handles larger road and bridge projects, which are contracted to private companies.

    "A non-maintained road is more than two-and-a-half times more costly over the lifecycle," Newell says. "The chip seal is the greatest tool for our road maintenance in Marion County." And so, a carefully choreographed dance is taking place this summer on selected roads in North Marion County.

    As flaggers direct traffic, a tanker sprays oil on a county road designated for chip sealing. Following closely behind, a chip spreader drops rock chips – washed gravel, up to three-eighths of an inch in size but half-inch on some roads.

    A gravel-filled dump truck has been backed up and attached to the chip spreader, which pulls the truck along as it replenishes the gravel in the spreader. Meanwhile, an operator moves the chip spreader's wings in and out, so as not to hit a rural mailbox.

    When one dump truck is empty, it pulls away and another – from the line of waiting dump trucks driving slowly in reverse – seamlessly takes its place.

    County employees armed with brooms sweep away excess gravel and fill low spots, as roller vehicles compact the chips into the oil. Later, a sweeper machine will brush any loose gravel onto the road's gravel shoulder.

    A layer of diluted oil, called a fog seal, will seal the chips and substantially reduce the chance of rocks hitting a windshield. A county paint crew will repaint the road lines.

    This chip-sealing process will extend a road's life by seven to nine years, while costing about $2 per square yard compared with $15 for asphalt overlay, according to Newell.

    Road maintenance is a combination of daily decision-making and long-term planning. Chip sealing requires a dry surface. The fresh asphalt oil is trucked from Madras, so a decision must be made by 3 a.m. each day whether rain will prevent working.

    The roads being sealed are selected five years in advance, so faulty culverts and other problems can be fixed first. Marion County keeps precise records of road conditions, determining where chip sealing will be most cost-effective.

    "We're engaged," Newell says. "We're engaged in a big way representing these roads and what the best product is we can put on them."

    A detailed map shows the 63.4 miles where chip seal will be applied this summer. Last year, the chip-seal workers were in central and east county. Next summer, they will be in east county again and up the Santiam Canyon, and in south county in 2020.

    The crew comprises a couple dozen workers or more, including dump truck drivers, flaggers, pilot-car drivers, sweepers, and heavy-equipment operators.

    Although temporary employees are added for the summer maintenance season, many are longtime county employees. Kendra Skinner, who recently was flagging drivers at Schultz and Arndt roads NE, started as a flagger while in high school. Working with motorists, she says, "We're not trying to inconvenience them. We're really not. We're trying to get them out as fast as possible."

    Depending on road width and other factors, a one-lane mile of chip seal can be completed in as little as 30 minutes while using roughly 10 dump trucks of rock and 5,000 gallons of oil.

    "We take pride in our chip seals. We have very, very few failures," says Pete Delapp, a county road operations supervisor.

    Delapp says that working for the county has been gratifying and eye opening. He understands the hard work that goes into keeping roads safe and well maintained for those traveling throughout Marion County.  

    Visit http://www.co.marion.or.us/PW/Engineering/Projects/Pages/ChipSeal2018.aspx for a full list of Marion County roads that are scheduled for chip sealing during the 2018 construction season.  ​

    Chip seals extend life of county roads
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