Sealcoat

The City of Lake Mills has traditionally maintained its 34 miles of serviceable asphalt pavements by crack sealing, resurfacing, and reconstruction. With this program a street’s useful life was 25-30 yrs. Then the price for resurfacing skyrocketed—up nearly 400% since 1998. Now the budget can only pay for half mile of resurfacing a year, or about 15 miles in 30 yrs.
An aggressive program of sealcoating on streets could almost double the useful life of a pavement. Public acceptance is essential, making it important to address problems of dust, possible bike or roller blade crashes, pedestrian tracking, and loose aggregate on the street and potentially getting into storm sewers.
Key elements used to deal with these concerns include:
1. Determining whether to specify black boiler slag
2. sweeping twice
3. protecting inlets
4. providing plenty of public information
5. careful scheduling
The sealcoating process is completed in five basic steps:
The first step is to make spot repairs to the existing asphalt surface and fill major cracks with a hot, rubberized crack fill material. The larger cracks must be filled because the viscosity and application rate of the chip seal petroleum will not fill the void of a larger crack.
The second step is to spray the liquid asphaltic cement onto the prepared street. The asphalt is applied at a rate of 0.25 to 0.40 gallons per square yard. The purpose of the liquid asphalt application is to seal the entire surface of the street and all remaining cracks. The asphalt also provides the binding material for the aggregate.
The third step is to apply the cover aggregate using a chip spreader. The used both a black boiler slag and a standard pea gravel. The black slag, 100% passing the 3⁄8” sieve, is a finer aggregate and it doesn’t seem to hold as much dust. Being black, it looks better and is easier to stripe. The blacker color allows for more heat absorption in the winter, requiring less salt. The pea gravel is
cheaper and adds more depth to the surface for longer protection. It is very important not to drive on the asphaltic cement prior to adding the aggregate. The asphaltic cement will stick to your tires and spray on to your car, it will also track into the driveway, curbs and garage floors.
The fourth step is to roll the cover aggregate into the asphaltic cement as soon as possible after it is applied. The rolling seats the aggregate without crushing it. There will be some loose aggregate on the roadway after it is rolled.
The fifth step is to sweep the excess aggregate from the street after traffic has driven on the street for several days. With boiler slag, a second sweeping is required after weveral weeks of being open to traffic.
Worry about negative reactions from politicos and residents keeps many public works departments from proposing chip seals on improved local streets. But we have reconsider because the economics are very convincing.
On August 30, 2012 we received quotes to sealcoat streets based on our street maintenance priority list. We received one quote from the Jefferson County Highway Department. I was informed on August 27 by Jeff Hollenberger, sales representative for Fahrner Asphalt Sealers, they would not be submitting a quote.
Jefferson County submitted a quote for chip seal of $1.40 per square yard, and $1.65 per square yard for slag seal. We requested quotes on both seal coating processes because we believe use of the chip seal process in non-residential areas will be more economical.
We accepted the bid from Jefferson County Highway Department to provide seal coating services at a cost of $25,281.05. Funding for this project to come from the Street Maintenance and use of County road funds.