If you have never been to Lynchburg, it's worth the trip. Located about 70 miles southeast of Nashville in beautiful rural Tennessee, the city features a historic town square with lots of shopping, eating, and friendly visiting opportunities. Lynchburg also happens to be home to the worldrenowned Jack Daniel's Distillery.
The distillery is the main attraction for most folks who visit Lynchburg. Dating back to 1866, it is the oldest registered distillery in the U.S., and is surrounded by a rich history of stories and legends, all intermingled with the distinctive taste of Tennessee whiskey.
The Jack Daniel's campus includes three separate tracts of land in and around Lynchburg, consisting of about 1600 acres. Much of this space is devoted to warehouses where the world-famous whiskey is stored and aged about four years until it is deemed ready to sell by the master tasters who sample the product before it is bottled and distributed.
Those warehouses see a steady flow of barrels coming in for aging and going out for bottling. This results in a lot of truck traffic and infrastructure that must be built and then maintained for coming decades of production. That's where concrete enters this story.
Making the switch
Jack Daniel's has always used asphalt paving for the roads leading to and adjacent to its warehouses. The company has spent money every year, typically in the spring, to maintain these surfaces by repairing potholes, patching, and overlaying. In some heavy traffic areas, concrete has replaced asphalt pavement that was quickly failing under such service conditions.
So when contractor Lee Adcock Construction suggested Jack Daniel's might consider roller compacted concrete (RCC) as an alternative to asphalt at a new warehouse, Jim Jeffries and Bill Spraggins from Jack Daniel's engineering and maintenance departments were open to learning more about it.
Adcock had done a lot of work for Jack Daniel's over the years, including constructing several warehouses.
Adcock was familiar with RCC thanks to the sales team at Irving Materials Inc. (IMI) and local representative, Mark Deason. Adcock had taken the initiative to learn more about the product on his own and felt that RCC would bring some important advantages to his client. Perhaps most importantly, he knew that RCC could be competitive on a first-cost basis with the competing material.
Before committing to using RCC, Jeffries and Spraggins wanted to do some research, so they turned to many concrete industry professionals. Alexander, Mark Niemuth, and Tim Langelier of Lafarge and Frank Lennox of Buzzi-Unicem provided background and technical information to the Jack Daniel's engineers, along with assistance on the structural design for the RCC option.
The team also arranged a tour of several RCC projects in Tennessee, including RCC pavement at the new Volkswagen plant near Chattanooga, an industrial manufacturing facility, and RCC pavement that had been installed at one of IMI's plants which has been subject to very heavy truck traffic for several years.
The right price
As it learned more about RCC, the Jack Daniel's team felt it would be ideal for this application and that using RCC for their pavements would dramatically reduce future maintenance costs. The initial bid for the RCC, provided by Robert Smith Contracting, Chattanooga, Tenn., was essentially equal to what Jack Daniel's had been paying for asphalt pavement. Even though the asphalt contractor reduced its price after learning that RCC was being considered, the Jack Daniel's team was convinced that RCC remained its best option and choose concrete.
Jack Daniel's decision to use RCC fit perfectly with a strong commitment to sustainable operations held by corporate owner, the Brown-Forman Corp. Using RCC would not require an imported foreign product such as asphalt.
The material also provides other environmental benefits, including cleaner stormwater runoff and better nighttime visibility, in addition to reduced maintenance costs.
With the decision made to use RCC, the team moved forward to the construction phase. The RCC section would be 5 inches thick on top of 6 inches of a compacted dense graded aggregate (DGA) base. This replaced the typical asphalt section of 6 inches of compacted DGA, 3 inches of asphalt binder, and 2 inches of asphalt finish course. IMI supplied 2537 cubic yards of concrete over five days.
Also of note on this project was IMI's ability to convert its local dry-batch concrete plant for RCC production through the use of a portable twin-shaft mixer developed by Stephens Manufacturing for exactly this type of application.
It took only four hours to "plug in" the twin-shaft unit to use the existing plant's batching and scale equipment. The twin-shaft unit was fed by the existing plant and then was able to load the RCC mix directly into dump trucks for hauling to Robert Smith Contracting's high-density paver at the Jack Daniel's campus jobsite.
One additional bonus from the twin-shaft mixer conversion was that it increased the plant's output from about 60 cubic yards per hour to almost 100 cubic yards per hour.
The total amount of concrete delivered to the jobsite was within 1 percent of the estimated quantity, a testament to both Robert Smith's and IMI's quality control throughout the production phase.
The completed warehouse has been in service for about six months and is already about half full of those special oak barrels. Now RCC has a small role in producing that unique treasure known as Jack Daniel's Tennessee whiskey.
Tonya Alexander is the sales manager for Irving Materials Inc. in Nashville, Tenn. E-mail email@example.com. Visit www.irvmat.com for more on the producer.
Alan Sparkman, executive director of the Tennessee Concrete Association, also contributed to this article.