Finding the Right Compaction Solution

Road construction can be a very profitable endeavor, provided jobs are completed properly and deadlines are met. But there's little or no margin for error. The strictest standards must be met. With so much on the line, it's no wonder that a growing number of roadbuilding contractors are turning to "intelligent" rollers that take the potential guesswork out of the asphalt compaction process.

One company that has embraced the technology is JoB Construction, a Poteau, OK-based asphalt contractor with a project territory that covers Oklahoma and Arkansas. Not unlike the decisions made by most businesses, JoB's choice to purchase an Intelligent Compaction roller wasn't made on a whim. It came because of a bad experience that the company was not eager to repeat.

Although JoB does its fair share of commercial work, the company's primary expertise is producing and paving asphalt on federal and state highways. "When we get to a job, the groundwork has already been completed," says Billy Hoffman, vice president of JoB Construction. "We're focused on the asphalt portion of a project."

Larger contractors that cover every phase of road construction — from excavation to paving — have the advantage of controlling an entire project from beginning to end. Any mistakes that the company should happen to make are its own. This doesn't make the reality of a penalty from the DOT any more pleasant, just slightly easier to swallow.

Lesson learned

For contractors like JoB that handle only one aspect of a construction operation, similar problems can be downright maddening if the error occurred prior to arrival on site and nothing could have been done to avoid failure. It was this type of scenario that JoB was looking to avoid with its investment in a BOMAG BW190AD-4 AM tandem-drum vibratory roller, a machine that the company now utilizes not only for asphalt compaction, but also to test the integrity of the base material already in place prior to paving.

JoB and its 45 employees have certainly found a comfortable niche with asphalt work. But there have been occasions where things haven't gone so smoothly. One such incident occurred during construction on a portion of U.S. Highway 270 near Mena, AR, a project that the company is finally bringing to a close after being sidetracked by a penalty that arose from complications JoB was powerless to control.

"We were helping to reconstruct the shoulders on the highway," says Hoffman. "It was an old road with tons of potholes, so we patched the holes as required by the state, and then laid a leveling course over it for traffic to travel on while we were building the shoulders. A short while later the subgrade fell under in one spot and caused our pavement to fail, and unfortunately we got stuck with the penalty."

In business for nearly 40 years, JoB wasn't about to let one setback get in the way of future business. The company also wasn't going to sit around and simply hope that the same thing wouldn't happen again. Instead, JoB went in search of a solution to prevent similar issues from ever occurring in the first place.

"The base that you're laying asphalt on is going to vary as you move down the road," says Hoffman. "The density may be 92 percent in one spot and 98 in another, and it can be difficult to obtain reliable readings over the course of a project. So we looked at different ways we could go about solving this issue."

JoB's equipment fleet consisted of four Cedarapids asphalt pavers and five Dynapac rollers before Hoffman made the decision to bring in the BW190AD-4 AM roller with the Intelligent Compaction system. "I read an article about Intelligent Compaction and it seemed to be exactly what we were looking for," says Hoffman.

The solution

The new roller is equipped with BOMAG's exclusive Asphalt Manager, a control system that measures the stiffness of the material being compacted by monitoring the reaction between the material being compacted and the resultant deflection of the roller's drum.