A good paving job will have a smooth, dense appearance that looks flat and tight, without any gaps between the aggregates at the surface. Yet, that appearance doesn't just happen. There are a lot of factors that affect mat quality.
The paver operator, the paving mix, even the distance from the asphalt plant to the jobsite all play a role in achieving optimum mat density. But the last person to touch the pavement is the roller operator. He/she is the one who has the greatest influence on smoothness.
"Over the years, operator performance has become more and more critical to the bottom-line success of most any paving job," says Todd Mansell, technical marketing manager, Sakai America. "With job profits based in part on bonuses and penalties in many jurisdictions, the operator must be able to adapt to different jobsite conditions by using all of the features offered on an asphalt roller."
Train for optimal performance
Most roller manufacturers, in conjunction with their dealers, offer training for end users of their equipment. That training is available in a variety of forms, including group seminars, hands-on courses or one-on-one training on the jobsite or at the manufacturer's training grounds.
Training gives operators the knowledge to overcome some of the hurdles that can crop up on a project, such as difficult weather conditions, clumpy mixes, extremely thick or thin lifts, joining of hot and cold lanes, etc. "The ability for an operator to successfully adapt his/her rolling pattern to successfully compact mixes such as Superpave, FAA and the ever-increasing variety of mix designs is arguably the greatest training challenge that must be met in order to maintain quality and productivity," says Mansell.
According to Wayne Tomlinson, training specialist, Volvo Road Institute, operators often retake courses offered through the Institute, in part to get hands-on training, as well as to get the latest information about what's happening in the industry. "During the three-day training, attendees will actually lay a mat and practice rolling patterns," he points out. "We have a lot of guys who keep coming back year after year."
"While the basics of paving haven't really changed, there can be some changes when new technology and machines are introduced," says Bill Nittinger, Northeast regional manager, Dynapac.
"Operators can learn how to use the machine the right way to give them the best results. It's good to keep the information in front of operators. A lot of it may seem basic, but the rules aren't always followed."
Compaction technology continues to evolve as manufacturers introduce new features to simplify operation. For example, Dynapac units offer soft stop and start features. And Sakai's ExactCompact monitors impact spacing, while Intelligent Compaction plots roller laps.
"[Such features] are a great help to the busy roller operator, allowing him to focus on the job at hand and make changes if necessary by using real-time information," says Mansell.
But operators need to be trained on how to use such features in order to achieve maximum benefit. "A lot of people may not understand that the operator is just as important as the machine," says Nittinger. "You can have the best machine in the world, but if the operator isn't running it at the right settings, the right speed, etc., it can affect the quality of the mat, and that quality is important to the life of the road. The better the operator, the better the machine, the better the performance and the longer the life of the road."
Operator training helps to minimize some of the most common mistakes when operating a roller - mistakes that can result in corrugated or "washboard" roads with dips, divots and indentations that compromise mat quality and road life.
"A good roller operator understands the process and what his/her job is within that process," says Bruce Monical, marketing manager, Hamm Compaction Division. "He/she can make or break the contractor's ability to achieve final payout. A good operator can help you; a poorly trained operator can hurt you."