Laborers learning the roller operator skill set should never learn in the breakdown phase of rolling. This first phase, when the roller is on the mat at its hottest, is crucial to effective compaction and attaining proper density so the breakdown phase should be the responsibility of an experienced roller operator.
Many contractors train their roller operators on compacting aggregate, giving them a feel for the roller and an opportunity to learn how it handles before moving over to asphalt. This is a good idea if you have that type of work available to you because the new operator can train without affecting the quality of the mat. (Rollers, however, should never be used on both aggregate and asphalt. Rollers used on stone end up with drums that are scratched and pitted and if the same roller is used on an asphalt mat the drum will leave those imperfections in the asphalt mat.)
If a gravel base is not available for training then roller operators should train on the finishing phase of rolling or possibly the intermediate phase. It takes as much as 18 months before a roller operator will learn what he needs to know and spends a lot of time on a variety of different jobs, to get to know how to handle the roller in all sorts of different jobs and mixes and conditions.
And if the roller operator wants to move on in the paving crew, the back-end operator or paver operator are the next logical steps.
The finishing touch
Compaction is the final accomplishment at the end of the day. Once the rest of the crew has done their jobs the roller operator takes all the lines out, makes sure the water drains properly, and rolls the joints as seamlessly as possible.
Then he needs to pull his roller off to the side, climb down and take a good look, making sure there are no stop marks, no lines, no joint marks, and that the finished asphalt mat looks like a black carpet.
If at the end of the day the roller operator walks around and knows that parking lot represents the best that he can do, that's what the contractor is going to get paid for.
John Ball is president of Top Quality Paving, P.O. Box 4398, Manchester, NH 03108. Reach him at firstname.lastname@example.org or attend his paving seminars and workshop at National Pavement Expo West, Dec. 3-5 in Las Vegas, or National Pavement Expo, Jan. 20-23, 2010 in Nashville, TN. For more information visit www.nationalpavementexpo.com.