Many people who work on asphalt paving crews learn their skills on the job. That can be good – if you learn at the hands of a master, or not so good – if you spend years unknowingly repeating the mistakes of the person who taught you. And if a supervisor or trainer teaches anything less than best practices to a whole crew over a long period of time, these small inefficiencies can add up to big productivity losses.
So what would be the value of teaching your crews the very latest and best practices and techniques for asphalt paving and compaction – learning these skills from some of the country’s top experts?
Paving machine manufacturers such as Ingersoll Rand recognize this need and conduct courses and seminars to help fill in this educational gap. I had the opportunity to attend one of Ingersoll Rand Road Institute’s three-day Paver and Compactor Operation and Maintenance classes in December to find out what a contractor might gain from sending his or her employees. The Paver and Compactor Operation and Maintenance class is one of a handful of courses that Ingersoll Rand offers. (For a list of similar courses, see the sidebar on right).
The military method
Our course was held in Phoenix, Arizona, and led by instructors Peter Fleming (pavers) and Wayne Tomlinson (compaction equipment.) Fleming is in his fourth decade of paving, having started with Blaw-Knox pavers in 1973 as a soldier working for the engineering corps of the British Army, and has worked as a paving consultant and troubleshooter all over world. Tomlinson, a U.S. Air Force veteran with 18 years experience at Ingersoll Rand, worked for eight years in the road development group as a compaction technology service rep and training specialist.
Our class totaled 14 students, including a group of county workers from Hawaii, two city paving crew members from Poway, California (north of San Diego), three instructors from the Michigan Laborers Training and Apprenticeship Institute and an Ingersoll Rand dealer salesman. A more typical class will have about 85 percent contractor personnel, Fleming says, but since this was late fall most contractors were busy finishing projects before winter set in.
Fleming made it clear from the outset that the class was not intended as a sales pitch for his company’s products. Fleming and Tomlinson quizzed each group on what brands of machines they used and then never failed to point out how the different brands of machines the students worked with differed in design and operation from these brands.
Fleming and Tomlinson use a military formula for conducting the classes, which boils down to: introduction, presentation and summary. Each section of material was presented first in the class room, and then reinforced outside with machine walk-arounds and practical exercises in paving and compaction.
In addition to the classroom and hands-on instruction, each student received a substantial package of printed material – a three-ring binder with hundreds of pages of detailed paver and compaction information, a smaller booklet on asphalt compaction, a pocket guide on the Blaw-Knox Blaw-Kontrol systems and a pocket guide of best practices. We also got two machine safety manuals and a slide-rule type calculator that lets you translate mat sizes into tons of asphalt, stone or dirt and determine the total cost and unit costs.
Day one commenced with introductions all around and then we quickly plunged into the heart of the matter: principles of paver operation and factors that affect screed performance. Since everyone in the class had some experience in paving, Fleming wasted no time in jumping into the critical details of how the tow-point angle and the screed’s angle of attack work together.
After about an hour of presentations and discussion we moved outside for a hands-on look at a paver and compactor, plus a discussion about the daily maintenance and walk-arounds. We also learned how to move the paver’s auger in and out around obstacles and how to do joint matching by eye using the edger plate. We finished up in the classroom with a presentation and discussion of the sensors that measure the head of material.
After lunch Tomlinson launched into compaction theory and best practices including a detailed look at Superpave principles and how Superpave mixes change how you compact asphalt lifts. He also talked about compaction patterns and emphasized that you always want to stop the roller at an angle to the mat. “You’d be surprised at how many people don’t know this,” Tomlinson said.
Day two began with a review of day one’s material, followed by machine walk-arounds and prepping the pavers and rollers for work. We then headed to the demo site for a hands-on paving experience. Rather than use asphalt, Fleming runs a mix of gravel and dirt through the Blaw-Knox PF-4410 paver used for all the demos. In addition to being less complicated and easier to clean up than asphalt, the gravel and dirt mix closely mimicked asphalt in the way it processed through the machine and responded to the screeds and the compactors.
On our first run of paving we learned how to control the screed and extensions to eliminate different mat faults and pave a level mat with manual controls. We also learned how to set up the material sensors ahead of the augers, a critical but often overlooked point. “Ninety percent of mat problems can be traced to head of material problems,” Fleming noted.
After paving a short stretch with the dirt and gravel mix, Tomlinson briefed us on the operation of the Ingersoll Rand DD-28HF compactor we were to use and then let us practice rolling patterns and joint compaction.
After lunch we paved another section to practice joint matching and learned more about material management at both ends of the tractor.
To close out the day, Fleming had us park the paver on a 4-foot-high ramp with the screed extended over the edge of the ramp and then showed us how to align the screed and its extensions – a view and a critical process that few in the class had ever experienced, and which made clear much of what had been discussed in class earlier.
Day three started in the classroom. Then we headed back out to see how to set up automatic grade and slope controls for the paver (contact and non-contact versions).
We paved one section with a string-line, one with a floating beam and another mat with the sonic controls guiding the screed and tow point height. We also set up the machine to lay these mats on a slope and learned how to set up and monitor the slope control equipment.
After lunch Fleming and Tomlinson took general questions from the students and then conducted a brief review of the last three days. After that came a test of 30 questions covering the basics. Most everybody scored 27 or more on the test, but by that time we’d heard all the important information repeated at least three times – testament to the usefulness of the military teaching model.
All of the students I talked to during the course said the three days gave them a huge leg up in learning how to pave better mats and improve efficiency. If ever a teacher had a captive audience, it was this one. The interest level was high, the questions were frequent and the intensity the students brought to the class was impressive. The general sense of things from the students was that they didn’t realize how much they didn’t know. Prior to the class many had been making the same mistakes or running into the same problems without being able to figure out solutions.
In heading up Poway’s program to pave all its streets, Tony Ulloa and Chris Arce had their hands full getting to know the IR/Blaw-Knox 3120 paver they had bought earlier in the year. “We will definitely be taking this information home with us and putting on some seminars for the rest of our crew,” says Ulloa. Arce mentioned that he learned a lot from the asphalt mix presentations. “I had been to a lot of seminars on this,” he says. “It’s just that none of them were as useful as this.”
The crew from the Michigan Laborers’ Training and Apprenticeship Institute had little paving experience to start with, but after a paving company donated a paver to the Institute, they signed up for the course so they could go back and give their apprentices in-depth training on these skills. “We had done some work with it,” says James Rubel, an instructor with MLTAI, “but we were learning the hard way, by trial and error, and there was still a lot we didn’t know.”
Meat on the bones
The knowledge and skill level of the students arriving at the Road Institute varies, Fleming says. “They have a skeleton of an idea of how to lay asphalt. We see it as our job to put meat on the bones of that skeleton. The students will, on return to work, have the knowledge and confidence they need to check their paver over and set up their screed correctly prior to starting work and to install the automatic grade and slope controls that have been sitting idle for such a long time.”
On the compaction side, Tomlinson says a comment he frequently hears is “I didn’t realize how difficult the roller operator’s job was; it’s not just going forward and backward.” At the completion of the course the student will understand the proper set up of the compactor (amplitude and frequency) for each particular jobsite and conditions and be able to perform rolling patterns consistently, he says. Students also learn that, despite what the supervisor may say, it can be a bad idea to try to “catch up to the paver” if they can’t achieve the proper impacts per foot. And finally, students get a sense of how important mat temperature is in achieving density and smoothness, he says.
Training to pave
The Ingersoll Rand Road Institute offers a variety of courses in the operation and maintenance of paving equipment. There are also special focus classes on paver systems and screeds, hydraulic and electrical systems, grade and slope control systems, Titan pavers, specialty paving products, basic, intermediate and advanced mechanics courses for asphalt and soil compactors, mobile hydraulic and electrical system fundamentals and a “train the trainer” seminar. Courses run in length from two to five days and are held in Chambersburg, Pennsylvania or Phoenix, Arizona. For prices and schedules visit the website.
- Roadtec’s training includes a two- day Paving Professionals Workshop and three Technical Service Schools programs (also two day) covering material transfer vehicles, pavers and cold planers. Visit this site.
- Terex’s Roadbuilding University offers a broad range of courses in asphalt and concrete pavers, material plants and related equipment ranging from two to four days in length. See this site.
- Wirtgen offers a number of service training classes on basic maintenance and repair of its equipment plus a class on foamed asphalt technology at no charge to qualified attendees. Contact program administrator Sandy Draper at (615) 501-0691.
- Other asphalt paving manufacturers offer individualized training for customers. For more information check with your local dealer.