Better Roads Digital Magazine
Issue link: https://read.dmtmag.com/i/85910
HighwayContractor hey are often the forgotten ones . . . until, of course, they're nowhere to be found when the paving crew needs more mix. Then, everybody from the superintendent in the fancy pickup right down to the rake jockey behind the screed is screaming about them. They are the truck drivers – admittedly for many paving contractors the most misunder- stood and frustrating "contributors" to the pav- ing job. Normally, we'd refer to everyone who plays a role as "members" of the team – but often those truckers aren't even that officially. A good number of road builders job out their trucking needs to subcontractors, often inde- pendent owner-operators in essence competing with the truck in front or behind them in line ahead of the paving train. What's a poor driver to do T 1. Load the truck using at least three drops. 2. Cover the load as required to maintain mix temperature and reduce emissions during transport. 3. Drive safely to the paving site. Avoid delays. Move into position ahead of the paving train. 4. Prepare to "break the load" and unload the mix. 5. Back the truck into position and align it with the material transfer vehicle, paver or wind- row. Be sure not to bump into push rollers. Even paving equipment experts – usually fo- cused on either the plant or the jobsite end of the equation – have historically tended to skip over the hauling part that links the two ends. Fortunately, that is changing. The very first page of text in Volvo Construc- tion Equipment's Paving and Compaction Guide, Best Practices, is devoted to Truck Driver Responsibilities. Primarily, these are to properly load the truck at the plant and to maintain consistent delivery of the hot mix – in a homogenous mass avoiding segregation – to the material transfer vehicle, paver or windrow at the jobsite. Says Volvo, the Best Practices for doing so: "If we're going to get serious about material tempera- ture differential and material segregation, we're going to have variable-pitch, counter-rotating augers in our paver hoppers. Instead of just conveying material to the back, you're actually pulling from the full length of the hopper and getting a very aggressive re-blending process, in- stead of just transferring. It'll just eat those cold clumps up," he says. "When you've got the long hauls and the cold ambient days, if you have augers it'll just take all those cold clumps away and you'll have a nice uniform mix materially and temperature that you can still put down." It's an evolution, points out Sunkenberg. "Windrow 6. As the paver or material transfer vehicle moves forward and makes contact with the truck or trailer tires, open the tailgate and discharge the mix. Follow instructions from the dump person, paver operator or material transfer vehicle operator. When discharging into a windrow, follow instructions from the dump person. 7. After discharging the mix, pull away from the material transfer vehicle, paver or windrow. 8. Move to the assigned cleanout are to re- move mix residue from the truck bed or tail- gate. 9. Return to the plant for the next load of hot mix. It's a simple process indeed, but one clearly fraught with challenges along the way. And, by stating the process clearly, the recognition of the important role truck drivers play in the pav- ing operation is an appropriate way to head off those challenges . . . before everyone starts yelling! paving in a lot of ways is the original material transfer vehicle, on just such a smaller scale," he says. Having a surge of material – in the case of windrow paving already on the roadway – allows the crew to avoid paver stops, running at a consistent 30 feet per minute all day long if desired. Where cooler temperatures or severe weather is an issue, a material transfer vehicle answers the need by placing a surge of material into re-mixing apparatus ahead of the paver. This accomplishes two objectives – eliminating temperature or material segregation and pro- viding for non-stop paving. "And those," says Sunkenberg, "are the things you are most concerned about with trucking." Better Roads February 2012 15