How Push Roller Maintenance Prevents Segregation & Rough Mats
BY John Ball
John Ball shares a quick tip for paving smoothness, preventing material segregation
When charging the hopper, our main objective is to get the mix out of the truck, uniformly, without segregation. This takes communication with the haul truck driver, which we discuss in several articles you can find on TheAsphaltPro.com website, including “Prevent Fatalities with Better Truck Driver Training, Best Practices.” By communicating with the haul truck driver, you can prevent him from bumping the paver when he stops in front of it.
The next thing to worry about is whether he’s stopping in front of a paver that’s ready to receive him.
When the paver operator brings the tractor forward and brings the push rollers to rest against the truck tires, they’ve got to be clean. If the push rollers up front are caked with material and unable to roll freely, that’s the first indication the paver’s not going to go smoothly down the road. The wheels will be hopping, and the paver will rise up and fall down going down the road until the wheel breaks free and moves freely.
The bar that holds the push rollers on has a pin in the middle that oscillates. It has a 3-inch radius to help turn the push roller. It’s not a straight solid bar; it turns with the truck. It doesn’t cause restriction on the tires of the truck or on the tires or on the paver. It can smoothly turn. It’s oscillating in the middle, but only if it’s clean of asphalt material buildup.
In this picture, you can see the asphalt has built up on the push rollers and the bar. Not only are the rollers gummed up to cause problems, mix will leak out through the holes in the rubber dams.
Maintenance on the paver is always important, but especially at the reception of the truck. Once we start to go forward, we want the pace to be smooth and not hiccupping down the lane.
In the field, no one thinks cleanup is a high priority, but it really is. Asphalt builds up on this front area and can affect the tow arm. It can cause the tow arm to pump up and down if you’re hiccupping down the lane. The tow arm is hooked to the tractor and could cause restriction. Or, if you’re using automation or sonics, it could cause something not to work properly if the push rollers are hitching and hiccupping.
Prevent Fatalities with Better Truck Driver Training, Best Practices
A 3-pound hammer can hack this material loose; you can fracture it and break it off. Sometimes you need a torch but if you whack it with a hammer, being careful to avoid the bearings that allow it to roll, you can fracture and knock the caked material loose.
What’s better is to use a shovel or rag to scrape or wipe the material off when it’s still warm immediately after the paving shift. If you can wipe the material easily in a few minutes at the end of the paving day, that’s so much easier and better than banging at hardened material before startup the next day.
However your crew has to do it, you want to have push rollers that turn smoothly to smoothly push the haul truck forward and to pave a smooth mat.
John Ball is the proprietor of Top Quality Paving & Training, Manchester, New Hampshire. For more information, contact him at (603) 493-1458 or tqpaving@yahoo.com.