New paving machines offer advantages that make them a necessity in some mainline paving operations. However, most pavers offer very long, useful life cycles. In some applications, a pre-owned asphalt paver may offer the best choice for the job. “If properly maintained, a paver can last up to 20 years,” says Mark Bolick, quality control and service manager, LeeBoy. “But you need to service the paver and replace worn or broken parts as soon as possible.”
Many 25-year-old, or older, machines are also still on the job. “Customers strip them down to the frame and rebuild them from the ground up,” says John Sunkenberg, Volvo Construction Equipment. “If you are on top of your wear parts, and continually work on the hydraulic components, you can keep running them. If you are not going to do a lot of that work, then the machine isn’t going to treat you well.”
The life expectancy of a paver really depends on the maintenance program. “With recommended maintenance, 7,000 to 8,000 hours is normal,” says Terry Sharp, Caterpillar Paving. “It also depends on the composition of the asphalt mix. The type of rock and the amount of fines in the mix can lead to variations in component life.”
Inspect Along Material Path
“When purchasing a used paver, there are many components that must be carefully inspected to ensure that you fully understand what you are buying,” Sharp says. “Feeder system components such as floor plates, augers, conveyor chains and flight bars receive much of the abuse due to contact with the heat and abrasive nature of asphalt.
“Thin floor plates tend to warp, auger flights become pointed, conveyor chains start to sag, flight bars allow mix underneath, and bearing seals become defective and allow mix to contaminate the internal components,” he states. “These are just a few of the areas to make note of when inspecting the feeder system for defects.”
The quickest wear items are the components exposed to the material path. “Major wear components include floor plates, screed plates, auger flights, conveyor chain and bars, feeder bearings, and the hopper flashing,” says Brodie Hutchins, Vogele America.
“The material initially contacts the conveyor chain and deck plate,” notes Sunkenberg. “That is probably where you have your greatest expense if replacements are needed, such as a new set of bearings, chains, and deck plates.”
Next is the auger. “The edges start to lose their thickness and overall diameter. They will also lose their effectiveness. As augers get worn down, they will not move material as well.”
Be sure to check chains and flights for wear and stretch. “Check the bearings to make sure they are not loose on the auger,” Bolick says. “Also check the thickness of the auger. The more they are used, the more they break down.”
“When inspecting the augers, check for missing or damaged bearings and seals, bent or worn auger shafts, damaged supports and thin flights,” Sharp says. “Worn auger flights can be indicated by streaks in the mat or sharp edges. If the castings and/or seals are damaged, mix can build up inside the chain case, which could cause more damage.”
Screed ConditionImpacts Mat Quality
Typically, the screed plate is the fastest wearing component. “All of the material put through that paver eventually passes under a screed plate,” Sunkenberg says. “Depending upon the area, you will probably replace a set of screed plates every year or twice yearly. If you compare limestone to granite, the paver is going to wear quite a bit differently.”
Screed plate wear can be a simple indicator of the shape of a screed. “Screed plates with visible wear near the front or rear can indicate improper setup or a twisted frame,” Sharp explains. “Binding thickness control screws can indicate worn-out bushings. Extender tubes should also be inspected for scoring and accumulation of dirt and debris. Buildup will cause damage to the bushings.”