On most pavers, mainline or commercial class, the material augers that displace asphalt to both sides of the screed are mounted in the hopper. As paving widths increase, these augers typically have difficulty shoving material efficiently to the widest expanses of the screed. This is why it is not uncommon to see laborers with shovels on either side of a paver helping direct asphalt to the entire length of the screed. Of course, this slows production, and considering the fact that these laborers are working 10-hour days shoveling 300° F materials, it is far from a pleasant activity.
So some machines now have material flow augers mounted directly to the screed. As the screed extends to handle wider paving widths, so too does the auger. Basically, this eliminates the need for laborers to redirect asphalt by completely automating the material flow process.
From the moment a paver hits the job site it's receiving several tons of hot, abrasive aggregate. And this isn't a temporary occurrence. Pavers typically run from sunrise to sunset with few breaks in between. No matter how durable the paver, regular maintenance is unavoidable. But will it be something that needs to be maintained once a week or once a day? These maintenance intervals can make a big difference to the bottom line of a paving operation — and the materials that make up a paver's wear components can be key.
All manufacturers will list the materials that make up their respective augers and screed surfaces. Basically, the type of materials used will indicate the expected life of these wear components. Durability is usually indicated through a hardness rating. For instance, depending on the manufacturer, one might find the option of having wear components constructed of heavy-duty steel with hardness levels of 400 or more. A popular supplier of such materials is Hardox. Compared to standard-grade steel components, a 400 brinell or Hardox hardened steel will offer four to five times longer life. Of course, this added life comes with a price, but in the long run, contractors will typically find the extra price for more durable wear components will be offset by the amount saved through reduced maintenance requirements.
Have paver, will travel
Equipment and maintenance costs are one thing, but how will the choice of a paver affect the rest of a contractor's operation? As strange as it might sound, some contractors make their paver decisions based on portability. This applies mainly to smaller, entry-level contractors who typically work on smaller projects, but travel costs are an important consideration for any size operation.
Consider a contractor that chooses a larger, conveyor-fed commercial paver for his business. Because of its size, this paver will require a dedicated trailer and pickup to tow it to the job site. Another pickup and trailer will be needed to tow the supporting equipment. On the other hand, most gravity-fed pavers can fit on a trailer, along with a roller, skid steer, and all the needed hand tools. In this case, the contractor has cut the operation's travel expenses in half, towing all necessary equipment in one load.
It's important to remember that all equipment decisions should be tempered with an interest in productive capability. If the contractor who selected the small paver based on travel costs is confronted with the opportunity to do more substantial work, his equipment is now limiting growth. In an effort to save money on travel costs, a contractor can potentially lose work that would pay for the additional overhead of a second towing setup. If a contractor wants a machine that can handle a wide range of applications, from driveways to county roads, and will allow for growth, productive capability dictates that a larger, conveyor-fed paver is the right choice. But if a contractor is limited to smaller jobs and doesn't see this changing in the relatively near future, a larger conveyor-fed machine might add more expense than necessary.
Manual or automatic?
Be it a gravity-fed paver or a conveyor-fed paver, one of the biggest technology changes taking place today is the implementation of electronics. This is apparent with the available full-screed automation packages and also with operator controls.
Instead of presenting a series of levers that manually control paver operations, digital controls utilize a series of toggle and jog switches for automatic control. The benefits of this technology are numerous. Electronic controls are more precise and efficient, and they're easier to use for operators of any experience level. But there is a catch. Electronics don't mix well with a few elements — heat, liquid, and dirt — all of which are ever present on a paving jobsite.