By now, your season is well underway, and your equipment will soon be feeling the long days just as you will be feeling them. Your pavement saws will work particularly hard, cutting out sections of asphalt or slicing through concrete in many instances with blades turning at better than 2,000 rpms all day long.
You can't do much to lighten the work load for these machines, but you can provide a little tender loving care that will help keep them running smooth the rest of the season.
Grease 'n' tighten
A little lubrication goes a long way, says Kevin Cote, technical field representative for Diamond Products located in Elyria, OH. Diamond manufactures a full line of pavement saws with blade capacities that range from 8 to 54 inches.
"Keeping the blade shaft bearings lubricated is tops on my daily maintenance to-do list," Cote says. "I tell operators of our units to grease these bearings at the end of every work day. They should give each bearing two pumps of grease while the machine is still warm from operation and while the shaft turning over at an idle speed. I say no more than two pumps because over greasing may blow out the bearing seal and ruin the bearing."
Making sure the blade shaft belts maintain the proper tension is important, as well, he adds. "With new saws, I advise operators to run them an hour or so and then retighten the belts without over tightening them, which could damage the belts and bearings. After that, they should routinely check the belt tension until the belts have stretched to their limit.
"A squealing sound indicates that a belt is slipping. At that point, the belt needs to be tensioned immediately to avoid wear and potential damage caused by the sheave."
Sawing concrete creates especially difficult operating conditions for pavement saws, adds Ed Varel, engineering project manager for Honeoye, NY-based Stone Construction Equipment. In addition to a complete line of concrete and asphalt preparation equipment, Stone manufactures three concrete saws, including the self-propelled CSP3 that accommodates up to a 20-inch blade.
"Operators working in these conditions should hit lubrication points daily and routinely clean the engine air filter." He, too, emphasizes the importance of checking belt tension, especially when cutting expansion grooves or using a saw in other tough conditions. Cutting a groove too deep, more than one or two inches in a pass, or cutting too fast can also damage blades."
When wet cutting, water is the lifeblood of a fast-turning blade and it works to suppress dust. Without adequate water, blades can overheat, warp, and ruin the cut. Part of any service regimen should include checking the water delivery system prior to the workday, and making sure tubes are free of dirt or debris. This is especially important if the water source is questionable, notes Ray Coblentz, engineering technician for EDCO. Located in Frederick, MD, EDCO offers a complete line of concrete and asphalt saws, from small walk-behind models to large self-propelled models with a 36-inch blade capacity.
The blade should also be checked every day to ensure it is tight and free of cracks or loose segments.
Another way to add longevity to your saw is to transport it properly. "Driving a saw up a high ramp is hard on the drive linkage, and allowing it to drop even a foot or less while unloading can damage the fork assembly," Coblentz says. "Before transporting a saw, the blade should be removed and the saw lowered on the main frame and secured with straps. Putting the weight on the main frame reduces the load on the fork assembly and hydraulic cylinders and strapping it down keeps the machine from bouncing."
Cutting Concrete versus Asphalt
Your pavement saw will likely cut equally well in either asphalt or concrete, as long as the blade matches the application. "The rule of thumb is to use a soft bond blade in hard material such as concrete and a hard bond blade in softer material such as asphalt," notes Diamond Products' Kevin Cote.
Sawing into these two different surfaces, however, is as different as night and day. For starters, a softer asphalt surface allows operators to saw deeper and faster than they would be able to saw in concrete.
In addition to surface hardness, the biggest difference between sawing asphalt and concrete is the virtual dust storm created by the latter. Wet sawing keeps dust to a minimum when sawing through concrete and in both applications (asphalt and concrete) adding water reduces heat build up in the blade.
Varel offers this final note about sawing in concrete versus asphalt. "With asphalt, the pavement saw will likely be used for patchwork, to cut out sections of asphalt where maneuverability is an issue. Smaller, walk-behind saws work better in this application. Larger, medium-range saws are better suited for cutting expansion grooves in concrete pavement or in similar applications where maneuverability is less of an issue."