These top road maintenance tips will help you use Cat motor graders to maintain roads on farms, quarries, mines and construction sites. Regular maintenance reduces road operating costs and increases overall productivity
Traffic, weather and environmental factors displace gravel, crushed rock, sand and soil onto a road’s shoulder and ditch slope, causing potholes and washboarding.
Follow these tips, as recommended by Cat, to achieve the best results when maintaining gravel roads.
1. Road dressing, shaping, dragging and cutting
Dress the road and shape the crown when moisture is present, either after rain or when the road has been sprayed with water.
Drag the surface when it’s hard and dry, with the cutting edge 90 degrees to the surface.
Cut to the depth of major potholes. Don’t fill potholes with loose material.
2. Maintain cutting edges
Cutting edge condition is very important for keeping the proper road profile. Cutting edges wear quickly, especially in the centre, so check edge wear frequently to prevent moldboard damage.
Maintain straight cutting edges by trimming them with a torch or dragging the cutting edges on a smooth concrete surface. Replace edges before wear occurs at the bottom of the moldboard.
3. Machine positions
Carry out normal maintenance work with the centreshift lock pin in the centre position, and the drawbar and circle centred under the mainframe. The mainframe should be straight or articulated only slightly.
Start with the moldboard top 5.1 centimetres ahead of the cutting edge. Adjust to the material and conditions. Use only enough downward pressure to accomplish the task.
4. Extend cutting edge life
For a longer life, the fixed tip angle presents a constant edge thickness to the wear surface. Changing the tip angle often will wear it more quickly.
New moldboards are designed to give support to cutting edges. To maintain this support, the cutting edges must be replaced before wear occurs on the bottom edge of the moldboard. Repair bent ends of the moldboard before installing new edges.
Use caution when back dragging material or backing up with the moldboard close to the ground. It could break the cutting edge. Use the thickest edges that allow you to do the job.
Cutting edges with carbide-tipped replaceable teeth generally give longer life than standard hardened edges. The Cat GraderBitsTM System provides four types of tips: standard, wide, penetration and sharp. The teeth can be replaced, repositioned and used in a solid or serrated configuration.
5. Judge your angles and pass width
For machine stability, use the widest possible pass width. Keep the moldboard angle as square to the frame as possible.
If material starts to flow around the leading end of the moldboard, or the rolling action dies, increase the blade angle.
The cutting width of a pass will depend on the length of the moldboard and moldboard angle. On wider roads, use blade extensions on one or both ends of the moldboard. Two extensions should only be used for light maintenance work.
On straight sections, steer the machine as straight as possible to maintain a straight shoulder and uniform crown.
Drive at the highest speed possible for maximum productivity but low enough to prevent machine bounce – 6 to 11 km/h.
6. Use crab mode to avoid bounce
For maximum machine stability when maintaining a road’s surface, keep the grader’s mainframe straight with the drawbar and circle centred under the frame.
If the machine tends to bounce, articulate the rear frame towards the toe of the moldboard 2 to 5 degrees. This crab mode is effective when cutting washboards with the moldboard.
In the crab mode, the front axle no longer runs perpendicular to the direction of travel. One front tyre is slightly ahead of the other, allowing one tyre to be on top of a corrugation while the other is on the bottom. As the tyres roll up and down through the washboard, the front axle will pivot up and down keeping the mainframe stable.
Do not use the crab mode when scarifying washboard areas. It could bend the scarifier shanks and/or linkage.
7. Regular road maintenance is key
Gravel roads can deteriorate quickly, especially following heavy rains. Regular grading is the only way to keep them in optimal condition. It’s important to understand the general principles of grading.
A number of factors determine how often you should grade a road. Look here for a guide to how often a road should be graded.
Haul roads take a particular beating from heavy vehicles using them. These tips are specific to haul road maintenance.
This best management practice guide is written for UK roads but is very useful.
How KH Plant can help
Now you know our top road maintenance tips for grading gravel roads, you need a reliable motor grader.
At KH Plant, we specialise in restoring Caterpillar 140G, 140H and 140K motor graders (and individual components) to as-new condition – so you can get the benefits of a new motor grader at a fraction of the cost of a new machine. Contact us for more information or to discuss your needs.
