An idle motor grader is costing money. A small time spent in producing a program for the working of a motor grader will save much expense. For example in laying of Overlay material a small program would be as follows.
- Motor Grader scarifies and shapes 1st and 2nd sections for overlay.
- Motor Grader cleans drains and does shoulder work while material is placed on the scarified 1st section.
- Motor Grader scarifies 3rd section then spreads and trims 1st section while material is placed on 2nd section.
This process would be repeated with maybe minor changes due to unexpected conditions.
Tipping of Material
The motor grader should not be waiting for the material to be delivered to site. One method is to have the trucks tip the material at pre-marked positions.
The 4.5 metre wide road requires 150 mm of overlay. The Trucks/Trailers have a capacity of 3m3. The compaction factor of the material is assumed to be 25%. To find the length that each load has to be placed in the following calculations can be done.
1 Find out how much material is required for every 1 metre in length of the road.
Cross-section is 4m x 0.15m = 0.6m2
Therefore for every 1 metre in length 0.4 x 1 = 0.6m3
Using the compaction factor to find additional material. 0.6m3 x 1.25 = 0.84m3.
To find the length of each load, divide the load by the material required for one lineal metre. 3.0 ÷ 0.84 = 3.6m
2 Place two rocks one on top of the other at every 3.6 lineal metres and then the trucks can tip between each section of rocks.
3 The Motor Grader may have to come back to the tipping site periodically to move the tipped material into a windrow to allow a free lane for the traffic.
The above method requires only one laborer to help the trucks after the supervisor has marked out the positions.