What is a grader?
A grader most commonly known as a motor grader or road grader is a multi-purpose earthmoving machine that is used not only in construction sites to create flat smoother surfaces in road building projects but also in the mining/quarry industry for mining underneath the ground surface. They are uniquely structured and are majorly characterized by a long, large and adjustable blade between the front and the rear twin wheels.
Due to the many uses attributed to this equipment and its precision in producing quality surface finishes within the shortest time possible, the rate of demand of graders has significantly increased over the last few years and for this reason, is therefore deemed as an absolutely necessary equipment in any construction site.
Key features you need to know about motor graders!
A typical common motor grader has three axles (front and rear twin axles), an engine, a cab and an adjustable blade. However most modern motor graders do have either a ripper,a scarifier, a loader bucket (or both) and a compactor attached to the front and rear axles respectively. This brings about an added advantage as such an equipment could perform multiple purposes within a short period of time.
The main function of the adjustable blade is to cut through uneven surfaces and produce the desired surface finish. The blades are normally fitted under the traction frame with rings that spin vertically so as to adjust the angle of the blade to any required specifications. For this reason graders can also be used in terrains with vertical profiles such as ditches and banks.
Also the blades are always well sharpened to ease its penetration through the soil and are also placed in a good position for the motor graders to perform more efficiently. They are also long structured and large so as to provide a large span of movement and cover a wider scope of work.
The cab is a protective casing to prevent the operators from being subjected to adverse environmental conditions. It’s also transparent to provide great visibility to the operator. It has a front and rear open glass to allow for free circulation of air.
The scarifier is usually used when breaking or tearing up an already existing pavement during its maintenance phase and can also be used when the road surface is very hard for the grader blade to cut through. If the motor grader used does not have the scarifier then an excavator loader bucket can be used to break the hard surface using its teeth. Therefore a motor grader with a scarifier is very essential when reconstructing pavements or in areas with extremely hard road surfaces.
A ripper is an attachment fitted on the rear end of a motor grader. It has claw-like structures that are thick, hard and pointed for the purpose of breaking up hard surfaces, asphalt or loosening materials. This is achieved by continuous raising and lowering of the ripper claws. It is also used to rip open boulders, huge roots and stumps for ease of their removal.
A loader bucket could also be attached to the front axle of a motor grader. It comes in handy during material handling, the removal of unwanted material or excess material, carrying of boulders and transferring them from one point to another.
What can you do with a motor grader?
Motor graders are used to perform a wide range of activities mostly in the following areas: in civil engineering projects to carry out fine grading, in the mining industry, in foundation works of large structural buildings, in spreading and earth moving and also in snow removal.
Motor graders were originally used in construction of unpaved roads such as dirt roads and gravel roads to level up the underlying terrain so as to produce flat and smoother surfaces and also carrying small quantities of material from one place to another. Up to now, graders are still being used in rural areas in the construction of low volume earth roads.
Secondly, they are used during either the construction or maintenance of paved roads to prepare the upper most layer by creating a flat surface for the laying of asphalt on it.
Thirdly, motor graders make sure that the rollers/ compactors are effectively used bearing the most minimum load on it. Also, motor graders are used in snowing areas for removal of snow and debris and later moving them from one place to another.
They are also used during foundation works of a certain project in setting the natural soil to the required level before the construction of large buildings. Consequently, graders can be used in the mixing of two or more materials in any construction site.
Motor graders with a scarifier enable the removal of the top layer of previously wrecked pavements damaged by heavy traffic and then spreading/resurfacing it with a new layer of either gravel, aggregates or asphalt and polishing it up.
Lastly, in the mining sites, graders can either be fitted with multiple attachments or are designed to perform specialized mining tasks.
The various brands of graders
Over the last century, there have been at least three leading brands that have significantly improved their graders to meet the huge demands arising in the construction industry. This has given them an upper hand thus are the most recognized and highly regarded brands due to their incredible features.
The frequently asked question is, does it really matter what grader brand you use? The grader brand does not matter, what matters is the specific operation you want from the grader brand. Having known that, pick the brand with the most satisfying operational features.
Below are the top most motor grader brands and their key features:
- Caterpillar (cat) Graders
The cat industry is the giants when it comes to the construction equipment machinery. They have been in the industry for quite some years, approximately over 40 years before other brands came in. For this reason they are more preferred and chosen by quite a number of people. The key features of cat graders are listed below:
The steering is auto articulated giving the operator better performance in tight spaces. This brings about improved productivity and reduced operator fatigue.
The new series in the market can detect any bounce effect and stabilize itself within a span of 15% speed adjustments.
The cross slope provides more precise accuracy levels and provides adequate control over the grader. It also has automated pitch adjustments for more precise grading.
- John Deere Graders
These types of brands have dominated over the agricultural sector however this doesn’t mean that they are not regarded more in the construction industry. Why choose John Deere Graders, here are some of its key features:
They have automated grader blade controls which greatly improves the productivity of a job by reducing the amount of time taken significantly.
John Deere motor graders offer the most comfortable and the smoothest power shift transmission thus enable an operator to work conveniently for longer durations.
Introduction of a pro system that uses a joystick steering wheel therefore an operator is able to choose how to handle the work given.
- Komatsu Graders
This is a Japanese brand and being the second largest construction equipment manufacturers have gained a wide preference across the world. The key features of Komatsu graders include:
They have reduced operator noise levels so as to provide a more comfortable working environment for the operator. They have ground level refueling tanks for easy access and also fast fuel filling.
They have advanced and improved hydraulic systems which provide excellent blade movement and adequate blade pressure.
How are graders maintained?
Proper maintenance is very essential for the motor grader to continuously perform effectively and efficiently and also to its optimum capacity.
Most importantly, the grader blade fitted to the moldboard must have a good sharp cutting edge. This increases the ease with which the blade cuts through the material. The degree with which the material is abrasive ultimately determines the rate in which the blade becomes worn out. Once the blade is worn out, it should be immediately replaced to avoid the moldboard from being at a risk of wearing out too leading to unnecessary replacements hence further costs.
Also, the graders’ air filters should be occasionally checked to ensure that no dirt has accumulated in there. Presence of dirt clogs the air filters thus reducing the efficiency of the graders and subsequently increasing the consumption of fuel. They therefore require the operators to constantly monitor them or introduce a pre-filter whose role is to reduce the amount of dirt particles entering the air filter. Use of pre-filters helps in reducing the number with which the operator would have to replace the air filter hence saving on costs that would have otherwise been accrued.
The teeth of the scarifiers or the rippers should be monitored and not allowed to wear out to the point where the scarifier shank is reached. If such happens then both the scarifier and the scarifier shank have to be replaced, a more costly task than just replacing the scarifier teeth alone.
The tyre pressure is another essential element that has to be checked and monitored regularly because tyre traction affects the graders’ grade precision. Consequently, the tyre threads should be of the required specification so as to provide adequate grip with the ground surface to prevent skidding of the machine.
For overall operator comfort and safety, the floor mat, brakes, seatbelts, steering wheel and handles should be regularly checked. Presence of loose handles, seatbelts makes the work more tedious and difficult to execute leading to lack of precision and prolonged working durations reducing overall productivity.
Why are graders convenient for road construction?
In conclusion, motor graders execute a variety of activities in the construction sites therefore is a vital equipment in any site. Not only is it used to produce flat surfaces on unpaved roads but also create smooth surfaces in paved roads for laying of asphalt.
They are also convenient in construction of roads along terrains with vertical profiles or curvatures using its adjustable blade, producing surface finishes with the desired specifications.
Graders can also be used in constructing/creating ditches for drainage purposes or curing of bank canals. Its adjustable blade is of advantage as it can be adjusted to any desired angle, creating the required ditch or bank outlook.
In reconstruction of existing pavements which are wrecked due to damages from excessive heavy traffic, graders’ rippers/scarifiers can be used to break the asphalt and then the grader lays a new material such as gravel or new asphalt on the pavement.