Different Rural Road Construction Surfaces: Pros and Cons
Typically road surface is defined as the durable surface material that is laid on an area intended to sustain vehicular or foot traffic. The type of road surface used in road construction largely depends on traffic volume and weight load that the road will have to carry and the weather conditions prevailing in that area. The urban road surfaces are generally of asphalt or concrete. However, when we talk about rural roads, then the road surface of such roads is different from the urban roads.
Here is a look at the different rural road construction surfaces, why a particular material is considered for the surface and the pros and cons of each one of them.
While nearly 61 per cent of Indian roads are paved, still the remaining 39 per cent of roads are unpaved which are mostly rural roads. Some of these unpaved roads are surfaced with the native material or earth and are called dirt roads which are generally narrow. Such road surface support few vehicles that too trucks or tractors and foot and animal traffic.
Advantages of dirt surfaced roads
1. These roads are low-cost roads.
2. Construction and maintenance of these roads do not cause any harm to the environment.
Disadvantages of dirt surfaced roads
1. As the name says, these roads generate lot of dust and this reduces visibility.
2. They become impassable during wet weathers due to potholes, ruts and ridges.
3. There are chances of skidding on such roads.
4. Earth surfaces also absorb some of the surface water unless it is quickly drained away from the road.
5. Washboarding i.e., the formation of corrugations across the surface at right angles to the direction of travel is another problem with dirt roads.
The unpaved rural roads in India are majorly surfaced with gravel and are called gravel roads or improved unpaved roads. Typically, gravel is practical, affordable and low maintenance surface for rural roads. Such road surfaces support low traffic volume, particularly of load-bearing trucks. Gravel can be easily put over freshly cut road and compacted or the existing surface is graded to create a crown, sloped shoulders and run-off ditches. In order to ensure that the gravel roads do not damage easily, drains are added at intervals so as to remove rainwater.
Advantages of gravel surfaced roads
1. These roads are low-cost roads.
2. They are easy to maintain.
3. Since these are basic roads, they preserve the rural ambience.
Disadvantages of gravel surfaced roads
1. Gravel surfaced roads can become difficult to use in wet weathers.
2. These roads require frequent maintenance especially after wet period or when the traffic at such roads increases.
3. These roads generate lot of dust and scattering of stones here and there.
4. Washboarding is a problem with gravel roads too.
5. Gravel surfaces also absorb some of the surface water.
6. Gravel roads deteriorate more quickly than bitumen surfaced roads.
It is an effective surface solution for rural roads which are meant for low traffic with minimal weight loads. Onto a pre-compacted aggregate, a bitumen rubber chip emulsion is sprayed and then rolled into the base layer to create a hard and sealed road surface. Such a surface solution which is durable and comparatively inexpensive is widely used in villages and small towns.
Advantages of bituminous surfaced roads
1. Such roads are waterproof, skid-resistant and also dust free.
2. They are low maintenance roads and their maintenance cycle is 5 years.
3. These are low-cost roads as compared to asphalt roads.
4. They are much more durable than gravel roads.
Disadvantages of bituminous surfaced roads
1. They can develop cracks during hot weather.
2. Such roads are rough and thus, can increase road noise.
3. Such roads generally cost more than gravel roads.
4. As compared to asphalt roads, they are not long-lasting.
Need of motor graders for different rural road construction surfaces
To construct and maintain all these types of rural roads, proper equipment are needed which include motor graders. Various tasks can be performed by motor graders for construction and maintenance of all rural road surface types. Some of these tasks include...
1. Grading task which can be easily performed by motor graders by cutting the surface of the unpaved road to the bottom of the potholes and/or washboards and then spreading the material across the surface of the roadway.
2. Motor graders can be easily used to restore ditch drainage. The most important and common drainage feature needed on a rural road is the roadside ditch. If the ditch becomes obstructed from eroded soil or debris, it must be cleaned.
3. Motor grader’s mouldboard easily helps to recover loose material and move it back on the roadway to restore shoulder drainage.
4. Problems with surface and shoulder shape can also be corrected with the motor grader. Motor graders can cut the material and relay it to the proper shape and crown.
5. Motor graders can even ease the process of eliminating high shoulders along the edges of gravel roads.
Apart from this, there are other jobs too that motor graders can perform while construction and maintenance of different rural road construction surfaces. While there are various foreign motor grader manufacturing companies in the country selling motor graders, almost none of such equipment are designed to suit the India roads of which more than 90 per cent are other than national highways and nearly 40 per cent are rural unpaved roads having surface of dirt, gravel and bituminous. However, Mahindra Construction Equipment’s the Mahindra RoadMaster G75 is made in India for the Indian roads. The RoadMaster G75 is created to offer an affordable, un-compromised and mechanised grading solution for small and medium roads in India. It is an ideal grading machine for spreading and grading of earthwork in different types of roadwork across the nation.
In a nutshell
So, be it dirt surfaced, gravel surfaced or bituminous surfaced roads (each having their pros and cons), motor graders can work efficiently in construction and maintenance of these rural roads.