What is Maintenance of Roads 

Maintenance of Roads is nothing but the art of keeping the existing road in good working condition for proper functioning of traffic.

Road Maintenance plays important role in the life span of roads and highways. Moreover it reduces the petrol consumption of vehicles and it prevents the wear and tear of vehicles tyres.

Necessity of the Maintenance of the Roads :

Roads are considered as the major parts for better communication from one place to another. Therefore it is very much important to keep these communicating paths intact for better comfort.

Below are given the reasons which highlight the necessity of road maintenance :

• To ensure safe and comfortable movement of passengers form place to place and goods at all the time.
• Maintenance of the roads from time to time prevents the accidents caused due to faulty and damaged roads.
  Maintenance of the roads is essential to move the traffic safely and smoothly.
• It increases the life of the road.
• To keep the safety of road user and to decrease the inappropriate movement of traffic.
• Maintenance of various components of roads such as pavement, drains, shoulders, side edges etc provides better service to the user of the road.

Classification of the Road Maintenance Operation :

Maintenance operation of highways are generally classified into 3 parts :

• Periodic and Routine Repairs
• Special Repairs
• Resurfacing

1. Periodic / Routine Repairs :

Through repairs or day-to-day repairs which are done properly to the road pavements are known as periodic or routine repairs. These are generally carried out to low cost roads.

Routine repairs are generally done by the departmental labours, whereas the periodic repairs are carried out by contractors which are invited at specific intervals.

2. Special Repairs :

Special problems need special solutions. Hence special repairs are carried out to overcome some serious special problems, so that the road may not get worsen in future.

These repairs are generally carried out for high class roads. These kind of repairs are difficult to carry out hence skilled labours are required.

3. Resurfacing :

When the surface dressing of the pavement is renewed which was severely damaged it is called as resurfacing. It is usually done for bituminous roads.

Maintenance of W.B.M Roads 

WBM means water bound macadam roads. WBM roads are rapidly damaged because of heavy traffic and variation in climatic conditions. Hence the maintenance of such roads is much essential so as to keep the roads in serviceable conditions for longer time.

The maintenance operation of wbm roads is generally divided into 2 parts

• Day-to-Day Maintenance
• Periodic Maintenance

1. Day to Day Maintenance :

Due to heavy mixed traffic and change in climatic condition, pot holes appears on the road surface and it becomes much essential to do the patch work to the pot poles. In short, day to day maintenance involves the patch work to the pot holes.

2. Through Maintenance :

A. Rut filling

When deep and clear ruts are formed the these ruts are filled by the greater size of patch work with respect to the pavement which is in good condition.

In rut filling process, continuous trenches with vertical sides are excavated then road metal is filled in trenches and compacted and these surface is then finished to the pavement which is in good condition.

B.Treatment to the corrugations :

If the corrugations are formed on the surface of W.B.M road, then excess binding material is removed.

C. Re-surfacing : 

When the surfacing becomes rough and weaved out then re-surfacing is preferably done to the pavement of W.B.M.  In the process of re-surfacing, the surface is picked upto the affected depth with the help of pick-axes.

The road metal retained on 20 mm sieve is then spread, hand packed and rolled and surface is finished.

3. Renewal :

When the surface is worn out to the greater extent and road cannot be maintained by patch work, then renewal  of WBM roads is essential. At the time of renewal of WBM road, the whole surface should be scarified ,upto the total depth by means of pick-axes.

The scarified surface of WBM should be well rolled. A mixture of fresh and screened metal is then applied on the rolled surface.

At the time at renewal of WBM road, the traffic can be continued and undisturbed by using temporarily shoulders as a diversion road.

Maintenance of Bituminous Road

Bituminous roads are most commonly adopted roads. It consist of flexible type of pavement. Following maintenance is commonly requires for bituminous roads.

1. Patching Pot Holes :

It comes under the part of day to day repairs. Due to heavy traffic, variation in climatic condition, variety of traffic and improper quality, the pot holes are developed on the surface of the road and has to be treated.

In case process of patching the pot holes , the pot jokes are first cut square or rectangular in shape upto the required depth. The holes are cleaned and broomed properly and a suitable tack coat or bitumen coat is applied.

Then usually a premixed patching mix is placed in the holes with the help of crow bars and the surface is rammed and rolled. The finished surface or the pot holes is kept slightly above the normal surface for compaction under traffic. In cold weather, cut back or emulsions are used as a refilling materials to repair the pot holes.

2. Patching Ruts :

The longitudinal depression or cuts formed in flexible pavement are known as ruts.

In the process of patching ruts, a continuous trenches are dug so as to enclose the ruts which becomes a solid foundation for the patch. Then patch work is further carried out as it is done in pot holes.

3.Patching Corrugations :

The corrugations are set up in case of bituminous roads due to bleeding which is normally happened in the summer. This can be repaired by cutting the crests or high ridges of corrugations.

Upto the small depth of depressions which are further cleaned, painted and filled up with the premix material.

4 . Base Repairs :

This repairs comes under the part of through maintenance in which cause of defect is first rectified and then necessary treatment is decided. If it is found that the particular defect is due to insufficient thickness of the base course, then it is repaired or corrected by providing the additional surface thickness.

In case of base repairs, the old surface of the base is first loosened by scarifying it to the full depth The old metal is screened and can be used in the bottom of base.

Then new base is prepared in layers not more than 75 mm in thickness and further covered with the surface finish

5. Surface Treatment :

Bleeding of bituminous surface is treated as soon as it appears bleeding treated by providing the layer of blotting material. Such as aggregate chippings or coarse sand and rolling is done if necessary.

A renewal coat or seal coat is applied when the cracks are set up on the road surface.

6. Re-surfacing :

The process of renewal or surface dressing of the pavement which is severely damaged or after it useful life is known as resurfacing.

If the existing wearing course a bituminous road is near about or completely worn out, then it becomes unfit for traffic and then it becomes essential to resurface the road entirely.

In the process of re-surfacing, the existing surface is repaired by suitable patching. A light tack coat is then applied over the surface and surface dressing is done.

Maintenance of Cement Concrete Roads :

1. Repairs of Blown-Ups :

Blown-ups is a raised portions of the road slab at transverse joints of cracks developed due to longitudinal expansion of the slab. In the process of repairs of blown-ups, 150 mm depth of pavement is removed and replaced it by the patch of concrete or bituminous material

Also Read : Cement Concrete Specification for Design Mix 1:2:4
Also Read : Workability of Concrete & Factors Affecting It
Also Read : Different Grades of Cement

2. Repairs of Cracks :

If the cracks developed on the surface of road are wide, then water and grits are flowed and penetrated into the road sub-grade. Therefore such cracks should be well treated immediately.

No need to repair to fine cracks or hair cracks because they do not admit surface water to sub-grades.

In the process of repair of cracks, cracks are thorough cleaned with the help of a suitable sharp pointed tool and then accumulated dirt is blown off with the help of blower.

Then coating of kerosene oil is applied on the surface crack so as to have proper holding or adhesion of the sealing material with the old concrete.

Atleast the crack is filled and finished with a molten sealing compound. The repairing word is especially carried out during summers.

3. Repair of Joints :

The joints of cement concrete pavement gets opened due to heavy traffic, poor quality of construction and improper design of joints. Hence repair of joints is must otherwise there will be entry of the surface water through these opened joints into the road sub-grade and it affects the riding surface.

There should be routine inspection of all the joints atleast twice a year. If sealing compound becomes weak or soft or looses its adhesion, then it is necessary to refill or reseal the joints.

In the process of resealing or refilling the joints, the old sealing compound is completely removed from the joints. It is done with the help of a sharp head pointed tool.

The joint is then properly cleaned with the help of vacuum cleaner or wire brush so as to make the joints free from any deposition of dust. Then the Joints is resealed with a sealing compound.

Note that, the joints should be dry while resealing. Proper care has been taken after resealing that spread the lime dust or sand on the top surface of the joints so that sticking of the sealing compound to the wheels of vehicles can be prevented.

4. Patch Repair :

If any depressions or holes are appeared on the surface of cement concrete roads, then these depressions or holes are treated by patch work which is done with bituminous material.

But if these depressions or holes are wide enough and appeared to be full depth of road slabs, then patching work done with bituminous materials is not suitable, then in such case concrete patching is more suitable.

In the process of concrete patching the patch holes are cut square or rectangular in shape to full depth of the road slab with edges parallel or perpendicular to the center line of the road.

Edges of patch holes are thoroughly cleaned after cutting. Then cement grouting is done on the sides of each patch holes. Then the cement concrete is placed and compacted into the patch hole.

After this the surface of patches are kept under water for better curing. Note that the proportions of the concrete mix should be kept as it was kept previously.

5. Settlement Due to Mud Pumping :

It is also called as sub-grade failure. The settlement of the slab take place due to the formation of cavities. This results in mud pumping and failure of the sub-grade or slab.

This defects is caused by the faulty construction of joints.The repair and maintenance of settlement due to mud pumping consists of filling of the joints and cracks, this can be done by mud-jacking.

This operation involves drilling the number of holes having diameter from 4 cm to 5 cm. These holes are grouted by cement mix or bitumen. Grouting is generally done by a mud-jacking machine.

Grouting mix or slurry should be more consistent so as to fill up the cavity entirely. The under sealing of the road slab can be done by pumping highly viscous asphalt through a drilled hole in the road pavement. This also helps to control the mud-pumping in future.

6.Surface Defects :

Due to unsound aggregates used into the construction of cement concrete roads, the concrete pavement may sometimes get disintegrated.

It can be repaired by making the disintegrated portion of slab free from dust and any foreign materials. Resealing the surface with proper surface treatment of bitumen or concrete can also be additionally done.