PAVEMENT FAILURES

• Generally it is observed that after the opening of newly constructed road or well maintained or newly widened road which is very good in the terms of level of service, But it is after some time with the use of traffic volume and constantly changing weathers, especially after monsoon or in monsoon the road quality is decorated at every use of traffic and after some time it gets completely decorated with uneven crack, pot holes, ruts, crack etc…. This problem is very much common in every road. Hence the quality and level of service is dropped down drastically as the road user increases but maintenance is overlooked.

• Pavements fail prematurely because of many factors. There are four primary reasons pavements fail prematurely, like Failure in design, Failure in construction, Failure in materials, Failure in maintenance.

• Here for case study we will pick one cluster of Amreli City, The district head quarter of Gujarat state. In the case study we will find the problems, causes and remedies.

• If the pavement remains failure one and doesn’t maintained as per need than V.O.C ( vehicle operating cost), Travel time, Traffic congestion, Traffic volume, Traffic density and lots of Precious man hours / time is wasted.

• So the pavement should be well maintained and good for smooth riding to road user which overcomes the V.O.C, Traffic congestion, Traffic volume, Traffic density and precious man hours.

INTRODUCTION

• The surface of the roadway should be stable & non-yielding, to allow the heavy wheel load of road traffic to move with least possible rolling resistance. The road surface should also be even along the longitudinal profile to enable the design speed. The earth road may not be able to fulfil any of the above requirement, especially during the varying conditions of traffic loads & the weather. At high moisture contents, the soil becomes weaker & soft & starts yielding under heavy wheel loads, thus increasing the tractive resistance discomfort & fatigue to the passengers of fast moving vehicle & cyclists thus a pavement consisting of a few layers of pavement materials is constructed over a prepared soil sub grade to serve as a carriageway.

• Based on the vertical alignment & the environmental conditions of the site, the pavement may be constructed over an embankment, cut or almost at the ground level of the ground water to keep the sub grade relatively dry even during monsoons.

DESIGN OF PAVEMENT

Flexible Pavements :-

Flexible pavements are those, which on the whole have low or negligible flexural strength & are rather flexible in their structural action under the loads.

Rigid Pavements:-

Rigid pavements are those which possess noteworthy flexural strength or flexural rigidity.

TYPES OF PAVEMENT STRUCTURE

Pavements fail prematurely because of many factors. When boiled down to the basics, there are four primary reasons pavements fail prematurely:

• Failure in design

• Failure in construction

• Failure in materials

• Failure in maintenance

PAVEMENT FAILURE

1. Fatigue Cracking (Alligator Cracking):-

Fatigue cracking is commonly called alligator cracking. This is a series of interconnected cracks creating small, irregular shaped pieces of pavement. It is caused by failure of the surface layer or base due to repeated traffic loading (fatigue).

DIFFERENT TYPE OF PROBLEM

2. Longitudinal Cracking:-

Longitudinal cracks are long cracks that run parallel to the canter line of the roadway. These may be caused by frost heaving or joint failures, or they may be load induced. Understanding the cause is critical to selecting the proper repair.

3. Transverse Cracking:-

Transverse cracks form at approximately right angles to the centreline of the roadway. They are regularly spaced and have some of the same causes as longitudinal cracks. Transverse cracks will initially be widely spaced (over 20 feet apart). They usually begin as hairline or very narrow cracks and widen with age.

4. Block Cracking:-

Block cracking is an interconnected series of cracks that divides the pavement into irregular pieces. This is sometimes the result of transverse and longitudinal cracks intersecting. They can also be due to lack of compaction during construction. Low severity block cracking may be repaired by a thin wearing course.

5. Edge cracking:-

Edge cracks typically start as crescent shapes at the edge of the pavement. They will expand from the edge until they begin to resemble alligator cracking. This type of cracking results from lack of support of the shoulder due to weak material or excess moisture.

6. Rutting:-

Rutting is the displacement of pavement material that creates channels in the wheel path. Very severe rutting will actually hold water in the rut. Rutting is usually a failure in one or more layers in the pavement. The width of the rut is a sign of which layer has failed. A very narrow rut is usually a surface failure, while a wide one is indicative of a sub grade failure.

7. Potholes:-

Potholes are bowl-shaped holes similar to depressions. They are a progressive failure. First, small fragments of the top layer are dislodged. Over time, the distress will progress downward into the lower layers of the pavement. Potholes are often located in areas of poor drainage, as seen in Figure Potholes are formed when the pavement disintegrates under traffic loading, due to inadequate strength in one or more layers of the pavement, usually accompanied by the presence of water.

8. De-lamination:-

De-lamination is a failure of an overlay due to a loss of bond between the overlay and the older pavement. Common causes of de-lamination include: wet or dirty surface during paving of the overlay, failure to use a tack coat, or poor compaction of the overlay. Proper paving techniques, including cleaning the surface and use of tack coat, will reduce the chances of de-lamination.

Introduction:-

• Amreli is a small city in Gujarat& it’s a district head quarter. The peninsula extends southwest into the Arabian Sea and is bounded on the northwest by the Gulf of Kachchh and on the southeast by the Gulf of Khambhat. Area, about 60,000 km² (about 23,000 sq. mi).Amreli has variety of lands like Medium black, loamy, sandy, and rocky. Main crop of this province is Cotton & Other local crop like Bajra, Wheat, sugar cane & Vegetables & in Fruits Main Is Mango.

• Amreli is located in Saurashtra region of Gujarat state with 20°45" to 22°15" North Latitude and 70°13" to 71° 45" East Longitude. It falls under the North Saurashtra Agro Climate Zone of Gujarat.

• The regional transport system of Amreli is essentially a road based system. The city of Amreli is connected to other parts of the country through a developed regional road (state highway and District Roads) system

CASE STUDY

Map:-

Problem:-

Our case study on Amreli to Lathi road (Amreli city).we will see in our study most common problem is Alligator Cracking and Transverse cracking. Main reason of road creaking is heavy loading vehicles passing on road. 24X7 hours transport heavy loading vehicles on road.

Reasons of Problem:-

• Traffic:-

Traffic is the most important factor influencing pavement performance. The performance of pavements is mostly influenced by the loading magnitude, configuration and the number of load repetitions by heavy vehicles

• Rainfall:-

The result of moisture ingress is the lubrication of particles, loss of particle interlock and subsequent particle displacement resulting in pavement failure.Average rainfall of Amreli city is 552mm.

• Construction Quality:-

Failure to obtain proper compaction, improper moisture conditions during construction, quality of materials, and accurate layer thickness (after compaction) all directly affect the performance of a pavement.

• Maintenance:-

Pavement performance depends on what, when, and how maintenance is performed. No matter how well the pavement is built, it will deteriorate over time based upon the mentioned factors.

Crack repairs are the proper and timely maintenance of cracks using sealing or filling techniques to extend pavement life. Crack repairs are very cost effective if done properly. A crack repair program begins by determining if crack repairs are suitable for the type of distress

1. Sealing versus Filling:-

2. Asphalt Resurfacing:-

3.Rejuvenation:-

4. Infrared Repair:-

5.Fog Seal (PASS):-

6. Chip seal:-

7. Self-Adhering Waterproofing Membranes:-

8. Shallow Surface Repair (Pothole):-

SOLUTION

• The pavement should be designed with precise future forecasting.

• The pavement should be constructed as per design only.

• The pavement should be maintained periodically...i.e. on the maintenance concept of routine, Periodic & complete maintenance.

• The road user should be as per consideration only...if the nature of traffic changes due to unexpected growth of the area than it should be well maintained.

• There should not be any delay in maintenance.

• The nature of traffic plays vital role for the life span of pavement so at the time of designing assumption of the future traffic is very much important.

CONCLUSION

By:-Malay Talaviya

THANK YOU