Task name 1
Review & comparison of distresses 2
• Longitudinal distress 3
• Alligator distress 3
• Ravelling distress 3
Repair Details 3
Causes of pavement damage: 4
Quality of raw materials: 4
Chemical reaction: 4
Leakage of water and other liquids from the sewage: 5
Describing the failure 5
• Longitudinal Cracking 5
• Alligator Cracking 6
• Ravelling cracks 6
Investigating the causes 7
Vehicle load 7
Easy damage of the joints 7
In appropriate Asphalt structure 7
Alternative treatments recommendations 7
Identification through Anisotropy equipment: 7
Automatic Road Pavement assessment 8
Automatic Road Crack Detection 8
Comparison & contrast with local and international codes 8
We are going to develop a case study on the design of a road in Dubai. I am a civil engineering student and I am going to evaluate and observe the surface of a road in Dubai. We have to examine the distresses that would be existing on the surface of the road. We were supposed to pick a road at any random place of the entire UAE while capturing certain photos depicting the failure of the road.
For the research and analysis, we have selected 32A, Um AlRmool, situated in Dubai. The width of the road is 9 m and the width is 4.2 m we have also created a drawing that supports the alternatives and developed alternatives to provide a design of the surface of road that is taken into consideration. There are photos that we have captured while analysing the surface of the road.
Review & comparison of distresses
There are various stresses that are observed on the road and they are the reason for the cracks and failures that are observed in the surface of the roads. On 32A, Um AlRmool, road, Dubai which we took under consideration, we found failures in the foam of Alligator Cracking, Longitudinal Cracking and Ravelling cracks. The distresses involved in this type of cracking are reviewed and discussed below.
There are two major types of stresses that are found on the surface of the road and they are:
The distresses which are formed due to the cracking, failure or other such irregular failure of the roads is termed as the surface distress. This kind of distress originates due to various reasons which involves poor climate, fatigue, vehicles load, weathering due to sand and water. It also involves the irregularities and problems that has occurred in the construction of the roads and use of poor, inadequate material in its construction also is a major reason of the cracks and failures that are observed in the roads.
The distresses that occur on the surface of the road on the pavement sides are termed as pavement distresses. The pavement distresses is widely observed due to the use of poor quality of materials on the sides or inappropriate filling that is made on the sides of the road in order to save time and cost. These pavement distresses involves rigid and flexible pavement distresses.
This types of stresses which are observed in our case on 32A, Um AlRmool, road are:
• Longitudinal distress
• Alligator distress
• Ravelling distress
They are reviewed and compared in the discussion below. The longitudinal distresses are formed on the surface in a linear pattern and tend to damage the surface in a straight line, whereas Alligator cracks tend to form a network of cracks on the surface of the road. The cracks that are formed due to the ravelling distress are observed to have a random pattern on the surface of the road. These distresses are tend to occur on the surface of the road that is taken into consideration by us.
The cracks that are caused on the road 32A, Um AlRmool, are due to the different types of distresses and they need to be understood and repaired.
The cracks that are formed due to the above mentioned 3 distresses that are formed on the surface of 32A, Um AlRmool, road are of two types of intensity- High intensity and low intensity.
Low intensity of cracks refers to the cracks that are less than ½ inch in width and are less frequent as compared to the other cracks. This types of cracks that are observed due to these three distresses are repaired by sealing the crack in order to provide any sort of material like water, moisture that may damage the road surface by further widening of the cracks.
High intensity cracks refers to the type of cracks that are more than ½ inch wide and are more frequent as compared to the other cracks. This type of cracks have to be worked upon immediately to avoid any sort of accident caused due to it. This cracks are repaired and reduced by placing a layer of Asphalt and other mixture in the areas that are affected by these cracks.
Causes of pavement damage:
The pavement constitutes to be one of the significant part of the road. The damage of the pavement is one of the major reason for the repair of the highway roads. These damages tend to make the roads more vulnerable to the cracks and other failures. It is found that there are two types of damage that occur on the pavements (Finn, Nair, & Abdullah, 1977):
Functional pavement damage:
It refers to the damage due to the faults in the functions of the pavement. It is tend to happen when the road does not fulfil the standard specifications and standards that are set by the governing bodies to ensure the quality and safety of roads.
Structural pavement damage:
It refers to the damage due to the external factors. It is caused by excessive vehicular movement, climate adversities, fatigue of the materials used and failure of the road design. This type of damage is majorly observed on the road that has been taken under observation by us.
We have found that the pavements on the 32A, Um AlRmool, road that we have taken in to consideration were having 3 types of failures in the forms of Alligator Cracking, Longitudinal Cracking and Ravelling cracks. We have developed that there are various causes of these pavement damages and they are as follows (Finn, Nair, & Abdullah, 1977):
Quality of raw materials:
The quality and strength of pavement is very much dependent on the quality of the raw materials that are used. The materials that are used for the construction of road should be of standard quality and there should not be efforts to save cost by compromising the quality.
The spilling of strong gases and other liquids that degrades the materials from which roads are made also damages the pavements on a large scale. The reaction might not be immediate but would gradually deteriorate the quality of pavements.
The surface of the pavements becomes vulnerable to the damages due to excessive heat or cold affects
Poor maintenance of roads also contributes to the damage of the pavement on the surface of the road.
Leakage of water and other liquids from the sewage:
There are sewage and other lines carrying water and gases below the pavements. Due to any type of error, the leakage of this fluids damages the foundation of the pavements and this makes it vulnerable for a major damage on a long term basis.
Describing the failure
The failure of the road design that may lead to the cracking and damage of the roads of the highway is due to various reasons. These reasons are divided on the three types of cracks that are observed. On the 32A, Um AlRmool, road we found following cracks after evaluating and analysing it (Pynn, Wright, & Lodge, 1999).
• Longitudinal Cracking
It is a form of cracking where the cracks are formed in the form of a vertical line near the centreline or towards the side and it graduates along the surface of the road. This types of cracks do not tend to form a network but they may increase in size with respect to time. This cracks is 30.53 m long on the road taken by us.
• Alligator Cracking
It is a form of cracking where the cracks are formed in the form of network that are linked to one other which on graduation of time would create a huge crack. It is generally observed that this cracks are found at the sides of the roads near the pavements. This cracks is 67.35 m long on the road taken by us.
• Ravelling cracks
It is a form of cracking where the cracks are formed in random form and they may be very deep on the surface of the road. The ravelling distress leads to this type of cracks on the surface of the road. This cracks is 5.4m in width 25 m in length on the road taken by us.
Investigating the causes
The failures that have been observed on the 32A, Um AlRmool, road involves formation of three types of cracks namely Alligator, Longitudinal and Ravelling cracks. We have studied the cracks and developed the causes of the failure on this road. This causes involve the failure of pavements too and they are found to be as follows (Wirtgen, 1981):
This serves to be one of the reasons for the formation of the Alligator cracks on the surface of the roads. This types of cracks are formed due to the frequency of traffic and vehicles on a continuous basis and especially on a particular region.
Easy damage of the joints
It refers to poor construction of the joints at the time of filling the roads and the pavements serves to be one of the major reason of longitudinal cracks that are formed on this roads.
In appropriate Asphalt structure
It refers to the use of improper and inadequate Asphalt during the construction of the pavements on the surface of the roads that may cause the scope for damage and make the road very much vulnerable for formation of ravelling cracks on the surface.
Alternative treatments recommendations
The various types of treatments that can be carried out to ensure that the failure in the form of these cracks that are observed on the surface of the roads are as follows:
Identification through Anisotropy equipment:
It refers to the understanding of the structure in the form of pores of the cracks. In this method, we can understand the structure and design of the surface of the road through 2D images that are formed using the Anisotropy device.
Automatic Road Pavement assessment
It refers to the treatment where there is provision of assessing the structure of the pavements on regular basis using the equipment which would continuously check the quality of the pavements (Fukuhara, Terada, & Nagao, 1990).
Automatic Road Crack Detection
It refers to the treatment where there is a constant assessment of the cracks or any irregularities that may further lead to formation of cracks on the surface of the roads (Fukuhara, Terada, & Nagao, 1990).
There are various methods that are to be undertaken to avoid and reduce the cracks that are formed on the surface of the roads.
Comparison & contrast with local and international codes
In the global market there are various such problems that are observed in the correction of road surface. Similar kind of problem was found in the European roads where “European Transport Safety Council (ETSC)” has rectified the cracks in the forms of alligator cracks on their roads through Asphalt filling in the form of layers at a high temperature.
In our case too, we have recommended filling the alligator, longitudinal and ravelling cracks on the surface of the roads through using the fillings and other such material from which the roads are made by an equipment at high temperature.
In this project, I have developed and analysed the design and surface of the 32A, Um AlRmool, road Dubai. I have developed a design that helps to evaluate the cracks that occur on this road. I have also discussed various remedies and treatments that can be used to overcome this problems. I have cleared various concepts in terms of road surface design and have developed an in depth understanding of the subject. I hope the research work and remedies developed by me helps to discuss the elements that causes cracks on the surface of the roads.
Finn, F., Nair, K., & Abdullah, A. (1977). THE USE OF DISTRESS PREDICTION SUBSYSTEMS FOR THE DESIGN OF PAVEMENT STRUCTURES. Volume I of proceedings of 4th International Conference on Structural Design of Asphalt Pavements, , (pp. 3-38). Ann Arbor, Michigan.
Fukuhara, T., Terada, K., & Nagao, M. (1990). Automatic Pavement‐Distress‐Survey System. Journal of Transportation Engineering, 280-286.
Pynn, J., Wright, A., & Lodge, R. (1999). Automatic identification of cracks in road surfaces. 7th International Conference on Image Processing and its Applications, 671 – 675.
Wirtgen, R. (1981). Method and apparatus for repairing longitudinal seams or cracks in road surfaces. US 4407605 A.