ABSTRACT
Pavement pothole is resulted by both environmental and structural causes. It is difficult to maintain the road on the same specification that was owned at the opening and problems start to appear represented in the flexible pavement cracks, holes and undulations and so on. Recognizing defects and understanding their causes helps us rate pavement condition and select cost-effective repairs. Periodic inspection is necessary to provide current and useful evaluation data. It is recommended that ratings be updated every year.
Maintenance is an essential practice in providing for the long-term performance and the esthetic appearance of an asphalt pavement. The purpose of pavement maintenance is to correct deficiencies caused by distresses and to protect the flexible pavement from further damage. A condition rating of the flexible pavement will help determine what pavement maintenance technique is necessary.
A methodology was proposed to investigate the flexible pavement condition; this study focuses on flexible pavement. A manual survey is performed following ASTM D 6433. The flexible pavement is divided into sections. Each section is divided into sample units. The type and severity of sample distress is assessed by visual inspection of the flexible pavement sample units and the quantity of each distress is measured. Typically, this procedure requires a team of at least two engineers.
The flexible pavement evaluation results from the manual PCI survey revealed that all sections of road were fair condition. Considered the section of road that surveyed, describing the condition pavement of the all road. The flexible pavement that has been studied at Koums area would seem to require maintenance. Thick overlay (sometimes called surface treating) is needed in a comprehensive pavement.
CHAPTER ONE
INTRODUCTION
1.1 Background
Roads play a major role in the development of all countries and societies by providing the essential links between different parts of the country to facilitate the movement of people and transport of goods. The importance of roads increases as the area of the country increases, especially in the absence of other means of transport such as railways and waterways, which is often occurred in developing countries.
The history of road engineering gives us an idea about the roads of ancient times. Roads in Rome were constructed in a large scale and it radiated in many directions helping them in military operations. Thus they are considered to be pioneers in road construction.
Since early 70's there has been vigorous economic development of countries on the Mediterranean coast of North Africa. However, this area lies completely or partially within regions of so called hot arid climates (Bashir, 2006).
The road network density is generally satisfactory, the total length of Libya's paved road network is about 34,000 km (2010), of which about 15000 km main roads, the secondary and agricultural road network is about at 18,000 km. The unpaved network is about 3,000 km long. There is also a network of seasonal tracks about 50,000 km (RLTA, 2010).
The highway network is classified into four main roadway types
1- Expressways: Roads arteries outside municipal borders link the cities and regions with two carriage ways and at least four lanes (two lanes or more in eachdirection).
2- Main roads: Roadways linking cities and regions or serving cities within municipal boundaries, there are single carriageway roads for good paved standard or dual carriage ways with 2 lanes in eachdirection.
3- Secondary roads: These link district centers andvillages.
4- Agricultural roads: Roads linking agricultural land and farms withmarkets.
Most of these roads have been implemented during the seventies and early eighties of the last century, and, therefore, most of them have reached old design. The weakness and lack of periodic maintenance programs and delayed repairs of the damage suffered by paving the roads in that there have contributed on functional and structuraldamage.
It is difficult to maintain the road on the same specification that was owned at the opening and problems start to appear represented in the flexible pavement cracks, holes and undulations and so on (Bashir, 2006).
It is easy to see why pavements deteriorate at various rates and why we find them in various stages of disrepair. Recognizing defects and understanding their causes help us of evaluate pavement condition and select cost-effective repairs. The flexible Pavement potholes shown on the following pages provide a background for this process. Periodic inspection is necessary to provide current and useful evaluation data. It is recommended that ratings be updated everyyear.
Obviously, most Pavement pothole results from both environmental and structural causes. However, it is important to try to distinguish between the two in order to select the most effective rehabilitation techniques.
1.2 Problem of Study:
Pavement pothole is a result of complex distress as pavement cracking through fatigue under repeated loadings and environmental cycles; deformation of the flexible pavement structure through shearing; and disintegration of materials when mechanical or chemical bonds are broken through weathering, infiltration, or loading. Underground conditions, structures, traffic characteristics, and environmental contexts all have a tremendous impact on the performance of highway pavements (Gary et al.,2009).
Due to variations in construction and material quality, the age of apavement structure may not accurately indicate the condition or the performance of the flexible pavement. However, the age of the flexible pavement may be used to further categorize pavement sectionsand may provide a relative condition of those sections (ADO,1999).
At the opening of the road, usually with high quality and specifications. But the passage of time and with the use of the road because of traffic loads applied on the road on a daily basis and continuous in addition air factors such as daily and seasonal rains and changes in temperatures, it is difficult to maintain the road on the same specification that was owned at the opening and problems start to appear represented in the flexible pavement cracks, holes and undulations and so on (RLTA, 2010).
Generally, good design does not prevent the occurrence of such defects in case of default in the construction or in the case of non-construction according to engineering specifications (cases of non-compliance with specifications). The cost of maintenance expense exceeds the cost of construction itself because it was disrupting traffic generated by the delay in the establishment of these roads.
Preventive maintenance is an essential tool for extending the life of a pavement. Used early in a pavement's life, preventive maintenance corrects small problems before they become big problems, saves money, reduces delays and improves safety and ride ability.
Therefore profession engineer maintained until the roads are always safety ways and the movement for passengers or goods are a comfortable and economical at all times (Bashir,2006).
Not all pavement structures are constructed alike, nor do all pavement structures perform identically. Therefore, it is necessary to monitor the maintenance requirements of each general type of pavement. By monitoring the performance of pavement sections of similar construction and usage, sufficient information can be developed to forecast maintenance requirements (ADO, 1999).
1.3 Objective of Study:
1. Investigate and evaluate the asphalt Pavement potholes by using pavement condition index (PCI).
2. Estimate the maintenanceoptions.
1.4 Scope of Study:
This study focuses on the estimation of roads flexible pavement condition through visual surveys using the flexible pavement Condition Index (PCI) method (following ASTM D6433 standard) of quantifying pavement condition. To accomplish this goal, part of the road network in Al-khoms area wasused.
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Item Type: Project Material | Size: 67 pages | Chapters: 1-5
Format: MS Word | Delivery: Within 30Mins.
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