reasons for pavements failure
The causes of pavement failures are multifaceted, reflecting a complex interplay of environmental, material, design, construction, and operational factors. Extensive research by Carter and Darter (2016) highlights the significant influence of traffic loads and climatic conditions on pavement performance. These external forces, combined with inadequate drainage systems, can lead to moisture infiltration, resulting in the erosion of pavement layers. Al-Badran and Al-Bayati (2018) further stress the importance of proper construction practices, noting that poor compaction and improper curing can compromise pavement integrity.
In addition to these factors, deficiencies in pavement design are a major contributor to pavement failures. Thiel and Ebrahimian (2017) emphasize the importance of a well-considered pavement design, pointing out that inadequate layer thickness and neglect of material properties can lead to premature distress. This section of the literature review identifies the causes of pavement failure on the Kabale-Kisoro road.
Zumrawi (2015) highlights that water is a major factor in reducing pavement or embankment service life, increasing the need for restoration procedures. Moisture entering through cracks accelerates pavement degradation, causing the surrounding structure to deteriorate. The origins of cracks vary in form, composition, loading capacity, movement, and deformation rate. A range of potential solutions should be considered to determine the optimal maintenance approach, with a more thorough analysis of economic, design, and stress factors.
The FWD is widely recognized as the most effective tool for assessing a pavement’s structural integrity (Brown and Tam, 1987). This non-destructive testing (NDT) device, mounted on a trailer, applies an impact load to the pavement surface using a falling weight on a 300 mm diameter circular plate.
ROMDAS machines can be equipped with FWDs or other devices to measure pavement deflections. This data helps assess the structural integrity of flexible pavements, identify weak spots, and develop effective restoration strategies (Federal Highway Administration, 2002).
Pavement distress manifests in various forms, each indicating specific underlying causes and mechanisms. Li and Sui (2016) categorize pavement defects into distinct types, such as cracking, rutting, potholes, and surface deformations. This classification is essential for pavement assessment, as it allows for a more nuanced understanding of the mechanisms driving distress. Alemayehu and Hailemariam (2019) emphasize the importance of accurate categorization, noting that different types of cracking—longitudinal, transverse, and alligator—can be traced to specific stress patterns and environmental conditions. This detailed understanding is crucial for developing effective mitigation strategies on the Kabale-Kisoro road.
Systematic surface rating methods are vital for assessing pavement condition. The Pavement Condition Index (PCI), a widely used approach, provides a quantitative measure of overall pavement condition (Samarakoon & Hewage, 2016). By evaluating different distress types and their severity, the PCI offers a comprehensive assessment that informs maintenance and rehabilitation decisions. Complementing the PCI, Cheng and Chen (2019) introduce the Visual Condition Rating (VCR), which provides a deeper evaluation of specific distress types. Together, PCI and VCR equip decision-makers with a thorough toolkit to evaluate pavement distress on the Kabale-Kisoro road, guiding informed maintenance strategies.
Design and operational factors are critical determinants of pavement distress. Hossain and Islam (2018) stress that meticulous pavement design, including layer thickness and material selection, is essential for distributing loads effectively and minimizing stress concentrations. Poor design can lead to premature fatigue and cracking. Madanat and Venkataraman (2020) similarly emphasize that improper construction practices, such as inadequate compaction and poor drainage, exacerbate distress conditions.
Operational factors, particularly traffic loads and maintenance practices, also play a central role. Wang and Zhang (2016) note that heavy traffic loads can accelerate pavement deterioration, especially if designs do not account for expected usage. Timely maintenance practices, such as crack sealing and patching, are crucial for preventing minor defects from escalating into major failures.
Pavement distresses are visible surface flaws, including cracks, spots, and ruts, which indicate underlying issues or deterioration. The type and extent of distress provide important clues about future maintenance and rehabilitation needs. While methods for measuring and identifying distress may vary among organizations, defects in asphalt pavement can generally be classified by appearance (David, 2006; Luo, 2005).
ROMDAS machines, equipped with various sensors and cameras, gather data on pavement condition, including surface damage, potholes, cracking, and rutting. This data is crucial for prioritizing maintenance and repair initiatives.
