Pavement Evaluation of Kampi Ya Moto - Eldama Ravine - Kamwosor B77 Road

Abstract

Assessing the performance of pavements is crucial to determining their serviceability and structural integrity. Pavement failure and deterioration begin shortly after the road is opened to traffic. Various factors, including traffic load, soil, environmental, economic, and stress distribution, contribute to this damage. Consequently, failure and deterioration of flexible pavements can be identified by alligator cracks, potholes, ruts, settlement, and localized depression. Evaluating the pavement's condition helps monitor and plan highway sections' maintenance. Kampi ya Moto-Eldama Ravine-Kamwosor road is a class B road constructed by the Kenya National Highways Authority (KeNHA) in 2008, with a length of approximately 79.5 Km. However, the pavement on this road showed severe distress that developed even before its design life of 15 years was attained. Despite frequent maintenance, the distress continued to reappear. The road had not undergone pavement evaluation since its construction. To minimize maintenance costs within the region, it was necessary to evaluate the road pavement to determine the type and severity level of distress and establish the contributing factors of structural and functional failure, thus allowing for suitable intervention measures. The study found that the main issues affecting the project road were potholes, depression, and edge damage. The severity level of these problems, as rated by the PCI, was fair. The road lacked proper drainage, which was identified as a significant factor contributing to pavement failure. The pavement structural survey revealed varying deflection on the homogeneous section, with higher deflections in some areas. To address these issues, it is recommended to install adequate drainage, repair existing damage as a short-term intervention, and provide a 50mm overlay to address all pavement defects as a long-term intervention.