ASSESMENT of ASPHALT PAVEMENT ROAD DEFECTS AND MANAGEMENT in THE CASE of GAMBELLA-ITANG-JIKAWO ROAD

Abstract

This research assesses asphalt pavement defects and their management on the Gambella-Itang Jikawo road, administered by the Ethiopian Roads Administration. Addressing gaps in the existing maintenance manual, including a lack of severity ranking for cracks and shoving, inadequate prioritization techniques, insufficient consideration of wet season site road conditions survey, and limited assessment methodologies, this study aims to improve road maintenance practices through site road condition surveys, traffic data collection, asphalt core sampling and testing, and questionnaires, the research provides a comprehensive assessment. The study’s significance lies in its potential to minimize maintenance costs and time, maximize safety and customer satisfaction, and contribute to efficient road networks. Data collection employed purposive sampling for site surveys (defective sections), asphalt core samples (defective locations), and traffic data (heavy loads, particularly trucks and truck trailers). Random sampling was used for questionnaires and Identified defects include longitudinal, transverse, edge and alligator cracks, potholes, depressions, rutting, and shoving. Core tests revealed issues such as excess fines, low coarse aggregate content, high air voids, low compaction, and low asphalt mix stability. Traffic data highlighted the impact of heavy truck trailer traffic, particularly related to refugee camp logistics. Questionnaire responses indicated challenges related to equipment breakdowns, material scarcity, price fluctuations (especially bitumen), the need for regular monitoring and temperature considerations and security concerns. The research concludes that identified defects are primarily caused by a combination of poor asphalt mix quality, heavy traffic loading, water damage (vegetation, surface water penetration, and ponding), and operational challenges (equipment, material and security). Recommendations include crack sealing, overlays, full depth patching, and milling for specific types; vegetation management and improved drainage (culvert installation); asphalt mix correction; traffic pattern analysis; equipment acquisition/ rental; alternative materials exploration; bulk bitumen purchasing/storage; regular road monitoring/assessment; temperature management for suitable environment for manpower; and stakeholder engagement for security.