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.
