Appraisal of Pavement Failures on Ado-Ekiti- Ogbagi Road, South-Western Nigeria

A detailed appraisal was carried out on the causes of road failure in Nigeria using the Ado-Ekiti – Ogbagi road as a case study. The various requisite controls to checkmate failures on Nigerian roads were also discussed. The type of failures observed on the road are depressions of diverse dimensions, disintegration, blow-up, sub-grade intrusion, pot-holes, surface stripping, cracking and sliding resulting from anomalous stress distribution due to excessive loading. Particle size analysis, Atterberg limits, compaction and C.B.R. tests were carried out on soil samples collected from road cuttings and pot-holes. The following average values were obtained from the analysis of the samples: liquid limit (25.07%), plastic limit (12.44%), plasticity index (12.63%) and maximum dry density (M.D.D.) of 19.68 g/cm 3 . These values are within the approved standards for road construction materials. Nevertheless, poor road design or outright refusal by contractors to keep to the agreed industrial standard or specification may have contributed to the observed failures on the road. The need for effective design of roads and maintenance policy was therefore advocated.