Causes of pavement failure of Edunabon – Sekona road, Osun State, Nigeria

Abstract

The study investigated the Edunabon-Sekona road, Osun State, in Southwest Nigeria, to determine the causes of its failure. A condition survey of a five kilometre stretch of the road was carried out to visually assess and characterize the pavement distresses. In-situ density tests were conducted using the core cutter method at intervals of 500 m along the route. Soil samples were collected at these intervals for laboratory tests and selected engineering properties were determined, using standard procedures. Deflection at every point as well the representative rebound deflection was determined using appropriate equations. The condition survey showed widespread distresses. The average in-situ density (IDD) value was 1.55 g/cm3, while the maximum dry density (MDD), relative density (RD) and deflection (δ) mean values were 1.94 g/cm3, 80 % and 0.66 mm, respectively. The representative rebound deflection (δrrd) was 1.10 mm. The study concluded that the pavement failed due to the low relative density and representative rebound deflection values of the subgrade.