Investigation of interior stress relationships on rigid pavements along Mbagathi road, Kenya

Abstract

This research was carried out on Mbagathi Road which is approximately 6km dual carriageway that starts at Langata Road (C58) roundabout and ends at Ngong road (C60) roundabout at City mortuary in Nairobi City. Mbagathi Road was opened to traffic in 2006 and yet distress features have been observed on the road thereby indicating deterioration yet most concrete pavements operate for over 20 years without showing any signs of deterioration. This research was carried out to determine the relationship in the observed pattern of deterioration of Mbagathi Road with the performance of concrete slabs and also to determine the magnitude and pattern of deflection of pavement slabs on. The study made use of deflection measurements using Falling Weight Deflectometer, pavement condition survey, traffic loading on Mbagathi Road through a 7-day traffic survey and determination of in situ concrete slab homogeneity. This research concluded that as the ratio of radius of circular loading, (a) to radius of relative stiffness, (l) increases, finite element stresses and deflections become progressively higher than Westergaard’s. In addition, the pattern of deflections are similar the progression of Westergaard’s deflections and stresses