Evaluation of flexible road pavements in Kenya

Abstract

Experience from some of the recently completed roads shows that road pavements have at times failed prematurely thereby leading to unplanned expenditure in the exercise of rehabilitating them. This paper outlines results of studies carried out to establish long-term behaviour of road pavements under tropical climatic conditions. The studies involved measurements of elastic deflections, pavement distortion and rutting, cracking as well as establishing traffic loading patterns for typical high standard trunk roads of varying design in Kenya. The results of the studies show that while pavements are weakened by repeated wheel load applications pavements also tend to develop strength with age. The results further showed that for a pavement approaching failure elastic deflections are a function of cracking and rutting; and that higher elastic deflections are obtained during the months of high rainfall and high temperatues. The paper recommends that there is need for road authorities to regularly monitor factors that relate to road pavement performance such as traffic loading, pavement condition, etc. in order to help in the financial planning for pavement strengthening and maintenance works and that the necessary funds should be set aside in the budget. (TRRL)