Advanced Use of the Cumulative Sum of Deviations Method to Identify Uniform Pavement Sections

With the ageing of road networks all over the world, more and more emphasis is placed on the cost-effective rehabilitation of pavements. A meaningful assessment methodology is therefore required, for the evaluation of the existing structural condition of pavements, and for the effect thereof on possible alternative rehabilitation options. The mechanistic analysis of the bearing capacity of pavements is a methodology that can accurately take into account the effect of rehabilitation measures. This methodology requires that material properties (elastic moduli or stiffness, etc) of existing pavement layers be determined and modelled accurately in order to calculate the structural capacity of the pavement to be rehabilitated. However, one of the most important aspects of such a methodology is to accurately identify uniform pavement sections for modelling purposes. Currently, the cumulative sum of deviations technique is used, during the rehabilitation design phase, to identify uniform sections for modelling purposes. The objective of this paper is to give guidelines on an advanced application of the cumulative sum of deviations method / technique to identify uniform pavement sections more accurately. This method / technique takes into account the variability of the pavement structural layers along the length of the road. It is based on a holistic approach, which also includes visual assessment data, rut depth measurements and deflection bowl parameters etc. This technique will assist the designer to get more accurate and reliable uniform pavement sections, which in effect will minimize errors in the data that will be used during the rehabilitation design process.