Main Roads Western Australia measures the performance of Western Australias road maintenance contracts using performance indicators derived from the data collected by the falling weight deflectometer (FWD) and the multi laser Profilometer (MLP). At present, the performance indicators derived from FWD data are based on simple empirical observations. These empirical strength indicators are constructed using only a fraction of the collected data. At present, most of the FWD data collected by Main Roads Western Australia is ignored. This paper discusses new structural performance indicators that could be employed by Main Roads Western Australia to make better use of its FWD data. The new indicators are derived via a theoretical consideration of the failure mechanisms in asphalt pavements, and existing knowledge of the layer thicknesses within the test pavement. Unlike the empirical strength indicators, they utilise the full spectrum of FWD data collected. A finite element program was used to evaluate these new performance indicators against those currently in use. The paper concludes by applying the new and old structural performance indicators at both network and project levels. The asphalt life predictions drawn from the both sets of indicators are compared to observations made on the Perth metropolitan road network. (a) For the covering entry of this conference, please see ITRD abstract no. E217099.
Abstract