INFLUENCE OF STRESS RANGE ON PLAIN CONCRETE PAVEMENT FATIGUE DESIGN

A concrete pavement fatigue design procedure accounting for the stress range induced by the applied loads is proposed. As a matter of fact the stress range, whose value is variable in time as temperature and traffic stresses in the pavement vary, affects the concrete fatigue strength, and laboratory fatigue laws accounting for such a parameter have been defined. The Tepfers's fatigue law has been checked and corrected according, to the experimental results of the AASHO Road Test. The structural analysis of several concrete AASHO sections has been performed superimposing the seasonal and daily variations of the warping stresses with the traffic induced stresses and imposing that the cumulative damage up to failure induced by the effective number of repetitions associated to each resultant stress condition satisfies the Miner's law. A corrected design fatigue law is therefore proposed and some practical design suggestions are developped based on the analysis of the influence of the stress range.