This paper provides general design guidance for bottom up fatigue cracking of thin flexible pavements. Throughout the paper the need for data along these lines is shown alongside the methods used to obtain the data and potential uses of the findings. The data was gathered as part of a study to evaluate geosynthetics in thin flexible pavements. Data was collected from strain gauges, pressure cells, and thermocouples in instrumented sections on a low volume road in Arkansas after 2,100 passes of controlled traffic with a Federal Highway Administration (FHWA) category 5 vehicle. Over 30,000 asphalt strain measurements were obtained. The distribution of asphalt strain measurements were heavily skewed, while the distribution of pressure measurements in the base layer were normally distributed. Finite element analysis was used to account for temperature effects, which made the asphalt strain distributions fairly normally distributed. Plots of damage were developed using transfer functions, finite element modeling, and the measured strains. The plots are central to the design approach, which improves the state of knowledge in mechanistic-empirical low volume road design.
Abstract