Bottom–Up Fatigue Cracking of Low-Volume Flexible Pavement Analysis from Instrumented Testing

Abstract

This paper provides general design guidance for bottom–up fatigue cracking of thin flexible pavements. Throughout the paper the need for the data is shown alongside the methods for obtaining the data and potential uses of the findings. The data were gathered as part of a study to evaluate geosynthetics in thin flexible pavements. Data were collected from strain gauges, pressure cells, and thermocouples in instrumented sections on a low-volume road in Arkansas after approximately 2,100 passes of controlled traffic with an FHWA Category 5 vehicle. More than 30,000 asphalt strain measurements were obtained. The distribution of asphalt strain measurements was heavily skewed, while the distribution of pressure measurements in the base layer was normal. Finite element analysis was used to account for temperature effects, which made the asphalt strain distributions fairly normal. 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.