Development of Prediction Models for Performance of Flexible Pavements in Kansas with Emphasis on the Effects of Subgrade and Unbound Layers

This study resulted from the need for better consideration of subgrade and unbound layers on performance flexible pavements in Kansas. Thus, main objective was to develop pavement prediction models with emphasis effects layers. To this end, distress data, which were collected over several years across state Kansas, including rutting, fatigue cracking, transverse roughness core analysis, served as input data into statistical models. The represented by corresponding results dynamic cone penetrometer (DCP) tests thickness layer. In addition, traffic volume average annual daily truck (AADTT). Multiple analyses identified positive correlations penetration index (DPI) rate total DPI percent good core. Negative correlation discovered between cracking code one, poor AADTT positively correlated codes one two while it had no zero. Thickness layer negatively core, Finally, recommendation minimum acceptable value California bearing ratio (CBR) provided based change rutting code. enables selection a CBR number required unit increase