A site assessment of pavement cracking in a drought environment: a case history

This paper builds upon the findings of a site investigation into the causes of longitudinal cracks that developed soon after the re-construction of Himes and Johnson Streets in the City of Norman, Oklahoma between May to September 2012. The re‒construction of the city street pavement and base course were completed during a protracted drought period, and shortly after completion of the pavement section longitudinal cracks occurred predominantly along the curb line. The case history concluded that the drought conditions resulted in significant subgrade soil shrinkage. The shrinkage caused changes in soil suction with depth resulting in tensile stresses in the asphalt pavement and stabilized subbase that lead to the pavement cracking. A simple practical moisture/suction variation model with depth (Hamberg) was used in conjunction with the soil water characteristic curve (SWCC) to make predictions of the soil suction changes that are resulting in the pavement cracking. The paper documents the comparison of the Hamberg model used in the case history with the Mitchell and finite element (FEM) models. The purpose of the comparison was to see if improved accuracy of the Mitchell model and a finite element model resulted in significant changes in the prediction of soil suction