Longitudinal cracking in pavements due to drying shrinkage of high-plastic subgrade soils has been a major problem in Oklahoma. Annual maintenance to seal and repair these distress problems costs significant amount of money to the state. The longitudinal cracks occur usually within the so-called edge moisture variation distance, where the climate plays a significant role in terms of changes in moisture content. The current study investigated the longitudinal drying shrinkage problems in pavement subgrade soils at three sites in Oklahoma. Two of the sites located in Norman and Oklahoma City are bike trails and the third site is along the Interstate Highway I-35 in Ardmore. The soil specimens collected from these sites were tested for the basic index properties as well as suction and unsaturated diffusivity measurements. Various ranges of the test results have been implemented in a suction profile and tensile stress prediction models for evaluating the typical suction changes and the corresponding tensile stresses in subgrade soils

US Transportation Collection