This report discusses the investigation of the premature cracking that occurred on the National Turn pike, Jefferson County (1989). A detailed distress survey was performed evaluating each slab throughout the project site. Falling Weight Deflectometer testing was performed on every third slab. In addition subgrade samples were taken, along with the installation of three water monitoring wells. Laboratory test were conducted on the subgrade samples.

Damage that occurred near the curb inlets and manholes is probably due to insufficient compaction. The remaining damage is most likely related to the combined effects of a very soft subgrade, high water tables, and traffic loads that are applied to the saturated or near-saturated subgrade.

Because complete reconstruction of this project is economically unfeasible, an intense maintenance program is recommended.

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The contents of this report reflect the views of the authors who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the University of Kentucky, the Kentucky Transportation Cabinet, nor the Federal Highway Administration. This report does not constitute a standard, specification, or regulation. The inclusion of manufacturer names and trade names are for identification purposes and are not to be considered as endorsements.