Conway, Ryan2017-04-112017-04-112017-02https://hdl.handle.net/11299/185567University of Minnesota M.S. thesis. February 2017. Major: Geological Engineering. Advisors: Randal Barnes, Lev Khazanovich. 1 computer file (PDF); ii, 135 pages.Concrete slab thickness is the key design characteristic of a concrete pavement. It is the most important design parameter and the major focus of control and inspection during construction. It is widely accepted that thickness deficiencies can reduce performance. In order to investigate possible correlations between Portland cement concrete (PCC) thickness with observed surface distresses, a combination of non-destructive ultrasonic thickness tests and distress surveys were performed on three existing highways prior to their rehabilitation. In addition to concrete thickness, concrete shear wave velocity was also measured in ultrasonic tests. Statistical and visual analysis were performed in order to investigate possible correlations between thickness and velocity variation and observed distress. The results of these analyses were inconclusive for thickness variation, but showed highly significant correlation for shear wave velocity. Investigation of the design documents for the some of the survey areas showed that the shear wave velocity survey was able to identify design changes which have significant impact on pavement performance. A methodology for the implementation of a shear wave velocity survey for identification of design changes which may influence pavement performance is presented.enMIRAPCC shear wave velocityPCC thickness variationultrasonic tomographyThesis or Dissertation