EVALUATION OF PAVEMENT DEFLECTION MEASURING EQUIPMENT. FINAL REPORT

This report documents the research performed on evaluation of pavement deflection equipment under Contract DTFH61-85-C-00115 for the Federal Highway Administration. The following devices were included in side-by-side field tests conducted in the Austin, Texas area during the week of August 11, 1986: the Benkelman Beam, C.E.B.T.P. Curviameter, Dynaflect, Dynatest Falling Weight Deflectometer (FWD), Kuab FWD, Phonix FWD, and the Road Rater. The report includes descriptions and comparisons of the devices through information obtained from a literature search, field tests and user survey conducted for this study. The side-by-side test program was performed over a broad range of pavement structures, including thick and thin flexible and rigid pavements, and composite pavements. The measured deflections were compared statistically. Mechanistic interpretations of the measured deflection basins were made and compared. The report concludes that, based on the interpretation of field data, all devices gave comparable results on the tested pavements, except the Curviameter which gives invalid results on rigid and composite pavements. In addition, the Benkelman Beam and Curviameter exhibited much larger variability in comparison with the other devices.