Several experiences with pavement deflection assessments compared with conventional material sampling and in-situ testing have revealed wide discrepancies between the results of deflection back- analyses, properties measured in the field and laboratory, and observed performance. This raises concern about the accuracy and application of non-destructive deflection testing for diagnosis and prediction of pavement performance. There has been little change in the elasticity-based interpretation of deflection testing or the deflection-based overlay design procedures for more than two decades. With the increasing evidence that higher axle loads and tyre pressures can overstress thin asphalt and granular pavements, there appears to be a need to re-assess the applicability and reliability of deflection-based approaches for predicting pavement response and to update overlay design procedures. (a).
Abstract