Sample Size of Pavement Deflections by Nomograph

Abstract

Pavement deflections are used for pavement condition and structural performance evaluation, and overlay design. The Benkelman Beam and the Dynaflect devices are generally used for pavement deflection measurements. A statistical test has been developed to determine the sample size of pavement deflections; the theory is based on the statistical t-distribution. Nomographic solutions are presented. Using the nomographs, adequacy of the sample size can be checked in the field immediately after the measurement of pavement deflections, either by the Benkelman Beam or the Dynaflect. No prior knowledge of statistics is necessary to use the nomographs.