Review of falling weight deflectometer deflection benchmark analysis on roads and airfields

A benchmark analysis method was developed using Falling Weight Deflectometer (FWD) data for comparative evaluation of the structural condition of flexible pavement structures. This is established as a preliminary design and analysis tool, and aspects of it are incorporated in TRH 12. Experiences with benchmark analyses on roads and airports are reviewed and adjusted criteria are recommended with a colour coded three tiered condition assessment method. Exploratory studies on additional deflection bowl parameters are conducted to gauge their potential for inclusion in benchmark analyses. Deflection bowl parameter benchmarking has found application at network level analysis in a number of road authorities worldwide. Modified Structural Number (SNP) and Pavement Number (PN) have recently also been illustrated as being able to accurately calculate from the full deflection bowl and can be used in such enhanced benchmark analyses of flexible pavement structures.