2010 - NZ - Structural Capacity Definition with FWDs

Pavement performance modelling for New Zealand roading networks, currently relies on an adjusted structural number (SNP) which is a single parameter intended to describe the performance of a multi-layered pavement structure in terms of its rate of deterioration with respect to all structural distress modes, as well as non-structural modes. This parameter had its origin in the AASHO road test in the late 1950s, before the advent of analytical methods. Hence refinement to keep abreast of current practice in pavement engineering is overdue.

This research describes the basis for a new set of structural indices and how these can be used to obtain improved prediction of pavement performance: both at network level and for project level rehabilitation of individual roads. The results are (i) effective use of all the data contained in RAMM, (ii) more reliable assignment of network forward work programmes, (iii) reduced cost through targeting only those sections of each road that require treatment and (iv) more efficient design of pavement rehabilitation through informed appreciation of the relevant distress mechanism that will govern the structural life of each individual treatment length.