Network-level flexible pavement structural evaluation

The Kansas Department of Transportation (KDOT) has a comprehensive pavement management system known as Network Optimization System (NOS). Annual condition surveys are conducted for NOS. Currently Structural Number (SN) of flexible pavements is computed using the AASHTO equation based on the center and fifth sensor deflections of a falling weight deflectometer (FWD). However, a rolling wheel deflectometer (RWD) can be used to collect deflection data at the network level. This study was conducted to see whether SN of flexible pavements can be obtained from this RWD deflection and NOS condition survey results. In this study, FWD deflection data, collected from 1998 to 2006, were analyzed. Multiple regression analysis was done. The results showed that there is a negative relationship between SN and center deflection. Equations can be used to calculate SN based on FWD (or RWD) center deflections and network-level condition survey results. The SN is more sensitive to the center deflection than the total pavement thickness.