ABSTRACT
The state of the practice for network structural evaluation of rigid and flexible pavements has recently taken aim towards assessing the incorporation of Traffic Speed Deflection Devices (TSDD) into pavement management activities. While several road studies by state agencies have been conducted with TSDD, this study will present findings from a comparison between the Traffic Speed Deflectometer (TSD) and the Falling Weight Deflectometer (FWD) on a 1,500-m airport runway at Vicksburg Municipal Airport, Mississippi. Normally, airfield pavement structural evaluations are performed by utilizing the FWD and Dynamic Cone Penetrometer (DCP) in conjunction with Ground Penetrating Radar (GPR). Since the FWD collects discrete data, it is of interest to pavement engineers to assess the practicality of integrating traffic speed deflection devices for more efficient and continuous data collection. The TSD utilizes a Doppler laser system for acquisition of deflection velocities along the wheel path that are then reduced towards a continuous deflection profile. This study has investigated the repeatability of collected TSD deflection profiles at 80 km/h, 56 km/h, 30 km/h and 8 km/h. The results show the repeatability between TSD trials to be largely consistent. The data collection speed was not shown to impact repeatability between trials. A comparison of aligned Impulse Stiffness Moduli (ISM) between the TSD and the Falling Weight Deflectometer (FWD) is also presented. The ISM values obtained by each device are shown to be in agreement for one side of the runway; the opposing side of the runway yielded significantly different ISM values.
