ABSTRACT
The French civil Aviation center (STAC) organized in October 2013 an international Falling and Heavy Weight Deflectometer (F/HWD) round robin survey on its test facility (Bonneuil-sur-Marne, France) in order to assess interchange ability of these pavement testing devices. This survey involved seven (7) devices from four (4) countries. Each device was first calibrated using the STAC’s precision dynamic weighing system. Crossed tests between the different devices were then performed on several tests points positioned over the flexible pavement of the test facility. All devices were tested in turn repeatedly on each point. For each measurement cycle, each device, on each test point, several test sequences were performed at several load levels. A thorough analysis was performed using the large collected data base. A repeatability study using the different drops from a same fall height was first carried out for all devices and a representative drop was selected. A linearity study was then processed using results from the different load levels which allowed standardizing results relative to applied load. Next step consisted in studying the effect of temperature by comparing for a given device on a given test point the results from the different measurement cycles, allowing standardizing the results with respect to temperature. Then, the reproducibility was analyzed by comparing the standardized results from the different devices on a given test point and a given measurement cycle. Finally, this parameter was compared with the discrepancies between results from a given device when considering the different test points.
