ABSTRACT
This study presents the correlation between deflections from the falling weight deflectometer (FWD) and those from the light weight deflectometer (LWD) over twenty asphalt pavement sections, which were selected as part of twelve major highways in Thailand. Each section had approximately 250-m long. The deflection measurements were taken at every 25 m interval along the trial section. Both FWD and LWD tests were performed at the same testing points. The results indicated that the correlation between deflections from the FWD and those from the LWD exhibited a linear relationship with R2 of 0.7. The FWD deflections were respectively ten times and six times the LWD deflections based on the field measurement and the elastic solution. Although a single combination of contact stresses was used, the difference in the measured and calculated deflections might be explained due to the pavement layer material characteristics, temperatures, testing constraints etc.
