VERIFICATION OF A CORRECTION METHOD FOR DEFLECTION OF BRIDGE RC SLABS MEASURED WITH A FALLING WEIGHT DEFLECTOMETER

The falling weight deflectometer (FWD) test, an effective and quantitative method, has been used to evaluate the soundness of road bridge slabs. In FWD tests using an impact load acting on asphalt concrete paved on the slabs, the measured deflection includes deformation of the asphalt concrete and is influenced by its stiffness. For periodic inspections and soundness evaluation, it is essential to eliminate the influence of temperature-dependent asphalt concrete from the measured deflection. The authors have analytically investigated a method for correcting such influence, including average temperature estimation inside asphalt concrete. However, the correction method proposed remains experimentally unverified. In this study, simulated RC slabs were constructed to verify the influence of the asphalt concrete and the accuracy of the correction method. The results verify the accuracy of the correction method in the winter season. However, the accuracy tends to decrease in the summer season, particularly for thick asphalt concrete with high average inside temperature.