Temperature correction of falling weight deflectometer measurements

In order to design pavements it is important to know the bearing capacity of the pavement. The bearing capacity can be derived from deflection measurements by a Falling Weight Deflectometer (FWD). The deflections next to the load center on asphalt pavements are strongly influenced by the temperature of asphalt layers. To get comparable results, the measured deflections have to be corrected to a reference temperature. The aim of the presented research project was to develop a function for temperature correction of FWD deflections which is suitable for the conditions in Germany. For this, two existing asphalt pavements were instrumented with temperature sensors in the asphalt layer, which continuously log the asphalt temperatures. FWD deflection basins were measured on the instrumented test sections at different temperatures and seasons. In addition, 20 more test sections with different thicknesses and asphalt materials were measured by FWD at different temperatures and seasons.