Non-destructive assessment of hot mix asphalt compaction/density with a step-frequency radar: case study on a newly paved road

A Step-Frequency Radar (SFR) is used for assessing the compaction of Hot Mix Asphalt (HMA) layers. The system is composed of a network analyser and an Ultra Wide Band (UWB) antenna placed above the road surface. The measurements are carried out on a newly paved road in Cagny (Normandy, France). The SFR system provides the permittivity of the first overlay. The data is corrected from vehicle vibrations and calibrated at fixed locations. Then, the HMA compaction is deduced with a Lichtenecker-Rother (LR) model. The results are compared with standard tests (gamma bench testing on cores and in-place nuclear gauge). We show that the SFR system allows the nondestructive assessment of HMA overlay with a high density of points and with accuracy close to the compaction provided by standard tests.