Status of roller mountable microwave asphalt pavement density sensor

This paper describes the status of development and initial field test resul ts of an innovative roller-mountable asphalt pavement density sensor. This concept measures the density of asphalt in real time using a differential m icrowave signal approach. Two antennas, one in front of a roller and the ot her behind it, measure reflected microwave signals from the asphalt, and a change in signal variability shows the operator when optimal compaction has been reached. This technique minimizes the need to quantify the hot mix as phalt properties that change during the compaction process. Several field s tudies have been conducted as part of this study to investigate microwave p roperties of asphalt pavement. Additionally, laboratory experiments were co nducted at Vilnius University to better understand the electrodynamical pro perties of hot mix asphalt pavement. This paper briefly discusses the curre nt asphalt density measurement approaches. This is followed by a descriptio n of the prototype design, construction, and subsequent field testing. Init ial results show that this new approach has promise and that additional ref inement is necessary. Future recommendations for enhancing this innovative asphalt pavement density sensor are also discussed.