Tapper 64

TAPPER 64 (T64) is a rolling seismic survey system developed for in-situ measurement of seismic shear-wave velocity (Vs) and thickness (H) of Hot-Mix Asphalt (HMA) pavement. The Vs is the best indicator of pavement stiffness. It consists of four 16-channel MEMS microphone arrays, about 30-cm long each, and radially-arranged to cover about 1-m width of pavement surface simultaneously. It is attached to a hitch receiver on the back of a small vehicle, and makes continuous rolling measurements at a nominal speed of 10-30 mph. Measured seismic data are processed in real time by the on-board laptop computer and the results of Vs and H are displayed in color-coded geo-referenced maps for the surveyed strip of pavement. T64 is developed by Park Seismic LLC under MnDOT contract #34287 [Federal Project Number TPF-5 (341)] funded by National Road Research Alliance (NRRA) during 2020 – 2022. Initial project development, theoretical and technical description, and the entire execution of the project are meticulously documented in a dedicated website. All hardware components were built by Norrfee Tech AB, a research consulting company in Lund, Sweden, hired by Park Seismic LLC.