Detection of Water and Ice on Bridge Structures by AC Impedance and Dielectric Relaxation Spectroscopy, Phases III and IV: Continued Field Testing and Refinement of Novel Water and Ice Sensor Systems on Bridge Decks

Abstract

During Phases III and IV of this project it was determined that the physical attributes of the prototypes developed during the earlier work was inappropriate for bridge deck installations. Mn/DOT engineers required that they be planar and not require drainage through the deck. As RWIS platforms had been widely deployed on decks throughout the state, we decided to adhere to the RWIS geometric format. This necessitated a significant re-engineering of the sensor hardware before installation and testing at remote bridge sites could proceed. To that end extensive development of a robust sensor meeting these requirements was developed and tested without compromise to the earlier performance results. In large part the maintenance of performance was achieved through a significant modification of the software to include Wavelet analysis of the raw data in the determination of surface state of the sensor platform (ice vs air vs water vs electrolyte present on the sensing electrode structure). The combined regression results for raw TDR responses treated by three analysis procedures are shown to give rise to very reliable results. Unfortunately, remote field testing of sensors installed on bridge decks was not accomplished.