Multi-reference impact testing of FRP bridge deck material

Over the past few years, fiber reinforced polymer (FRP) materials have been introduced into the infrastructure engineering field as potential bridge components. As part of this process, a continuous frve-span reinforced concrete deck on steel-girder bridge over the Great Miami River in Dayton, Ohio has been slated to have it's existing deck replaced with FRP decking material. However, prior to actual replacement, initial laboratory investigations were performed on samples of FRP deck material. These investigations involved small-scale multi-reference impact tests. The purpose of these tests was to determine whether modal experimental and analytical methods could be successfully applied to FRP material and if a proper and accurate measure of in-situ flexibility could be identified from acquired impact data. Following the completion of initial tests, FRP samples were subjected to cyclic loadings and eventually failed. Multi-reference impact tests were then performed on a damaged sample. Throughout this paper, the authors discuss the before and after damage impact tests performed on this particular FRP sample, present the parameters - natural frequencies, mode shapes, flexibility - identified from these respective tests, and provide a comparison of the before and after damage test results. These results are subsequently used to assess the potential of multi-reference impact testing and modal flexibility as tools for the health-monitoring/condition assessment of FRP infrastructure systems.