Electrical impedance tomography to monitor unsaturated moisture flows, and to detect corrosive elements and cracking in cementitious materials
Abstract »Electrical impedance tomography (EIT) is an imaging modality which uses electrical measurements to reconstruct two- or three-dimensional (2D/3D) electrical conductivity distributions in target objects. In this paper, we discuss two recent applications of EIT in structural health monitoring.
First, we study the feasibility of EIT for imaging unsaturated moisture flows in cement-based materials. In the experiments, specimens are monitored with EIT during the water ingress in the specimens. The results indicate that EIT is able to detect the moisture movement and to show approximately the shape and position of the water front.
Secondly, we propose an EIT -based multi-functional surface sensing system, or sensing skin, for detecting and localizing the ingress of chlorides and cracking – two phenomena which are of concern in many structures, including reinforced concrete structures. In the experiments, the sensing skin is tested on a polymeric and concrete substrate. The results demonstrate the feasibility of the multi-functional multi-layer sensing skin for detecting and localizing corrosive elements and cracking, and for distinguishing between them.
Biography: Aku Seppänen is an Academy research fellow at the University of Eastern Finland. He received his PhD degree in 2006 from the University of Kuopio. He has authored 31 journal papers and three book chapters. His research focuses on inverse problems, with applications to imaging, nondestructive testing, and remote sensing. Homepage
Affiliation: University of Eastern Finland Department of Applied Physics 70211 Kuopio Finland