TY - CHAP
T1 - Tomographic Imaging of Cementitious Materials
AU - Hou, Tsung Chin
N1 - Funding Information:
This research was partially funded by the National Science Foundation under Grant CMMI–0724022. The authors would like to express their gratitude to Professor Victor C. Li (University of Michigan) for offering unfettered access to ECC materials and for allowing us to use his MTS-810 load frame during the experimental phase of this study. For measurement of strain in the plate specimens by optical means, the assistance provided by Prof. Gustavo Parra-Montesinos (University of Wisconsin–Madison) and Mr Hai Dinh (GS E&C) was greatly appreciated. Additional assistance was provided by Dr Shunzhi Qian (Nanyang Technological University) and Dr En-Hua Yang (Nanyang Technological University).
Publisher Copyright:
© 2016 Elsevier Ltd. All rights reserved.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2016
Y1 - 2016
N2 - Cement-based materials such as concrete are brittle in nature and crack when subjected to tensile strain. Current strategies for crack detection are primarily based upon visual inspection by trained inspectors, but such approaches are labor-intensive and expensive. Direly needed are sensors that can be incorporated into structural health monitoring systems for automated quantification of crack damage. As cementitious composites remain the most dominant construction materials of structures, this study explores the use of these materials as their own sensor platform capable of measuring mechanical behavior under loading. Fundamentally, this self-sensing functionality is achieved based upon electromechanical properties. First, the piezoresistivity of cementitious composites is quantified to establish the material as a multifunctional system that is capable of self-sensing. Second, electrical impedance tomography (EIT) is proposed for measuring internal strain fields using only electrical measurements taken along the boundary of the structural element. The featured advantage of EIT is that it is a distributed sensing approach offering measurement of strain fields across 2D or 3D. Furthermore, the approach is well suited for imaging cracks that appear as conductivity reductions in EIT-derived conductivity maps. Finally, to validate the accuracy of the EIT technique, it is applied to fiber-reinforced cementitious composite elements loaded by axial tension-compression cycles and three-point bending.
AB - Cement-based materials such as concrete are brittle in nature and crack when subjected to tensile strain. Current strategies for crack detection are primarily based upon visual inspection by trained inspectors, but such approaches are labor-intensive and expensive. Direly needed are sensors that can be incorporated into structural health monitoring systems for automated quantification of crack damage. As cementitious composites remain the most dominant construction materials of structures, this study explores the use of these materials as their own sensor platform capable of measuring mechanical behavior under loading. Fundamentally, this self-sensing functionality is achieved based upon electromechanical properties. First, the piezoresistivity of cementitious composites is quantified to establish the material as a multifunctional system that is capable of self-sensing. Second, electrical impedance tomography (EIT) is proposed for measuring internal strain fields using only electrical measurements taken along the boundary of the structural element. The featured advantage of EIT is that it is a distributed sensing approach offering measurement of strain fields across 2D or 3D. Furthermore, the approach is well suited for imaging cracks that appear as conductivity reductions in EIT-derived conductivity maps. Finally, to validate the accuracy of the EIT technique, it is applied to fiber-reinforced cementitious composite elements loaded by axial tension-compression cycles and three-point bending.
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U2 - 10.1016/B978-1-78242-326-3.00007-5
DO - 10.1016/B978-1-78242-326-3.00007-5
M3 - Chapter
AN - SCOPUS:84966771368
SN - 9781782423263
SP - 121
EP - 149
BT - Innovative Developments of Advanced Multifunctional Nanocomposites in Civil and Structural Engineering
PB - Elsevier Inc.
ER -