PSI - Issue 64

ScienceDirect Available online at www.sciencedirect.com ^ĐŝĞŶĐĞ ŝƌĞĐƚ Structural Integrity Procedia 00 (2023) 000 – 000 Available online at www.sciencedirect.com ^ĐŝĞŶĐĞ ŝƌĞĐƚ Structural Integrity Procedia 00 (2023) 000 – 000 Available online at www.sciencedirect.com Procedia Structural Integrity 64 (2024) 1152–1159

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2452-3216 © 2024 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SMAR 2024 Organizers 10.1016/j.prostr.2024.09.161 2452-3216 © 2024 marco.liebscher@tu-dresden.de; wenkui.dong@tu-dresden.de This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SMAR 2024 Organizers 1. Introduction The introduction of steel reinforcement enhances the tensile strength and ductility of concrete. Despite the widespread application and numerous advantages of steel-reinforced concrete in construction and structural engineering, it also has some drawbacks, such as corrosion issues in humid environments, construction complexity, substantial weight, and higher costs. Hence, it is essential to develop a new kind of reinforcement to replace steel 2452-3216 © 2024 marco.liebscher@tu-dresden.de; wenkui.dong@tu-dresden.de This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SMAR 2024 Organizers Abstract A novel reinforcement of mineral-impregnated carbon fiber (MCF) composite has been introduced to replace traditional steel or fiber-reinforced polymer (FRP) reinforcements, primarily attributed to its high-temperature endurance, cost-effectiveness, and sustainable utilization. Previous studies have investigated the advantages of MCF in terms of its processing and exceptional mechanical performance over a wide temperature range, however, superior inherent electrical conductivity and related piezoresistivity of carbon fibers (CFs) embedded within the matrix have not yet been explored systematically. In this study, we explore the utilization of MCF as highly sensitive stress sensors for structural health monitoring (SHM), including the electrical resistance, piezoresistivity, and underlying mechanisms of MCF composites under cyclic flexural stresses. Additionally, the effect of two different electrode configurations is examined. The findings reveal that the MCF exhibits a significant stress-sensing capacity under cyclic flexural loading within an elastic regime. Specifically, MCF with outer electrodes shows superior electrical conductivity, albeit with less significant fractional changes of resistance (FCR) and stress-sensing sensitivity. Conversely, MCF with inner electrodes exhibits the opposite trend. These outcomes provide valuable insights into the intrinsic self-sensing capability of MCF and propel its potential applications as a multifunctional composite, particularly in fields such as 3D-printed smart sensors and SHM for concrete infrastructures. Keywords: Mineral-impregnation; Piezoresistivity; Cement-based sensors; Electrical conductivity; Mechanical sensing. 1. Introduction The introduction of steel reinforcement enhances the tensile strength and ductility of concrete. Despite the widespread application and numerous advantages of steel-reinforced concrete in construction and structural engineering, it also has some drawbacks, such as corrosion issues in humid environments, construction complexity, substantial weight, and higher costs. Hence, it is essential to develop a new kind of reinforcement to replace steel © 2024 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SMAR 2024 Organizers SMAR 2024 – 7th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures The first attempt of utilizing mineral-impregnated carbon fibre reinforcements as load sensors for structural health monitoring Wenkui Dong a* , Marco Liebscher a* , Jitong Zhao a , George Karalis a , Mu Xu a , and Viktor Mechtcherine a a Institute of Construction Materials, Technische Universität Dresden, 01062 Dresden, Germany Abstract A novel reinforcement of mineral-impregnated carbon fiber (MCF) composite has been introduced to replace traditional steel or fiber-reinforced polymer (FRP) reinforcements, primarily attributed to its high-temperature endurance, cost-effectiveness, and sustainable utilization. Previous studies have investigated the advantages of MCF in terms of its processing and exceptional mechanical performance over a wide temperature range, however, superior inherent electrical conductivity and related piezoresistivity of carbon fibers (CFs) embedded within the matrix have not yet been explored systematically. In this study, we explore the utilization of MCF as highly sensitive stress sensors for structural health monitoring (SHM), including the electrical resistance, piezoresistivity, and underlying mechanisms of MCF composites under cyclic flexural stresses. Additionally, the effect of two different electrode configurations is examined. The findings reveal that the MCF exhibits a significant stress-sensing capacity under cyclic flexural loading within an elastic regime. Specifically, MCF with outer electrodes shows superior electrical conductivity, albeit with less significant fractional changes of resistance (FCR) and stress-sensing sensitivity. Conversely, MCF with inner electrodes exhibits the opposite trend. These outcomes provide valuable insights into the intrinsic self-sensing capability of MCF and propel its potential applications as a multifunctional composite, particularly in fields such as 3D-printed smart sensors and SHM for concrete infrastructures. SMAR 2024 – 7th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures The first attempt of utilizing mineral-impregnated carbon fibre reinforcements as load sensors for structural health monitoring Wenkui Dong a* , Marco Liebscher a* , Jitong Zhao a , George Karalis a , Mu Xu a , and Viktor Mechtcherine a a Institute of Construction Materials, Technische Universität Dresden, 01062 Dresden, Germany Keywords: Mineral-impregnation; Piezoresistivity; Cement-based sensors; Electrical conductivity; Mechanical sensing.