PSI - Issue 64

ScienceDirect Structural Integrity Procedia 00 (2023) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2023) 000 – 000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

Procedia Structural Integrity 64 (2024) 539–548

SMAR 2024 – 7th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures Piezoresistive investigation of calcium aluminate cement-based MWCNT/NCB composite at elevated temperatures Alamgir Khan a , Yingzi Yang a, *, Hassan Bilal b , Zhichao Xu a a School of Civil Engineering, Harbin Institute of Technology, Harbin, 150090, China b Department of Engineering, University of Palermo, Viale Delle Scienze, 90128 Palermo, Italy Abstract Ordinary Portland cement (OPC)-based self-sensing smart sensors can be affected by exposure to elevated temperatures, which can negatively affect their mechanical strength, electrical resistivity, piezoresistivity, stress/strain sensitivity, and reversibility. Therefore, this study aimed to investigate the mechanical properties, electrical resistivity, and piezoresistive characteristics of calcium aluminate cement (CAC)-based multiwalled carbon nanotube (MWCNT)/nano carbon black (NCB) conductive composite sensors with different concentrations at normal temperature and after exposure to 200 °C and 400 °C. The results indicate that the CAC-based MWCNT/NCB composite fillers exhibit good mechanical properties, low electrical resistivity, and fully reversible piezoresistive sensing properties at both normal and elevated temperatures. The elevated temperature treatments led to a more extensive sudden increase in piezoresistivity. Moreover, CNCB2 with higher concentrations achieved peak compressive strength and fractional changes in electrical resistivity (FCR) sensitivity at 200 °C. Therefore, this study provides a new understanding and pathway for developing CAC-based MWCNT/NCB smart sensors for structural health monitoring (SHM) and for multifunctional applications at normal and elevated temperatures. © 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. Keywords: Calcium aluminate cement, MWCNT/NCB, Electrical resistivity, Elevated temperature, Mechanical properties, Piezoresistivity. SMAR 2024 – 7th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures Piezoresistive investigation of calcium aluminate cement-based MWCNT/NCB composite at elevated temperatures Alamgir Khan a , Yingzi Yang a, *, Hassan Bilal b , Zhichao Xu a a School of Civil Engineering, Harbin Institute of Technology, Harbin, 150090, China b Department of Engineering, University of Palermo, Viale Delle Scienze, 90128 Palermo, Italy Abstract Ordinary Portland cement (OPC)-based self-sensing smart sensors can be affected by exposure to elevated temperatures, which can negatively affect their mechanical strength, electrical resistivity, piezoresistivity, stress/strain sensitivity, and reversibility. Therefore, this study aimed to investigate the mechanical properties, electrical resistivity, and piezoresistive characteristics of calcium aluminate cement (CAC)-based multiwalled carbon nanotube (MWCNT)/nano carbon black (NCB) conductive composite sensors with different concentrations at normal temperature and after exposure to 200 °C and 400 °C. The results indicate that the CAC-based MWCNT/NCB composite fillers exhibit good mechanical properties, low electrical resistivity, and fully reversible piezoresistive sensing properties at both normal and elevated temperatures. The elevated temperature treatments led to a more extensive sudden increase in piezoresistivity. Moreover, CNCB2 with higher concentrations achieved peak compressive strength and fractional changes in electrical resistivity (FCR) sensitivity at 200 °C. Therefore, this study provides a new understanding and pathway for developing CAC-based MWCNT/NCB smart sensors for structural health monitoring (SHM) and for multifunctional applications at normal and elevated temperatures. © 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. Keywords: Calcium aluminate cement, MWCNT/NCB, Electrical resistivity, Elevated temperature, Mechanical properties, Piezoresistivity. © 2024 The Authors. Published by Elsevier B.V. Peer-review under responsibility of SMAR 2024 Organizers

* Corresponding author. Tel.: +86-136-24614006. E-mail address: yzyang@hit.edu.cn * Corresponding author. Tel.: +86-136-24614006. E-mail address: yzyang@hit.edu.cn

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.2024.09.303 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 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