Electrical Properties of Strain-Hardening Cement Composite (SHCC) with Multi-Walled Carbon Nanotubes Exposed to High temperature up to 900 °C

• Published in: Journal of physics. Conference series 2023-07, Vol.2548 (1), p.12021
• Main Authors: Jeong, W J, Wang, Q, Yun, H D, Seo, S Y
• Format: Article
• Language: English
• Subjects: Carbon; Change detection; Cooling; Electrical properties; Electrical resistance; Heating; High temperature; Multi wall carbon nanotubes; Physics; Strain hardening; Structural health monitoring; Temperature; Thermocouples
• ISSN: 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/2548/1/012021

Cement-based sensors mixed with carbon nanotube (CNTs) for structural health monitoring were studied to detect changes in electrical resistance under the influence of temperature, pressure, and mass. Strain-hardening concrete composite mixed with CNT was heated to 900 °C to analyze the electrical resistance characteristics at high temperatures. The temperature and electrical resistance were measured using a thermocouple and an LCR meter during the heating and cooling processes. The resistance trend changed between 300 and 400 °C during the heating process, after which the resistance change rate with respect to temperature decreased. At 700 °C or higher, the resistance became larger as the initial resistance increases. In the cooling process, when the temperature dropped below 700 °C, a rapid change in resistance was observed, and the resistance began to drop sharply between 500 °C and 600 °C to become negative resistance. Following this, self-sensing ability decreased owing to changes in the resistance with respect to temperature. Multi-walled carbon nanotubes could not be distinguished by scanning electron microscope imaging after heating.