Oral Presentation Ninth International Symposium on Life-Cycle Civil Engineering 2025

Self-Sensing Behavior of Steel-Fiber Reinforced Cementitious Sensors with Different Ultrasonication Energy-Introduced Liquid MWCNTs (109779)

Jin-Seok Woo 1 , Jin-Hui Lee 1 , Jae-Yong Jeong 1 , Hyun-Do Yun 1 , Sun-Woo Kim 2 , Wan-Shin Park 2 , Won-Chang Choi 3
  1. Department of Architectural Engineering, Chungnam National University, Daejeon, Rep. of Korea
  2. Department of Construction Engineering Education, Chungnam National University, Daejeon, Rep. of Korea
  3. Department of Architectural Engineering, Gachon University, Seongnam-si, 13120, Rep. of Korea

Structural health monitoring (SHM) is gaining significant attention in the field of building maintenance. In particular, cement composites containing uniformly dispersed carbon nano-tubes (CNTs) exhibit excellent mechanical and electrical properties. In this study, liquid multi-walled carbon nanotubes (MWCNTs) were ultrasonically dispersed to achieve uniform dispersion, and their electrical properties were compared based on dispersion energy. Additionally, to embed sensors within buildings, changes in electrical resistance were observed by comparing specimens with and without steel fibers, which were incorporated to enhance tensile performance. The impact of steel fiber incorporation on the cement composite sensors and their electrical properties was also examined. As in previous studies, uniform dispersion was confirmed at ultrasonic energy levels of 500J and 1000J. Electrical properties were evaluated by measuring the initial resistance using an LCR meter and analyzing piezoresistive performance. Further-more, considering the fatigue performance of buildings, repeated compression tests were con-ducted. In these tests, changes in electrical resistance were compared with stress and vertical strain to evaluate piezoresistive performance, and performance indicators were derived through linear regression analysis. The results showed that specimens with steel fibers exhibited higher compressive strength. Although noise phenomena slightly reduced strain recovery capabilities, these specimens demonstrated a wider measurement range, highlighting their potential for practical applications.