Department of Civil, Construction and Environmental Engineering, North Dakota State University, Fargo, ND 58105, USA.
School of Civil Engineering and Architecture, Hainan University, Haikou 570228, China.
Sensors (Basel). 2023 Feb 27;23(5):2602. doi: 10.3390/s23052602.
In order to achieve effective monitoring of concrete structures for sound structural health, the addition of carbon nanotubes (CNTs) into cementitious materials offers a promising solution for fabricating CNT-modified smart concrete with self-sensing ability. This study investigated the influences of CNT dispersion method, water/cement (W/C) ratio, and concrete constituents on the piezoelectric properties of CNT-modified cementitious materials. Three CNT dispersion methods (direct mixing, sodium dodecyl benzenesulfonate (NaDDBS) and carboxymethyl cellulose (CMC) surface treatment), three W/C ratios (0.4, 0.5, and 0.6), and three concrete constituent compositions (pure cement, cement/sand, and cement/sand/coarse aggregate) were considered. The experimental results showed that CNT-modified cementitious materials with CMC surface treatment had valid and consistent piezoelectric responses to external loading. The piezoelectric sensitivity improved significantly with increased W/C ratio and reduced progressively with the addition of sand and coarse aggregates.
为了实现对混凝土结构的有效监测，以确保其健康状况良好，在水泥基材料中添加碳纳米管（CNTs）为制造具有自感知能力的 CNT 改性智能混凝土提供了一个有前途的解决方案。本研究探讨了 CNT 分散方法、水胶比（W/C）和混凝土成分对 CNT 改性水泥基材料压电性能的影响。考虑了三种 CNT 分散方法（直接混合、十二烷基苯磺酸钠（NaDDBS）和羧甲基纤维素（CMC）表面处理）、三种 W/C 比（0.4、0.5 和 0.6）和三种混凝土成分组成（纯水泥、水泥/砂和水泥/砂/粗骨料）。实验结果表明，经 CMC 表面处理的 CNT 改性水泥基材料对外加载具有有效且一致的压电响应。随着 W/C 比的增加，压电灵敏度显著提高，而随着砂和粗骨料的添加，压电灵敏度逐渐降低。
