Abstract:
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.
摘要:
为了实现对混凝土结构健康的有效监测,在胶凝材料中添加碳纳米管(CNT)为制造具有自感知能力的CNT改性智能混凝土提供了有希望的解决方案。本研究考察了CNT分散方法的影响,水/水泥(W/C)比,和混凝土成分对CNT改性胶凝材料压电性能的影响。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),三个W/C比(0.4、0.5和0.6),和三种混凝土组成成分(纯水泥,水泥/砂,和水泥/砂/粗骨料)被考虑。实验结果表明,经过CMC表面处理的CNT改性胶凝材料对外部载荷具有有效且一致的压电响应。随着W/C比的增加,压电灵敏度显着提高,随着沙子和粗骨料的添加,压电灵敏度逐渐降低。