Maria Cruz Alonso, Javier Puentes
Eduardo Torroja Institute for Construction Sciences (IETcc-CSIC), Construction Dpt. Serrano Galvache 4, 28033 Madrid, Spain.
Materials (Basel). 2020 Mar 2;13(5):1106. doi: 10.3390/ma13051106.
This paper aims to demonstrate the self-protection and self-sensing functionalities of self-compacted concrete (SCC) containing carbon nanotubes (CNT) and carbon microfibers (CMF) in a hybrid system. The ability for self-sensing at room temperature and that of self-protection after thermal fatigue cycles is evaluated. A binder containing a high volume of supplementary mineral additions (30%BFSand20%FA) and different type of aggregates (basalt, limestone, and clinker) are used. The self-diagnosis is assessed measuring electrical resistivity (ER) and piezoresistivity (PZR) in compression mode within the elastic region of the concrete. Thermal fatigue is evaluated with mechanical and crack measurements after heat cycles (290-550 °C). SCC withstands high temperature cycles. The protective effect of the hybrid additive (CNT+CMF) notably diminishes damage by keepinghigher residual strength and lessmicrocracking of the concrete. Significant reductions in ER are detected. The self-diagnosis ability of functionalized SCC isconfirmed with PZR. A content of the hybrid functional additive (CNT+CMF) in the percolation region is recommended to maximize the self-sensing sensitivity. Other parameters as sample geometry, sensor location, power supply, and load level have less influence.
本文旨在展示在混合体系中含有碳纳米管（CNT）和碳微纤维（CMF）的自密实混凝土（SCC）的自我保护和自我传感功能。评估了其在室温下的自我传感能力以及热疲劳循环后的自我保护能力。使用了一种含有大量辅助矿物掺合料（30%矿粉和20%粉煤灰）和不同类型骨料（玄武岩、石灰石和熟料）的胶凝材料。通过在混凝土弹性区域内的压缩模式下测量电阻率（ER）和压阻率（PZR）来评估自我诊断。通过热循环（290 - 550°C）后的力学和裂缝测量来评估热疲劳。SCC能够承受高温循环。混合添加剂（CNT + CMF）的保护作用通过保持较高的残余强度和减少混凝土的微裂缝显著减少了损伤。检测到ER有显著降低。通过PZR证实了功能化SCC的自我诊断能力。建议在渗流区域使用混合功能添加剂（CNT + CMF）以最大化自我传感灵敏度。其他参数如样品几何形状、传感器位置、电源和荷载水平的影响较小。
