Mortar sensors were fabricated as beams incorporating different amounts of carbon nanofibers (CNFs) synthesized in-situ on cement particles. Changes in electrical resistivity were measured and compared to recorded changes in compressive stress, temperature, and humidity. Sensing mechanisms and corresponding models were developed. The findings of the study indicate that the piezoresistive effect is influenced by the critical concentration of CNFs inside the composite matrix and the tunneling effect. In addition, water absorption and desorption, as well as the amount of chemically bound water played an important role in humidity sensing. Thermal fluctuation-induced tunneling conduction was dominant for the temperature sensitivity.

中文翻译：

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纳米改性波特兰水泥复合材料的传感机制


砂浆传感器被制成梁，其中包含不同数量的碳纳米纤维（CNF），在水泥颗粒上原位合成。测量电阻率的变化，并与记录的压应力、温度和湿度的变化进行比较。开发了传感机制和相应的模型。研究结果表明，压阻效应受到复合基体内部 CNF 临界浓度和隧道效应的影响。此外，水的吸收和解吸以及化学结合水的量在湿度传感中发挥着重要作用。热涨落引起的隧道传导对于温度敏感性起主导作用。