Influence of temperatures and water contents on the electrical resistance and piezoresistivity of carbon nanofibers (CNFs) cement mortar were investigated in this paper. Electrochemical impedance spectroscopy (EIS) and equivalent circuits were determined to explore the conductive and mechanical mechanism. Results indicated that the electrical resistance decreased with the increasing CNFs dosages in all environments. When CNFs content was less than 1.5%, the electrical resistance of dried specimens with environment temperature ranging from −30 °C to 20 °C increased linearly with the ascending temperature. However, when the temperature ranged from 20 °C to 40 °C, the electrical resistance decreased with one dimensional Gauss function with the increasing temperature. While, when dried CNFs mortar possessed the CNFs content of 1.5%, 2.0% and 2.5% or specimens were in water saturated state, the resistance of all specimens and temperatures conformed to one dimensional Gauss function. Moreover, when CNFs mortars were at the temperature of 20 °C, the relationship between electrical resistance and water contents could be described as exponential function of 10. Additionally, CNFs mortar with 2.5% CNFs performed favorable piezoresistivity. The strain-sensing performance of CNFs mortar deteriorated when temperature decreased from 20 °C to −30 °C. When temperature was higher than 20 °C, self-sensing property became worse with the increasing temperature. Nevertheless, the sensitivity of CNFs mortar first decreased and then increased with the increasing water contents. CNFs mortar samples in dried state and 20 °C showed the optimum self-sensing performance. Furthermore, the EIS curves were sensitive to temperatures and water contents and effective to reveal the conductive mechanism.

研究了温度和含水量对碳纳米纤维（CNFs）水泥砂浆电阻和压阻的影响。确定了电化学阻抗谱（EIS）和等效电路，以探索导电和机械机理。结果表明，在所有环境中，电阻随着CNFs剂量的增加而降低。当CNF含量小于1.5％时，环境温度为-30°C至20°C的干燥样品的电阻随温度上升而线性增加。然而，当温度在20℃至40℃的范围内时，电阻随着温度的升高而以一维高斯函数降低。而干燥的CNF砂浆的CNF含量分别为1.5％，2.0％和2。5％或试样处于水饱和状态，所有试样的电阻和温度均符合一维高斯函数。此外，当CNF砂浆的温度为20°C时，电阻和水含量之间的关系可以描述为10的指数函数。另外，CNFs砂浆的2.5％CNF表现出良好的压阻性。当温度从20°C降至-30°C时，CNF砂浆的应变传感性能下降。当温度高于20°C时，自感性能随温度升高而变差。然而，随着含水量的增加，CNFs砂浆的敏感性先降低然后升高。CNF砂浆样品在干燥状态和20°C下显示出最佳的自感性能。此外，