简单介绍了碳纤维水泥基复合材料的制备及其电阻率测试方法,研究了不同掺量的碳纤维水泥基复合材料电阻率随温度变化的规律.研究结果表明,碳纤维水泥基复合材料具有温敏特性,在温度升高的初始阶段,试件电阻率随温度的升高而下降,呈现NTC效应;当温度升高到一定数值,电阻率随温度的升高而逐渐升高,呈现出PTC效应,并且随着碳纤维掺量的变化,NTC/PTC转变温度也发生变化.基于试验结果,对NTC/PTC效应的转变机理进行了初步探讨.
An introduction was given to the methods for preparation of the carbon fiber reinforced cement-based composites (CFRC) and its electrical resistivity testing. The relationship between the electrical resistivity and temperature of CFRC at different mixing ratios of carbon fiber was studied. The result shows that CFRC is of certain thermal-resistance characteristics, and its electrical resistivity decreases with the increase of the temperature at the initial stage of temperature rise, demonstrating NTC effect of the test samples, and that the electrical resistivity increases with the rise of the temperature as the temperature rises to a certain value, demonstrating FTC effect of the test samples. It is also indicated that, with the variation of the mixing ratio of carbon fiber, the NTC/PTC transition temperature will also change. Moreover, the mechanism of transition of NTC/PTC effect was also discussed based on the experimental results.