Conductive Properties Of Carbon Fiber Cement-based Composites Research

Carbon fiber cement composites (can be called CFCC) is a normal cementitious materials with Short-cut carbon fiber. This material is not only has excellent mechanical properties but also possesses the sensing ability, and the temperature-sensitive of the CFCC is an important aspect. When the voltage on the CFCC ends when the following is issued, it will give out heat. Using this feature, conductive concrete can be used for structural deformation calibrations, indoor heating, cold local roads and bridges of snow removal of ice.This article first analyses the effect of dispersant and silica fume in carbon fiber cement composites during the preparation of sample; And then the factors affecting the conductivity of CFCC are studies; Finally, the study focus on the temperature-sensitive of CFCC, and on this basis, the new structure has been designed that consists of carbon fiber cement composites and common cement composites, and then the possibilities of this special structure to be used for Deicing is discussed. The following conclusions have been obtained in this thesis:1. Dispersant and Silica fume, in the CFCC preparation processes, were able to enhance carbon fiber cement property in dispersivity. The effect of the two kinds of material in the dispersion of carbon fiber is the interlocked, and there is no embodiment of superposing effect.2. The electrical resistivity of CFCC would reduce as the increase of the carbon fiber to cement ratio, but increase as the time growing. When the growth of carbon fiber is less than 0.4%, the electrical resistivity of CFCC would decrease with the increase of water ratio in the sample, while increase when it is greater than 0.4%.3. Carbon fiber cement composites have a good temperature-sensitive. In the different fiber volumefly, The thermo EMF of CFCC linearly increases with increasing temperature difference, and the higher volumefly of fiber, the higher the TEP; Within the scope between 20℃and 90℃, carbon fiber cement mortar resistivity will fall with increase of temperature, and paste electrical resistivity will rise with the increase of temperature ,and fall later, showing the PTC and NTC effect. 4.With the effect of applied voltage, carbon fiber cement mortar laminated structure will heat better. In voltages of 20～30v , the average power of the sample will be between 300-500W/m~2, with about 6℃temperature rise in an hour, meeting the actual needs basically.