Polyacrylonitrile (PAN) based graphite felt , made of PAN precursor in an inert gas in high temperature and antipyretic have a variety of forms, such as continuous products, carbon fiber, short carbon fiber and short carbon fiber. It has many applications in engineering because of its excellent physical and chemical properties and electrical conductivity. Continuous carbon fibers are often used in resin matrix composites as reinforcements.
The most widely used short cut carbon fiber is a small amount of chopped carbon fiber mixed with concrete, forming carbon fiber concrete, which has a variety of functional characteristics such as pressure sensitivity, temperature sensitivity, thermoelectric and electrothermal effects. Based on the above features, carbon fiber reinforced concrete materials can be used in the temperature and deformation self diagnosis and adaptive aspects of concrete structures, such as intelligent deicing and snow melting system of concrete pavement [5]. But the production process of continuous carbon fiber is relatively complex, the price is higher; and the short cut carbon fiber mixed with concrete, need the chopped carbon fiber completely uniformly dispersed in the concrete, it is a big problem in materials, the functional properties of carbon fiber reinforced concrete material is affected, especially the heating effects the size based conductive network formation in carbon fiber, namely by carbon fiber components reduce the concrete resistance and Joule heat.
Graphite felt is a soft cloth formed by the bonding of chopped carbon fibers, and each fiber forms a conductive network with each other. In the concrete smart materials, because the carbon fiber felt easily cut into the desired shape size, sample only need to be paved in concrete.
PAN based graphite felt with electrothermal effect good and stable; the thermal efficiency of carbon fiber of different types are different, therefore, can choose the optimal thickness, to achieve efficient and economic purposes; in a certain temperature range, the temperature stability of PAN based graphite felt the rise and the input power is proportional to the input power can be selected according to the need the temperature rise; graphite felt with a temperature sensitive effect, linear resistivity increased with the temperature of graphite felt decreases, this effect can be used for temperature detection structure; combined with temperature sensitive effect and heating effect, is expected to realize the adaptive temperature regulating structure.
