| It is well known that ice or snow accumulation on the roadway has a great influence on transportation in cold winters. Not only does it affect national economy and life of inhabitants severely, but also it is a potential danger to traffic safety. However, the most commonly used deicing salt will reduce the endurance of the concrete road surface. Therefore, seeking the new method of deicing or snow-melting is of great importance to our daily life.Supported by the 863 program under grants No. 2002AA005010-1 and National Science Foundation under grants No. 50078042, this dissertation makes use of the Joule heating effect of carbon fiber electrically conductive concrete to deice or melt snow. The study in this paper will provide a theoretical and experimental basis for the future application of carbon fiber conductive concrete. The following conclusions and innovation can be obtained:(1) The MARC finite element analysis software and subroutine program is used to analyse the model of deicing or snow-melting and heat transfer problems in practical deicing or snow-melting successfully. The results are found to be in good agreement with relevant literature. When the wind scale exceeds 3, the influence of wind is apparent and must be taken into account in practical design. The study of the influence of heat insulation layer on the result of deicing or snow-melting illustrates that if the cost of making heat insulation layer is high and the price of the electricity is proper, the heat insulation layer can be abandoned.(2) After a series of experiments and theoretical analysis about electrically concrete concrete are finished, a smart control system is put forward to reduce the input power to 300 W/m2 or below when the ambient temperature is -20℃. This technical index in 863 programs has been partly achieved ahead of schedule.(3) Based on the research on rational ratio of conductive percolation model and making of the electrically conductive concrete, small plates and a large slab having good properties are made successfully. Especially, the volume content of carbon fibers has been reduced from previous 1.5%~2% to 0.73% (with 20% Silica fume). This content results in a substantial decrease in the cost of conductive concrete. The relevant experiments illustrates A.C. power is more suitable for deicing or snow-melting than D.C. Silica fume can improve the dispersion of carbon fibers and then reduce the electrical resistivity of carbon fiber cementious composites. At a certain volume content, when the ratio of cement, sand and stone is l:l:2(by weight), the properties of the CFRC is the best on the whole.(4)A self-adaptive fuzzy controller is designed to finish the total control procedure after considering all kinds of factors. The control charts of single power source and total system are finished. Heat radiation thermometer is most suitable for monitoring the surface temperature of concrete slab in deicing or snow-melting.(5) A series of deicing or snow-melting field tests are finished in cold climate for the first time. The results illustrate the validity of the previous computations and design and the feasibility of the method in this paper.
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