The Deicing And Snow Melting Investigation Of Graphene Film-based Self-heating Pavement

In the cold region of our country,the frequent snowfall at every year always results in shutdown of transportation infrastructures,such as highways,airport runways,etc.which could trigger many traffic accidents.This would not only block the patency of these infrastructures and even seriously threaten people's lives and their personal property,but also cause huge economic losses to the nation and society.With respect to such still open questions on road icing and snowing,research communities from all over the world intend to find an efficient method to maintain the road clean from the snow and ice.Up to now,there are numerous the state-of-the-art methods developed for removing snow and ice on pavements,including human labor or machines,chemical agents,thermal energy,conductive concrete heating object,to name a few.But there are still some inevitable shortcomings,such as environmental pollution,pavement structure corrosion,high cost,facility complexity and property deterioration,limiting the wide applications of these methods.Based on the progresses made by people in the past,it is essentially critical to develop a new reliable and practical approach for melting ice and snow in practice,which enable to overcome the shortcomings of current methods and maintains the stable development of national economy.In this paper,a new type of self-heating pavement system is established by adopting graphene conductive films as a high efficient heating element,while a series of researches for heating properties and the applications on snow and ice melting are conducted simultaneously.The main contents in this thesis can be summaried as follows:(1)Through deeply investigating the reaction mechanism of graphene oxide production,adjustment of controlling parameters was made to optimize procedure in the preparation.Finally,a rapid,efficient,macro-controllable preparation method of ultralarge-size(~300?m)graphene oxide was proposed.Moreover,graphene oxide precursor with as-expected high quality was obtained to prepare conductive graphene film.(2)A glass substrate depositing based method was applied to prepare graphene films,which can realize a self-assembly,in situ reduction and easily transferring preparation.The as-fabricated graphene films possess uniform structure and stable performance,they can be transferred from glass substrate and packaged easily.Experimental studies have demonsterated that the graphene film has a tensile strength up to 12 MPa and good flexibility.Conductivity of such film with a thickness of 20?m was as high as 6000 S/m at room temperature.Moreover,note that the graphene film has excellent Joule heating effect,piezoresistive stability,temperature-dependent resistance and thermal fatigue.As a superb heating object,graphene film presents its promising on ice melting.(3)Based on the remarkable Joule heating effect,graphene films can be employed as an highlyefficient heat source to construct a new type of self-heating pavement system through separately packaged and uniformly integrated procedure.At first,we establish a heating conduction model of the heating pavement in theoty,and qualitatively analyze the factors that dominate the pavement temperature field of melting snow,affording the basic theoretical guidance on parameter analysis for experimental studies.After that,both heat transfer efficiency and thermal performance of this self-heating asphalt pavement were experimentally investigated.Finally,the influences of parameters such as ambient temperature and heat flux on the time and energy consumed during the snow melting were studied.(4)The experimental performance between graphene heating film based pavement model and a non-heat source pavement structure were compared at outdoor conditions.Through independent laboratory analysis and in-situ comparison,we have conducted the snow melting experiment of the new pavement system to study the applicability of such self-heating pavement in practical snow melting applications.The results show that the self-heating pavement based on graphene film has advantages of high efficiency,good stability,and outstanding safety in both snow melting and anti-snow requirements.