| The airport asphalt concrete pavement could produce diseases represented by rutting and cracks during service.The modified asphalt concrete with thermoplastic modified asphalt as the binder to assist the SMA grading structure becomes the main paving material for the airport pavement,when it has the maintenance and repair engineering for severely damaged areas.However,due to the reference of large aircraft with high tire pressure and multi-wheel group as load characteristics,rutting and other diseases still occur on the pavement of the airport.Therefore,this paper discusses the feasibility of using epoxy asphalt mixture,which has excellent rutting resistance,as the paving material for airport pavement under non-suspension construction conditions.Firstly,the requirements of initial strength and final strength of epoxy asphalt mixture for airport pavement under non-stop construction conditions are defined.Then,taking the gradation structure of epoxy asphalt mixture as the breakthrough point,six gradation curves were obtained by changing the chosen unit weight of 105%,100%,95%,90%,85%and 80%based on Berey gradation design theory.The volume parameter characteristics,initial road performance and final road performance of epoxy asphalt mixture under different design densities were studied.The results show that the initial road performance index of epoxy asphalt mixture can meet the navigation standard of airport road surface under non-stop construction conditions.When the chosen unit weight is 105%,100%and 95%,the epoxy asphalt mixture forms a loose framework structure.Under the other three design densities,the suspension dense structure of epoxy asphalt mixture is formed.The epoxy asphalt mixture with the loose skeleton structure has better initial road performance than the epoxy dense asphalt mixture with suspension structure.However,after the curing reaction is completed,the final road performance of the epoxy asphalt mixture of the loose skeleton structure is lower than epoxy asphalt mixture with suspended dense structure.Secondly,in order to ensure that the pavement layer of epoxy asphalt mixture on the airport road surface can meet the navigation requirements as soon as possible,this paper selects the loose skeleton structure mixture as the next research object.The author explores how to ensure the epoxy asphalt mixture has good initial pavement performance.The skeleton compactness is introduced as an index to evaluate the skeleton structure of the mixture,and the degree of skeleton compaction of the epoxy asphalt mixture was adjusted by changing the Bailey parameters(CA ratio and FA_c ratio).Then the relationship between pavement performance and skeleton compactness of epoxy asphalt mixture is established.Principal component analysis was used to analyze the initial road performance and final road performance of epoxy asphalt mixture under all different grading curves.The results show that the denser the skeleton structure of epoxy asphalt mixture is,the better its composite pavement performance is.Then the finite element model of the airport epoxy asphalt pavement overlay structure layer is established.The compression rebound modulus of the epoxy asphalt mixture in different curing conditions is determined by the uniaxial compression test as the material parameters of the model.By simulating the stress-strain response of the pavement structure under aircraft load,the change of the overlay modulus of the upper layer has a great influence on the vertical compressive strain in the superposed layer structure,and has a little influence of the other layers of the structural layer.In addition,epoxy asphalt overlay can effectively prevent the damage caused by tensile stress,compressive stress and shear stress because of its high modulus,which could also restrain the occurrence of pavement diseases. |
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