Analysis Of Asphalt Pavement Structure On The Concrete Bridge Deck Under Rainy And Ice-Snow Conditions

With the booming development of highway traffic of our country,there have been more and more highways in pluvial ice-snow areas,and the commonly used bridges and asphalt pavement need to bear much rain and ice,heavy load,overload and other complex environment and loading conditions.At this time,the load-bearing deformation characteristics,stability and fatigue durability of cement concrete bridge deck asphalt pavement structure became one key problem of project construction and normal operation.So,it is necessary to do a deep research on it.For this reason,based on the physical engineering of expressway,evolution law of temperature field,stress field,waterproof durability and interlayer shear of asphalt pavement structure under three typical temperature conditions:low temperature,normal temperature and high temperature,and the influence law of various factors and its guiding significance to practical engineering are disdussed by some methods in this paper,which include field test,indoor test,theoretical analysis and numerical simulation.Firstly,based on the project,the temperature field of asphalt pavement structure of cement concrete bridge deck was tested based on the project,and the finite element simulation analysis was carried out.The temporal and spatial evolution of temperature field of asphalt pavement structure on bridge deck was obtained under three typical temperature conditions:low temperature,normal temperature and high temperature.Then the temperature variation interval of asphalt pavement on bridge deck under typical temperature was determined.Next,the influence of temperature on the modulus of asphalt mixture was discussed.Then,an integral model of five-span continuous T-beam curved bridge was established.The three-dimensional finite element method was used to analyze the structure of the bridge.The stress and deformation of the structure under the action of vehicle load and temperature load and their influence on the asphalt pavement of the bridge deck were analyzed.The linear superposition principle was used to analyze the coupling effect of the vehicle and temperature loading.On this basis,the substructure model of local bridge segment was established,and the results of deformation analysis of the whole structure were taken as the boundary conditions.The most disadvantageous load position of the corresponding stress of the pavement layer was determined.Finally,the influence of different factors on pavement layer under three typical temperature conditions was studied respectively,and presented the corresponding pavement structure design scheme.Then,according to the freeze-thaw cycle test,the change law of the strength index of the asphalt pavement surface layer with the freeze-thaw times is obtained.The influence law of bridge deck structure layer emptying water swelling on mechanical properties of asphalt pavement structure is obtained by using the finite element analysis.In addition,the advantages and disadvantages of fyt-2 waterproof binder and SBS modified asphalt in some aspects and their influence law are obtained,which include high and low temperature stability,corrosion resistance,anti-pollution,impermeability and and puncture resistance.Finally,based on the larbortatory direct shear test of cement concrete bridge deck and asphalt pavement,the influence of water,temperature,surface roughness and synchronous gravel sealing layer on interlayer shear performance are obtained.Then,an empirical formula considering the combined effect of water and temperature is put forward to,and the interlaminar shear fatigue and creep tests are adopted so as to obtain the influence of material characteristics,environmental factors,traffic load and pavement structure on the shear fatigue life and shear creep resistance.In turn,the checking method of shear stress on bridge deck pavement is put forward.