Microscopic Analysis Of Asphalt Pavement Water Damage Based On Computational Fluid Dynamics

With the construction and development of China’s highway, semi-rigid asphaltpavement has been widely applied.However, due to natural factors as well as factorssuch as vehicle load, many highway open to traffic several years later, the asphaltsurface will produce a large number of pockmarked face, loose, slurry pump,potholes, shaped crack and other damage phenomena.A variety of destructivephenomenon are related with water directly or indirectly.To this end, our road workers conducted a lot of research around the waterdamage problem.A lot of people committed to study the failure mechanism and extentof damage of water damage, protective remedial measures and new materials.In orderto calculate the size of the hydrodynamic pressure and the schedule changes,a part ofresearchers committed to use the finite element method to simulate asphalt pavementstructure and to analyze the failure mechanism of asphalt pavement early waterdamage.However, very few people analyze the pressure distribution of the asphaltpavement pore and the stress distribution within the structure of asphalt mixture underhydrodynamic effects from the microscopic point of view.In this paper, based on previous studies combined with computational fluiddynamics,assume the asphalt pavement pore model.The pressure distribution, the fluidvelocity distribution and the distribution of the flow field of the inside of asphaltpavement pores has been analyzed.The stress distribution of the asphalt around thepore is calculated and analyzed.Then combine the test measured cohesion strength ofthe asphalt itself and adhesion between asphalt and aggregate to determine the formand location of the asphalt early water damage.Firstly, by observing the distribution of pore asphalt pavement,combining thefactors such as shape and size of the pore in the specimen, the number of gap junctionpores and so on. Analyze the form of the pore in the asphalt pavement.Combining with test measured adhesion strength between asphalt and aggregate to determine theform and location asphalt early water damage.Secondly, based on the basic theory of fluid dynamics and turbulence theory,select the standard k model which used to calculate turbulence then calculateand analyze the standard model of asphalt pavement pore.Get the distribution of porefluid pressure within the asphalt pavement; explores the location of the firstoccurrence of damage about the asphalt mixture; compare the distribution of fluidpressure in the case of different number of gap junction pores, size and connectivitycas; analyze the case of the outlet gap size has changed.Six cases about the colsed gaplied in a different location has been analyzed and the effect of the internal porepressure distribution caused by different position of closed gap has been studied.Thirdly, the establishment of a fluid-structure interaction model is finished, theone-way coupling has been applied and the stress distribution of asphalt mixture inthe time-varying loads has been calculated.Through the analysis of the size anddirection of the stress,the possible failure location and the order of the destructionabout asphalt mixture has been inferred.Finally,by using previous test methods,measure the size of the cohesion strengthof the asphalt itself and adhesion between asphalt and aggregate,contrast the forces ofasphalt mixture and analyze the failure modes about asphalt mixture early waterdamage.