Stress analysis of pavement structure considering Poisson ratio effect of asphalt mixtures

The Poisson ratio μ variations of the asphalt mixtures versus temperature were measured by the indirect tensile test using the digital image processing technique.Under low temperatures,when the load ratio changes from 0.3 to 0.8,μ keeps relatively invariable,and increases nonlinearly while approaching the peak load.Under high temperatures,μ grows with load ratio increasing.A 3-D finite element analysis model was used to analyze the 3 typical pavement structures under rectangular uniform load considering the changes of modulus and μ of the top asphalt layer under different temperatures.The results indicate that the μ of the asphalt mixtures has significant effect on the maximal lateral and shear strains.When the modulus ratio of the top and middle lagers is less than 0.8 and the μ of the asphalt top layer increases to a certain extent,the asphalt mixtures around the edge of wheel mark tend to flow towards both sides of the rut under the action of load,leading to the unstable rut. It is necessary to consider the harmonized combination of the asphalt structure layers and the effect of μ in the structure design of asphalt pavement.