Pavement performance evaluation for different combinations of temperature conditions and bituminous mixes

Abstract The effectiveness of 2D axisymmetric finite element analysis in predicting the performance of flexible pavements at different temperatures is illustrated in the present study. The critical parameters are examined for variation in thicknesses and material properties of the bituminous layer, to select the right binder grade of bituminous mixes for the particular climatic condition or the selected temperature profile. To observe the effect of decrement in temperature profile of the under layer on the performance of the pavement, variation in modulus of dense bituminous macadam is analyzed for material properties reported as per IRC: 37-2012. For the modern trucks, which usually have more than 0.800 MPa tyre pressure, the right binder grade of bituminous layer comprising a wearing course and dense bituminous macadam is 1700 MPa for 250 mm-thick bituminous layer. When more stiffer binder is used, drastic change in the value of critical parameters is observed. A reduction of 18.98 and 5.25 % in horizontal tensile strain and vertical compressive strain, respectively, is observed at a 200 mm thickness of bituminous layer and around 21.12 and 6.72 % in horizontal tensile strain and vertical compressive strain, respectively, at 250 mm thickness of bituminous layer. As the values of the critical parameters are noticed well within the allowable limits at 200 mm, it is concluded that the use of a stiffer binder for DBM makes the pavement safe as far as fatigue of bituminous layer and rutting in subgrade is concerned with the reduction in thickness of the bituminous layer even at higher temperature. It is observed that the use of waste plastic/rubber is found in safe limits at 250 mm-thick bituminous layer for the selected condition. It is concluded that the use of too soft a bituminous mix results in lowering the structural capacity of the pavement at high temperatures and too hard bituminous mixes would become brittle at low temperatures.