Fatigue and rutting strain analysis on lime stabilized subgrades to develop a pavement design chart

Roadbeds made up of weak coastal subgrade soil, subjected to changes in moisture contents due to seasonal wetting and drying or due to any other reason, undergo volumetric changes leading to pavement deterioration. Two important factors that govern pavement design are soil subgrade strength and traffic loading. There has been a move towards the use of the mechanistic approach in pavement design in many developed countries. The scope of this study is to increase the subgrade strength with the addition of lime to fulfill design specification, this leads to economy in the structural thicknesses of the pavement on subgrade strengths of 2%, 3% and 4% CBR values with traffic intensities of 1, 5, 10, 20 and 30 million standard axles. In this study, a multilayer elastic analysis using KENLAYER computer program was carried out to determine the tensile strain at the bottom of bituminous, lime stabilized layers and compressive strain on lime stabilized subgrades. Also, the design catalogues have been developed for the above subgrade strengths.