Utilization of the Lime as Subgrade Stabilizer in the Pavement Construction

Performance of the pavement is largely attributed to the quality of the sub-base and subgrade layer. In country like India, nearly, 0.8 million square km of the total area covers expansive soils which are also known as black cotton (BC) soil. The shrinkage and swelling characteristics of the BC soils are biggest challenge to any highway construction projects. Many researchers in the past few years had attempted to stabilize black cotton soil using different materials like lime, fly ash, brick powder mixture, etc. In the present study, an attempt has been made to investigate the use of hydrated lime to meet the CBR criterion set by Ministry of Road Transport and Highways, Government of India. BC soil collected from the different sites of the Maharashtra region has been tested for the suitability as subgrade material. It was found to be unsuitable as it has very less CBR value, as well as high plasticity. In order to improve, lime has been added to examine strength and deformation criterion of the subgrade material of the flexible pavement. The modification in the flexible pavement design due to the use of lime treated subgrade has been studied with the use of IIT Pave software. The stabilized layer thickness of subgrade has been designed as per the different lime dosages for different CBR values. Lastly, the field implication of lime stabilised subgrade has been explored in this study.