Selection of Most Suitable Stabilized/Solidified Dredged Soil to Use in Highway Subgrade Layer Construction

The dredging of lakes, rivers, drains or water bodies etc. is a regular practice all over the world and disposal of these dredged soils is a major problem due to scarcity of open land in the urban areas. At present for handling this problem, engineers and soil experts are trying to find out alternative solutions such as use of dredged soil as constructional material in different development projects. This study deals with the contaminated dredged soil of Najafgarh drain, a major connecting drain of Yamuna river (Delhi) and aims at its use as alternative highway subgrade material after stabilization/solidification with cement, bottom ash and steel slag in different ratios. As the dredged soil contains certain amount of organic matter that influence the chemical process of stabilization/solidification, thus thermal treatment of raw dredged soil has also been carried out to ascertain its effects on stabilization/solidification. At the end, samples out of all those have satisfied the acceptance criteria of highway subgrade material have been selected and finally the most suitable sample out of them has been decided along with assessment of its degree of suitability to use as highway subgrade materials. For both the cases, concept of fuzzy logic of Prof. Latfi Zadeh has been introduced.