Geo-engineering properties of lime treated plastic soils

For a long time, we are facing problems like failures of small and big structures. The biggest problem behind this is swelling soils. This is very unstable soil. Its property varies from hard to soft and dry to wet. It exhibits swelling and shrinkage with different water content. As a result, many structures usually face excessive settlement and differential movements, which causes damage to foundation systems and other structural elements. We are aware about this situation for a long time, but unable to make improvements due to absence of technologies till now. Through physico-chemical modifications, lime can control the plasticity, swelling and shrinkage of soil effectively. Also, lime can stabilize soil through cementation which increases strength and stiffness remarkably. In this work the plasticity characteristics, swell shrinkage properties, compaction characteristics and strength properties of plastic soils with a wide plasticity range treated with lime has been evaluated experimentally. Based on the unconfined compressive strength the optimum lime content of soils has been found out. For this purpose, commercial high plastic clay (i.e. bentonite) having liquid limit of 340% is mixed with different proportions to a residual soil having liquid limit 34% and four different soils were synthesized over a wide range of plasticity. The physical properties of raw soils were found out. The four soils were amended with different lime content and the index properties as well as engineering properties have been studied by conducting relevant experiments conforming to Indian standard code of practice. Based on the experimental results it is observed that the liquid limit and plasticity reduces as lime content increases, swell and shrink characteristics decreases with lime content. Also, lime has a significant effect on strength.