Experimental Study on Volumetric Shrinkage Behavior of Indian Clays

Abstract

Volumetric shrinkage behavior of clays due to drying is important for various engineering applications. Structures built on the plastic soils experience unwanted settlements or often experienced an increase in flow rates through fractured (cracked) clay soils used in dams and landfill cover system due to reduction in water content. The decrease in moisture content causes reduction in the soil volume due to the decrease in diffuse double layer thickness. The study of shrinkage characteristics of plastic clays requires variation of void ratio over a wide range of water contents. Laboratory estimation of entire volumetric shrinkage curve is often cumbersome due to practical problems in the accurate estimation of total volume or soil density. In this work, laboratory tests for the estimation of volumetric shrinkage curve are presented. The test results on low plastic clay and high plastic clay using the resin and standard mercury replacement techniques are presented. The residual red soil and two bentonite clays of different quality used in this work for developing the volumetric shrinkage curve from the slurry state to below shrinkage limit state. The mechanism behind the resin technique for the estimation of volume is given. The advantage of resin technique and limitation of standard shrinkage limit test method will be presented in detail in this paper.KeywordsShrinkageVoid ratioVolume changeWater contentDegree of saturation