Effect of the Mixing Properties on Hydraulic Containment Performance of Soil-Cement Applied to Cutoff Wall
Takeshi KATSUMI, Masato WATANABE, Iwao SUMINAGA and Ryoichi FUKAGAWA
Abstract:Hydraulic conductivity and unconfined compressive strength on soil-cement mixtures that are applied to the waste containment cutoff wall are investigated to examine the effect of mixing proportion. Under several different sand/clay ratios, the fresh mixture is set to have the same Table Flow Value (20 - 23 cm). Processed Kaolinite clay is used for the clay portion. Cement is added at 15% of dry soil. Hydraulic conductivity tests were conducted using flexible-wall permeameters. The test results show that the hydraulic conductivity of soil-cement specimens ranges from 1 x 10-8 - 5 x 10-7 cm/s. The lowest hydraulic conductivity and the highest compressive strength are obtained when the sand portion is 80%. For the mixtures having the sand portion of 0 - 80%, the hydraulic conductivity and compressive strength is significantly correlated to the density and porosity of the specimen. Certain amount of sand portion contributes to the reduction of water/cement ratio to achieve the target Table Flow Value, consequently results in the denser mixture, and decrease the hydraulic conductivity. Key Words:Soil-cement, Cutoff wall, Hydraulic conductivity, Porosity, Waste containment, Hydraulic barrier, Sand, Clay