الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Cement-Bentonite slurry is commonly used in vertical cut-off walls, excavation trench supporting and in prevention of harmful wastes ingress. It acts as a barrier to control the flow of underground water depending on its low permeability. Different researches were carried up to study the geotechnical properties of Cement-Bentonite slurry and its hydraulic conductivity. However, there is a lack of research about using Geopolymer-bentonite as a slurry material in geotechnical barrier applications. Replacing cement with sodium silicate activated slag (Geopolymer) reduces the energy usage required for cement production and decreases the adverse impact of CO2 emissions on the environment.
This research compares the geotechnical properties and performance of geopolymer-bentonite (GB) and cement-bentonite (CB) cutoff walls to investigate the suitability of GB backfills in slurry wall applications without adding sand to the mixtures. The research investigated the engineering properties of Geopolymer-Bentonite slurry mixtures with percentages (10%, 15% and 20%) of Geopolymer using unconfined compressive strength (UCS) and direct shear test. The oedometer test was used for getting hydraulic conductivity (k) of the mixtures. Results were compared with cement- bentonite slurry and found that Geopolymer bentonite slurry samples are higher in compressive strength, shear strength and lower in hydraulic conductivity. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) were used to identify the elemental composition of materials and the reaction products in the microscopic level to verify the laboratory engineering results. The results encourage the use of geopolymer as an alternative to cement in cutoff walls.