Document Type
Thesis
Date of Award
5-31-1990
Degree Name
Master of Science in Civil Engineering - (M.S.)
Department
Civil and Environmental Engineering
First Advisor
Raj P. Khera
Second Advisor
Jay N. Meegoda
Abstract
Experiments were conducted on calcium bentonite from different sources to determine its suitability as a material for slurry wall. The emphasis was placed on cement-bentonite types of materials. A few tests were conducted on specimens consisting of soil-bentonite materials. Permeability, swelling potential, and immersion tests were conducted. Specimens were initially permeated with water to determine which variety of bentonite was most suitable and later with chemicals. In cement bentonite specimens, the effect of addition of blast furnace slag, fly ash, and sand were also studied. Addition of slag cement lowered the permeability value by an order of magnitude, and with increased slag content the permeability reduced further. A portion of the slag cement, replaced with fly ash from the Mercer generation station gave lower permeability value than without fly ash. Specimens with bentonite and cement, when mixed with 10 percent of sand gave lower permeability values than without sand. Chemicals did not alter the permeability significantly. Permeability values decreased from the initial values with the increasing duration of flow indicating that calcium bentonite is a stable material in an chemical environment. There was no significant variation in the swelling index of calcium bentonite in different pH environments. Immersion tests on cement bentonite specimens indicates that the concentrated chemicals attack severely compared to the diluted chemicals. Specimens in concentrated acid crumbled whereas in concentrated phenol they developed wide cracks. Toluene did not affect the specimen significantly. The experiments conducted so far provide an encouraging results to use calcium bentonite (from Greece) with slag cement as material for slurry wall. There is a need to study further the effect of chemicals to substantiate this conclusion.
Recommended Citation
Tirumala, Ramnarayan K., "Calcium bentonite in containment structures" (1990). Theses. 2970.
https://digitalcommons.njit.edu/theses/2970
