SHEAR STRENGTH BEHAVIOR OF BENTONITE MODIFIED BY TETRAMETHYLAMMONIUM CATIONS
Over the past decades, bentonite exchanged with quaternary ammonium cations to form organobentonite has gained increasing attention. Due to its high sorption capacity for organic contaminants and low friction angles, organobentonite has many applications, including in the areas of contaminant site remediation, landfill clay liners, and as a pipe jacking lubricant and drilling mud. Although many properties of organobentonites have been studied in detail, such as sorption capacity, swelling, and hydraulic conductivity, little data are available on the strength of this engineered clay. This study presents the results of the shear strength behavior of tetramethylammonium cations exchanged bentonite (TMA-bentonite) as a function of organic loading. TMA-bentonites had higher shear strength and higher hydraulic conductivity than the unmodified bentonites. The initial shear modulus increased with the amount of TMA loaded on the bentonite surfaces, i.e. as the organic loading was increased. The tested samples were normally to lightly overconsolidated, but always exhibited peak behavior and positive pore pressures in the stress strain curve. This study sets the stage for further investigation of more complicated organic cations, such as tetramethylammonium (TEA) and hexdecyltrimethylammonium (HDTMA).
bentonite hydraulic conductivity organobentonite organoclay shear strength tetramethylammonium
Bate BATE Susan E.BURNS
School of Civil and Environmental Engineering, Georgia Institute of Technology, USA
国际会议
International Symposium on Geoenvironmental Engineering(国际环境岩土工程研讨会
杭州
英文
543-548
2009-09-08（万方平台首次上网日期，不代表论文的发表时间）