Electro-osmotic chemical treatments : Effects of Ca2+ concentration on the mechanical strength and pH of kaolin
Chang, Hao-Wei (National Taiwan University of Science and Technology. Department of Construction Engineering)
Krishna, Paramsamangalam Gopi (National Taiwan University of Science and Technology. Department of Construction Engineering)
Chien, Shao Chi (Aletheia University. Department of General Education)
Ou, Chang Yu (National Taiwan University of Science and Technology. Department of Construction Engineering)
Wang, Ming Kuang (National Taiwan University. Department of Agricultural Chemistry)

Data:	2010
Resum:	Electro-osmotic chemical treatment is an innovative method to improve the strength of soft clays for geotechnical engineering purposes; the effectiveness of the treatment may be related to treatment time, the concentration of the solutions injected, and to variation of pH in the clay. The objective of this study was to investigate the relationship between the above-mentioned factors and the improvement in strength when calcium chloride solution was used as an injection material. A series of tests was carried out by injecting different concentrations of calcium chloride solution into a kaolin suspension, for different treatment times, during electro-osmosis. After the tests, the pH, cone resistance, water content, and concentration of Ca in the kaolin at different locations were measured and analyzed. The results show that the concentration of Ca in the kaolin, the pH, and the strength were increased near the cathode with increases in concentration of CaCl2 and treatment time. An insignificant increase in strength, due to ion exchange over the entire specimen, for short treatment times of 2 to 24 h, was observed because of a small increase in concentration of Ca and in pH. During long-term treatment (120 h), a considerable increase in concentration of Ca (137. 0 mg/g) and pH (pH = 10) was observed near the cathode. This led to a pozzolanic reaction, which in turn caused a significant increase in the mechanical strength of the kaolin.
Drets:	Tots els drets reservats.
Llengua:	Anglès
Document:	Article ; recerca ; Versió publicada
Matèria:	Electro-osmotic chemical treatment ; Ion exchange ; Pozzolanic reaction ; Calcium chloride
Publicat a:	Clays and Clay Minerals, Vol. 58, Núm. 2 (2010) , p. 154-163, ISSN 1552-8367

DOI: 10.1346/CCMN.2010.0580202

10 p, 1.1 MB  Accés restringit a la UAB

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