DBPapers
DOI: 10.5593/sgem2017H/63/S26.072

IMPACT OF SALINITY ON THE CONSISTENCY LIMITS OF CLAYEY SOILS

J. Fronczyk, K. Markowska-Lech, A. Tkaczyk, M. Bak
Thursday 23 November 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgemviennagreen.org, SGEM2017 Vienna GREEN Conference Proceedings, ISBN 978-619-7408-29-4 / ISSN 1314-2704, 27 - 29 November, 2017, Vol. 17, Issue 63, 571-578 pp; DOI: 10.5593/sgem2017H/63/S26.072

ABSTRACT

Anthropogenic pollution originating e.g. from waste landfills can migrate into the ground and significantly change its properties. Moreover, the interaction between soil and pollutants may change soil behavior as well as cause geotechnical problems. The aim of the study was the assessment of the impact caused by inorganic contaminants on consistency limits (plastic limit and liquid limit) of fine-grained soils. Laboratory tests were carried out on bentonite, kaolin and clay using KCl, MgCl2 and NaCl solutions. The concentrations of soluble salts were at 0.1 mol/L, 1 mol/L and 2 mol/L. Laboratory test results have shown that due to chemical interaction, the Atterberg limits of fine-grained soils had changed. The highest changes in the liquid and plastic limits were observed for bentonite. The contact of bentonite with 0.1M KCl and NaCl solutions resulted in the increase of the liquid limit values from the value determined for distilled water. A further increase of salt concentration resulted in the decrease of the liquid limit below the original value. MgCl2 caused a decrease of the liquid limit with increasing salt concentration. For all chemicals, the plastic limit values decreased from the original value. By adding NaCl and KCl, the liquid and plastic limits of clayey soil increased from their original values. The contact of clay with MgCl2 solutions increased the liquid limit from the original value, with the greatest effect observed for the lowest salt concentration. The plastic limit values did not change significantly during the contact of clayey soil with saline solutions. Moreover, no trend was observed in the liquid limit and the plastic limit values of kaolin under the influence of the analyzed salts. In conclusion, the study has shown that the impact of inorganic salts on clay and kaolin was less than that on bentonite.

Keywords: clayey soils, liquid limit, inorganic salts, ions concentration and valence plastic limit,