Chloride concentration and pHs influence on the Atterberg limits of Søvind Marl

The Atterberg limits play a great role in the assessment and classification of soils. The pore water and it components have a great influence on the behavior of the clay. When finding the Atterberg limits, de-ionised water is used to homogenize the clay. De-ionised water badly resembles the pore water in the soil. It is therefor tested how using de-ionised water and a Saline solution resembling the pore water yields different results during laboratory testing.

First the Atterberg limits are found using Saline solutions with a Chloride concentration between 0 % and 8 % and a constant pH that resembling the pH of the pore water, to determine the influence of Chloride in the water used during laboratory testing. Following the Atterberg limits are found and compared using both de-ionised water and a Saline solution with a Chloride concentration and pH resembling the pore water.

It is found that for Søvind Marl, there is a correlation between the liquid limit found and the Chloride concentration and pH of the Saline solution used in laboratory testing, differences in the liquid limit of up to 30 % is observed.