Determination of sulfate content in marine clays

Improving the engineering behavior of soft clays using lime has been used for several decades. Even though chemical stabilization of clays has proved to improve the engineering properties, problems arise when calcium – based stabilizers are used in soils rich in sulphate bearing minerals. Therefore lime stabilization technique should be cautiously applied in sulphate enriched environment or in marine clays containing sodium sulphate. Sulphate content is thus clearly the most important property to consider when evaluating such soils as foundation medium or for construction purposes. Thus the key issue in deciding how to properly stabilize sulphate bearing soils using lime is to efficiently determine the sulphate content of soils and to determine the threshold quantity of sulphate likely to cause damage. This paper focuses on a comparison of different methods used to quantify sulphate in soils.