ABSTRACT
ABSTRACT: This paper presents some results of tests performed in highly compressible materials submitted to drying. It is outlined the methodology used to obtain their SMCC, aiming the understanding of their behaviour when exposed to solar drying, an important information to achieve new disposal concepts and methods. The studied material was a silty clay waste from the alumina industry, known as “red mud”. These materials usually have a caustic liquid (pH around 13) as pore fluid. Sometimes, to neutralize the residues before their disposal, sulphuric acid is added to them. Four different techniques were used to obtain the relationship between moisture and suction. They were: the filter paper method, small tensiometers installed directly in contact with the waste inside a drying box, a suction probe and osmotic desiccators. The methodology employed and the difficulties and advantages found using these techniques are presented. The pore fluid influence in some properties such as the SMCC, the tensile strength and drying curves is presented and briefly analysed.
