Laboratory tests and equipment with suction control

Since more than twenty years the Laboratorio de Geotecnia (CEDEX) has been devoted to the research and development of suction controlled devices on the basis of both mechanical and thermodynamical approaches. After reviewing the different methods used and developed in the Laboratorio de Geotecnia, a new equipment based on the control of the vapor phase in equilibrium with the soil sample at constant temperature, for high suction values is described. The results obtained with this equipment in the study of the swelling behaviour of a gypsum marl formation are included.