the damages caused by swelling clays to the roads and highways are well known, also the importance of an adequate characterization of these soils for design purposes. concerning the measure of swelling pressure in the laboratory, the controlled strain oedometer method consumes a lot of time of technical staff and that represents an important cost. in order to reduce operation costs in the laboratory, a swelling pressure device that requires a minimum of supervision time was developed. the methodological work started with a bibliographical review. thus, the conception of the swelling pressure device was based on the advantages and disadvantages of existing devices. elsewhere, an experimental work consisting in the characterization of two swelling clays, one of medium activity and other of high activity, permitted to point out the sensibility of the swelling pressure to variation of the dry density. to complete the design of the swelling pressure device, a series of aspects were considered such as shape, dimensions, materials and available stress transducers. once the shape, the internal dimensions and the material were selected, a numerical model of the device was carried out by finite element techniques in order to optimize the thickness of the walls and reduce production costs. finally, a data acquisition system is proposed as a part of the device design, completing the necessary elements to build a reliable device to measure swelling pressure with a minimum cost in terms of supervision time.