Radar exploration applied to historical buildings: A case study of the Marques de Llió palace, in Barcelona (Spain)

Historical and heritage buildings have been remodelled lots of times in his large history, especially for old private ones. For some years these historical buildings have been used for other public o private uses than the one which were designed. Especially important are the remodelling carried out during the last few decades, using extensively concrete. These changes to adapt and restore the structures were performed in order to develop specific uses and, generally, they are not enough documented.The modifications made and the changes in the employ of these buildings also alter their structural behaviour, which must be calculated when new functions of the structures are considered. In this way, it is required the knowledge of the structural inner elements. The analysis of this kind of constructions has to preserve the integrity of the old remaining elements. Hence, non-destructive techniques have to be applied in order to determine exactly the old elements, the new ones and to determine the different components of the buildings. Now a day, high frequency radar techniques has been enough improved to be use to acquire a high confidentially, accurate and precise information about all these different elements and different parts of the structure.In this work we present a case study of the high frequency radar techniques applied to a S. XV building that was remodelled in several times. The last change was carried out during the 60 decade of the last century. In this arrangement, it is supposed that almost all the floors were replaced by a beam-flooring blocks structure. The GPR data obtained in the survey allow determining the specific zones affected by this last remodel work that affects mainly the floors of the first and second level of the building. It was also possible to determine the typology of the constructive elements and pieces, detecting some of the bars inside the beams. We also have detected some oldest structural change and the adopted solutions. Finally, results allow us to separate the different zones of the building depending on the structural elements supporting the floor.