Adobe in monumental architecture: chemical-physical analysis, archeology and 3D reconstruction to determine building techniques in the La Joya (Mexico) and Arslantepe (Turkey) sites

This paper aims to further the knowledge of the raw materials used in the elaboration processes of the earthen architecture in archaeological sites. Although earth as a building material has a wide distribution in the world, there is little information on the way raw materials were processed in antiquity. For this reason, we are proposing an "architectural"study comparing some of the buildings of two pluristratified sites: on the one hand Arslantepe (V millennium BC - VII century AD), in the Province of Malatya, Turkey, and on the other hand La Joya (I millennium AD), in the State of Veracruz, Mexico. The methodology used to achieve the objectives is based on: a) the chemical, physical and mechanical analysis of building material samples - mud-bricks, mud-plasters and fills; b) the architectural analysis of wall bonding and construction systems; and c) the 3D virtual reconstruction of the major buildings, supported by archaeological evidence. The combination of these different lines of evidence allowed explaining and contextualizing the main features of earthen architecture in these two cultures. Preliminary results reveal that the ancient builders developed a profound knowledge of the possibilities of the building materials in a given environment, empirically deriving the most effective solutions. All the data analyzed so far show a highly sophisticated architectural design on both sites. The structural calculations for load distribution, the choice of the most appropriate sediments for each architectural function, "the aggregate technology" in the mud-brick and mud-plaster mixtures, and other relevant topics developed in this work prove that mechanisms regulating the earthen architecture, when transmitted overtime, are actually more effective than previously thought.