Mexico is the cradle of great ancient civilizations that promoted earth-based architecture (cob, mud-brick, structure fills). Nowadays, such earth-based materials are widely investigated to understand their composition, mechanical properties and its resistance to aging. The present study evaluates the effect of composition on flexural and impact properties as well as water absorption capabilities. Soil was used from pre-Columbian site of la Joya, in Mexico, to manufacture experimental mud-bricks emulating the ancient technique using cut grass and asphalt emulsions. It was found that mechanical stabilization and material cohesion are in function of the additive's nature. Flexural and impact strengths of samples were examined and results were correlated to damage mechanisms by using acoustic emission technique exhibiting the onset, propagation and fracture. Mechanical properties were found to be higher in samples with synthetic additives, compared to control samples.

Most earthen historical buildings have been abandoned for decades, exposed to the weathering and the passage of time. In Mexico, the low status of earthen constructions has increased these deterioration processes, resulting into the risk of disappearance of this significant architectural heritage. Historical adobes from monumental buildings in the State of Michoacan were sampled and collected in the localities of La Huacana (H) and Santa Cruz de Morelos (SC). The specimens were characterized in the materials laboratory, assessing their physical-chemical, mechanical and durability properties. An interdisciplinary methodology was designed through institutional cooperation and the application of different test methods. The adobes showed totally different compositions and proportions, and stabilizers like vegetal fibers, nevertheless, the mechanical performance of both samples was very similar, achieving respectable values in the context of historical adobe structures. Several correlations were found through the analyses: the physical properties like the density, the color or the electrical resistivity were related with the mechanical and durability ones; the non-destructive testing (NDT) allowed to calculate the dynamic elasticity modulus and infer the mechanical behavior; the chemical characterization enabled to obtain the elemental and mineralogical composition; and the Atterberg limits gave the soil classification. The research showed the broad diversity of earthen solutions and demonstrated how the granulometry is not a limitation to the adobe production, since the local soils can achieve similar mechanical and durability behaviors. Furthermore, H presented very different composition than the guidelines for earthen construction; nevertheless, the samples showed better durability performance and lower capillarity absorption rates. It is hoped that the results obtained with this research can help the further development of the earthen materials characterization and the decision-making process for the restoration and conservation of historical and vernacular constructions.

Adobe is resistant to sudden temperature changes and fire, acting as an effective thermal and acoustic barrier in construction. This article investigates the thermal, resistance, compression, plasticity and absorption properties of biocomposite adobe, proposing that the combination of adobe with agave bagasse significantly improves its efficiency compared to blocks composed of zacate, agave fibers and soil. This study was conducted in a mezcal and traditional adobe producing area in the State of Mexico, in line with the principles of circular economy. Results indicate that adobe enriched with agave bagasse presents several improvements in its physical and mechanical properties, which reduces its environmental impact. This research highlights the importance of adobe as a fundamental element in the revaluation of earthen architecture, contributing to the promotion of heritage identity.