Organic Stabilizers of Plant Origin in Archaeological Structures: Influence of Cactus Mucilage in the Making of Sacrificial Mortars

Today we have a wide variety of raw earth stabilizers, both of natural origin (animal, mineral or plant) and artificial. Thanks to them it is possible to provide greater stability to the earth that needs it, through physical, mechanical or chemical mechanisms. However, selecting the most suitable stabilizer for each type of earth remains a challenge, due to the variability in the nature of the substrate and its adaptation to climatic conditions. For this reason, it is essential to carry out previous studies and tests, both in the laboratory and in situ, that allow us to understand and optimize its properties. This research focuses on the use of plant-based stabilizers and their influence on the properties of raw earth. In particular, the effects of different mucilages from the plant species Opuntia spp., Austrocylindropuntia subulata (Mühlpfrdt. Backbg) and Opuntia huajuapensis (Bravo) are analyzed through experimental studies. The research includes, on the one hand, the laboratory evaluation of the adhesion capacity of these compounds on three types of supports: brick, raw earth and stone; and, on the other, field experimentation, where these substances have been integrated into mortars and coatings. The results of this study will contribute to the understanding of their potential as natural stabilizers in raw earth construction.