Weathering of earth-painted surfaces: Environmental monitoring and artificial aging

Relating damage development to the specific environmental conditions is of paramount importance to design effective conservation strategies for archaeological and historical sites. For this reason, artificial weathering is a highly debated topic in materials science applied to Cultural Heritage. In this work, we report on the weathering of decorated earthen plasters from Templo Pintado in Pachacamac (Region of Lima, Peru) and define a methodology to accelerate aging of painted raw earth surfaces. Weathering was simulated by exposing the surfaces to wet-dry and sandblasting cycles and resulting damage was estimated via the amount of material removed from the original surface. The results are in agreement with weathering dynamics observed in situ, which allows designing suitable methodology for the preparation of samples to be used in testing procedures addressing the preservation of surfaces.