This research delves into the analysis of Roman mortars utilised in the construction and restoration of the Forum Traiani thermal baths in Central Sardinia, Italy, a region characterised by a high hydrogeological risk due to potential flooding events. The primary objective of the study is to gain insights into the ancient Roman production and restoration technologies, particularly within the context of a challenging environmental setting.
Through a comprehensive approach involving various analytical techniques, including mineralogical-petrographic characterization, physical analysis, and examination of particle-size distribution of aggregates, the researchers aimed to unravel the composition and characteristics of the mortars used in the construction of the thermal baths.
The investigation revealed a stratigraphic sequence of mortars comprising Trullissatio, lime renders, and finishing coats, each exhibiting distinct properties in terms of binder/aggregate ratios and hydraulicity levels. Notably, the presence of amorphous reactive glass phases in volcanic rocks suggested past restoration interventions on the structures. Physical-mechanical tests conducted on the mortars unveiled variations in densities and porosities, with the thickness of the mortar layers found to be associated with the binder/aggregate ratio.
Furthermore, the study highlighted the diverse components present in the mortar compositions, including sands, bioclasts, and mafic crystal-clasts, shedding light on the intricate technologies and materials employed by the ancient Romans in their construction and restoration endeavours.
Overall, this research contributes valuable insights into the technological processes and material choices of Roman builders, offering a deeper understanding of ancient construction practices within the specific context of a hydrogeologically challenging archaeological site.
