INNOVATIVE MORTARS FOR MOSAIC CONSERVATION: ANCIENT ROMAN TECHNIQUES MEET MODERN RESTORATION NEEDS

The primary goal of this research is to develop mortars for the conservation of ancient Roman mosaics, with a focus on creating sustainable and compatible restoration materials. This study analyzes the composition of archaeological samples from the ancient city of Aquileia, examining both tesserae and mortars to understand their original makeup and guide the development of innovative mortar formulations. Traditional restoration methods often used cement pastes that were incompatible with the original substrates, leading to degradation and instability. In light of the green revolution, there is a pressing need for eco-friendly restoration materials that minimize environmental impact and ensure operator safety. To address this, the research aims to develop innovative mortars that not only match the original Roman mixtures but also promote sustainability. Two primary formulations were created, using slaked lime and Natural Hydraulic Lime 3.5 as binders, to replicate the original Roman mortar. Additionally, the study explored the use of a natural gel derived from the Opuntia ficus-indica plant, known as “Nopal gel” added in the mortar formulations. This resulted in two additional mortar types that showed promise in enhancing compatibility and sustainability. The research also tested self-healing properties by incorporating a polymeric capsule with a reactive core into two more mortar formulations, making a total of six different mortars produced. These mortars were analyzed for their physicochemical and rheological properties, as well as their chemical composition. The findings suggest that the inclusion of Nopal gel, significantly enhances the mechanical characteristics of the mortars, making them closely resemble the Roman formulations. This innovation ensures long-term durability for both the conservation intervention and the original substrates, demonstrating the potential for improved, sustainable restoration techniques in mosaic conservation.