Optimization of Earthen Plaster Mixes, Stabilized with Waste Natural Fibers

Earthen plasters, long used in construction, now offer the opportunity to be optimized in terms of performance and adapted to current needs for comfort, sustainability and circularity. This work is part of the ITER project – Ecological and Recyclable Earthen Plasters – which aims to optimize earthen plaster mix tures enhanced with waste materials from local agricultural and stone-processing supply chains. In particular, the study presented in this paper concerns a double investigation campaign carried out to refine the selection of fibers to implement in the plaster mixes. The examined fibers are agricultural by-products rooted in the Eastern Sicily territory: rice, wheat, cotton lint, sisal, and hemp shives. In the first testing campaign, the performances of the mixtures made with different types of fibers were compared. The second campaign subsequently aimed at assess ing the optimal fiber length, focusing only on sisal fibers, which had shown the best results in the previous phase. Furthermore, the paper reports the observations that emerged during both campaigns, concerning the preparation methods for the mixtures and their interaction with the fibers used.