Performance Evaluation of Lime Cork Plaster Reinforced with Broom Fibers for Infill Walls

Recent earthquakes have underscored the significant seismic vulnerability and poor energy performance of existing reinforced concrete (RC) buildings, with particular deficiencies observed in non-structural components such as masonry infill walls. Conventional retrofit strategies typically address seismic and thermal deficiencies separately, often leading to increased costs and invasive interventions. This study explores the development of an innovative plaster that combines seismic strengthening with thermal insulation. The proposed plaster is produced using natural raw materials of local Calabrian origin and reinforced with broom fibers to enhance both ductility and mechanical strength. Experimental investigations included mechanical characterization through compressive and flexural strength tests, toughness, and ductility evaluation, as well as thermophysical analyses and further complementary tests. The results demonstrate that fiber reinforcement ensures adequate strength and significantly improves deformability, making the material suitable for seismic retrofitting of infill walls. In fact, the results show that the fiber insertion improves the post-critical behavior of the plaster through a significant increase in its ductility. Moreover, the thermal tests confirm a notable reduction in heat transfer, enhancing the energy performance of building envelopes. The complementary tests have demonstrated the suitability of the designed plasters for the intended applications.