Experimental Tests on Natural and Sustainable Plasters for Non-structural Reinforcement

Recent earthquakes have revealed the vulnerability of secondary building elements, underscoring the urgent need for sustainable solutions that simultaneously improve their seismic resilience and energy performance. In this context, natural fiber-reinforced composite materials represent a promising alternative, combining structural enhancementwith reduced environmental impact. Their wider adoption in construction could significantly lower CO 2 emissions associated with building heating and cooling, while promoting sustainable practices. This study investigates a plaster-based composite composed of natural hydraulic lime and silica sand, modified with cork granules and cellulose fibers extracted from broom. Mechanical tests were conducted to evaluate its suitability for seismic retrofitting and its potential contribution to energy efficiency. The results show that the inclusion of cork reduces mechanical strength; however, the material remains structurally adequate for infill wall retrofitting, confirming cork’s effectiveness without compromising overall performance. Moreover, broom fibers significantly enhance tensile strength and post-cracking ductility, improving the seismic response and long-term durability of the mortar. Overall, natural fiber-reinforced plaster matrices offer a sustainable and effective solution for the retrofitting of infill walls, providing simultaneous improvements in seismic resilience and energy efficiency for residential buildings.