Eco-Sustainable Plasters with Recycled Tyre Aggregates: Experimental Characterization and Numerical Application to a School Building

The construction industry significantly contributes to the global ecological footprint, underscoring the urgent need to integrate circular economy strategies into both construction materials and methodologies to mitigate environmental impacts. The circular economy model promotes sustainability by transforming waste into valuable resources and reducing the volume of unused waste. In this context, the building sector is increasingly adopting recycled components to produce environmentally friendly construction materials. This research focuses on incorporating recycled tyre rubber as an aggregate in eco-friendly mortars intended to strengthen existing masonry buildings. It is structured into two distinct phases. Phase one consists of laboratory experiments in which three types of mortar samples are prepared and tested: control samples (without rubber), rubber-infused samples, and mixtures combining rubber with steel fibres. These specimens are evaluated for various physical and mechanical properties, including density, flexural and compressive strength, and surface hardness. The test data is analyzed to determine the most effective and sustainable mortar composition. Phase two applies the laboratory findings in a real-world setting. A mortar blend containing recycled rubber and steel fibres from end-of-life tyres is used to reinforce structural components of an Italian school building, aiming to enhance its seismic performance.