Production and thermomechanical characterization of wool–geopolymer composites

Load‐bearing and thermal insulating wool waste/geopolymer composites with fire‐resistant properties were produced and characterized. Two formulations, with different amounts of wool fibers, corresponding in the final composites to about 23 vol% and 31 vol%, were tested. The composites exhibited an average density of 1.0 g/cm³, with a thermal conductivity of 0.2 W/mK, and compressive and flexural strength around 9 and 5 MPa, respectively. The flexural strength and fracture behavior were improved by the presence of the fibers, which promoted the onset of a toughening mechanism in the material. Results showed that a geopolymer matrix loaded with 23 vol% of wool fibers is suitable as flame‐resistant barrier, as reaction to fire is in class A2 (UNI‐EN 13501‐1), and as insulating structural partition in buildings because it ensures a consistent load‐bearing ability coupled with thermal insulating properties, similarly to other man‐made fiber products, with a considerable gain in terms of cost and environmental impact.