Modeling of Physical–Chemical and Thermomechanical Properties of Glasses From Recycled Waste

This research focuses on understanding the high-temperature phase evolution occurring during the vitrification of heterogeneous construction and demolition wastes (CDWs). The aim of this project is to transform this widely distributed and mostly unused waste stream into a homogeneous, engineered, glass-based material with predictable properties, valuable for the glass industry. Starting with vitrification experiments, CDW samples ( < 63 μm) were heated to target temperatures ( T ) of 1100◦C, 1200◦C and 1300◦C and held isothermally for either 2 or 8 h. The experimental products were chemically characterized by electron microprobe (EMP) analysis, and the results show that the SiO2 - and Al2 O3 -rich samples (RAS and PRO) achieved a high degree of vitrification at ∼ 1300◦C, forming a homogeneous glassy matrix. Conversely, the high CaO content in the TAL sample hindered complete vitrification by promoting the stability of calcium-rich crystalline phases (e.g. larnite) up to temperatures as high as 1600◦C, as shown by x-ray diffraction patterns on the treated samples. Building on these findings, the GlassNet model was employed to design a blend of PRO sample with the addition of fly ash (FA.REI) and glass waste (VF3) to improve thermomechanical performance. The model predicted an optimized mixture (Exp.a), fully composed of waste materials, for acoustic and thermal insulation applications, thus demonstrating waste recycling potential for producing new high-performance materials with practical applications.