Induction melting by using a cold crucible is a suitable technology for the immobilisation of ash residues after incineration of solid radioactive waste. We investigated the possibility of using glass composites produced by stirring the ash into meltedglass. Glass composites containing 15 -40 wt. % of ash were obtained in both laboratory and bench scale units. Infrared spectroscopy, electronic paramagnetic resonance, X-ray diffractometry, TEM and SEM analyses were applied in order to characterise the structure of the glass composites obtained. The glass composites consisted of a relatively homogeneous glass matrix with embedded polycrystalline aggregates. The fraction of aggregates increases when the fraction of ash rises. The isothermal curing of composites at 1100 °C leads to dissolution of the ash components into the melt as well as to their inclusion into the glass structure, according to the analysis of the spectra obtained.