Potential Applications of Granite-Cement Composite Based on Granite Powder Waste for Radioactive Wastes Solidification: Impact of freezing-thawing treatment

Abstract The freezing/thawing (F/T) reliability of radioactive final waste form (FWF) is experiencing progressive important structural task during the long term disposal period. In this study, a cement-granite composite matrix (GCC) based on granite (G) scrape wastes, at 20% to the mass of the cement (C) mixed at 35 mass% plain water relative to both C & G masses, was developed. The frost resistance of the developed composite was evaluated through freezing and thawing cycling. The F/T integrity of the GCC was assessed through the evaluation and determination of the mass losses, compressive strength and porosity values. The alterations in internal microstructures of granite-cement composite were examined by applying X-Ray diffraction (X-RD), thermal analysis (TA) and scanning electron microscopy (SEM). It was dedicated that ameliorations in the characters of the GCC, under consideration, due to freezing/ thawing treatments could be differentiated into three steps: slow-impairment step, fast-spoil step, and stable step. The obtained experimental results, after 180 days of F/T treatment, recommended a basis for the suitability of the developed granite–cement composite and candidate it for solidification/stabilization of some low and medium radioactive wastes. However, evaluation of frost stability in large-scale composite structures is mandatory.