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This study concerns the corrosion behavior of steel in different room temperature cured alkali-activated fly ash mortars exposed to chloride solution. The corrosion process was monitored by polarization resistance and corrosion potential measurements and the results were interpreted in the light of a complete microstructural, mechanical and chemical characterization of the mortars. The most compact alkali-activated mortars have higher porosity and lower mechanical properties than a cement-based mortar (CEM), but the protectiveness afforded to the rebars is slightly higher than that obtained in CEM. The reason for this discrepancy is connected to a lower chloride content accumulated in the former mortar type and to a specific inhibition of the rebar corrosion afforded by the pore electrolyte in alkali-activated mortars

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The characterization of corrosion patinas on bronzes is preliminarily connected to the determination of proper conservation strategies. Moreover, it also provides an essential contribution to the comprehension of the mechanisms of formation of patinas.Concerning the last aspect, several studies highlighted that bronze corrosion behaviour cannot be assimilated to that of pure copper. In particular, decuprification and relative enrichment of tin in the corrosion layers were observed. Tin therefore, together with its insoluble salts, plays an important role in the mechanism of formation of bronze patinas. Thus, the characterization of Sn-based corrosion products becomes fundamental, although remaining quite problematic. This work reports several case studies where Sn-based corrosion products grown in bronzes have been identified, thanks to the hyphenated system scanning electron microscopy-energy dispersive spectrometry-Raman structural and chemical analyser. Combining the main characteristics of these techniques, different Sn-containing compounds, mainly crystalline and nanosized tin dioxides, were detected in bronze patinas exposed to different environments (to the atmosphere, in both natural and accelerated ageing conditions, and to the soil). The main issues regarding the interpretation of Raman spectra of these compounds are presented and discussed.

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