Mineralogical characterization of the Tournemire argillite after in situ interaction with concretes.

摘要: Abstract This study aims to investigate, through mineralogical characterization (SEM, XRD) and mass-balance calculations, the effects of contact time, concrete types presence free water on Tournemire argillite under in situ conditions. Three sampling zones from Excavation Disturbed Zone (EDZ) areas have been chosen: (1) dry contacts, collected at tunnel masonry/argillite interface (contact time – 125 years), (2) wet taken close drained below roadbed with canal draining Cernon fault 15 7 years) over 70 m years). shows that: • absence water, no significant modification is observed after years, except for pyrite dissolution gypsum precipitation. precipitation gypsum, recrystallization mixed-layer clays, neoformation zeolites K-feldspars overgrowths are observed. At concrete/argillite near fault, important dolomite leaching chlorite kaolinite occur. These processes enhanced low flow rate nature (compound cement Portland CEM II 32.5). Evidence oxidation linked EDZ (pyrite oxidation, Fe-oxy-hydroxide precipitation)