Abstract: The invention relates to an electrolysis installation comprising at least two rows of electrodes that are immersed at least in part in a liquid electrolyte giving off one or more gaseous species of corrosive nature at the electrodes, at least one separation membrane being disposed between two adjacent rows of electrodes. Each membrane is constituted by carbon fiber reinforcement stiffened by a carbon matrix and presents porous portion that is permeable to ions and impermeable to the or each gaseous species, given off at the electrolytes.

Abstract: A composite material protected by oxidation at intermediate temperatures exceeding 850.degree. C. comprises fiber reinforcement densified by a matrix which includes at least one self-healing phase including a glass-precursor component such as B.sub.4 C or an Si--B--C system, together with excess free carbon (C) at a mass percentage lying in the range 10% to 35%. The, or each, self-healing phase can be interposed between two ceramic matrix phases, e.g. of SiC. While the material is exposed to an oxidizing medium, oxidation of the free carbon promotes oxidation of the precursor and transformation thereof into a glass capable of plugging the cracks in the matrix by self-healing.