TY JOUR TI EFFECT OF FINE-GROUND SILICA MARL ON THE STRUCTURE AND PROPERTIES OF COMPOSITE GYPSUM BINDER KW silica marl KW specific surface area KW active adsorption centers KW composite gypsum binder KW properties JO Bulletin of Belgorod State Technological University named after. V. G. Shukhov AU Vorob'ev, E.L. AU Chernysheva, N.V. AU Drebezgova, M.Y. AU Sardarbekova, E.K. PY 2026 IS 11 PB Belgorod State Technological University named after V.G. Shukhov