TY JOUR TI THE EFFECT OF MECHANICAL ACTIVATION IN A ROTARY BALL MILL ON THE PROPERTIES OF BINDER COMPOSITIONS WITH THE ADDITION OF VOLCANIC SAND KW mechanical activation KW rotary ball mill KW volcanic sand KW composite binder KW specific surface area KW compressive strength KW setting time JO Bulletin of Belgorod State Technological University named after. V. G. Shukhov AU Zagorodnyuk, L.K. AU Chernukha, D.G. AU Ivanov, G.V. AU Sorokin, M.A. PY 2026 IS 11 PB Belgorod State Technological University named after V.G. Shukhov