TY JOUR TI HYDROPHOBIC PROPERTIES OF CEMENT STONE WITH WASTE ADDITIVES OF LECITHIN EXTRACTION KW Cement KW additives KW lecithin KW waste KW cement stone KW concrete KW water absorption KW contact angle KW surface free energy JO Bulletin of Belgorod State Technological University named after. V. G. Shukhov AU Kharlamov, V.A. AU Lopanov, A.N. AU Dement'ev, K.V. AU Sysoev, P.I. PY 2025 IS 10 PB Belgorod State Technological University named after V.G. Shukhov