TY JOUR TI METHODS OF ACCEPTANCE OF WORKS ON FIRE-RESISTANT TREATMENT OF METAL STRUCTURES KW quality of fire retardant treatment KW fire protection KW metal structures KW fire resistance limit KW intumescent material JO Siberian Fire and Rescue Bulletin AU Gorbunov, A.S. AU Korovchenko, A.V. AU Akhmetshin, I.F. PY 2021 IS 2021 PB FSBEE HE Siberian Fire and Rescue Academy EMERCOM of Russia