TY JOUR TI CAUSES OF LOW INNOVATIVE ACTIVITY OF ENTERPRISES IN THE INDUSTRY OF BUILDING MATERIALS KW the industry of building materials KW innovations KW the level of innovation activity KW innovation-active enterprises KW labor productivity JO Bulletin of Belgorod State Technological University named after. V. G. Shukhov AU Balabanova, G.G. PY 2018 IS 3 PB Belgorod State Technological University named after V.G. Shukhov