TY JOUR TI DETERMINATION OF CRACK RESISTANCE OF PRESTRESSED REINFORCED CONCRETE BEAMS OF TRAPEZOIDAL CROSS-SECTION KW prestressed reinforcement KW reinforced concrete beam KW trapezoidal cross-section KW crack resistance KW numerical experiment JO Bulletin of Belgorod State Technological University named after. V. G. Shukhov AU Nikulina, Y.A. PY 2021 IS 6 PB Belgorod State Technological University named after V.G. Shukhov