METHOD FOR ASSESSING FIRE RESISTANCE OF MONOLITHIC REINFORCED CONCRETE BEAM SLABS OF INTERIOR SURFACES OF BUILDINGS Russian patent published in 2018 - IPC G01N25/50 

FIELD: fire safety.

SUBSTANCE: invention relates to the field of fire safety of buildings and structures and can be used to classify monolithic reinforced concrete beam slabs of interior surfaces of buildings according to their resistance to high temperatures of fires. Essence of the invention lies in the fact that testing of monolithic reinforced concrete beam slabs of interior surfaces of a building is carried out without destruction, using a set of individual quality indicators, evaluating their value using statistical control. For this purpose, it is necessary to determine the geometric dimensions of the beam slab, the heating circuit of the design section in fire conditions, the placement of the reinforcing bars in the section, the depth and degree of fire protection, the rate of thermal diffusion of concrete, the magnitude of the test load on the monolithic reinforced concrete beam slab and the intensity of the stress in the bars of the longitudinal working reinforcement. Further, the fire resistance limit of a beam slab is determined based on of the loss of bearing capacity F_U(R), using analytical equation (1); on the basis of loss of insulating ability F_U(J) using power function (2). When describing the process of resistance of a monolithic reinforced concrete beam slab to the impact of a standard fire, the degree of fire protection of the reinforcing bars C, cm, the intensity of their stress J_σc (within 0.1÷1.0) and the index of thermal diffusion of concrete D_vt, mm²/min, as well as characteristics of the reinforcement of the beam slab of the interior surfaces of a building and the static scheme of its operation are taken into account.

EFFECT: improving the accuracy of determining the actual fire resistance of monolithic reinforced concrete beam slabs of interior surfaces of a building without full-scale fire impact, increasing the reliability of statistical quality control and non-destructive testing.

6 cl, 7 dwg, 1 tbl