EVALUATION METHOD FOR FIRE-RESISTANCE OF REINFORCED CONCRETE COLUMN OF BUILDING Russian patent published in 2017 - IPC G01N25/50 

FIELD: fire safety.

SUBSTANCE: testing of reinforced concrete columns of a building is performed without destruction according to a complex of single quality indexes by evaluation of their magnitude with the help of statistical control. For these purposes, geometrical dimensions of reinforced concrete column, diagram of the unsafe cross section heating under fire conditions, rate of reinforcement of concrete, and mounting conditions; density, humidity, and thermal diffusion index of concrete; magnitude of test load on fire resistance, rate of the unsafe cross section stress, reliability index of a reinforced concrete column by its designation (responsibility level), conditions of the unsafe cross section heating during a fire, burial depth of longitudinal reinforcement, scape solidity of a column and its flexibility are defined. The description of the process of resistance of a loaded reinforced concrete column to fire exposure is represented by a mathematical relationship considering the smallest size of the cross section of a component, rate of reinforcement α_μs, stress intensity J_σo, characteristic strength of concrete for resistance to axial compression R_bn, and thermal diffusion index of concrete D_bm, mm²/min, as well as magnitude of integrated index of a reinforcement concrete column. Fire resistance limit of a reinforcement concrete column is defined using an analytical expression.

EFFECT: provision of possibility for definition of fire resistance of a reinforced concrete column without field fire exposure, improvement of accuracy of statistical control quality and non-destructive testing.

6 cl, 7 dwg, 1 tbl