Determination of stress losses in reinforcement from shrinkage and creep of concrete.

The initial prestress of the reinforcement does not remain constant, but already during the manufacturing process (when the reinforcement is tensioned), and also decreases over time due to losses caused by the physical and mechanical properties of concrete and reinforcement, the technology of manufacturing structures and elements. When tensioning the reinforcement on the stops, one distinguishes between the first losses occurring during the tension of the reinforcement (due to the relaxation of steel stresses; the temperature difference between the tensioned reinforcement and the device that perceives the tension forces; deformations of steel forms and anchors of the tensioning devices), and the second losses occurring after compression and increasing in the process operation of the structure (from shrinkage and creep of concrete). The article provides a rationale for the proposed methodology for the practical calculation of prestressing losses in reinforcement from shrinkage and creep of concrete at an arbitrary time of storage of reinforced concrete structures. In a numerical experiment, the optimal parameters of the calculation formulas of the proposed method are revealed. [ABSTRACT FROM AUTHOR]