EXPOSURE OF THE LOAD CAPACITY OF THE RC STRUCTURAL SYSTEM UNDER CORROSION DAMAGE TO COLUMNS

A number of accidents, such as the partial collapse of a residential building in Surfside on June 24, 2021, or the collapse of the roof structure of Basmanny Market in Moscow on February 23, 2006, show that aggressive medium impacts on reinforced concrete structures lead over time to a decrease in their strength resistance resource under accidental impacts. At the same time, the investigations in this field mainly deal with structural members under bending, while eccentrically compressed and corroded reinforced concrete members have been considered either in particular aspects or the obtained solutions are rather complicated for their practical application. In this regard, the purpose of the article was to assess the influence of the corroded depth on the load capacity of eccentrically compressed reinforced concrete columns of structural frames, as well as to predict the time of exhaustion of their load capacity under constant serviceable loads. The paper adopted the phenomenological model of V.M. Bondarenko to take into account long-term corrosion processes. It had been established that an increase in the corroded depth leads to a decrease in the load capacity of eccentrically compressed reinforced concrete members due to a decrease in the effective cross-sectional depth and effective slenderness ratio. The relative depth of the destroyed concrete varies depending on the current stress-strain state of the structural member. The time to reach the critical corroded depth depends significantly on the parameters of aggressive medium and the stress-strain state of the structural member and may differ by several times when implementing avalanche or descending damage kinetics.