EXPERIMENTAL STUDIES OF THE KINETICS OF THE DEVELOPMENTAL CORROSIVE DAMAGES OF CONCRETE IN BENT REINFORCED CONCRETE ELEMENTS UNDER FORCE AND ENVIRONMENTAL EFFECTS

The article deals with the main aspects of the development of concrete corrosion damage in reinforced concrete structures. It is noted that the main quantitative indicators of such damages are the depth and the damage factor. Their change in time characterizes the kinetics of the development of concrete corrosion damage. The kinetic model of corrosion damage development by V.M. Bondarenko is presented as perspective for inclusion into normative documents. For the purpose of its additional substantiation special experimental studies of loaded samples of reinforced concrete beams and non-loaded samples in the form of concrete cubes and prisms under prolonged exposure to sulfate- and chloride-containing aggressive media have been conducted. New experimental data on peculiarities of accumulation of corrosive damages of concrete taking into account the influence of different operational factors have been obtained. It is established that damage development has a pronounced fading character over time and depends on the type of operating medium, the presence of cracks, the sign and level of stresses acting in the concrete. In case of sulfate corrosion, the damage coefficient of the outer layer of concrete in the transition zone does not take into account the value equal to zero. It is concluded that the adopted model quite reliably describes the development of corrosive damages of concrete in these corrosive environment.