Corrosion Fatigue Damages of Rebars under Loading in Time

Abstract

Nowadays, a relatively small number of studies concern the study of corrosion processes in reinforced concrete structures under load. Additionally, rather little research has been carried out concerning changes in the stress–strain state parameters of structures under the simultaneous action of aggressive environment and load. This issue requires additional experimental and theoretical investigation. Determination of mechanical properties, fatigue characteristics and susceptibility to corrosion cracking was performed on samples of reinforcing St3GPF steel. The chemical composition of steel was determined by structural analysis. The spectral method for the determination of alloying elements and impurities in steels is based on the excitation of iron atoms and admixtures by electric discharge, decomposition of radiation into a spectrum, followed by its registration on photoplate with the use of electrograph. Experimental tests of samples in an aggressive environment under the action of statically applied tensile force showed that corrosion damage has little effect on the strength characteristics. At the same time, the decrease in area reduction and the decrease in strain were recorded. Additionally, the action of cyclic loads in an aggressive environment leads to a significant reduction in the fatigue limit to values from 20 to 24% of the yield strength of the original samples, which is 2–3 times lower than the fatigue limit of undamaged samples.

Investigation of defective reinforced concrete beams with obtained damage of compressed area of concrete

“…Very important to determine the behavior and stress-strain state of different types of rebar with a defect (Blikharskyi and Maksymenko, 2021). Especially need to investigate the possibility of occurrence these defects during all time of exploitation (Blikharskyy et al, 2021a;Macek et al, 2020). The study of the damage influence in joist slabs (Semko et al, 2018) also demonstrates a significant effect of defects on the deformability of concrete and reinforcement and their joint work.…”

Corrosion-Fatigue Life Prediction Modeling for RC Structures under Coupled Carbonation and Repeated Loading

“…As the corrosion degree increases, the fatigue stress ranges increase, and the fatigue resistance decreases [10]. Considering the time-variant of fatigue stress range and fatigue resistance, Equation ( 26) can be rewritten as follows:…”

“…Both repeated loading and environmental action will cause material deterioration in RC structures. Fatigue damage and reinforcement corrosion are the dominant reasons for the performance degradation of RC structures [9,10]. The fatigue failure mechanism of corroded RC structures is more complex than that of RC structures without corrosion.…”

Specifics of physico-mechanical characteristics of thermally-hardened rebar

“…It is important to note, that this material is complex multicomponent heterogeneous system with synergistic properties, which on the one hand allows its effective use in a wide range of structures, and on the other -causes the ambiguity of its stress-strain state under the influence of external impacts (Fomin et al, 2021;Klymenko, et al, 2020;Klymenko et al, 2019). Modeling the work of reinforced concrete structures under adverse external influences should account specific properties of individual components, -concrete stone and steel bars (Bobalo et al, 2019b;Bobalo et al, 2020;Blikharskyy et al, 2021b;Blikharskyy et al, 2021a;Bambura et al, 2018;Czajkowska et al, 2020;Karpiuk et al, 2020;Blikharskyy et al, 2020b;Lipiński, 2017;Kramarchuk et al, 2021).…”