Mechanical Properties Decay of Corroded Reinforcement in Concrete—An Overview

Abstract

Among the leading consequences of corrosion in reinforced concrete structures (RCS) the cross section reduction in steel bars should be mentioned, coupled to a decay of their mechanical material properties. This paper recalls the main literature findings on the topic and describes a wide collected database of experimental tensile tests performed on naturally corroded reinforcements. The principal predictive degradation laws available in the scientific literature to assess the residual mechanical properties of the corroded reinforcements are synthesized. A first attempt to evaluate the reliability of the literature decay laws to simulate the mechanical performance of naturally corroded steel reinforcement subjected to both uniform and pitting corrosion is performed. Finally, some remarks are suggested on both the tested naturally corroded steel reinforcement and the available degradation laws.

Modelling Strategies for Reinforced Concrete Elements under Corrosion Degradation

“…A sensible reduction in the structural capacity of corroded RC elements is observed for corrosion levels higher than 10% in mass loss [24,25]. At this stage, the bond strength can be considered completely loss [14,16], and relevant variations in the reinforcement mechanical properties can be observed in case of pitting corrosion [17]. Moreover, the concrete constitutive law reduces due to the cracking caused by the oxides' expansion [9,10,[26][27][28].…”

“…In detail, linear relationships relate strength and corrosion level CL, while the ultimate deformation can follow a linear or an exponential trend. A complete review on the degradation laws of corroded reinforcements can be found in [17].…”

“…In detail, linear relat relate strength and corrosion level CL, while the ultimate deformation can follow or an exponential trend. A complete review on the degradation laws of corrod forcements can be found in [17]. The state-of-the-art on the monotonic behavior under compression highligh the buckling effects become relevant for slenderness ratios (λ = l/ϕ) higher than 10 Only two models are available in the scientific literature concerning the mechan formance in compression of corroded reinforcement, respectively, developed for [35] and pitting corrosion [36,37].…”

“…The corrosion influence on the constitutive law of the confined concrete is considered by means of the relationships proposed in [27], based on the classical Mander's model [33]. Concerning the reinforcement material properties, the degradation law for pitting corrosion proposed in [17] and in [36] for the tensile and the compressive behavior are introduced, respectively.…”

“…Under corrosion, RC elements progressively decrease their structural capacity due to: (i) concrete cracking and the decay of its compressive strength [9,10], (ii) modification of the bond-slip law between reinforcement and concrete [11][12][13][14], (iii) variation in the tension-stiffening effects [15,16], and (iv) the cross-section reduction of steel reinforcements and the decay of their mechanical properties [17].…”