A practical approach for monitoring reinforcement corrosion in steel fiber reinforced concrete elements exposed to chloride rich environments

Abstract

The use of fibers in Reinforced Concrete (RC) elements changes their cracking pattern, leading to narrower and more closely spaced cracks. In addition, the presence of fibers can improve the steel-to-concrete bond behavior reducing the steel-to-concrete interface damage after cracking. Cracks and steel-toconcrete interface damage work like paths, for aggressive agents, to reach the rebar in cracking elements, reducing the initiation period of the corrosion process, and favoring the corrosion at the intersection between cracks and reinforcement. In this context, this article discusses an experimental program on tension ties mechanically cracked and exposed to a chloride-rich environment with the purpose to check and eventually adequate the typical electrochemical measurements, used in the case of RC elements, for Steel Fiber Reinforced Concrete (SFRC). Adjustments related to degradation morphology and interference of steel fibers are proposed and used on Fiber Reinforced Concrete (FRC) elements for monitoring the influence of cracks and fibers on corrosion propagation. Finally, these proposed modifications were checked and validated against the results obtained by monitoring SFRC beams in the cracked stage.Discussion on this paper must be submitted within two months of the print publication. The discussion will then be published in print, along with the authors' closure, if any, approximately nine months after the print publication.

Cellulose nanofibers to improve the mechanical and durability performance of self-healing Ultra-High Performance Concretes exposed to aggressive waters

“…A value equal to 1 for the different indices mean a total recovery of the related performance, this is, a specimen totally healed would reach the same properties than an uncracked one. -12 specimens precracked (1) -4 specimens tested up to failure -8 specimens recracked (1) -4 specimens tested up to failure -4 specimens recracked (1) -4 specimens tested up to failure Water permeability ( -titration test of 2 pre-cracked and 1 uncracked specimens (1) half of the specimens were immersed in geothermal water, the other half were stored in the moist room; (2) all specimens were immersed in geothermal water; (3) all specimens were immersed in salty water (33 g/L NaCl).…”

“…Nonetheless, reinforced concrete structures exposed to extremely aggressive environments need continuous maintenance along their service life, primarily because of the sensitivity of the reinforcement, necessarily employed to temper the inherent weakness and brittleness of concrete in tension, to the corrosion induced by different environment born aggressive substances. For this reason, the durability of reinforced concrete structures has been and continues to be a topic of increasing interest in the scientific community and in the society since maintenance interventions are expensive and increase all along the service life of the reinforced concrete structures [2], [3]. In fact, yearly cost of corrosion reaches a 3.4% world GDP.…”

Effect of different material constitutive models in estimating the residual moment capacity of RC beams subjected to natural corrosion

“…This process generates expansive oxides that ultimately lead to cracking and spalling of concrete cover after a considerable time into the structure's life. Exposure of RC structures to chloride environment can accelerate the passive film breakdown, leading to localized attacks or pits (Gomez et al, 2023;Lan et al, 2018). Pitting occurs when the damage exists in relatively small and spatially separated areas.…”