Corrosion behavior of steel reinforcements in sustainable low-resistive cement mortars|Comportamento a corrosione di rinforzi in acciaio immersi in malte cementizie sostenibili a bassa resistività elettrica

This work was carried out within the H2020 EnDurCrete project (GA n degrees 760639). In this study, innovative cement mortars with low electrical impedance were manufactured with sustainable carbon-based additions, such as biochar (BCH) at 0.5 vol% and recycled carbon fibers (RCF) at 0.05 vol% on the total mix. Electrical impedance (ZRe) of mortar of cement mortars and corrosion behavior (Ecorrand Rp) of embedded steel reinforcements were evaluated during both the curing period (i.e., 28 days) and weekly wet/dry cycles in a 3.5% NaCl solution. Results show that the combination of BCH and RCF reduces by approximately 60% the ZRe value compared to the plain mortar. However, the lower electrical impedance of mortars with carbon-based additions with respect to the plain mortar does not impair negatively the corrosion behavior of embedded rebars, both during the curing and the exposure to wet/dry cycles in the chloride-rich solution, since they seem to be even more protective for reinforcements during the whole experimentation.