Corrosion-to-mechanical ratio analysis of reinforced steel in concrete with eggshell partial cement replacement

In this investigation mechanical aspects and corrosion resistances of the reference concrete sample and the concrete with eggshell replacing ordinary cement Portland (OCP) with embedded steel bars are evaluated. It is found that the compressive and tensile strengths reach acceptable levels when 10 wt.% of the cement is replaced with eggshell content. Four different curing periods are evaluated, i.e. at 1 day, 7, 28 and 365 days. The compressive values initially reaches of about 12 MPa and ∼40 MPa after 365 days is attained. All the examined samples reach the requirements prescribed into Brazilian’s standards. Concatenated analyses indicate results of strength associated with the lightweight aspects and corrosion resistances slightly higher than the reference. This is associated with initial rebar passivation behavior promoting its interesting corrosion resistance in a long-term curing. Since there exists a great preoccupation with the cement consumption and its CO 2 emission, the eggshells adequately used (size and proportions) seems to be a very interesting strategy as environmentally and eco-friendly aspect. • Eggshell sizing close to OCP cement is used. • Eggshell replaces 10 wt.% cement content and no substantial deleterious effects on mechanical behavior is verified. • A passivation is verified at initial curing period favoring the corrosion resistance of reinforced steel concrete. • Correlation among mechanical strength, lightweight effect, and corrosion resistance indicates that eggshell addition is interesting strategy. • With eggshell addition, minimal required mechanical behavior is attained.