Effect of HSO<sub>3</sub><sup>−</sup> and alternating current on corrosion behaviour and mechanism of CoCrFeNi HEA in a simulated marine environment

In the present investigation the effect of the urban environment of the city of Xalapa, Ver., México in the depth carbonation in Sustainable Concrete made with Agro-Industrial and Industrial Waste Materials like Sugar Cane Bagasse Ash (SCBA) and Silica Fume (SF), was evaluated. The Sustainable Concretes and the Conventional Concrete (Concrete of reference) were designed for a relation water/cement= 0.65 according to the indicated for the ACI 211.1. The Conventional Concrete was elaborated with 100% of Portland cement, and the Sustainable Concretes with partial substitution of Portland cement for the waste of SCBA and SF in percentages of 10, 20, 30, 40, and 50%. The results through the application of phenolphthalein, indicate that the Carbonation depth is proportional to the increase of the substitution of Portland Cement for agro-industrial and industrial waste. The sustainable concrete with 50% of substitution of SCBA-SF presents the worst performance, with a carbonation depth of 1.48 cm, which represents an increment of more of 350% than the conventional concrete at being exposed for one year to the present environment of study.

Carbonation Depth of Sustainable Concrete Made with Agroindustrial and Industrial Waste Exposed to the Urban Environment of the City of Xalapa, Ver; Mexico

Baltazar-García,

Baltazar-Zamora,

Sánchez-Sánchez

et al. 2023

Anticorrosive Efficiency of the AISI 316 SS in Sustainable Ecological Concrete Manufactured with SCBA-SF Exposed to Magnesium Sulphate

Baltazar-García,

Baltazar-Zamora,

Landa-Ruiz

et al. 2023

In this research, it was evaluated the anticorrosive efficiency of AISI 316 SS embedded in Sustainable Ecological Concrete (SEC) manufactured with partial substitutions of Portland Cement by combinations of SCBA and SF in 10%, 20%, and 30%. For the electrochemical evaluation, the Sustainable Ecological Concretes (SEC) were exposed to solution at 3.5% of MgSO4, these aggressive ions are found in soils, industrial or marine environments and that interact with the civil works that are built in these places. The dosage or proportioning of the Sustainable Ecological Concrete (SEC) mixtures was carried out as indicated by ACI 211.1. The anticorrosive efficiency of the AISI 316 SS was evaluated through the tests of the potential of corrosion (Ecorr) and corrosion rate (Icorr) during a period of 180 days of exposition to the aggressive medium. The values of Ecorr indicate in the AISI 316 SS a 10% of corrosion risk and uncertainty at the end of monitoring, according to the norm ASTM C-876-15, in all the mixtures, but the values of Icorr in the specimens manufactured with SEC indicate resistance to sulfate corrosion more than 10 times compared to conventional concrete and AISI 1018 steel.

Behavior of Potential of Half-Cell AISI 1018 and GS in Concrete Buried in Sand in the Presence of MgSO4

Baltazar-García,

Baltazar-Zamora,

Santiago-Hurtado

et al. 2024

This project, in the area of reinforced concrete corrosion, evaluated the potential of half-cell AISI 1018 CS (Carbon Steel) and GS Steel (Steel with galvanized coating); 15 cm long bars were used as reinforcement in specimens of concrete buried in a Type SP Sand (contaminated with 0% and 3% MgSO4). The experimental arrangement of this research represents the case of the elements of the foundations of concrete structures that are planted near marine areas where this type of soil exists with the presence of high contents of depassivating ions such as sulfates. The study specimens were made with two concrete mixtures with a water/cement ratio 0.45 but with different types of cement (Portland Cement and Sulfate Resistant Cement). For monitoring the half-cell potential according to ASTM C 876-15, the specimens were buried in the clean SP soil and in the same soil but contaminated with MgSO4. After more than 270 days of exposure to uncontaminated SP sand contaminated with MgSO4, the behavior of the half-cell potentials or corrosion potentials show that the specimen made with the sulfate-resistant cement and reinforced with GS Steel (Steel with galvanized coating) presents the highest resistance to corrosion by MgSO4 at a concentration of 3%.