Green fabrication of mechanically stable superhydrophobic concrete with anti-corrosion property

Abstract

Anti-corrosion of concrete widely used in marine structural engineering is an important issue in the study of preventing the penetration of seawater to concrete that may lead to damage of concrete structures and corrosion of internal steel bars. Superhydrophobic concrete with anti-corrosion property is a potential candidate for mitigating marine corrosion. Environmental friendliness and mechanical stability are important factors to be considered in the application of superhydrophobic concrete. Here, a green method is proposed to fabricate superhydrophobic concrete using nontoxic modified sands and sandpapers polishing. Sands modified with stearic acid provided low surface energy, while sandpapers polishing supplied rough structures for superhydrophobic concrete. The as-fabricated concrete showed superhydrophobic property with a water contact angle of ~153.7° and a water sliding angle of ~4°. Mechanical polishing test was performed on the as-fabricated concrete, which showed a robust mechanical stability. To illustrate the anti-corrosion property, electrochemical test and long-term soaking test in 3.5 wt% NaCl solution were carried out. The compressive strength and flexural strength of the ordinary concrete and the as-fabricated concrete at different ages were compared. The as-fabricated concrete with mechanical stability and anti-corrosion property is expected to be applied in marine structural engineering for anti-corrosion.