Design of monolithic superhydrophobic concrete with excellent anti-corrosion and self-cleaning properties

Abstract

The issues of cracking, spalling, and corrosion of concrete structures are major causes of significant losses. One of the most effective strategy to prevent these phenomena from occurring is to keep concrete from being wetted. However, many hydrophobic modifiers are liquid, which are difficult to transport and easy to volatile. This work selects silica as the substrate and uses fluorine-free silane as the hydrophobic modifier to design and develop a self-made solid superhydrophobic powder that can be directly mixed with cement and sand to produce monolithic superhydrophobic concrete (SC). Benefiting from the rough structure and low surface energy, the SC surface maintains superhydrophobicity with a large water contact angle (WCA) of 153.8°, causing droplets to easily roll off from the SC surface. The SC has a lower corrosion current density (Icorr = 3.878 ×10−6 A·cm−2) and a higher corrosion potential (Ecorr = – 0.368 V), and its corrosion resistance is significantly improved than that of ordinary concrete (OC). In addition, the adhesion between pollutants and concrete is effectively reduced, and the surface resistance to dust and dirt is enhanced. This work developed a simple and convenient strategy for the preparation of SC with excellent anti-corrosion and self-cleaning properties, which has great engineering and scientific significance.