Internal superhydrophobic marine concrete: Interface modification based on slag microstructure regulation

Abstract

Structures in coastal environments are susceptible to damage from the combined effects of loading, scouring, corrosion, rust-frost-crystallization expansion forces, etc. Superhydrophobic materials can effectively alleviate these problems due to their excellent water rejection properties. However, in practical applications, superhydrophobic performance failure occurs after the surface is subjected to various stresses. To further explore this point, this article prepared an integrated superhydrophobic protective material using solid waste material slag to achieve the resource utilization of solid waste materials. Superhydrophobic particles covered with paraffin wax (SPP) reduce the direct damage of external forces on hydrophobic particles, extend their service life, and achieve self-healing of superhydrophobicity. Its comprehensive performance indices, including all-round wettability, water repellences, carbonisation resistance and electrochemical corrosion performance, were investigated. The results show that the contact angles of the superhydrophobic mortar inside and outside the contact angle are more than 150°, indicating three-dimensional superhydrophilicity. The 30% SPP dosage of superhydrophobic mortar in 48 h water absorption compared to ordinary mortar reduced by 78%, 120 h water permeability up to 0.72%; and carbonized 28 days after no traces of carbonisation; in the electrochemical corrosion experiments to prevent corrosive liquids from entering the reinforcing bars in the concrete has good anti-corrosion properties. In the electrochemical corrosion experiment, the corrosive agent effectively prevents the corrosive liquid from entering contact with the steel reinforcement in the concrete, and the resulting material has good anti-corrosion performance. These key characteristics can provide unique advantages for a wide range of applications in coastal environments, such as construction, bridging, decoration, transportation and power transmission.