Concrete anti-carbonation coating is used for crash walls, with the core purpose of preventing the penetration of harmful substances such as carbon dioxide and chlorides, thereby protecting the internal reinforcement. The key performance indicator is excellent resistance to carbon dioxide diffusion, with carbonation depth (28-day accelerated carbonation test) effectively reduced by over 90%. It also features a low chloride ion migration coefficient, significantly delaying reinforcement corrosion.

This material typically comes as a two-component polymer-modified cement-based or high-performance epoxy resin system. Its characteristics include high adhesion (concrete pull-off adhesion often exceeds 2.5 MPa, and can even reach above 3.0 MPa), a thermal expansion coefficient similar to that of concrete substrates, and excellent alkali resistance, avoiding peeling and cracking caused by mismatches.

In addition to its core anti-carbonation function, this coating generally offers excellent impermeability (low water absorption, e.g., ≤5%) and certain resistance to chemical media (salt spray resistance, acid rain resistance). Its dense film effectively blocks the intrusion of water, chloride ions, and other harmful substances, providing comprehensive protection for concrete.

Application scenarios primarily target reinforced concrete crash walls in harsh environments. Typical scenarios include: cross-sea bridges and coastal areas, resisting chloride salt erosion from sea breeze and salt spray; industrial cities and acid rain regions, preventing acidic gases from carbonating concrete; and areas with frequent freeze-thaw cycles, where its impermeability reduces water intrusion, thereby enhancing frost resistance.

In coating systems, it often serves as an intermediate layer or sealing primer. A typical application process includes: substrate treatment (grinding, cleaning) → applying a high-permeability sealing primer → troweling/spraying the concrete anti-carbonation coating → applying a weather-resistant topcoat (such as fluorocarbon topcoat). It acts as a crucial link, ensuring the durability and protective effectiveness of the entire coating system.