In this study, we investigated the properties of zinc-rich lithium silicate coatings using various moduli of lithium silicate and zinc powder ratios, which are defined as the mass ratios of zinc powder over lithium silicate. Coating properties examined included film-forming ability, workability, mechanical behavior, resistance to highly alkali or acid solutions, and weather resistance (ultraviolet exposure test). The results showed that the zinc powder ratio significantly influenced workability and filmforming ability. When the zinc powder ratio of the coating was low, the coating delaminated and cracked. When the zinc powder ratio was high, the workability of the coating was found to be poor; the coating was observed to be sticky and hard to mix; thus, applying a uniform layer of coating on the steel substrate was difficult. Additionally, the modulus of lithium silicate affected the mechanical performance of the coating as well as cathodic protection capability. A coating using a lower modulus yielded a coating of more desirable thickness, hardness, viscosity, and adhesive property. In addition, the cathodic protection lasted longer.

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