Performance of Soy Methyl Ester-Polystyrene as a Concrete Protectant: A State-of-the-Art Review

Freeze–thaw cycles, application of deicing salts, and rebar corrosion are becoming main sources of concrete deterioration in bridge decks and pavements. During the past few decades, concrete surface treatments have begun to receive wide acceptance because of their effectiveness in sealing the concrete. Surface treatments achieve this by limiting fluid ingress, thereby reducing damage associated with freeze–thaw cycles, deicing salt application, and rebar corrosion. Soy methyl ester-polystyrene blends (SME-PS) have been shown to be an innovative, promising method of topical sealing. SME-PS, which is a derivative of soybean oil and expanded polystyrene, has been continuously studied since 2008. In this context, a comprehensive literature review compared the performance of SME-PS with that of traditional concrete sealers, including organic, inorganic, hybrid, and biotic sealers. These sealers were reviewed for performance in reducing water absorption and chloride penetration and improving freeze–thaw durability of concrete. The reviewed papers indicate that SME-PS possesses superior performance as a concrete protectant for reducing water absorption, chloride penetration, and freeze–thaw damage. To further enhance the feasibility of SME-PS, future studies may include investigating the physical and chemical protecting mechanisms of SME-PS, understanding the factors that affect the penetration behavior of SME-PS in concrete, and evaluating the short and long-term effectiveness of SME-PS in concrete.