Jialuo He

Soy methyl ester-polystyrene (SME-PS) is an organic material derived from soybeans, which has proven to be an effective protectant for concrete surfaces. This study investigated the long-term performance of cement paste samples treated with SME-PS under laboratory accelerated aging conditions (AAC). The specimens were subjected to cyclic conditions: 8 h of UVA radiation (simulating solar radiation), followed by 6 h of darkness with water condensation and a high temperature of 40°C for 28 days. After the AAC exposure, the samples were immersed in a deicing salt solution, specifically a 29.8 wt. % calcium chloride solution, for 7 days. To evaluate the long-term behavior of SME-PS, a series of experiments, including visual observation, thermogravimetric analysis (TGA), and low-temperature differential scanning calorimetry (LT-DSC) was conducted. Visual observations revealed slight damage in SME-PS-treated samples after AAC exposure, while control samples experienced microcrack formations. SME-PS chemical compositions remained unaffected by AAC, in contrast to the control samples where a decrease in the quantity of calcium hydroxide and an increase in calcium carbonate content were observed as a result of carbonation during AAC exposure. LT-DSC results indicated that SME-PS-treated samples showed a significant reduction in the enthalpy of fusion associated with calcium oxychloride (CAOXY) formation, indicating that the SME-PS remained effective after AAC exposure, while control samples exhibited higher CAOXY enthalpy of fusion.

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.