Resistance of hydrophobic concrete with different moisture contents to advanced freeze-thaw cycles

This article is aimed at investigating the long-term performance of three original hydrophobic materials, namely, sodium acetate, fluoropolymer, and silicone resin. Their performance was compared with traditional silane when applied to fully dry concrete, fully saturated concrete, and concrete with 2 and 4% moisture content. A recently developed freeze-thaw process, which is based on temperature and humidity variations, was employed in this study to assess the durability of applied materials. The outcomes of the adopted freeze-thaw system were compared with the results obtained from running a conventional freeze-thaw test. Mass change, water absorption, and microcracks development of treated concrete were investigated and compared with untreated concrete after completing 6 months of freeze-thaw cycles. Results confirmed the high affinity of the proposed materials to moisture at application time compared with silane. Additionally, it was demonstrated that moisture content has a critical impact on the bonding between applied materials and concrete, hence their efficacy in enhancing the durability of concrete.