UCST polymer modified full-dimensional water-repellent cementitious materials with enhanced durability

Abstract

Water penetration through freeze-thaw (F-T) cycles can significantly deteriorate the performance and even lead to the failure of concrete constructions. In response, hydrophobic cement-based materials have recently emerged as an innovative solution to improve resistance to environmental erosion during service. Despite their potential, challenges such as poor dispersion, incomplete hydrophobic coverage and suboptimal mechanical properties remain. To address these issues, an Upper Critical Solution Temperature (UCST) polymer was innovatively incorporated to create a full-dimensional water-repellent material with enhanced dispersion, improved mechanical properties, and increased F-T resistance. Further research is also focusing on assessing the compatibility of the UCST polymer with both cationic and anionic air-entraining surfactants. The performances and durability of material were assessed using a universal machine, X-ray diffraction (XRD), scanning electron microscopy (SEM), and F-T testing equipment. The results demonstrated a 20 % increase in compressive strength, an 80 % improvement in flexural strength, and a notable enhancement in durability, with the modified materials enduring 120 % more F-T cycles compared to the control groups.