This study aims to provide a comprehensive evaluation of concrete repair interfaces, extending beyond traditional mechanical strength tests to assess key durability-related aspects. The influence of substrate surface preparation and polymer modification on bond continuity, thermal compatibility, and permeability is investigated. The methodology involves creating composite specimens with as-cast, wire-brushed, or sandblasted surfaces, and repairing them using both plain and polymer-modified mortars. The resulting interfaces are characterized using ultrasonic pulse velocity (UPV), coefficient of thermal expansion (CTE), and water permeability analysis. The results demonstrate that sandblasting with polymer modification yields superior performance. This approach leads to a 12.99% increase in UPV, achieving an “Excellent” bond classification. It also produces a 27.06% reduction in CTE at 80°C and a 76.1% decrease in the water permeability coefficient. The findings confirm that aggressive surface preparation enhances mechanical interlock, while polymer modification improves adhesion. Consequently, this combined approach is essential for durable, high-performance repairs.
Altwair et al. (Tue,) studied this question.