The construction industry faces increasing pressure to reduce its environmental impact and promote the valorization of industrial waste. In this context, this study examines the influence of progressively replacing limestone fillers (LF) with sanitary ceramic fillers (SCF) on the properties of self-compacting sand concrete (SCSC) designed for structural repair applications. Five concrete mixtures were produced with substitution rates of 0%, 25%, 50%, 75%, and 100%, allowing a progressive evaluation of the influence of sanitary ceramic fillers across the entire replacement range. The fresh-state behavior was evaluated using mini-slump flow and V-funnel tests, while mechanical performance was assessed through compressive and flexural strength tests at 7, 28, 90, and 180 days. The bond strength between the SCSC and the substrate was determined by the pull-off test which represents a key parameter for evaluating the durability and reliability of concrete repair systems. The results indicate that increasing the SCF substitution rate reduces flowability, with the mini-slump flow decreasing from 26.5 cm to 22.8 cm (≈14% reduction), while the V-funnel flow time increased from 7.2 s to 12.5 s. Mechanical strengths exhibit a nonlinear evolution with the substitution ratio, with significant improvements observed at higher substitution levels. The incorporation of SCF also influenced the bond behavior with the substrate. While the C50 formulation showed an intermediate response reflecting microstructural adjustments at moderate substitution levels, the C100 mixture achieved the highest overall mechanical and bond performance among all investigated formulations. These findings demonstrate that sanitary ceramic waste can be effectively used as an alternative filler in SCSC for structural repair applications, contributing both to sustainable waste valorization and to the development of high-performance repair materials.
