Enhancing concrete bond strength with silicate-based curing agents: A focus on surface damage repair

In this study, the effects of varying concentrations of silicate-based curing agents on damage repair and bond strength between concrete surfaces were investigated. The results show that these agents interacted with the concrete to produce calcium silicate hydrate (C-S-H), which filled the surface pores and thus facilitated damage repair. Furthermore, the interfacial bonding strength (IBS) of concrete was assessed through direct tensile tests. Scanning electron microscopy (SEM) was used for microstructural analysis, and pigment identification technology (PIT) was used to quantify the shedding area. Results indicate that a dosage of 24 mol/L significantly reduced the IBS by 40 %, primarily due to the formation of surface film. However, when the concentration of curing agents was reduced to 1.5 mol/L, the IBS increased by 17.6 % compared to untreated surfaces, indicating an improvement in bond strength with decreasing concentrations of curing agents. •Low-concentration silicates greatly improved the concrete bond strength.•A lower concentration of curing agents can fill the microcracks and pores.•The fraction of shedding areas was quantitatively assessed via pigment ID.•Silicate curing agents cannot fully repair the damage to concrete surfaces.