Investigation on the working performance of a non-dispersible grouting material for the crack repairment of underwater structures

Underwater structure repair is highly susceptible to various factors, including the pressure of the underwater environment and dynamic water flow. Traditional materials used for repairs are prone to dilution and dispersion, resulting in a subpar repair outcome. To address the limitations of traditional grouting materials, specifically their poor retention rate and vulnerability to erosion caused by dynamic water, an underwater non-dispersible crack repair grouting material was developed. It is composed of liquid epoxy resin, curing agent, and aggregate (ECA). Comprehensive and systematic testing was conducted to evaluate the performance of ECA grout. The results show that optimized ECA grouting material has advantages such as a high retention rate under dynamic water erosion, strong adhesion, high fluidity, high early strength, and suitable setting time. The ECA grout demonstrates excellent underwater working performance. In addition, the microstructure was analyzed using X-ray diffractometry (XRD), Fourier-transform infrared spectroscopy (FTIR), and environmental scanning electron microscopy (ESEM). The results show that the addition of aggregates to the epoxy resin does not cause any chemical reaction. Furthermore, the aggregates are bonded together by epoxy resin. Due to the formation of cross-linked microstructures, the microstructure becomes more compact. The addition of aggregates during the curing process has good compatibility and stability, which enhance the performance of the ECA grout. The material has been successfully applied in a restoration project of underwater cultural relics protection facilities, effectively addressing and repairing the existing defects. Its potential value as a reference for similar projects is substantial.