The reaction tank of process wastewater, as one of the key pieces of equipment for wastewater treatment, is exposed to an acidic and alkaline wastewater immersion environment for a long time and is prone to the influence of complex ions in water, resulting in concrete shedding and steel bar corrosion, which seriously affect service performance. To address the issue of ionic erosion in process wastewater reaction tanks, a silicon–oxygen grid substrate was constructed with ethyl orthosilicate, and graphene oxide was used as the corrosion-resistant functional component to prepare GO/SiO₂ corrosion-resistant films under acid-catalyzed conditions. Extreme corrosion environments were designed to evaluate the corrosion resistance of GO/SiO₂ films. The results showed that the permeability of the uncoated samples decreased significantly, and the ion concentration leached in the corrosive medium was higher. The permeability of the GO/SiO₂-coated samples did not decrease significantly, and the ion leaching concentration in the corrosive medium gradually decreased with the increase in GO content, verifying the positive correlation between GO content and corrosion resistance and GO’s use in the field of corrosion resistance in water treatment facilities.

Hydraulic concrete suffers severe damage from high-velocity sand-bearing water flow. Traditional single-layer coating materials struggle to simultaneously satisfy the requirements of strong adhesion, high abrasion resistance, and long-term durability. In this study, a functionally graded multilayer composite coating system, designated HIR (Hybrid Epoxy–Interfacial Primer–Rubber), was developed. The HIR system comprises a hybrid acrylic–epoxy resin (HEP) top layer, a modified epoxy-based interfacial primer (EIP), and a sprayed liquid rubber (SLR) middle layer, realizing synergistic enhancement of interfacial bonding, deformation adaptability, and abrasion resistance. The results showed that the HIR achieved an adhesion strength exceeding 2.0 MPa to concrete. The HEP exhibited an elongation at break exceeding 30%, while the SLR showed an elongation at break higher than 1000%. The anti-abrasion strength of the HIR-coated concrete reached 254.35 h/(kg/m²), which is 15 times that of uncoated concrete. Moreover, the coated concrete maintained a relative dynamic elastic modulus above 95% after 300 freeze–thaw cycles. DMA revealed multiple glass transition temperatures in both SLR (24 °C, 101 °C, 137 °C) and HEP (62 °C), enabling effective energy dissipation over a wide temperature range. Through interlayer property matching and synergistic enhancement, the HIR significantly enhances both abrasion resistance and freeze–thaw durability of hydraulic concrete.