Research on the Erosion Mechanism of Concrete Surface by Limnoperna fortuneiand Its Prevention Using Protective Coatings

Biofouling caused by the attachment and erosion of the Limnoperna fortunei and other aquatic organisms has become one of the major technical challenges threatening the operational safety of water diversion projects. Protective coatings are among the primary technical measures for enhancing the durability of hydraulic concrete. To provide effective guidance for the selection and design of surface protective coatings for hydraulic concrete from the perspective of bioerosion mechanisms, this study investigated the deterioration effects of Limnoperna fortunei on concrete by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), chemical titration, and carbonation analysis. The results show that the attachment of Limnoperna fortunei is coupled with the carbonation process of concrete, which significantly aggravates structural deterioration, leading to reduced compressive strength, increased carbonation depth, decomposition of hydration products (calcium hydroxide and calcium silicate hydrate gel), and the development of a looser and more porous internal structure. Based on the above bioerosion mechanism, field exposure tests were conducted using CW-series fluorocarbon resin coatings and modified epoxy resin coatings. The results demonstrate that both coatings can effectively inhibit the attachment of Limnoperna fortunei, retard the carbonation process of concrete, and mitigate the loss of calcium-bearing components. These findings provide a scientific basis and technical support for protecting hydraulic concrete against bioerosion in water diversion projects.