Application of Thermal Spraying Technology in Concrete Surface Ceramic-Based Coating

Abstract

Enhancing the durability and extending the service life of concrete are crucial for promoting its sustainable development. Applying surface coatings is the primary technical method used to improve concrete durability. In this study, based on the plasma thermal spraying technology, a thermal-sprayed, ceramic-based coating was prepared on a concrete surface and evaluated using the drawing method, X-ray diffraction scanning electron microscopy with energy dispersive spectroscopy, X-ray computed tomography (X-CT), and frictional wear. Subsequently, performance tests were conducted. The test results showed that mullite powder was a suitable ceramic-based coating material. The coating had a good interfacial bonding ability with the concrete surface; moreover, the bonding site exhibited a chimeric state with an adhesion strength of 3.82 MPa. The wear rate of the coating material (0.02‰) is lower than that of the concrete matrix (0.06‰), resulting in improved surface wear resistance. SEM analysis reveals that the coating contains a considerable amount of amorphous or microcrystalline phases. The internal structure of the coating exhibits porous characteristics, with a total porosity of 10.35% and pore diameters predominantly ranging from 4 μm to 16 μm. At a distance of 80 μm from the coating site, the elements Al, O, and Si significantly contribute to the mullite components. The porous structures within the coating products are further verified using X-CT. This study offers a new possibility for ceramic coatings on hydraulic concrete.