Surface Pre-Coating of Fly Ash Ceramsite for Interfacial Microstructure Evolution and Mechanical Enhancement of Lightweight Concrete
Year: 2026
Type: article
Abstract: : The widespread application of fly ash ceramsite lightweight aggregate in high-performance concrete is restricted by its inherent defects, including high porosity, high water absorption rate and weak interfacial transition zone (ITZ). In this study, a high-performance surface strengthening coating composed of micro-namo silica fume and modified acrylate emulsion was designed and prepared, aiming to modify its macroscopic mechanical and durability properties. The results show that, the coating treatment improved 28‑day compressive, flexural‑tensile, and axial tensile strengths by 21.2%, 16.0%, and 20.6%, respectively, along with the elastic modulus and ultimate tensile strain. The coated concrete achieved an impermeability grade exceeding W14, retained over 85% of relative dynamic elastic modulus after 150 freeze‑thaw cycles, and maintained compressive strength above 90.0% after 20 wetting–drying cycles, with a corresponding relative dynamic elastic modulus of 67.24%. Microstructural observation, pore parameter analysis, and microzone mechanical testing were performed to reveal the underlying mechanisms. The performance improvement is mainly attributed to the strengthening of the traditionally weak interfacial transition zone (ITZ). Additionally, the coating refines the pore structure, stabilizes its distribution, and acts as a physical barrier, further enhancing resistance to freeze‑thaw and wetting–drying cycles.
Source: Buildings
Authors: Hua Wei, Anyi Chen, Chunhe Li, Hao Lu
Institutions: Nanjing Hydraulic Research Institute, University of Miyazaki
Language: English
Subfield: Civil and Structural Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,137
OpenAlex ID: W7205011093