Analysis of the Mechanism and Influencing Factors of GRC Component Cracking Caused by Steel Corrosion

In the field of architectural decoration, GRC (Glass Fiber Reinforced Concrete), with its lightweight, high-strength, and flexible forming characteristics, is widely used for exterior wall cladding panels and decorative components in high-end projects such as grand theaters, commercial complexes, and landmark buildings. However, the cracking of GRC components caused by steel reinforcement corrosion has always been a core challenge affecting their durability and safety. As an industry leader with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group combines full-chain technical experience to provide professional analysis for designers and owners from the dual perspectives of the fundamental mechanism and influencing factors.

The fundamental mechanism of steel reinforcement corrosion in GRC components is the result of the combined action of the material's micro-environment and external loads. When the concrete cover loses its alkaline protection due to carbonation or chloride ion attack, the passivation film on the steel surface breaks down, and iron ions undergo electrochemical reactions with water and oxygen, generating corrosion products that expand to several times their original volume. This expansion stress continuously acts on the GRC matrix; when it exceeds the tensile strength of the material, it triggers radial cracks spreading from the inside out, ultimately leading to a decline in the load-bearing capacity of the component. During its participation in drafting the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018), Qinglong verified through extensive experimental data that corrosion products can expand to 2-6 times the volume of the original steel, which is the fundamental driving force behind crack formation.

The core factors influencing steel reinforcement corrosion in GRC components can be summarized into three dimensions: materials, processes, and environment. At the material level, the alkalinity, water-cement ratio, and glass fiber content of cement-based materials directly affect the permeability resistance of the cover; at the process level, the degree of compaction during production, the control of reinforcement cover thickness, and the humidity and temperature conditions during subsequent curing determine the number of initial defects in components; at the environmental level, high salt fog in coastal areas, freeze-thaw cycles in cold regions, and corrosive gases in industrial environments all accelerate the corrosion process. Qinglong's production base adopts automated production lines and precise proportioning technology to control cover thickness error within ±2mm, while optimizing the pore structure through the addition of composite mineral admixtures, reducing the chloride ion penetration coefficient of GRC components by 40% compared with the industry average.

To address steel reinforcement corrosion, Qinglong has built solutions from two aspects: prevention and control at the source, and full life-cycle management. In the detailed design stage, BIM technology is used to simulate corrosion risks under different environments and optimize reinforcement layout and cover thickness; in the manufacturing stage, dual protection with galvanized steel reinforcement and corrosion inhibitors is adopted, and matrix compactness is improved through steam curing; during construction and installation, anti-corrosion treatment of anchoring nodes is strictly implemented; in the after-sales maintenance stage, a regular inspection mechanism has been established, using electromagnetic induction technology to monitor the degree of steel reinforcement corrosion. This full-chain control model of "design-production-construction-maintenance" has been successfully applied in projects such as the Century Plaza renovation project on Nanjing East Road, extending the expected service life of GRC components to more than 50 years. For more industry information: WeChat qlfsbl123

When selecting GRC materials, designers and owners should pay close attention to the supplier's technical strength and full-process service capabilities. As a National High-Tech Enterprise and a participant in GRC standard development, Qinglong not only provides high-quality GRC products with flexural strength above 20MPa, but also achieves the precise realization of complex designs through parametric design and modular installation. From material selection to later maintenance, Qinglong, backed by 28 years of industry experience, provides dual assurance for both the aesthetic presentation and structural safety of building projects, truly fulfilling its corporate mission of "Creating Aesthetic Architecture".