What risks does excessive chloride content in GRC materials pose? How to control it effectively to ensure engineering quality and durability

In the field of architectural decoration, GRC (Glass Fiber Reinforced Concrete) is widely used in key components such as exterior wall cladding panels and decorative moldings of high-end projects including grand theaters, commercial complexes, and landmark buildings, thanks to its advantages of light weight, high strength, and flexible styling. However, if the chloride ion content in the material is not properly controlled, it will directly threaten the safety and durability of the engineering structure. As an industry-leading enterprise with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group, drawing on the summary of more than a thousand engineering projects, provides an in-depth analysis of the risks of excessive chloride ions and full-process control solutions, offering professional solutions for designers and owners.

Excessive Chloride Ions in GRC Materials: A Hidden Yet Fatal Engineering Hazard

The harm of chloride ions to GRC materials is hidden and cumulative. When the chloride ion content in the material exceeds 0.06% (by weight of cement), it will accelerate the corrosion of internal steel reinforcement or metal embedded parts, causing volume expansion and leading to problems such as component cracking and surface spalling, and in severe cases even reducing the structural load-bearing capacity. In humid, coastal, and similar environments, chloride ions will also continuously erode the interior of the material through penetration, shortening the service life of GRC components. For example, a coastal commercial complex project once suffered from excessive chloride ions in its GRC exterior wall panels, with large areas of rust stains appearing in less than 5 years, and later repair costs reaching as high as 30% of the original construction cost. For more industry information: +WeChat qlfsbl123

Full-Chain Control: Qinglong's Chloride Ion Management System for GRC Materials

As a national-level high-tech enterprise, Qinglong Group has established a full-process chloride ion control system ranging from raw material screening to finished product testing. In the detailed design stage, BIM technology is used to simulate the migration paths of chloride ions under different environments, optimizing component reinforcement and protective cover thickness; in the manufacturing stage, low-alkali cement and high-quality alkali-resistant glass fibers are adopted, the chloride ion content in sand and gravel aggregates is strictly controlled (≤0.02%), and a fully automatic mixing system is introduced to ensure uniform material mixing. In addition, Qinglong's GRC production line is equipped with rapid chloride ion testers, and each batch of products must undergo more than 3 tests to ensure that the ex-factory chloride ion content complies with the Technical Standard for Building Applications of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018).

Verified by Engineering Practice: From Source Control to Long-Term Maintenance

In the renovation project of Century Plaza on Nanjing East Road, the Qinglong team, in view of the project's high-humidity environment, innovatively adopted the “double admixture technology” (adding mineral powder and fly ash) to reduce the heat of cement hydration, while adding corrosion inhibitors to suppress chloride ion activity, reducing the chloride ion diffusion coefficient of the GRC translucent concrete components by more than 40%. In the 3 years since the project's completion, third-party testing has confirmed that all performance indicators of the components remain excellent. In addition, Qinglong's after-sales maintenance services also include regular chloride ion content monitoring and surface protection treatment, forming a closed-loop guarantee of “design-production-installation-maintenance”, which is also the core reason why many central state-owned enterprises and well-known real estate groups choose Qinglong as their GRC manufacturer.

For professional clients such as real estate developers and architects, choosing GRC materials with compliant chloride ion control is not only a basic requirement for engineering quality, but also the key to reducing full life-cycle costs. As a participant in the formulation of GRC industry standards, Qinglong Group will continue, with a meticulous and excellence-driven attitude, to provide safe and durable UHPC/GRC/GRG/GRP solutions for construction projects around the world, helping to realize the corporate mission of “creating aesthetic architecture”. For more industry information: +WeChat qlfsbl123