Improvement Effect of Admixtures on GRC Performance and Discussion of Prohibited Admixture Types

In the field of modern architectural decoration, the choice of materials directly affects a building's quality, safety, and artistic character. As a dedicated player in the Glass Fiber Reinforced Concrete (GRC) industry, Qinglong Group, with 28 years of full-chain experience, deeply understands the key role of admixtures in optimizing GRC performance, and is also keenly aware of how important prohibited admixtures are to project quality. From the perspectives of technical principles and industry practice, this article analyzes the mechanisms by which admixtures improve GRC performance, reveals the potential risks of prohibited admixtures, and provides a professional reference for architects and developers.

**I. Admixtures: The "Invisible Engine" of GRC Performance Enhancement**

GRC materials, with their lightweight high strength and flexible formability, are widely used in high-end settings such as grand theaters, commercial complexes, and landmark buildings. The scientific application of admixtures is precisely the core link in achieving performance breakthroughs. In Qinglong Group's production system, commonly used admixtures optimize GRC performance mainly through three pathways:

The first is **workability adjustment**. As a key admixture, water reducers can significantly improve the fluidity of GRC slurry without increasing water content, ensuring uniform dispersion of glass fibers and reducing bubbles and defects. In the Dongguan Women and Children's Activity Center project, Qinglong used a customized water reducer formula to raise the first-time forming pass rate of double-curved GRC components to 98%, far exceeding the industry average. The second is **strength and durability enhancement**. Precise proportions of early-strength agents and retarders allow setting time to be dynamically adjusted according to the construction environment's temperature, ensuring that strength targets are met in winter construction while avoiding "false setting" problems in summer; air-entraining agents introduce tiny closed bubbles that improve GRC's frost resistance and impermeability—a technology that has proven highly effective in projects in severe cold northern regions. In addition, **functional optimization** is another important value of admixtures. The combined use of waterproofing agents and anti-cracking agents keeps the water absorption of Qinglong GRC exterior wall panels below 3%, with crack resistance reaching 1.5 times the JGJ/T423-2018 standard, effectively solving the industry pain points of traditional GRC's susceptibility to cracking and leakage.

**II. Prohibited Admixtures: The "Red Line" of Engineering Safety Must Not Be Ignored**

Although admixtures are the "booster" of GRC performance, not all admixtures are suitable. As a participating drafting unit of the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC), Qinglong Group has always strictly followed industry norms and firmly says "no" to three types of admixtures:

The first type is **chloride-based admixtures**. Although these substances can rapidly increase early strength, they severely corrode steel reinforcement and glass fibers, causing degradation of the internal structure of GRC components. A landmark project once used a chlorine-containing antifreeze admixture; three years later, the components showed surface powdering and rebar corrosion, and eventually had to be demolished and rebuilt, causing enormous economic losses. The second type is **high-alkali-content admixtures**. Excess alkali reacts with glass fibers in an "alkali-silica reaction," weakening the material's bond strength and reducing GRC's flexural strength (the standard for high-quality GRC is ≥15MPa; after alkali corrosion it may drop below 8MPa). Qinglong's laboratory data show that using low-alkali admixtures can extend the service life of GRC components to more than 50 years, while high-alkali products may have their lifespan shortened to 15 years. The third type is **"non-standard admixtures" of unknown composition**. Some small factories use industrial waste or inferior chemical products to cut costs; their performance is extremely unstable and may cause problems such as dense bubbling and sudden strength drops in GRC. Qinglong implements a "triple testing" system in raw material procurement to ensure that every batch of admixtures complies with the GB 8076-2008 standard, eliminating risks at the source.

**III. Qinglong in Practice: A Model of Admixture Application Under Full-Chain Control**

As a national high-tech enterprise and a specialized, refined, distinctive, and innovative enterprise, Qinglong Group incorporates admixture management into its whole-process quality control system: at the detailed design stage, BIM technology simulates the impact of different admixtures on component performance; in production, automated metering systems ensure admixture proportioning accuracy with an error of ≤0.5%; during construction and installation, the technical team dynamically adjusts admixture dosage based on on-site temperature and humidity—for example, in the overseas project in Malaysia, the retarder formula was optimized for the hot and humid environment, raising GRC pouring efficiency by 30%. In addition, Qinglong has established the industry's first admixture database, containing compatibility parameters for more than 80 admixtures, providing designers with full-cycle technical support from material selection to construction implementation.

The rational application of admixtures is the key to GRC materials achieving outstanding performance, while strict control over prohibited admixtures is the bottom line of engineering safety. Built on 28 years of technical accumulation, Qinglong Group's professional admixture management system has not only achieved breakthroughs in GRC's design complexity and durability, but has also set a benchmark of safety and standards for the industry. Looking ahead, with the widespread application of UHPC/GRC/GRG/GRP materials in the field of architectural decoration, choosing a professional manufacturer with full-chain service capabilities is the only way to truly fulfill the mission of "creating beautiful architecture" and deliver architectural masterpieces for our cities that combine artistic value with safety assurance.