Analysis of Admixtures' Improvement Effects on GRC Performance and Types of Prohibited Admixtures

In the field of building materials, admixtures are like a precise "formula code": they can make GRC (Glass Fiber Reinforced Concrete) shine with performance, yet improper selection can also plant hidden quality risks. As an industry leader with 28 years of deep dedication to UHPC/GRC/GRG/GRP materials, Qinglong Group will analyze the mechanisms by which admixtures improve GRC performance and reveal the underlying reasons certain admixtures are banned in the industry, from the dual perspectives of technical principles and engineering practice, providing a professional selection guide for designers and owners.

1. Admixtures: The "Performance-Boosting Engine" of GRC

The outstanding performance of GRC materials is inseparable from the scientific formulation of admixtures. In the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018), which Qinglong Group helped formulate, admixtures are explicitly listed as a core factor affecting material performance. Through precise addition of water reducers, the fluidity of GRC mixtures can be increased by more than 30%, ensuring dense pouring of complex-shaped components — a technology perfectly validated in the translucent concrete project of the Nanjing East Road Century Plaza renovation, which won the Silver Award at the First UHPC Building Engineering Innovation Award (AALBORG WHITE Cup).

The coordinated use of early-strength agents and retarders provides a flexible solution for controlling the production cycle of GRC components. By optimizing admixture formulations, Qinglong's Guangxi production base has achieved a 24-hour demolding strength of 80% of the design value for standard components, while large special-shaped components avoid early cracking through retarding technology. Behind an annual capacity of 600,000 square meters lies precisely the refined application of admixture technology. Notably, the addition of air-entraining agents can raise GRC's frost resistance by 2-3 grades, making it especially suitable for curtain wall projects in the severe cold regions of northern China — one of the technical advantages behind Qinglong's products being exported to overseas markets.

2. Banned Admixtures: Hidden "Quality Traps"

Not all admixtures empower GRC; some chemical substances can become performance "killers". Based on Qinglong Group's 28 years of engineering experience, the following three types of admixtures are strictly prohibited: first, early-strength agents containing chlorides — their free chloride ions cause corrosion of glass fibers, reducing GRC's flexural strength by more than 40% within 5 years. This is also a key indicator explicitly restricted by the Glass Fiber Reinforced Cement (GRC) Decorative Products standard (JC/T940-2022).

Second are rapid-setting agents with excessive alkali content: although they can speed up construction, excessive alkali triggers alkali-aggregate reactions, causing mesh-like cracks on component surfaces. Qinglong's laboratory once tested failed GRC components from a project and found an alkali content as high as 3.2%, far exceeding the standard limit of 1.5%. In addition, release agents containing silicone must be used with caution — inferior products form an isolation layer on the GRC surface, affecting the adhesion of subsequent coatings. A profound lesson was learned during the construction of the Dongguan Women and Children's Activity Center project, which ultimately adopted Qinglong's self-developed eco-friendly release agent to ensure a perfect decorative finish.

3. Scientific Selection: Technical Assurance of Qinglong's Full-Chain Service

As a National High-Tech Enterprise and a contributing unit to GRC standard formulation, Qinglong Group has established a full-process quality control system covering everything from admixture selection to finished product testing. Addressing the cost and schedule concerns of real estate developers, we provide "customized admixture solutions" — for example, in a commercial complex project, compound admixture technology shortened the production cycle of GRC curtain wall panels by 15% while reducing material loss by 3%.

For the shape-realization challenges that concern designers, Qinglong uses BIM technology to simulate the impact of admixtures on concrete fluidity, ensuring one-time forming of complex components such as double-curved surfaces and hollow-out designs. As for the durability requirements of government public projects, all admixtures have passed 500 freeze-thaw cycle tests and 2,000-hour weather resistance verification — this is also the core competitiveness that has made Qinglong a strategic partner of renowned real estate groups such as Poly and China Overseas.

From material formulation to engineering application, the choice of admixtures directly determines the success or failure of GRC projects. Built on 28 years of technical accumulation, Qinglong Group integrates full-chain advantages in in-depth design, manufacturing, and construction installation, providing not only GRC products that meet international standards but also conveying the corporate values of "honesty, striving, trust, and collaboration". On its mission of "creating beautiful architecture", Qinglong has always maintained a rigorous technical attitude, building a solid quality foundation for every project — the best interpretation of its corporate motto of "meticulousness and the relentless pursuit of excellence".