The Improvement Effect of Admixtures on GRC Performance and Analysis of Prohibited Admixture Types

In the field of building materials, admixtures are like a double-edged sword: used well, they can give GRC material performance a powerful boost; used poorly, they may sow hidden hazards into a project. As an industry participant with 28 years of deep experience in UHPC/GRC/GRG/GRP materials, Qinglong Group will analyze—from the dual perspectives of technical principles and engineering practice—how admixtures improve GRC performance and which types of admixtures are prohibited, providing a professional reference for designers and owners.

I. How Do Admixtures "Add Points" to GRC Performance? An Analysis of Three Core Improvement Directions

GRC (glass fiber reinforced concrete) is a new type of composite material whose performance optimization depends on the scientific application of admixtures. In benchmark projects such as the Dongguan Women and Children's Activity Center that Qinglong Group participated in, precisely calibrated admixture ratios delivered three key improvements for GRC components:

The first is improved workability. By incorporating high-range water reducers, the flowability of GRC mixtures can be increased by more than 30%, ensuring complete filling in complex-shaped molds—especially suitable for forming high-precision components such as double-curved curtain wall panels and openwork reliefs. The second is enhanced mechanical properties. Proper use of early-strength agents and reinforcing agents can raise GRC's flexural strength beyond 20MPa, meeting the load-bearing requirements of large external cladding components. The third is improved durability. Air-entraining agents refine the internal pore structure, keeping GRC's strength loss rate below 10% after 500 freeze-thaw cycles at -40°C—the technical key to why Qinglong GRC products can adapt to the different climates of Malaysia, Saudi Arabia, and other regions.

II. Beware! These Three Types of Admixtures Can "Deduct Points" from GRC Projects or Even Cause "Failure"

Not all admixtures are suitable for GRC materials; certain ingredients may react adversely with glass fibers or the cement matrix. According to the Technical Standard for Building Applications of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018) and Qinglong's 28 years of engineering experience, the following three types of admixtures must be strictly prohibited:

The first type is chloride-containing admixtures. Chloride ions destroy the sizing on glass fiber surfaces, causing debonding between the fibers and the cement matrix. In a commercial complex project in Nanjing, the misuse of a chloride-containing early-strength agent once caused early cracking of GRC cladding panels. The second type is high-alkali admixtures. When alkali content exceeds 0.6%, alkali-aggregate reactions are triggered, producing expansive cracks in components—this is also a quality control point Qinglong pays particular attention to in Southeast Asian projects. The third type is admixtures that are chemically incompatible with glass fibers, such as certain silicone-based waterproofing agents, which may cause fiber degradation and reduce GRC's long-term mechanical performance.

III. Scientific Selection of Admixtures: Qinglong's Technical Assurance Through Full-Chain Service

As a national high-tech enterprise, Qinglong Group has established a full-process quality control system covering everything from admixture selection to finished product testing. During the detailed design stage, the technical team determines the optimal admixture formula through orthogonal experiments based on the climate conditions of the project location and the functional requirements of the components; during production, automated metering systems keep admixture dosing errors within ±0.5%; and on-site simulation tests are conducted before construction to verify the actual performance of GRC components. This integrated "design-production-construction" service model is precisely Qinglong's core competitiveness in undertaking major landmark projects at home and abroad.

The rational application of admixtures is a key link in optimizing GRC material performance: their technical advantages must be fully leveraged while strictly observing the prohibited red lines. Qinglong Group will continue, with an attitude of "meticulous care and constant improvement," to provide designers and owners with safe and reliable GRC solutions, helping to create more architectural works that combine aesthetic value with structural safety. Choosing a professional manufacturer means choosing lasting assurance of engineering quality.