How Do Admixtures Improve GRC Performance? Which Admixtures Are Prohibited?

In the field of modern architectural decoration, GRC (Glass Fiber Reinforced Concrete) has become the ideal choice for high-end projects such as grand theaters, commercial complexes, and landmark buildings, thanks to its advantages of light weight, high strength, and flexible shaping. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group deeply understands the key role of admixtures in optimizing GRC performance, and is equally clear about which admixtures must be strictly prohibited to safeguard project quality. Today, we will take an in-depth look at how admixtures improve GRC performance and which categories are prohibited, providing professional reference for designers and owners.

I. The Four Core Ways Admixtures Improve GRC Performance

1. Improving Workability: In GRC production, high-efficiency water reducers are indispensable admixtures. They can significantly reduce the water content of concrete, improve the fluidity and plasticity of the mix, ensure uniform dispersion of glass fibers, and reduce strength defects caused by uneven mixing. During the detailed design stage, Qinglong Group precisely adjusts the water reducer dosage according to the geometric complexity of each project, so that the GRC slurry can both meet the casting requirements of complex curved surfaces and ensure structural stability after molding.

2. Optimizing Mechanical Properties: Early-strength agents and accelerators can speed up the setting and hardening of GRC, increase early strength, and shorten the production cycle, making them especially suitable for large projects with tight schedules. An appropriate amount of expansion agent can compensate for concrete shrinkage, reduce cracks, and improve the durability of GRC components. Taking a landmark building project Qinglong participated in as an example, through the rational use of compound admixtures, the flexural strength of its GRC exterior wall cladding panels reached over 20MPa, far exceeding the industry standard.

3. Enhancing Durability: Air-entraining agents can form tiny bubbles inside GRC, improving frost resistance and impermeability, making them particularly suitable for buildings in cold regions or humid environments. In addition, rust inhibitors can effectively protect glass fibers and steel bars (if any) from corrosion, extending the service life of GRC components. Testing shows that Qinglong's GRC products can withstand 200 freeze-thaw cycles without damage, and their weather resistance meets the requirements for long-term use in coastal areas.

4. Improving Surface Quality: Water-retaining agents can reduce bleeding on the GRC surface, avoiding defects such as honeycombing and pitted surfaces, and enhancing the decorative effect. For projects pursuing a high-end texture, Qinglong also adds special surface modifiers to give the GRC surface a variety of decorative effects such as faux stone and faux metal, meeting designers' individual needs. For more industry information: +WeChat qlfsbl123

II. Two Types of Admixtures Strictly Prohibited in GRC Production

1. Chloride-based admixtures: Although such admixtures can effectively lower the freezing point and promote early strength, they severely corrode glass fibers and steel bars, causing a sharp drop in the strength of GRC components and the loss of durability. Qinglong Group strictly complies with the Technical Standard for Building Applications of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018), resolutely prohibits the use of admixtures containing chlorides, and safeguards product safety at the source.

2. High-alkali-content admixtures: Excessive alkali will undergo alkali-aggregate reaction with glass fibers, destroy the fiber structure, and reduce the mechanical properties of GRC. In raw material selection and admixture compounding, Qinglong always keeps the alkali content below 0.6%, ensuring long-term product stability. Meanwhile, the General Technical Conditions for Ultra-High Performance Concrete (UHPC) Non-Load-Bearing Components, whose formulation the company participated in, also makes strict provisions on alkali content, leading the healthy development of the industry.

III. Qinglong Group: Practitioner and Standard Setter of Professional Admixture Application

As a national high-tech enterprise and vice-chairman unit of the China GRC Association, Qinglong Group not only possesses advanced admixture compounding technology, but has also established a sound quality control system. From admixture selection during detailed design, to precise dosing in manufacturing, to performance monitoring after construction and installation, Qinglong always maintains the attitude of "meticulous and striving for perfection", providing customers with full-chain GRC solutions. The company's annual production capacity of 600,000 square meters, as well as strategic partnerships with well-known real estate groups such as Poly, China Overseas, and Vanke, fully demonstrate market recognition of Qinglong's GRC products. In the future, Qinglong will continue to focus on the innovative development of UHPC/GRC/GRG/GRP materials, contributing to its mission of "creating aesthetically beautiful buildings".