What Are GRC Raw Materials: Common Material Types and Properties

The texture of architecture stems from the careful selection of materials. As a representative of new architectural decorative materials, GRC (glass fiber reinforced concrete) owes its product performance and artistic expressiveness directly to the scientific proportioning of its raw materials. As an industry leader with 28 years of deep expertise in the UHPC/GRC/GRG/GRP materials field, Qinglong Group will analyze the core composition, characteristics, and material selection logic of GRC raw materials from a professional perspective, providing designers and owners with an in-depth reference for material selection.

GRC Raw Material System: The Scientific Synergy of Four Core Components

The outstanding performance of GRC materials stems from their unique composite material system, mainly composed of four categories: cementitious materials, reinforcing materials, aggregates, and admixtures. During the detailed design phase, Qinglong Group optimizes the raw material mix according to project requirements (such as load, environment, and shape complexity), ensuring that products combine structural safety with decorative artistry.

1. Cementitious Materials: The Foundational Guarantee of Strength and Durability

Cement, as the core cementitious material of GRC, is typically Grade 42.5 or higher Portland cement or sulfoaluminate cement, and the gel formed by its hydration reaction is the main source of material strength. The special cement used at Qinglong's production base is strictly screened and must meet the requirements of compressive strength ≥40MPa and flexural strength ≥6MPa to ensure the stability of GRC components under long-term loads. In addition, according to special project requirements (such as impermeability and frost resistance), active supplementary materials such as slag powder and fly ash are compounded to reduce hydration heat while improving material density. This technical solution has been successfully applied in multiple cold-region projects undertaken by Qinglong.

2. Reinforcing Materials: The “Skeleton” Role of Glass Fibers

Alkali-resistant glass fiber is the key reinforcing component that distinguishes GRC from ordinary concrete, typically accounting for 3%-5% of the material volume. Qinglong uses imported alkali-free glass fiber roving (zirconium content ≥16%), which, after treatment with a special sizing agent, bonds with the cement matrix to raise GRC flexural strength to 15-20MPa and improve fracture toughness by more than 30 times compared with ordinary concrete. In terms of production technology, Qinglong's original three-dimensional random distribution technology ensures uniform fiber dispersion within components, effectively avoiding cracking risks caused by stress concentration. This technological advantage enabled Qinglong GRC to precisely realize complex curved shapes in landmark projects such as the Dongguan Women and Children's Activity Center.

3. Aggregates and Fillers: The Key to Optimizing Density and Surface Quality

Quartz sand, as the main aggregate, has a particle gradation that directly affects GRC's molding performance and surface texture. Qinglong determines the optimal sand-cement ratio (typically 1:1.2-1:1.5) through gradation tests and selects refined quartz sand with a particle size of 0.15-0.6mm, which ensures concrete fluidity for easy pouring while forming a dense structure. For projects with high decorative requirements (such as stone-imitation effects), fillers such as marble powder and iron oxide pigments are added. In the Nanjing East Road Century Plaza renovation project, Qinglong precisely controlled the filler ratio, enabling GRC components to perfectly replicate the texture and color of natural stone.

4. Admixtures: The “Secret Weapon” of Performance Adjustment

Admixtures such as water reducers, retarders, and water-retaining agents are the “behind-the-scenes heroes” of GRC production. Qinglong's technical team dynamically adjusts admixture formulas according to climate conditions: 0.2%-0.5% retarder is added during summer construction to extend initial setting time, while early-strength agents are added in winter to ensure strength development; for large-span components, polypropylene fibers are incorporated to improve toughness, increasing the product's crack resistance by more than 25%. These refined admixture applications are precisely the technical guarantee that enables Qinglong GRC to adapt to the climatic conditions of different regions across the country.

Material Selection Standards: Full-Process Control from Laboratory to Construction Site

Selecting high-quality GRC raw materials requires balancing technical parameters with engineering practice. Qinglong has established a “three-level quality inspection system”: raw materials must pass 12 indicator tests including compressive strength and alkali resistance before entering the site; an online monitoring system is used to adjust the mix in real time during production; and finished products undergo durability tests such as freeze-thaw cycles (200 cycles) and impact resistance before leaving the factory. These stringent quality control standards have enabled Qinglong GRC products to withstand extreme environments such as high temperature and humidity, and strong ultraviolet radiation in overseas projects in Malaysia, Australia, and beyond.

As a contributing editor of the national Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC), Qinglong Group has always believed that the scientific selection of raw materials is the cornerstone of fulfilling its mission of “creating aesthetically beautiful architecture.” From the curved curtain walls of grand theaters to artistic sculptures in landscape gardens, every component of GRC raw materials carries the dual responsibility of structural safety and aesthetic expression. Choosing a professional GRC manufacturer means choosing not only the material itself, but also a material solution system proven by 28 years of engineering practice.