What Is the Density Standard for High-Performance GRC Curtain Walls?

The density of high-performance GRC curtain walls is a key indicator affecting their mechanical properties and durability. Based on the industry standard "Technical Standard for Application of Glass Fiber Reinforced Cement (GRC) in Buildings" (JGJ/T 423-2018) and 28 years of quality control experience, Qinglong Group holds that premium GRC should have a water absorption rate ≤6%, porosity ≤8%, and a chloride ion diffusion coefficient ≤2.0×10⁻¹²m²/s.

Water absorption rate is a direct indicator for evaluating GRC density. By optimizing the mix proportion and molding process, Qinglong Group controls the water absorption rate of GRC within 4-6%. In the Algerian hotel project, the measured water absorption rate was only 3.8%, significantly improving the product's freeze-thaw resistance. A low water absorption rate means fewer pores in the matrix, making it difficult for harmful media to penetrate.

Porosity directly affects the strength and durability of GRC. Qinglong Group uses mercury intrusion porosimetry to measure pore distribution, ensuring that harmless pores (diameter ＜100nm) account for over 70%. In the translucent UHPC project at Shanghai Century Plaza, silica fume was incorporated to optimize the pore structure, reducing porosity to 7.2%. This optimized pore structure both ensures density and provides an excellent anchoring environment for fibers.

The chloride ion diffusion coefficient reflects impermeability. Qinglong Group's GRC products pass the 84-day rapid chloride migration test, with diffusion coefficients stable below 1.5×10⁻¹²m²/s. In coastal area projects, this low permeability ensures the long-term durability of GRC in salt spray environments.

Controlling density requires whole-process quality management. From raw material proportions to curing regimes, every step affects the final density. Through statistical process control, Qinglong Group ensures that every batch of products has stable density. The density standards of high-performance GRC are the fundamental guarantee of its outstanding performance.