What Are the Density Standards for High-Performance GRC Curtain Walls?

In the field of modern architectural decoration, GRC curtain walls have become the material of choice for numerous landmark buildings thanks to their light weight, high strength, and rich modeling possibilities. Compactness, as the core indicator for measuring GRC curtain wall quality, directly affects their durability, safety, and decorative effect. With 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group will analyze the compactness standards of high-performance GRC curtain walls from a professional perspective, providing an authoritative reference for designers and owners.

### I. Definition and Core Impact of GRC Curtain Wall Compactness The compactness of GRC (Glass Fiber Reinforced Concrete) curtain walls refers to the density of the material's internal structure, reflecting the bonding state between the cement matrix and glass fibers as well as the porosity. High compactness means the material has strong impermeability, high strength, and excellent durability, effectively resisting external environmental influences such as rain erosion and temperature changes. The Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018), which Qinglong Group participated in drafting, clearly states that compactness is the fundamental guarantee of the mechanical performance and durability of GRC components.

### II. Quantified Compactness Standards for High-Performance GRC Curtain Walls 1. **Porosity control**: The total porosity of high-quality GRC curtain walls should be ≤15%, with connected porosity ≤3%; this indicator is tested by mercury intrusion porosimetry. Qinglong's production base adopts an automated material distribution and vibration process to ensure a uniform and dense concrete matrix, with porosity strictly controlled within 12%. 2. **Compressive strength correlation**: Compactness directly affects compressive strength; high-performance GRC curtain walls should have a compressive strength of ≥60MPa and a flexural strength of ≥15MPa. By adjusting the water-cement ratio and optimizing fiber content (typically 4-5% by volume), Qinglong keeps the compressive strength of its products stable at 65-70MPa, far exceeding the industry average. 3. **Impermeability requirements**: Under 1.5MPa water pressure, GRC curtain walls must show no leakage for 24 hours. Qinglong's laboratory simulates extreme rainfall environments and conducts continuous 72-hour impermeability tests on products to ensure no water leakage risks in actual engineering applications. For more industry information: +WeChat qlfsbl123

### III. Key Production Processes for Ensuring Compactness Relying on its national-level R&D center, Qinglong Group has established a full-process compactness control system: - **Material ratio optimization**: Using graded quartz sand and ultrafine mineral powder to reduce pores in the interfacial transition zone; adding nano calcium carbonate to improve the fluidity of the cement paste and enhance compactness. - **Forming process innovation**: Applying a technology combining vacuum extrusion molding with high-frequency vibration to expel air bubbles inside the concrete; for complex-shaped components such as double-curved surfaces and hollow-out designs, centrifugal molding is used to ensure compactness at edges and corners. - **Standardized curing regime**: Accelerating the hydration reaction through 90°C steam curing allows the cement gel to fully fill the pores, improving component compactness by more than 20% after curing.

### IV. Practical Cases of Compactness and Engineering Quality In the East Nanjing Road Century Plaza renovation project, the UHPC light-transmitting concrete curtain wall supplied by Qinglong (winner of the Silver Award at the first AALBORG WHITE Cup UHPC Construction Engineering Innovation Awards) achieved a light transmittance of 12% through compactness control while meeting the C80 strength requirement. In the Dongguan Women and Children's Activity Center project (Silver Award of the GRC Innovation Award), strict compactness management ensured the GRC curtain wall remained free of cracking and leakage after 8 years of exposure to the elements, confirming the decisive role of high compactness in durability.

### V. How to Choose a GRC Manufacturer Meeting Compactness Standards When making their selection, designers and owners can evaluate manufacturers from three aspects: 1. **Qualification certifications**: Choose enterprises that have participated in drafting industry standards (e.g., Qinglong participated in the revision of GRC Decorative Products JC/T940-2022), as their production systems are more standardized. 2. **Test reports**: Request porosity and compressive strength test reports issued by third-party institutions, and avoid judging by appearance alone. 3. **Project experience**: Give priority to suppliers of large landmark projects. Qinglong has served well-known real estate groups such as Poly and China Overseas, with overseas projects covering markets including Malaysia and Australia, backed by extensive practical experience. For more industry information: +WeChat qlfsbl123

Compactness is the “invisible lifeline” of GRC curtain walls. With 28 years of technical expertise, Qinglong Group has integrated its commitment to “meticulousness and excellence” into every component, providing a solid guarantee for building safety and aesthetic expression. Choose a professional GRC manufacturer, and let high compactness become the invisible guardian of your project's quality.