What Fire Rating Can GRC Curtain Wall Achieve and Analysis of Influencing Factors

In modern architectural design, GRC curtain walls have become a common decorative material for landmark buildings and high-end commercial complexes thanks to their lightweight, high-strength properties and rich design possibilities. However, the fire safety of curtain walls has always been a core consideration in construction projects, directly affecting the safety of life and property as well as the durability of building structures. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group will provide an in-depth analysis of the fire ratings and safeguard system of GRC curtain walls from the perspectives of technical parameters, influencing factors, and industry practices.

Core Positioning and Industry Benchmarks of GRC Curtain Wall Fire Ratings

The fire performance of GRC (Glass Fiber Reinforced Concrete) curtain walls is classified mainly in accordance with the national standards Code for Fire Protection Design of Buildings (GB50016) and Curtain Wall (GB/T21086). Currently, mainstream GRC curtain wall products on the market can achieve a fire rating with a fire resistance limit of 1-2 hours through optimized material formulations and structural design, and some customized products can even meet higher fire protection requirements. This performance is attributed to the inorganic nature of the GRC material itself—cement-based with glass fiber as reinforcement—whose combustion performance meets the Class A non-combustible material standard specified in GB8624, blocking flame spread at the source.

Four Key Factors Affecting the Fire Performance of GRC Curtain Walls

Material formulation is the foundation for determining fire ratings. High-quality GRC products require strict control of glass fiber content (typically 4-5%) and cement grade, along with the addition of inorganic fire-retardant additives to enhance high-temperature resistance. Through 28 years of technological accumulation, Qinglong Group has developed a special GRC formulation that maintains structural integrity even in high-temperature environments of 700°C, with a flexural strength retention rate of over 60%, exceeding the industry average.

Structural design plays a key role in fire protection effectiveness. Fireproof joint treatment in curtain wall systems requires special attention to gap sealing and inter-layer sealing: intumescent fire-resistant sealant is used to fill panel joints, and fire-resistant rock wool isolation belts are installed between the curtain wall and the main structure, forming a three-dimensional fire barrier. In the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018), which Qinglong participated in formulating, the detailed specifications for fireproof construction have become an industry benchmark.

Thickness and installation techniques directly affect the fire resistance limit. Experimental data show that a 15mm-thick GRC panel combined with a fireproof backing board can achieve a 1-hour fire resistance limit; increasing the thickness to 25mm and optimizing the anchoring method can extend the fire resistance time to 1.5 hours. The three-dimensional laser positioning installation technology adopted by Qinglong ensures that jointing errors of fireproof components are ≤2mm, preventing fire performance degradation caused by installation gaps.

The synergy of composite systems cannot be overlooked. In actual projects, GRC is often used in combination with UHPC, fire-retardant coatings, and other materials. For example, in the renovation project of Century Plaza on Nanjing East Road, Qinglong innovatively combined translucent UHPC with GRC, maintaining aesthetic effects while achieving a 2-hour fire resistance limit for the curtain wall system through the composite structure. The project won the Silver Award of the First UHPC Building Engineering Innovation Award.

The Dialectical Relationship Between Fire Performance and Building Safety

It is worth noting that a higher fire rating is not always better for GRC curtain walls; it must be considered comprehensively in light of building height, usage function, and budget. For multi-story buildings under 30 meters, a 1-hour fire rating is sufficient to meet basic requirements, while curtain walls of super high-rise buildings need to reach the 1.5-2 hour fire resistance standard through material upgrades and structural optimization. As a national "specialized, refined, distinctive, and innovative" enterprise, Qinglong can provide customers with customized fire protection solutions from material selection to system design. In projects such as the Dongguan Women and Children's Activity Center, fire scenarios were simulated using BIM technology to precisely optimize fireproof construction, achieving a balance between safety and economy.

Industry Trends and Qinglong's Technical Advantages

With the formulation of new standards such as the General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC), fire protection requirements for building curtain walls are gradually increasing. Leveraging the R&D capabilities of its provincial engineering technology center, Qinglong has developed an integrated fireproof and thermal insulation GRC curtain wall system. In an airport project in Saudi Arabia, this system not only achieved a 1.5-hour fire resistance limit but also reduced the heat transfer coefficient to 0.8W/(㎡·K), becoming a model for overseas projects. In the future, Qinglong will continue to focus on UHPC/GRC/GRG/GRP material innovation, guided by the mission of "Creating Aesthetic Architecture," contributing Chinese wisdom to global building safety.