Can UHPC Curtain Wall Panels Achieve a Class A Fire Rating? Fire Performance Optimization and Compliance Solutions

The fire resistance rating of UHPC curtain wall panels directly affects building fire safety, and Class A fire resistance is a core requirement for high-end public buildings and high-rise buildings. Clarifying the fire resistance characteristics of UHPC materials and the corresponding optimization solutions is key to achieving Class A fire resistance. Drawing on its fire protection project experience, Qinglong explains the key points.

1. Basic Fire Resistance Characteristics of UHPC Materials

UHPC is essentially an inorganic non-combustible material, composed mainly of cement, quartz sand, and steel fibers. According to the Classification for Burning Behavior of Building Materials and Products (GB 8624-2012), UHPC materials without added combustible components can achieve Class A burning performance and possess a natural fire resistance advantage. Qinglong's standard UHPC curtain wall panels, tested by third parties, have all reached Class A1 burning performance — non-combustible with no toxic gas release, and maintaining structural integrity for more than 1.5 hours at high temperatures (800°C), far exceeding ordinary concrete materials. However, it should be noted that applying combustible coatings or using combustible connectors on UHPC panels will lower the overall fire resistance rating, requiring targeted optimization.

2. Key Optimization Measures for Achieving Class A Fire Resistance

Component optimization: Increase UHPC panel thickness to 25-30mm with embedded steel mesh or stainless steel fibers to enhance high-temperature resistance; 30mm thick UHPC panels can achieve a fire resistance limit of 2.0 hours, meeting Class A fire resistance requirements. Avoid combustible auxiliary materials: use inorganic fireproof coatings for surface coatings, stainless steel for connectors, and fire-rated silicone sealant (temperature resistance ≥1000°C). In the Shenzhen Pingshan High-tech Zone Comprehensive Service Center project, Qinglong achieved overall Class A fire resistance with this configuration. Joint fire protection design: Fill fire-resistant rock wool (Class A burning performance) with a width ≥500mm between the curtain wall and the main structure to form a fire isolation zone that blocks flame spread, and add fire baffle plates at connector locations to prevent connector failure at high temperatures.

3. Fire Protection Design Practices for Different Building Types

High-rise buildings (height >50m): Use 30mm thick UHPC panels combined with double-layer fire-resistant sealing and fire isolation zones, achieving a fire resistance limit ≥1.5 hours. Qinglong applied this in the Shanghai Xinghewan high-rise project, meeting high-rise building fire codes. Commercial complexes: Use Class A1 UHPC panels in densely populated areas with no combustible surface decoration and joint fire separation distances ≥600mm, combined with automatic fire extinguishing systems to enhance fire safety. Industrial buildings: Use high-temperature resistant UHPC panels with refractory aggregates in high-temperature production areas, raising the fire resistance limit to 2.5 hours. Qinglong adopted this solution in the Shenzhen Yirui Biotechnology Building industrial plant project. Historic building renovation: Balance fire protection with appearance by using Class A UHPC wood-imitation components to replace combustible wood while preserving the traditional character.

4. Key Points for Fire Performance Testing and Acceptance

Entrust an authoritative third-party institution to conduct fire performance testing, covering items such as burning performance, fire resistance limit, and smoke toxicity, to ensure compliance with Class A standards. On-site acceptance should check key aspects such as fire isolation zone installation, fire-resistant sealant application, and fire protection treatment of connectors, ensuring construction meets design requirements. Establish fire protection archives, retain test reports and construction records, conduct regular fire performance re-inspections, check fire protection material aging every 3 years, and promptly replace damaged components. Through rigorous fire protection design and control, Qinglong has enabled UHPC curtain wall panels to successfully achieve Class A fire resistance standards in multiple major projects, providing reliable protection for building safety.