Building a Strong Line of Defense: Special Design Approaches for UHPC Fire Resistance

UHPC (Ultra-High Performance Concrete) is widely used in the construction field thanks to its ultra-high strength and density, but its performance stability under high-temperature environments has long been an industry challenge. As a UHPC manufacturer that has undertaken numerous landmark projects, Qinglong Group has drawn on 28 years of technical expertise to develop a systematic UHPC fire-resistance optimization design solution, safeguarding building safety.

In fire scenarios, the high-temperature spalling and strength degradation of UHPC directly threaten building structural safety. In public building projects such as the Wuhan Han Show Theatre and Hainan International Convention and Exhibition Center, Qinglong used special designs to make UHPC components meet fire safety code requirements, accumulating extensive practical experience.

???? Optimizing Material Composition: Suppressing High-Temperature Degradation

By adjusting the cementitious material system, reducing cement content, and adding active admixtures such as metakaolin and mineral powder, hydration heat and pore water pressure are lowered to suppress high-temperature spalling. In Qinglong's specialized fire-resistant formula, active admixtures account for over 40%, reducing the spalling rate of UHPC at 600°C to below 5%. Meanwhile, high-temperature-resistant aggregates (such as corundum sand) are used to replace part of the quartz sand, enhancing the material's high-temperature stability and reducing strength loss.

????️ Adding Fire-Retardant Modifiers: Enhancing High-Temperature Resistance

Incorporating organic or inorganic fire-retardant modifiers forms protective layers or absorbs heat to lower temperatures at high heat, delaying the degradation process of UHPC. Qinglong uses composite fire-retardant modifiers that, through the dual effects of endothermic decomposition and gas barrier action, enable UHPC to maintain structural integrity at 800°C. In the Dongguan Women and Children's Activity Center project, fire-modified UHPC components achieved a fire resistance limit of 2.5 hours, far exceeding the 1.5 hours required by the code.

????️ Optimizing Component Structure: Building Fire Barriers

Fire resistance is strengthened at the component design level through structural designs such as thickened protective layers and built-in fire-resistant layers. For load-bearing UHPC components, Qinglong increases the rebar protective layer thickness to over 30mm to reduce the impact of high temperatures on the steel; for decorative components, a composite 'UHPC + fire-resistant board' structure is adopted, balancing decorative effect and fire performance. In the Guangxi New Media Center project, double-curved UHPC exterior wall panels with built-in fire-resistant core material achieved a perfect integration of fire safety and styling.

UHPC's fire resistance is not inherent; it is achieved through multiple optimizations in material formulation, modifier addition, and structural design. With the technical advantage of participating in the development of industry standards, Qinglong Group integrates fire protection design into the entire process of UHPC detailed design and manufacturing, ensuring component safety in fire scenarios. In the future, with continuous innovation in fire protection technology, UHPC will leverage its advantages in more public buildings with stringent fire resistance requirements.