What Special Designs Are Required to Achieve the Fire Resistance of UHPC and Key Technology Analysis

**Special Designs Required to Achieve UHPC Fire Resistance and Key Technology Analysis**

In the field of building safety, the fire resistance of materials is a critical line of defense protecting lives and property. As a dedicated technology specialist in ultra-high performance concrete (UHPC), Qinglong Group, with 28 years of full-chain experience, deeply understands the performance challenges UHPC faces in high-temperature environments. This article analyzes the pathways to achieving UHPC fire resistance from three dimensions—material formulation optimization, structural design innovation, and composite protection technology—providing professional solutions for designers and building owners.

### 1. Material Formulation: The Core Foundation of UHPC Fire Resistance The high strength of UHPC stems from its dense microstructure and steel fiber reinforcement system, but this also makes it prone to cracking at high temperatures due to the accumulation of internal steam pressure. Qinglong has solved this challenge through three major technological breakthroughs: **First**, introducing nano-scale mineral admixtures (such as silica fume and ultrafine mineral powder) to optimize the thermal stability of cement hydration products and reduce porosity at high temperatures; **Second**, adopting a low-calcium calcium aluminate cement system to reduce the decomposition rate of Ca(OH)₂ at around 500°C, delaying strength loss; **Finally**, innovating the steel fiber surface treatment process by using zirconia coating technology to enhance the interfacial bond between fibers and the matrix, preventing premature fiber debonding at high temperatures. According to third-party testing, Qinglong UHPC retains over 60% of its compressive strength in an 800°C fire environment, far exceeding industry standards.

### 2. Structural Design: From "Passive Endurance" to "Active Protection" Traditional UHPC component design often focuses on mechanical performance while neglecting fire resistance requirements. Drawing on experience from thousands of engineering projects, Qinglong proposed the concept of a "gradient fire-resistant structure": **First**, setting a 5-10mm thick protective layer with low thermal conductivity on the component surface, using a composite of lightweight ceramsite and basalt fiber to form a thermal barrier; **Second**, optimizing the reinforcement method by controlling steel fiber spacing within 20mm to form a three-dimensional fire protection network, preventing structural embrittlement caused by localized high temperatures; **Third**, using BIM technology to simulate fire temperature field distribution and applying thickening treatment to node areas (such as beam-column connections and embedded parts), ensuring that critical areas achieve a fire resistance limit of over 3 hours. Taking the Nanjing East Road Century Plaza renovation project as an example, the Qinglong UHPC translucent concrete curtain wall, with this design, successfully passed the 90-minute fire resistance limit test at the National Testing Center.

### 3. Composite Protection: Multi-Technology Synergy for Enhanced Fire Resistance Reliability The fire resistance of a single material is limited. Qinglong innovated the "UHPC+" composite protection system to achieve a 1+1>2 effect: **Composited with GRC**, utilizing GRC's porous structure to absorb high-temperature expansion stress, reducing the risk of internal cracking in UHPC; **Combined with GRG**, forming a "UHPC load-bearing layer + GRG fireproof layer" double-layer structure in interior decoration, where GRG releases crystalline water when exposed to fire, achieving physical cooling; **Synergized with fire-retardant coatings**, using ultra-thin intumescent fire-retardant coatings that rapidly form a carbonized protective layer in the early stage of a fire, buying reaction time for UHPC. This full-chain solution has been validated in projects such as the Dongguan Women and Children's Activity Center, winning the AALBORG WHITE Cup GRC Building Engineering Innovation Award.

As a National High-Tech Enterprise and a participant in industry standard development, Qinglong has always upheld the mission of "Creating Beautiful Buildings" and regards fire resistance as one of the core competitive strengths of its UHPC products. From material R&D to project implementation, from detailed design to after-sales maintenance, Qinglong safeguards building safety with its full-chain service capabilities. Looking ahead, we will continue to explore collaborative fire protection technologies combining UHPC with other new materials, driving the industry toward a safer and greener future.