Study on UV Aging Resistance of Outdoor UHPC Panels: Influencing Factors, Testing Methods, and Improvement Strategies

As a high-performance representative among new architectural decoration materials, outdoor UHPC panels' UV aging resistance directly affects the aesthetic durability and safety of building facades. In high-end application scenarios such as grand theaters, commercial complexes, and landmark buildings, how UHPC components maintain stable performance under long-term exposure to intense UV environments has become a key technical topic of focus for designers and owners. As an industry leader with 28 years of deep expertise in the UHPC/GRC/GRG/GRP materials field, Qinglong Group has developed systematic solutions in anti-aging material research and engineering practice through its full-chain technical expertise.

I. Analysis of the Core Factors Behind UV Aging of UHPC Panels

The damage UV causes to UHPC materials is essentially the result of the combined action of photo-oxidation reactions and thermal stress. First, Ca(OH)₂ in cement-based materials decomposes under UV exposure, thickening the surface carbonated layer and triggering micro-cracks; second, polymer-modified components such as polypropylene fibers are prone to molecular chain breakage under long-term UV radiation, reducing material toughness. Accelerated aging tests at Qinglong's R&D center found that when UV irradiance exceeds 300W/m², the surface color difference (ΔE value) of ordinary UHPC panels can reach 8.5 after 1,000 hours, with a flexural strength loss exceeding 12%. In addition, alternating changes in humidity and temperature intensify the destructive effects of UV, which is particularly evident in coastal high-humidity regions.

II. Scientific and Rigorous UV Resistance Testing Methods

To accurately evaluate the aging resistance of UHPC panels, Qinglong has established a dual verification system covering laboratory testing and outdoor exposure. The laboratory uses xenon lamp aging test chambers to simulate full-spectrum UV exposure, strictly controlling irradiance, black panel temperature (63±3℃), and spray cycles, and conducts 5,000-hour accelerated aging tests in accordance with the GB/T 16422.2 standard. Key testing indicators include: surface gloss retention rate (required ≥80%), flexural strength variation rate (controlled within ±5%), carbonation depth (≤2mm), and microstructural integrity. For outdoor exposure, extreme climate regions such as Hainan and Xinjiang are selected, with data collected in real time via embedded RFID chips. The General Technical Conditions for Ultra-High Performance Concrete (UHPC) Non-Load-Bearing Components, for which Qinglong participated in drafting, has now incorporated UV aging performance into its core technical indicators.

III. Practical Strategies for Enhancing the UV Resistance of UHPC Panels from Multiple Dimensions

To meet outdoor application requirements, Qinglong has formed a closed technical loop spanning material formula optimization, production process upgrades, and surface protective treatment. On the raw material side, a silica fume–mineral powder composite admixture system is used to improve matrix density; 0.2% nano titanium dioxide modifier is added, using photocatalysis to inhibit free radical generation. During production, steam curing (90℃×48h) promotes the stability of hydration products and reduces free calcium content. For surface treatment, a dual-coating protection system has been developed: the base layer uses a silane impregnation agent (penetration depth ≥3mm), while the top layer is coated with a fluorocarbon coating containing nano zinc oxide (thickness 50-80μm); testing shows this system can extend the weathering life of UHPC panels to more than 25 years. In the Nanjing East Road Century Plaza renovation project, Qinglong's translucent UHPC panels combined with anti-UV processes achieved stable performance with no obvious discoloration over 3 years under intense sunlight.

As a national high-tech enterprise and a participant in industry standard development, Qinglong has always made material durability research a focus of technological innovation. From UV impact simulation analysis during the detailed design stage, to whole-process quality control in production, and regular performance testing in after-sales maintenance, Qinglong has formed anti-aging solutions covering the entire life cycle of UHPC/GRC/GRG/GRP materials. Going forward, Qinglong will continue to explore the integrated application of nano-composite technology and intelligent monitoring systems, creating architectural decoration materials that combine aesthetic expressiveness with long-term reliability for designers, and helping to realize the corporate mission of "Creating Beautiful Architecture."