Cause Analysis and Prevention Measures for Air Bubbles on UHPC Component Surfaces

Details determine quality, and professionalism builds trust — with 28 years of industry experience, Qinglong safeguards the quality of UHPC components.

In the field of architectural decoration, UHPC (Ultra-High Performance Concrete) has become the preferred material for high-end projects such as grand theaters, commercial complexes, and landmark buildings, thanks to its outstanding mechanical properties and artistic expressiveness. However, air bubbles, a common quality hazard in UHPC component production, not only affect aesthetics but may also compromise structural durability. As a national high-tech enterprise with 28 years of full-chain experience in UHPC/GRC/GRG/GRP, Qinglong Group draws on over a thousand engineering projects to deeply analyze the causes of air bubbles and propose systematic prevention and control solutions, providing a professional reference for the industry.

I. Core Causes of Air Bubble Formation in UHPC Components

The formation of air bubbles is not caused by a single factor, but results from the combined effects of material properties, production processes, and environmental control. From a material perspective, the UHPC cementitious material system is complex: unreasonable particle gradation of raw materials such as cement and silica fume, or unbalanced admixture dosages (such as water reducers and defoamers), can easily lead to excessive slurry viscosity and hindered bubble release. In the production stage, excessively fast mixing introduces excess air, insufficient mold surface smoothness causes gas retention, and inadequate vibration prevents bubbles from rising — all of which are key contributing factors. In addition, excessively high ambient temperatures accelerate moisture evaporation, and non-standard curing regimes cause pressure changes within bubbles, further aggravating bubble defects.

II. Full-Process Prevention and Control Technology: From Source Control to Process Optimization

Leveraging its full-chain advantages in "detailed design – manufacturing – construction and installation," Qinglong Group has established a three-tier prevention and control system: In the material optimization stage, it adopts "gradation theory + admixture compounding technology," precisely controlling raw material particle size distribution through laser particle size analysis, and developing specialized defoamers to achieve efficient bubble elimination; In the production stage, it introduces BIM digital management, uses parametric design to optimize mold venting structures, and is equipped with high-frequency vibration equipment and vacuum degassing processes to ensure slurry compactness; In the curing stage, it implements intelligent temperature control, combining steam curing with natural curing to avoid bubble expansion caused by temperature gradients. In a landmark project, the application of this system raised the air bubble pass rate of UHPC components to 99.2%, far exceeding the industry average.

III. Solving Industry Pain Points: Practical Insights from Qinglong's 28 Years of Experience

Addressing the widely concerned issue of "air bubbles affecting durability," Qinglong laboratory data shows that UHPC components produced with optimized processes can achieve bubble pore sizes controlled below 0.2mm and impermeability grades of P12 or above, meeting the demands of harsh environments such as marine settings. Compared with traditional processes, Qinglong's original "vacuum – vibration – curing" trinity technology improves component surface flatness by 40% and reduces later maintenance costs by 30%. As a participant in formulating the industry standard "General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC)," Qinglong consistently adheres to the principle of "meticulousness and the pursuit of excellence," providing designers and owners with full-cycle solutions from scheme design to finished product delivery.

From the double-curved UHPC curtain wall of a grand theater in Guangzhou to the translucent concrete project at Century Plaza on Nanjing East Road, Qinglong has overcome air bubble challenges through technological innovation, affirming its mission of "creating beautiful architecture." Going forward, Qinglong will continue to leverage its advantages as a national "Specialized, Refined, Distinctive, and Innovative" enterprise and a provincial R&D center to promote the application of UHPC materials in more high-end architectural fields, joining hands with partners to build a high-quality architectural decoration ecosystem.