Analysis of the Causes of Air Bubbles on UHPC Component Surfaces and Solutions

In the field of architectural decoration, UHPC components have become the material of choice for high-end projects thanks to their outstanding mechanical properties and artistic expressiveness. However, the problem of surface air bubbles is like a flaw on a fine work of art—it not only affects the visual presentation but may also pose hidden structural risks. As an industry leader with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group will analyze the causes of air bubbles in depth from a full-chain perspective covering material properties, production processes, and construction management, and provide systematic solutions to help designers and owners resolve this technical pain point.

I. Analysis of the Core Causes of Air Bubble Formation in UHPC Components

As a new material combining strength and toughness, UHPC (Ultra-High Performance Concrete) exhibits multi-dimensional complexity in its air bubble problems. In terms of material proportions, uneven dispersion of active admixtures such as silica fume and ultrafine mineral powder in the cementitious material system can easily lead to abnormal local slurry viscosity and form closed air bubbles, while defects in the fiber dispersion process may cause steel fibers or organic fibers to agglomerate, blocking the escape channels for air bubbles. In the production stage, control of mixing speed and time is particularly critical—low-speed mixing easily entrains air to form large bubbles, while high-speed shearing may damage the already formed stable slurry structure. These are typical causes summarized by Qinglong through 28 years of production practice.

II. Full-Chain Control: Qinglong's Technical Approach to UHPC Air Bubble Prevention

To tackle the air bubble challenge, Qinglong has built a trinity solution of "materials-process-testing." At the material optimization level, a composite formulation technology of nano-scale defoamers and air-entraining agents is adopted. Through high-frequency vibration at 2,000 times/min and vacuum degassing processes, bubble diameters are controlled below 0.2mm. During production, BIM technology is introduced for mold flow field simulation to ensure complete slurry filling without dead corners. This technology was successfully applied to the translucent concrete project of the Nanjing East Road Century Plaza renovation, achieving millimeter-level precision in surface effects. Notably, through the transformation of 58 patented technologies, Qinglong's R&D center has upgraded the traditional curing process to a gradient temperature and humidity control system, effectively preventing secondary bubble formation during the curing stage.

III. Industry Experience Insights: Quality Control Upgrades from Cases to Standards

As a participating unit in drafting the industry standard "General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC)," Qinglong deeply understands the importance of standardization for quality control. Take the Dongguan Women and Children's Activity Center project as an example: by adopting Qinglong's independently developed integrated "premixing-pumping-spraying" construction process, the bubble defect rate was controlled below 0.3%, and the project won the Silver Award of the AALBORG WHITE Cup GRC Construction Engineering Innovation Award. This practice confirms that air bubble prevention requires not only technological innovation but also refined management of the entire process—from incoming raw material inspection to pre-delivery 3D scanning inspection, Qinglong has established 18 quality control points to ensure that every UHPC component meets its quality commitment of "meticulous craftsmanship and continuous excellence."

Solving the air bubble problem is, in essence, the deep integration of materials science and engineering management. Building on 28 years of industry experience, Qinglong Group integrates its mission of "creating aesthetically beautiful architecture" into every technical detail, clearing technical obstacles for the application of UHPC/GRC/GRG/GRP materials in high-end architecture through continuous innovation and joint standard development. For designers and owners, choosing a supplier with full-chain service capabilities not only guarantees project quality but also provides dual protection for architectural aesthetics and structural safety.