Research on Surface Repair Methods and Applications for UHPC Shaped Components

Guardian of Architectural Aesthetics: UHPC shaped component surface restoration technology keeps the perfect fusion of art and structure ever new.

In the field of contemporary architectural decoration, UHPC (Ultra-High Performance Concrete), with its outstanding mechanical properties and freedom of form, has become the "artistic expression medium" for high-end projects such as landmark buildings and commercial complexes. However, complex shaped components are prone to surface defects during production, transportation, and installation, and how to restore their design aesthetics and structural integrity through scientific restoration technology has become a core concern of the industry. As an industry leader with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group, drawing on its full-chain technical accumulation, has developed a systematic solution in the field of shaped component surface restoration.

### Analysis of the Types and Causes of Surface Defects in UHPC Shaped Components

Although UHPC materials feature high strength and high toughness, problems such as surface air bubbles, micro-cracks, and uneven color may still occur in the production of special-shaped components (such as double-curved curtain wall panels, hollow reliefs, and landscape sculptures) due to factors like material mix ratio, casting process, and curing conditions. Take a UHPC exterior wall project for a grand theater as an example: local honeycomb pitting appeared on its single-curvature shaped components after demolding, and inspection by Qinglong's technical team determined that it was caused jointly by insufficient vibration and inadequate mold venting design. In addition, bumps during transportation and stress concentration during installation may also cause edge damage or surface scratches, affecting the final decorative effect.

### Qinglong's Full-Process Restoration Technology: From Defect Diagnosis to Fine Restoration

To address different types of surface defects, Qinglong has established a standardized "diagnosis-restoration-inspection" process. At the material level, its self-developed UHPC-specific repair mortar, through adjusting the silica fume and steel fiber content and the admixture proportions, ensures compatibility and mechanical matching between the repair layer and the substrate, achieving a flexural strength of over 18MPa and forming an integrated load-bearing system with the parent material. For air bubble and honeycomb defects, the "V-shaped groove cleaning + high-pressure grouting + fine polishing" process is adopted: an ultrasonic detector is first used to locate the defect area, modified epoxy resin slurry is then injected for filling, and finally fine polishing with 300-grit sandpaper keeps the flatness error of the repaired surface within 0.5mm/m.

In the field of color difference restoration, Qinglong has innovatively applied "spectral analysis + nano color matching" technology: color data of the original component surface is collected with a spectrophotometer, and nano-grade pigments are precisely blended to ensure that the color difference value ΔE between the repaired area and the overall surface is ≤2.0, achieving an effect indistinguishable to the naked eye. In a UHPC sunshade panel project for a commercial complex, this technology successfully resolved localized yellowing caused by batch differences, winning high recognition from the designer and the owner.

### Engineering Application and Value Enhancement of Restoration Technology

Surface restoration of UHPC shaped components is not merely "mending defects" but a process of "enhancing value". In the translucent concrete project of the Century Plaza renovation on Nanjing East Road, Qinglong's team addressed the edge spalling of more than 2,000 UHPC translucent components with a restoration solution of "prefabricated mortise-tenon connection + epoxy resin reinforcement", which not only eliminated structural safety hazards but also preserved the integrity of the translucent effect; the project won the Silver Award of the First UHPC Construction Engineering Innovation Award under the AALBORG WHITE Cup. In addition, in overseas projects such as the UHPC relief restoration for a landmark building in Malaysia, Qinglong achieved efficient delivery of cross-border restoration services by combining remote technical guidance with localized construction, demonstrating the technical strength of Chinese building material enterprises.

### Industry Trend: Technological Upgrading from Passive Restoration to Active Prevention

As the architectural decoration industry raises its requirements for refinement, surface restoration technology is shifting from "after-the-fact treatment" to "proactive prevention". Relying on its provincial engineering technology center, Qinglong has developed a component production simulation system based on BIM technology, which uses digital twins to predict defect-prone areas in advance and optimize mold design and casting parameters, reducing the repair rate by more than 30%. Meanwhile, the self-healing UHPC material under research, by introducing microcapsule technology, is expected to achieve autonomous healing of micro-cracks, providing new ideas for the full life-cycle maintenance of shaped components in the future.

As a national high-tech enterprise and a participant in the formulation of UHPC industry standards, Qinglong has always taken "creating beautiful architecture" as its mission and regards surface restoration technology as a key link in safeguarding architectural aesthetics. From detailed design to after-sales maintenance, Qinglong's full-chain service system not only solves practical problems for customers but also drives industry progress through technological innovation, helping UHPC/GRC/GRG/GRP materials shine in more high-end buildings. In the future, Qinglong will continue to focus on material performance and process optimization, providing solid technical support for creating architectural works of art that stay ever new.