Exploration and Practical Research on Surface Repair Methods for UHPC Shaped Components

Every fine repair is an utmost safeguard of architectural art — the technical philosophy behind surface repair of UHPC sculptural components

Amid the wave of deep integration between contemporary architectural aesthetics and engineering technology, UHPC (Ultra-High Performance Concrete) has become the "language of form" for high-end projects such as landmark buildings and cultural venues, thanks to its ultra-high strength, excellent durability, and outstanding shaping capability. However, as decorative components that pursue the utmost visual effect, UHPC components are prone to surface defects during production, transportation, and installation, and the repair techniques directly affect the final appearance of the building. With 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group has, through more than a thousand engineering projects, built a systematic surface repair solution for UHPC sculptural components, providing the industry with a repair paradigm that combines technical rigor with artistic expression.

Causes of UHPC Surface Defects and Repair Principles

The surface defects of UHPC sculptural components mainly stem from the dual challenges of material characteristics and process complexity. During prefabrication, due to the requirement for ultra-high density, problems such as air bubbles, color variation, and micro-cracks tend to appear in areas of complex shapes; bumps during transportation and installation, as well as temperature changes, may cause damage to edges and corners. Through defect statistics from more than 500 projects nationwide, Qinglong's technical team found that honeycombing/pitted surfaces (38%), surface scratches (27%), and edge/corner damage (21%) are the three most common types of defects. Repairs must follow the three principles of "authenticity, durability, and aesthetics": the repair material must match the substrate in composition and color to ensure long-term weather resistance, and repair marks must be kept within a visual deviation of 0.1mm, which places extremely high demands on material formulation and construction techniques.

Four-Step Repair Process: From Defect Diagnosis to Fine Restoration

Qinglong's original four-step repair method of "diagnosis – pretreatment – repair – post-treatment" has been applied to benchmark projects such as the translucent concrete at Century Plaza on Nanjing East Road and the Dongguan Women and Children's Activity Center. In the diagnosis stage, 3D scanning technology is used to build a digital model of the defects, precisely analyzing their depth, area, and surrounding texture; in the pretreatment stage, high-pressure water jetting (pressure controlled at 30-50MPa) removes the loose layer, forming a rough interface to enhance the adhesion of the repair material; in the core repair stage, Qinglong's specially formulated UHPC repair mortar (compressive strength ≥120MPa, elastic modulus matched to the substrate) is selected according to the defect type and applied in layers using techniques such as micro-troweling and injection, with each repair layer controlled at 3-5mm in thickness; finally, fine polishing (progressively finer sanding from 800 to 1500 grit) and nano-scale pore-sealing treatment achieve a seamless blend with the original component surface.

Full-Chain Assurance System: From Material R&D to On-Site Service

As a national high-tech enterprise, Qinglong has built a full-chain repair assurance system covering material R&D, production quality control, and construction management. On the materials side, the independently developed special UHPC repair material has obtained 3 invention patents, and the steel fiber content (1.5-2%) and quartz sand gradation in its formulation have been optimized through more than 2,000 tests; on the production side, the MES system enables full life-cycle traceability of components, with key processes equipped with high-definition visual inspection equipment; on the construction side, supported by its Grade II qualification as a professional contractor for building curtain wall engineering, Qinglong has formed a professional repair team equipped with on-site testing tools such as portable strength testers and color difference meters. This trinity model of "material – process – service" has enabled Qinglong to maintain a first-time acceptance pass rate of over 98% in the repair of UHPC/GRC/GRG/GRP components.

Architecture is frozen art, and repair craftsmanship is the meticulous care of this art. Qinglong Group's 28 years of industry accumulation are reflected not only in the innovative application of UHPC/GRC/GRG/GRP materials, but also in the relentless pursuit of every detail. From the magnificent curtain walls of landmark buildings to delicate decorative lines, Qinglong, with the craftsman spirit of "meticulousness and constant refinement," provides a solid guarantee for the perfect presentation of architectural art, practicing its corporate mission of "creating aesthetically beautiful architecture." In the field of new architectural decorative material manufacturing, such repair solutions that deeply integrate technical rigor with artistic expressiveness are becoming the core benchmark for measuring a company's overall strength.