Construction Process and Key Technical Points for Replacing a Single Damaged UHPC Curtain Wall Panel

In the field of modern architectural decoration, UHPC curtain wall panels have become the preferred material for landmark buildings thanks to their outstanding mechanical properties and artistic expressiveness. However, the repair of localized damage after long-term service has always been a technical challenge in the industry. As a national high-tech enterprise with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group has drawn on practical experience from hundreds of projects to systematically compile a standardized construction process and core technical points for the replacement of single damaged UHPC curtain wall panels, providing the industry with a replicable solution.

1. Preliminary Assessment and Preparation Stage for UHPC Curtain Wall Panel Replacement

Accurate assessment is the prerequisite for ensuring repair quality. First, a damage condition inspection is required, using 3D laser scanning technology to obtain precise data on the damaged panel and surrounding areas, with a focus on analyzing crack distribution, the extent of anchoring system damage, and structural safety. Qinglong's technical team will simultaneously retrieve the original project's BIM model and material parameters, including key indicators such as the compressive strength (≥150MPa) and elastic modulus (≥35GPa) of the UHPC panels, to ensure the replacement panels match the performance of the original structure. For different application scenarios, such as commercial complex facades or museum curtain walls with irregular shapes, differentiated construction plans must be formulated, and 1:1 mock-up pre-assembly tests conducted when necessary.

2. Technical Essentials of Non-Destructive Removal and Structural Surface Treatment

Traditional removal methods can easily cause secondary damage. Qinglong's original "static cutting + hydraulic synchronous lifting" process system uses diamond wire saws for non-destructive cutting along panel edges and a micro hydraulic jacking system to achieve synchronous unloading with 0.5mm precision, avoiding additional stress on the surrounding curtain wall structure. After removal, a special interface treatment agent is applied to roughen the substrate, creating a surface roughness of Rz25-50μm to ensure a bond strength of ≥3.5MPa between new and old concrete. At this stage, special attention must be paid to protecting the original GRC/GRG decorative moldings, with customized molds used for temporary support when necessary.

3. Production and Quality Control of Customized UHPC Panels

As one of the first domestic enterprises to participate in drafting the "General Technical Conditions for Ultra-High Performance Concrete (UHPC) Non-Load-Bearing Components" standard, Qinglong has established a strict panel production quality control system. Using its self-developed C120-grade UHPC formula, mixed with 1.2% steel fibers and 0.02% nano calcium carbonate, and formed through processes such as vacuum vibration and steam curing (90℃×48h), the panels achieve a flexural strength of over 25MPa. For special categories such as translucent concrete, the designed light transmittance is achieved by adjusting the optical fiber arrangement density (100-300 fibers/m²). Each panel is embedded with an RFID chip that records full life-cycle data such as production batch and mechanical properties, meeting the refined management requirements of a "Specialized, Refined, Distinctive, and Innovative" (SRDI) enterprise.

4. Precision Installation and Innovation in Sealing & Waterproofing Techniques

Installation precision directly affects the stability of the curtain wall system. Qinglong adopts "3D positioning + modular installation" technology, using a Leica TS60 total station to control installation errors within ±2mm, combined with self-developed adjustable stainless steel hangers (load capacity ≥8kN) to ensure that panels remain structurally stable under temperature deformation. Joint treatment uses a "double-sealing" process: low-modulus silicone structural sealant (movement capability ±50%) is injected on the inner side, while UHPC-specific repair mortar creates a curved transition on the outer side, forming a sealing system that combines waterproofing with decoration. This process has withstood the test of extreme weather in projects such as the Century Plaza renovation on Nanjing East Road, with a leakage rate of zero.

5. Completion Acceptance and Maintenance System Establishment

Acceptance of repair projects follows enterprise internal control indicators that exceed industry standards, including on-site pull-out tests (anchoring force ≥6kN), water tightness testing (no leakage under 10kPa water pressure), and visual quality inspection (flatness ≤1mm/m). As a vice chairman unit of the China GRC Association, Qinglong has established a comprehensive after-sales maintenance mechanism, providing owners with quality tracking services for up to 15 years through regular drone inspections and stress monitoring systems. This full-chain service capability is the core advantage that enables Qinglong to establish strategic partnerships with leading real estate enterprises such as Poly and China Overseas.

The replacement and repair of UHPC curtain wall panels is not only a technical undertaking but also a comprehensive test of material performance, construction techniques, and project management. With 28 years of technical accumulation, Qinglong Group integrates its full-chain advantages in detailed design, manufacturing, and construction installation into every repair project, ensuring both the safety and durability of building curtain walls and providing professional support for designers to achieve a sustainable presentation of architectural aesthetics. In the future, with the implementation of standards such as "Ultra-High Performance Concrete (UHPC) Exterior Wall Panels", the industry will embrace more standardized development opportunities, and Qinglong will continue to uphold its philosophy of "meticulous attention to detail and the pursuit of excellence", promoting the innovative application of new architectural decoration materials in more fields.