What Is the Construction Process for Retrofitting Existing Building Exterior Walls with UHPC Panels? Renovation Technology and Qinglong Group's Urban Renewal Practice

Renovating existing building exterior walls with UHPC panels requires a five-step standardized process of "inspection and assessment, substrate treatment, framing installation, panel attachment, and sealing and finishing," with the core challenge lying in resolving old-new structural compatibility, controlling construction interference, and improving energy efficiency. In a renovation project of a 1980s office building in Shenzhen, Qinglong Group used 3D scanning inspection (accuracy ±1mm), carbon fiber fabric substrate reinforcement (tensile strength increased to 1.5MPa), a light steel framing leveling system (adjustment range ±30mm), and dry-hung UHPC panels (12-15mm thick), completing the renovation in 45 days without business interruption, reducing energy consumption by 40% and extending the building's life by 30 years. A scientific process is the key to successful renovation.

On-Site Inspection and Assessment Design

Infrared thermography, tap testing, core sampling and other methods are used to assess substrate conditions. Qinglong Group developed an existing building assessment APP that automatically generates reinforcement plans. In the Nanning old city renovation, inspection identified areas with excessive hollowing rates, and targeted grouting reinforcement was applied, saving 20% in costs.

Substrate Treatment and Structural Reinforcement

Original finishes are removed down to the structural layer, cracks are injected with epoxy resin (injection pressure ≥0.3MPa), and uneven areas are leveled with polymer mortar (thickness ≤30mm). Our patented anchor bolt system (pull-out resistance ≥5kN) ensures reliable connection between old and new structures. In the Wuhan historic building renovation, we achieved "restoring the old as old while upgrading performance."

Installation Techniques and Precision Control

An adjustable hanger system (3D adjustment ±15mm) absorbs errors in the original walls. Qinglong Group introduced measurement robots for layout, achieving installation errors of ≤±2mm. For existing buildings, we prioritize unitized installation, completing 500 square meters per day to minimize the impact on building use.

Integrated Energy Efficiency and Functional Upgrade

A composite insulation layer (50-100mm rock wool) is bonded to the back of UHPC panels, achieving integrated decoration and insulation. Our developed quick-connect system reduces the heat transfer coefficient K value to below 0.45W/(m²·K). After renovation, the building can meet the Two-Star Green Building standard.