Detailed Construction Process for Retrofitting Existing Building Exterior Walls with UHPC Panels: Steps, Key Technical Points, and Precautions

Existing Buildings Reborn: A Full-Process Guide to UHPC Panel Facade Renovation Construction

Amid the wave of existing building stock renovation, ultra-high performance concrete (UHPC) is becoming the preferred material for facade renovation thanks to its outstanding mechanical properties and design expressiveness. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group deeply understands the technical pain points and aesthetic demands of building renewal. This article systematically breaks down the standardized construction process for UHPC panel facade renovation, providing professional technical guidance for designers and owners.

I. Preliminary Assessment and Scheme Design: The Scientific Starting Point of UHPC Renovation

Successful facade renovation begins with accurate preliminary diagnosis. Qinglong's technical team uses 3D laser scanning and structural testing technologies to comprehensively evaluate the substrate of existing buildings, focusing on wall flatness (error must be controlled within ±5mm), structural load-bearing capacity, and anchoring point strength. Based on measured data, combined with the building's original style and the owner's requirements, parametric design of UHPC panels is completed through BIM technology, achieving an organic fusion of "old building + new skin". At this stage, special attention should be paid to the performance differences between UHPC panels and traditional materials such as GRC and GRP. For example, the compressive strength of UHPC can exceed 150MPa, 3-5 times that of ordinary concrete, which makes ultra-thin panel design (thickness down to 20mm) possible.

II. Detailed Design and Component Production: The Core of UHPC Customization

As a national high-tech enterprise, Qinglong has an industry-leading UHPC component production line with an annual capacity of 600,000 square meters. The detailed design phase requires completing panel division optimization (single panel weight recommended ≤50kg), connector joint construction (using stainless steel embedded parts + adjustable bolt systems), and surface texture treatment (achieving stone-like, metal-like and other effects). The production process strictly implements the ISO9001 quality system, ensuring component strength and durability through automated material distribution, high-frequency vibration, and steam curing (80℃ for 24 hours). Notably, the early-strength characteristics of UHPC reduce demolding time to 12 hours, significantly improving production efficiency.

III. Substrate Treatment and Installation: Dual Guarantees of Safety and Precision

On-site construction follows the principles of "safety first, precision above all". Substrate treatment includes old wall cleaning, defect repair, and interface agent application. For common hollowing and cracking issues in existing buildings, Qinglong's patented repair technology is used for structural reinforcement. The installation stage adopts a standardized process of "surveying and setting out → embedded part fixing → keel installation → UHPC panel hoisting → joint treatment", achieving an installation error of ≤2mm through a 3D positioning system. Especially for high-rise buildings, Qinglong has developed dedicated hoisting equipment, working with a team holding a Grade II professional contracting qualification for building curtain wall engineering, to ensure construction safety and efficiency. Compared with traditional stone curtain walls, UHPC panel installation can reduce hoisting costs by 40%, and the weight is only 1/4 that of stone, greatly reducing structural load.

IV. Joint Treatment and Quality Acceptance: Details Determine Final Quality

Joint treatment is a key process affecting the waterproofing and aesthetics of UHPC facades. Qinglong uses customized weather-resistant sealant (movement capability ±25%), combined with foam rod filling and backer design, to form multiple layers of waterproofing barriers. Quality acceptance implements internal control indicators higher than industry standards, including: panel surface flatness ≤1mm/m, joint width deviation ±0.5mm, and anchoring force testing ≥15kN. As a participating drafting unit of the industry standard General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC), Qinglong integrates 28 years of engineering experience into every acceptance step to ensure project delivery quality.

From the renovation of historic buildings on Shanghai's Bund to the renewal of old factory areas in Guangzhou, Qinglong's UHPC facade renovation solutions have been successfully applied to over one hundred projects. This solution, combining durability (design service life of over 50 years), economy (30% reduction in full life-cycle costs), and aesthetics, is redefining the value enhancement path for existing buildings. As a professional supplier in the field of UHPC/GRC/GRG/GRP materials, Qinglong has always upheld the mission of "creating beautiful architecture", injecting new vitality into urban renewal through technological innovation and full-chain services.