How to Select UHPC Strengthening Components in Old Building Renovation: Analysis of Key Factors and Practical Pathways

Adhesive selection determines the safety and service life of GRC decorative panels — 28 years of industry experience shows you how to choose scientifically

In the field of architectural decoration, GRC (glass fiber reinforced concrete), with its lightweight high strength and rich modeling possibilities, has become the material of choice for high-end projects such as grand theaters, commercial complexes, and landmark buildings. However, the bonding quality between GRC decorative panels and the substrate has a direct bearing on building safety and service life. As an industry leader with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group draws on its full-chain service experience to provide designers and owners with a key technical guide to adhesive selection.

I. Core Principles for Adhesive Selection of GRC Decorative Panels

The bonding system of GRC decorative panels must meet both mechanical performance and environmental adaptability requirements. During the drafting of the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018), Qinglong Group found that a high-quality adhesive should possess three key characteristics: first, bond strength compatibility — products with tensile bond strength ≥1.0MPa should be selected according to the weight of the GRC panel (typically 40-60kg/㎡); second, deformation compatibility — the elastic modulus must match the difference in expansion coefficients between the substrate and GRC to prevent cracking caused by thermal stress; and finally, weather resistance and durability — performance must remain stable in environments from -40℃ to 70℃, which is also the key technical assurance behind the export of Qinglong GRC products to Southeast Asia, Australia, and other regions.

II. Substrate Characteristics Drive Adhesive Type Selection

Different substrate materials have different requirements for adhesives. For concrete substrates, Qinglong recommends cement-based adhesives, whose hydration reaction produces a dual effect of mechanical interlocking and chemical bonding, making them particularly suitable for load-bearing applications such as exterior wall cladding panels. If the substrate is a steel structure or aluminum panel, epoxy adhesives offer superior interfacial adhesion, but care should be taken to keep the application environment temperature above 5℃. Notably, in the Nanjing East Road Century Plaza renovation project, Qinglong successfully achieved a stress-free connection between translucent GRC components and the steel structure using a custom-modified epoxy adhesive; the project won the Silver Award of the AALBORG WHITE Cup UHPC Construction Engineering Innovation Award.

III. Impact of Environmental Factors on Adhesive Performance

Humid environments (such as underground utility corridors and areas around swimming pools) require hydraulic adhesives, which can cure normally even underwater; in high-temperature, high-radiation areas, high-temperature-resistant silicone adhesives should be given priority — the special silicone sealant used by Qinglong in a project in Saudi Arabia can withstand continuous temperatures of 80℃. In addition, to counter salt spray corrosion in coastal regions, the anti-corrosion adhesive system developed by Qinglong has passed 5,000 hours of neutral salt spray testing, ensuring a service life of more than 20 years for GRC decorative panels.

IV. Key Points for Matching Adhesives with Construction Techniques

For thin plastering applications, polymer-modified bonding mortar is recommended, with thickness controlled at 3-5mm to avoid hollowing; for point bonding installation, the effective adhesive coverage must be ≥40%, with points arranged in a quincunx pattern to ensure uniform load distribution. In the Dongguan Women and Children's Activity Center project, Qinglong innovatively adopted BIM pre-assembly technology combined with a dedicated adhesive, achieving GRC component installation tolerances of ≤2mm; the project won the Silver Award of the GRC Construction Engineering Innovation Award.

As a national high-tech enterprise and a participant in the formulation of GRC industry standards, Qinglong Group has always upheld the mission of "creating aesthetically beautiful architecture", providing full-chain services from detailed design to after-sales maintenance. When selecting a GRC adhesive, it is advisable to take into account substrate characteristics, environmental conditions, and construction techniques, and to contact professional manufacturers for customized solution design where necessary. Qinglong's 28 years of engineering practice show that scientific adhesive selection is the first line of defense for the safety and durability of GRC decorative systems, and a key guarantee for achieving the unity of architectural aesthetics and structural safety.