Why Aggregates Larger Than 5mm Are Not Recommended for UHPC: An Analysis from Material Properties and Performance Impact Perspectives

In the development of contemporary building curtain wall technology, demountable connection technology for GRC curtain walls is becoming a key breakthrough for achieving building sustainability and whole-life cycle management. As an industry practitioner with 28 years of experience in detailed design and engineering of UHPC/GRC/GRG/GRP materials, Qinglong Group deeply understands the strategic value of demountable connection technology in improving curtain wall system maintenance efficiency and reducing whole-life cycle costs. This article will systematically analyze the implementation solutions for demountable connections of GRC curtain walls from three dimensions: design concept innovation, technical path innovation, and engineering practice verification.

Reconstructing the Design Logic of GRC Curtain Wall Demountable Connections

The core of demountable connection technology lies in establishing a full-process system of "modular construction - reversible installation - convenient maintenance." During the detailed design stage, it is necessary to break away from the traditional rigid connection mindset and adopt a design strategy of "independent component load-bearing + flexible node adjustment." The three-dimensionally adjustable connectors innovatively applied by the Qinglong team in a cultural center project, combining stainless steel embedded sleeves with replaceable bolts, achieve a three-dimensional adjustment margin of ±30mm, meeting installation precision requirements while providing operational space for later replacement. This design thinking applies not only to new construction projects but can also empower curtain wall renovation of existing buildings through BIM technology.

Innovative Practices on Multi-Dimensional Technical Paths

Achieving demountable connections for GRC curtain walls requires building an integrated technical system encompassing materials, structure, and workmanship. At the material level, high-performance GRC panels (flexural strength ≥18MPa) are combined with aviation-grade aluminum alloy connectors, ensuring structural safety while reducing the self-weight of connection nodes; at the structural level, two core node types—"plug-in" and "interlocking"—have been developed, where plug-in nodes enable rapid assembly and disassembly through a tongue-and-groove structure, while interlocking nodes enhance seismic performance using a wedge-shaped self-locking principle; at the workmanship level, digital pre-assembly technology is introduced, combining factory-prefabricated standard connectors with on-site laser positioning installation to control installation errors within 2mm. The demountable connection technology laboratory established by Qinglong at its Nanning production base has completed over 100,000 fatigue tests, verifying the long-term reliability of the nodes.

Value Verification and Optimization in Engineering Scenarios

The application of demountable connection technology in actual projects demonstrates significant value. In a commercial complex project, after adopting Qinglong's demountable GRC curtain wall system, the replacement time for a single panel was reduced from 8 hours with traditional methods to 1.5 hours, and maintenance costs dropped by 62%. For coastal high-humidity environments, the innovatively developed corrosion-resistant demountable nodes extend node service life to more than 25 years through dual protection of fluorocarbon coating plus sacrificial anode. Particularly noteworthy is the application of this technology in existing building renovations, such as a historic building facade renewal project, where demountable connections achieved non-destructive integration between the new GRC curtain wall and the original structure, preserving the building's historic fabric.

With the deepening of building industrialization and green construction concepts, demountable connection technology for GRC curtain walls will become an important direction for future development. Leveraging its deep accumulation in material R&D, structural innovation, and engineering practice, Qinglong Group is continuously advancing the standardization and industrialization of this technology. Industry peers are advised to focus in project practice on node waterproofing detail design, material compatibility matching, and the establishment of digital operation and maintenance systems, jointly building a sustainable GRC curtain wall technical system. As a national high-tech enterprise and a participant in GRC industry standard formulation, Qinglong will continue its mission of "creating beautiful architecture," providing more innovative and economical solutions for the building decoration field.