The handling of irregular joints in aluminum curtain wall construction is a core aspect, directly impacting the structural safety, waterproofing, and aesthetics of the curtain wall. Irregular joints typically refer to non-standard angles, curved surfaces, or complex geometric shapes in the curtain wall, such as corners, edges, and curved transitions. Due to their irregular geometric forms, these joints require refined processes to achieve structural and aesthetic harmony.
In the structural connection of irregular joints in aluminum curtain walls, aluminum alloy core molding technology is a key process. For corner joints with varying angles, the core mold determines the bending angle through profile cross-section molding. The column, after being machined and beveled, fits into the core, with the gap controlled within a reasonable range to accommodate profile dimensional deviations. For example, when the left and right bending angles of the column are inconsistent, a boss can be molded onto the core. This boss is machined and milled to accommodate small-range angle changes, and machined screws are used for fixation on both sides, ensuring connection strength while avoiding frequent mold openings. For bidirectional inclined members, whether in-plane or out-of-plane, the aluminum insert is designed with a folded cross-section or a cross-section cut into a polygonal shape, achieving angle adaptation through factory pre-processing.
Sealing technology is crucial for the waterproof performance of irregular joints. Multiple sealing structures are required at the joints, such as filling the inner side with structural adhesive and the outer side with weather-resistant adhesive, forming double protection. At corners or joints, expansion joints must be reserved between the aluminum alloy plate and the frame, filled with fireproof rock wool, and then sealed with sealant to prevent rainwater penetration. For dynamic joints such as settlement joints and expansion joints, expandable aluminum alloy covers with built-in spring devices or elastic sealing materials are required to adapt to the deformation needs of the main structure while maintaining a smooth appearance.
Three-dimensional spatial positioning and digital processing technology are the foundation for precise construction of irregular joints. Using a BIM model and a total station, the three-dimensional coordinates of each joint are measured and adjusted to ensure that the installation positions of the keel and panels meet the design requirements. For example, at the curved transition sections of irregularly shaped curtain walls,
the curved surface needs to be divided into small units. Digital cutting and processing are used to pre-assemble the frame and panels, reducing on-site errors. Furthermore, 3D digital positioning and layout technology can extract the coordinates of the support system, mounting points, and panels, using a laser total station to mark control points on the main structure, forming the outer contour line to guide hoisting accuracy.
The panel installation process must balance structural safety and aesthetics. Panels for irregularly shaped nodes typically employ customized designs, such as hyperbolic panels or diamond-shaped splices, requiring precise positioning through a dedicated mounting system. For example, a U-shaped aluminum alloy base is used to connect with square steel, and stainless steel bolts are used for in-plane adjustment. Hanging grooves and brackets are installed on the panels, with nut tightening adjusting the left and right positions, and vertical bolts adjusting the elevation. During installation, horizontal and vertical control lines must be laid out, and customized plastic pads are used to adjust the flatness of the panels, ensuring that the height difference between adjacent panels meets specifications.
Detailed processing is key to improving the quality of irregularly shaped nodes. At corners, right-angled aluminum alloy plates can be bolted to the exterior wall panels, or shaped aluminum plates can be used for finishing. The top coping requires a metal plate cover, with a gap left for caulking after fixing. Settlement joints require segmentation of the curtain wall frame, employing a double-layered waterproof structure (inner and outer), sealed with shaped aluminum plates and sealant. Furthermore, the fireproofing design of irregularly shaped nodes must comply with regulations, such as filling with fireproof rock wool and installing fire-resistant isolation strips, to enhance the safety of the curtain wall.
The selection of materials and processing precision for irregularly shaped nodes are equally important. Aluminum alloy profiles must possess high strength and corrosion resistance, with surface treatments such as fluorocarbon spraying or anodizing to improve weather resistance and aesthetics. During processing, parameters such as bending angles and chamfer dimensions must be strictly controlled to avoid installation difficulties due to processing errors. For example, CNC bending machines can control the bending angle error of panels, ensuring a natural and smooth transition of curved surfaces. The treatment of irregular-shaped nodes in aluminum curtain walls requires the comprehensive application of technologies such as structural connection, sealing, digital processing, panel installation, detail treatment, and material control. Through meticulous construction, the goals of structural safety, reliable waterproofing, and aesthetic appeal can be achieved. As architectural designs become increasingly complex, innovation and optimization of irregular-shaped node technology will become a core competitive advantage in curtain wall engineering.
