The Construction Technology of GRC Panel Curtain Wall

The application of GRC panels in the construction of dry-hung curtain walls is becoming increasingly widespread. To ensure the effectiveness of GRC panel dry-hung curtain walls, it is essential to enhance both design and construction management. The following are key construction techniques for GRC panel dry-hung curtain walls.

Preparations before Construction 

Thoroughly study the actual conditions of the construction site and project characteristics and make preparations for scaffolding and safety net installation. Carefully inspect the quality of the steel structure framework to ensure its compliance. Inspect the GRC panels and other components upon delivery to ensure material compliance. Arrange certified personnel to enter the construction site and ensure they wear the required safety equipment. Inspect the machinery, equipment, and tools needed during the construction process.

Surveying and Setting out

During the phase of surveying and setting out, construction workers need to perform a series of tasks, including leveling measurements, setting out, axis control, and elevation control. The main steps are as follows: Determine the subdivision dimensions for each GRC panel surface and establish a horizontal subdivision reference line. Using steel wires, suspend and secure lines at the designated positions along the horizontal reference line according to the dimensional requirements on the blueprints. Based on the axis positions, use a theodolite to establish vertical subdivision dimensions on the wall surface.

Install the Main Keel 

Firstly, weld the connecting parts. Determine the height of the main keel and then determine the length of the connecting parts. Use electric welding to spot-weld the embedded parts to the connecting parts and then perform full welding. Determine the height and length of the weld seam according to the design requirements and apply suitable corrosion protection to the weld seam. Secondly, install the main keel. Inspect the model, dimensions, and specifications of the main keel to ensure they meet the design requirements. Then transport the components to their specific locations while protecting their surfaces. Install and secure the main keel in a bottom-to-top sequence. After the first main keel is installed, align the lower end of the second keel with the first one, leaving an appropriate width of expansion joint in between. Adjust the three-dimensional direction of the main keel as necessary based on the position of the measurement reference line, keeping errors within 1mm.

Install the Secondary Keel

The secondary keel is made of angle steel, and its installation is also based on the position of the reference line. The accuracy of the bolt hole positions on the crossbeam significantly affects the precision of the secondary keel installation. Therefore, it is essential to accurately position the bolt holes on the crossbeam. When installing the secondary keel, the installation process typically includes four steps: angle bracket connection, anti-seismic washers, angle steel installation, and bolt fixation.

Install the GRC Panel

After the main keel and secondary keel are installed and appropriate protective measures have been taken, the dry hanging of GRC panels begins, proceeding from the bottom to the top. First, draw two horizontal control lines at the lower part of the curtain wall, and install the GRC panels from the middle section of the wall. After the first GRC panel is installed, use it as a reference point to suspend the lines and secure the hanging panel once the calibration is complete.

Lifting equipment for GRC panels can utilize electric hoists. Once the panel's hanging position is determined, use screws to secure the connection piece at the bottom of the GRC panel to the steel frame behind it. During the installation of GRC panels, secure the panel hangers first, and then insert the lower connection piece of the GRC panel onto the steel angle bracket of the secondary keel, and use bolts to connect the upper groove of the GRC panel to the steel angle bracket of the secondary keel.

Gluing and Waterproof Treatment

Before gluing, it is essential to inspect the installation quality of the GRC panel first, then repair any damages with the same material and adhere the protective paper to both sides of the panel's adhesive seam. Foam strips should be evenly filled into the seam, and the distance between the panel's surface and the foam strips should be controlled. Clean the adhesive contact surface, then use a gluing gun to evenly inject sealing adhesive into the seam. After injection, the adhesive should be smoothed immediately, and then the protective paper should be removed.

In the construction process of large GRC panel dry hanging curtain walls, the gluing step is indispensable as it not only affects the appearance of the curtain wall but also determines the curtain wall's waterproof performance. Construction personnel should handle this step with great care.

To ensure the construction quality of GRC panel dry hanging curtain walls and create building projects that combine aesthetics and practicality, it is essential to develop a scientifically sound construction plan based on the characteristics of GRC materials and implement it in the actual work. Strictly adhere to the regulatory requirements throughout the construction process, and control the quality of each stage of the work, in order to guarantee a high-quality outcome for GRC panel dry hanging curtain wall construction.