What Is the Role of a Load Pocket in GRC Components?

"Force pack" is a colloquial term for a local reinforcement detail in GRC components, referring specifically to a locally strengthened zone formed around embedded parts (such as undercut anchors or lifting points) by increasing GRC thickness, raising the reinforcement ratio, or incorporating built-in steel members. Its core function is to "disperse concentrated stress, provide reliable anchorage, and prevent local failure," making it a key safeguard for safe load transfer at connection nodes. In the large-cantilever GRC components of the Shenzhen Yirui Biotechnology Building, Qinglong Group successfully transferred enormous cantilever loads safely to the main structure through a carefully designed composite force pack of "steel skeleton + high-strength GRC."

Dispersing and Transferring Concentrated Stress

The tension, shear, or bending moment borne by embedded parts acts on the GRC matrix in the form of "concentrated forces" through their base plates and anchor bars. If the GRC thickness or strength is insufficient, splitting or pull-out failure can easily occur around the anchorage points. By increasing the concrete thickness in this area and adding reinforcing fibers/rebar, the force pack significantly improves local bearing capacity and splitting resistance, effectively spreading the concentrated force over a larger GRC cross-section and preventing brittle failure caused by stress concentration.

Ensuring Effective Anchorage of Embedded Parts

The anchorage capacity of an embedded part depends on its bond and mechanical interlock with the surrounding GRC. The force pack provides a deeper, more solid "gripping" volume. For undercut anchors, sufficient anchorage depth is the prerequisite for tensile pull-out capacity; for embedded steel plates, adequate concrete cover thickness provides ample bonding area and shear-key action. Qinglong determines the minimum dimensions and detailing requirements of each force pack through calculation, ensuring that under the most unfavorable loads, failure occurs in the metal part itself rather than in the anchorage zone.

Enhancing Local Stiffness and Integrity

During component hoisting, turning, and installation, the lifting points bear enormous dynamic loads. The force pack increases the stiffness of this area, reduces local deformation, and ensures hoisting safety. At the same time, it binds the embedded part more firmly with the GRC matrix into one integrated body, improving the integrity of the connection node, making load transfer smoother, and reducing the risk of fatigue damage caused by micro-movements over long-term use.

Design Points and Construction Forms

The design of a force pack must consider the load magnitude, direction, and GRC panel thickness. Common forms include: 1) Locally thickened boss: thickening the GRC behind the embedded part to form a pedestal. 2) Built-in reinforcing mesh: laying multiple layers of alkali-resistant glass fiber mesh or rebar mesh around the embedded part. 3) Composite steel skeleton: for heavy components, welding the embedded part onto a small steel frame and embedding the entire assembly into the GRC. Qinglong individually identifies and designs all force packs in detail during the detailed design stage, and conducts rigorous in-process inspections during production to ensure construction quality.