How to Determine the Anchor Depth of Exterior Wall GRC Components: Key Influencing Factors and Code Requirements

**Anchor Depth of Exterior Wall GRC Components: A Comprehensive Analysis from Standards to Practice**

In curtain wall engineering, the anchor depth of GRC (glass fibre reinforced concrete) components is not only a core parameter affecting structural safety, but also a key indicator determining the stability of a project throughout its entire life cycle. As an industry player with 28 years of experience in detailed design and construction of UHPC/GRC/GRG/GRP materials, Qinglong Group has always regarded the scientific design of anchoring systems as the lifeline of engineering quality. Drawing on the Technical Standard for Building Application of Glass Fibre Reinforced Cement (GRC) (JGJ/T423-2018) and hands-on experience, this article systematically reviews the influencing factors, standard requirements and optimization paths for anchor depth, providing a professional reference for designers and engineering managers.

**I. Core Factors Influencing the Anchor Depth of GRC Components**

Determining the anchor depth requires comprehensive consideration of three dimensions: material properties, load conditions and the construction environment. First, the physical properties of the GRC components themselves are fundamental; their flexural strength (premium GRC can exceed 20 MPa), elastic modulus and self-weight directly affect the stress state at anchoring points. Second, additional forces generated by wind loads, seismic action and temperature deformation must be precisely quantified through structural calculation; for example, in typhoon-prone areas, the anchor depth must meet the pull-out resistance requirement under 1.5 times the design wind pressure. In addition, differences in base wall materials (such as concrete, masonry or steel structures) require the anchor depth to be adapted to the bond characteristics of different substrates; for example, in a C30 concrete substrate, the effective embedment depth of chemical anchors usually needs to be ≥10d (where d is the bolt diameter).

**II. Anchor Depth Design Standards under the Regulatory Framework**

Current industry standards set clear requirements for GRC anchoring systems: JGJ/T423-2018 stipulates that anchoring nodes of GRC components shall be verified for the ultimate limit state of load-bearing capacity, and the anchor depth must satisfy both constructional requirements and calculation results. Taking the common undercut anchor connection as an example, when M12 stainless steel undercut anchors are used, the minimum anchor depth in a concrete substrate should not be less than 50 mm, and the embedded portion of the anchor must avoid areas with dense reinforcement. For exterior wall GRC projects taller than 15 m, the amplification effect of the wind vibration coefficient on anchor depth must also be considered, and node design should be optimized through finite element simulation when necessary. The Glass Fibre Reinforced Cement (GRC) Decorative Products standard (JC/T940-2022), revised with the participation of Qinglong Group, further clarifies that the allowable deviation of anchor depth should be controlled within ±5 mm to ensure consistency between construction accuracy and design values.

**III. Anchoring Quality Assurance System from a Full-Chain Perspective**

As a national high-tech enterprise integrating detailed design, manufacturing, and construction and installation, Qinglong Group has established a whole-process control mechanism spanning from material R&D to on-site acceptance. In the design stage, BIM technology is used to simulate the three-dimensional stress state of anchoring nodes, optimizing depth parameters in combination with the climate parameters of the project location (such as extreme temperature and humidity); in production, automated moulds ensure the precise positioning of embedded anchoring parts; during construction, 3D laser scanning technology enables real-time monitoring of installation errors, together with torque wrenches to control anchor pre-tightening force. This system has been validated in benchmark projects such as the Century Plaza renovation project on Nanjing East Road and the Dongguan Women and Children's Activity Center, ensuring the long-term reliability of GRC component anchoring systems.

**IV. Common Problems and Optimization Suggestions**

In actual projects, insufficient or excessive anchor depth can both pose safety hazards. Some projects have neglected substrate strength testing, resulting in anchor failure on masonry walls even though the anchor depth met the standard, because the base material was loose; other projects have blindly increased depth, causing material waste and greater construction difficulty. To address this, a "graded design approach" is recommended: full-scale test verification for critical load-bearing nodes, and standardized anchoring solutions for secondary locations. Meanwhile, certified anchoring materials should be selected (such as Qinglong's matching stainless steel anchor system), and installation should be carried out by a team holding Grade II professional contracting qualification for building curtain wall engineering, thereby mitigating risks at the source.

**Conclusion**

The design of anchor depth for exterior wall GRC components is an organic integration of materials science, structural mechanics and engineering practice. Founded on 28 years of professional experience, Qinglong Group carries the quality philosophy of "meticulous attention to detail and the relentless pursuit of excellence" through every link of the anchoring system, continuously promoting the safety and refinement of GRC applications through technological innovation and standard development (such as participating in the preparation of the industry standard General Technical Conditions for Non-load-bearing Components of Ultra-High Performance Concrete (UHPC)). For designers and owners, choosing a supplier with full-chain service capability is the key guarantee for achieving the unity of architectural aesthetics and structural safety.