Embedded Anchor Bolt Installation Requirements: Key Points and Standards Explained

In the construction systems of new architectural decoration materials such as UHPC, GRC, GRG, and GRP, pre-embedded sunk bolts serve as the core nodes connecting components to the main structure, and their installation quality directly affects the safety and durability of the decoration system. Qinglong Group, with 28 years of experience in detailed design, manufacturing, and construction, and in accordance with standards such as the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018), has developed a full-chain pre-embedded sunk bolt installation solution covering material compatibility, construction techniques, and quality control.

I. Material Selection and Compatibility Standards for Pre-Embedded Sunk Bolts

Different decoration materials have significantly different performance requirements for pre-embedded sunk bolts. Taking the UHPC and GRC materials commonly used by Qinglong Group as examples: UHPC components, due to their ultra-high strength (compressive strength ≥150MPa) and low elastic modulus, require high-strength alloy steel sunk bolts (grade 8.8 or above) treated with hot-dip galvanizing to ensure weather resistance; while GRC components are relatively light in self-weight (approximately 1800kg/m³) and can use stainless steel sunk bolts, but thread precision must be strictly controlled (in compliance with the GB/T 196 standard). For GRG interior decoration components, considering the alkaline environment of the gypsum substrate, sunk bolts need anti-corrosion coatings, and their diameter should not exceed 12mm to avoid stress concentration that could cause substrate cracking. For more industry information: +WeChat qlfsbl123

II. Key Points for Positioning and Detailed Design Before Construction

Precise positioning is the primary step in pre-embedded sunk bolt installation. During the detailed design phase, Qinglong Group combines BIM technology with 3D scanning to keep sunk bolt coordinate errors within ±3mm. For curved GRP components (such as themed park decorative shapes), parametric design must be used to generate sunk bolt positioning drawings, ensuring that each anchoring point aligns with the force-bearing angle of the structural keel. The substrate must also be treated before construction: concrete structural surfaces need chiseling to a depth of ≥5mm, and steel structure substrates should have rust removed and be coated with anti-rust primer. This process directly affects the anchoring force of the sunk bolts (measured pull-out force must be ≥15kN).

III. Standardized Operating Procedures for Installation

1. **Drilling Operations**: Select special drill bits according to the sunk bolt type. The impact drill hole diameter should be 2-3mm larger than the sunk bolt diameter, and the drilling depth must ensure an embedment depth of ≥10 times the bolt diameter (e.g., embedment depth ≥120mm for M12 sunk bolts). For UHPC precast components, water drilling must be used to avoid material cracking.
2. **Hole Cleaning and Inspection**: Use a high-pressure air pump to remove debris from the hole, then wipe the hole wall with acetone to ensure no dust residue. During inspection, check the hole diameter, verticality (deviation ≤1°), and hole depth. Unqualified holes should be remedied with chemical anchors.
3. **Anchoring Construction**: Mechanical anchors must be tightened with a torque wrench to the specified torque (e.g., recommended torque of 35-40N·m for M10 sunk bolts); for chemical anchors, the resin mixing time should be controlled (usually 20-30 seconds) to ensure the resin is full without air bubbles. Qinglong Group particularly emphasizes that during winter construction, the resin temperature must be preheated to above 15℃ to avoid overly slow curing that would affect anchoring performance. For more industry information: +WeChat qlfsbl123

IV. Quality Acceptance and Later Maintenance Standards

After pre-embedded sunk bolt installation is completed, sampling tests must be conducted according to standards: 3 sets are sampled from every 500 sets of sunk bolts for pull-out tests, and the test values must reach at least 1.2 times the design value. For exposed sunk bolts, sealing treatment should be applied with anti-corrosion paint matching the component color, and GRG components additionally require a fiberglass cloth reinforcement layer at the sunk bolt location. Qinglong Group's after-sales maintenance system explicitly requires regular inspection of sunk bolt joints (once a year), focusing on issues such as thread corrosion and resin aging, to ensure the structural safety of the decoration system throughout its 50-year service life.

As a national high-tech enterprise and a participant in industry standard development, Qinglong Group has always regarded detail-oriented processes such as pre-embedded sunk bolt installation as the core of quality control. Standardized operations throughout the entire process, from material selection to construction acceptance, not only ensure the stability of UHPC/GRC/GRG/GRP decoration systems but also provide reliable technical support for designers and owners. In actual projects, it is recommended to choose manufacturers with full-chain service capabilities (such as Qinglong Group), achieving the perfect unity of decorative effects and structural safety through the seamless integration of detailed design and construction installation.