Analysis of Installation Requirements and Key Technical Points for Embedded Anchor Bolts

In the construction systems of new decorative building materials such as UHPC/GRC/GRG/GRP, pre-embedded anchor bolts serve as the core nodes connecting components to the main structure, and their installation quality directly affects the safety and durability of the decorative system. Qinglong Group, with 28 years of experience in detailed design, manufacturing, and construction, always regards the standardized installation of pre-embedded anchor bolts as a critical process when undertaking large landmark projects, providing reliable assurance for projects through full-chain technical control.

### I. Installation Standards and Technical Prerequisites for Pre-Embedded Anchor Bolts The installation of pre-embedded anchor bolts must meet the dual requirements of material compatibility and structural load-bearing capacity. For UHPC components, due to their ultra-high strength characteristics, anchor bolts must be high-strength bolts of grade 8.8 or above, with hot-dip galvanized anti-corrosion surface treatment to ensure durability in humid environments; GRC/GRG components require expansion or chemical anchors selected according to their self-weight and load-bearing characteristics, with an embedment depth of no less than 10d (d being the bolt diameter). During the detailed design stage, Qinglong Group uses BIM technology to simulate the stress state of anchor bolts and, in accordance with the "Technical Standard for Building Application of Glass Fibre Reinforced Cement (GRC)" (JGJ/T423-2018), proactively mitigates installation conflict risks.

### II. Key Technical Points: From Precise Positioning to Standardized Construction **1. Millimeter-Level Precision Control in Measurement and Setting Out** Three-dimensional laser scanning technology is used to re-survey the installation base surface, ensuring axis deviation ≤3mm and elevation error within ±5mm. Qinglong's construction team embeds RFID chips during the prefabrication stage at the Nanning production base, achieving full traceability of anchor bolt positions through digital means and avoiding the cumulative errors of traditional manual setting out. **2. Standardized Process for Drilling and Hole Cleaning** The drilling diameter must be 2-4mm larger than the bolt diameter, and the verticality deviation of the hole wall must not exceed 1°. When cleaning holes, a high-pressure air pump must be used to remove dust; before chemical anchor installation, a special brush must be used for secondary cleaning to ensure full bonding between the adhesive and the concrete substrate. In the Century Plaza light-transmitting concrete project on Nanjing East Road undertaken by Qinglong, this process effectively increased anchoring force by more than 30%. **3. Torque Control and Anti-Corrosion Treatment** When tightening high-strength bolts, a torque wrench must be used, tightened in two passes according to the design torque value, with final tightening torque deviation controlled within ±10%. Exposed bolt sections must be coated with anti-corrosion paint and fitted with protective caps; joints of GRC components are filled with elastic sealant, forming multiple anti-corrosion barriers. The "General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC)", which Qinglong participated in formulating, particularly emphasizes the full life-cycle management requirements for anchor bolt anti-corrosion.

### III. Quality Acceptance and Solutions to Common Problems Pull-out tests must be conducted during the acceptance stage, with the measured pull-out force no less than 1.2 times the design value, and 3% of the anchor bolts in each inspection batch randomly sampled for testing. To address hole position deviations that may occur during construction, Qinglong's technical team innovatively adopts adjustable adapters, allowing position correction within ±15mm, thereby avoiding secondary damage to the structure caused by re-drilling. In addition, for lightweight components such as GRP, optimizing anchor bolt spacing (usually controlled at 500-800mm) ensures stability while reducing damage to the substrate.

As a national high-tech enterprise, Qinglong Group has incorporated pre-embedded anchor bolt installation technology into its enterprise standardization manual, and drawing on practical experience from 2,000+ projects, has formed a closed-loop management system covering design, production, and construction. Whether for UHPC curtain walls in large municipal projects or GRG shaped ceilings in high-end commercial complexes, rigorous anchor bolt installation craftsmanship has always been Qinglong's core competitiveness in ensuring project quality, and the technical cornerstone for fulfilling its mission of "Creating Aesthetic Architecture".