FAQ
1. What material is commonly used for the anchor plate of curtain wall embedded parts?
Answer: Q235B steel is typically used. For special load-bearing sections, Q355B steel may be employed.
Q235B is a carbon structural steel with a yield strength above 235 MPa, sufficient for the mechanical load requirements of most curtain walls. Besides good strength, it offers excellent toughness, with an elongation after fracture of over 26% for standard thickness and no cracks in bend tests.
2. What material is commonly used for the rebar of face-mounted embedded parts?
Answer: HRB400 or HRB400E hot-rolled ribbed steel bar is standard, with a yield strength above 400 MPa. It provides high strength and good weldability, with HRB400E offering excellent seismic performance. For heavy loads, long spans, or high bearing capacity, HRB500 material can be used.
3. What is the required zinc coating thickness for hot-dip galvanized curtain wall embedded parts?
Answer: Hot-dip galvanizing applies a zinc layer to the component surface to enhance corrosion resistance.
According to the GB/T 13912-2020 standard:
For workpieces over 6mm thick: the average zinc coating should be ≥85μm, with a minimum local thickness of ≥70μm.
For workpieces 3-6mm thick: the average zinc coating should be ≥70μm, with a minimum local thickness of ≥55μm.
4. Why is plug welding required for face-mounted embedded parts?
Answer: Plug welding (also called hole welding) is used for face-mounted embedded parts to ensure more reliable force transfer, higher strength, better resistance to pull-out, shear, and fatigue, and more consistent quality.The anchor plate hole should be bell-mouthed (countersunk). The inner diameter should be 2-4mm larger than the rebar diameter, with a bevel angle of approximately 45 degrees. Welding must completely fill the hole, with perimeter welding around it. Current must be controlled to avoid burning through or damaging the steel plate.
5. What are the dimensional tolerance standards for curtain wall embedded parts?
Answer: Standard specifications generally require length and width tolerances within ±3mm and thickness tolerances within ±0.3mm. Actual execution should follow the specific requirements of the curtain wall design.
6. What is the standard spacing for curtain wall main mullions?
Answer:
Glass Curtain Walls: A conventional spacing of 1.2 meters is standard, accommodating 1.2m wide glass panels. Design spacing typically ranges from 0.9m to 1.5m based on actual loads.
Stone Dry-hang Curtain Walls: Due to heavier panels, conventional spacing is 0.8m to 1.0m.
Aluminum Panel Curtain Walls: Due to lighter panels, spacing is generally 1.2m to 1.5m.
7. How to resolve issues of omitted or misplaced face-mounted embedded parts?
Answer: Use post-installed embedded parts secured with chemical anchors or mechanical anchors for remedial work. The use of expansion bolts for fixation is strictly prohibited. Pull-out tests must be conducted upon completion of installation to ensure safety and reliability.
8. What calculations are required for embedded part design?
Answer: The design calculations encompass:
Load Analysis: Tension, Shear, Bending Moment, Torsion.
Anchor Rebar Calculation: Number of bars, diameter, tensile strength, development length in concrete.
Anchor Plate Calculation: Plate thickness, area & layout, check for local bearing pressure.
Weld Calculation: Weld tensile capacity, weld leg size, weld length, penetration check.
Combined Load Analysis: Interaction of Tension & Shear, Interaction of Tension & Bending.
Detailing and Code Compliance Check: Verification against all applicable standards and detailing requirements.