Highway Metal Corrugated Pipe φ55/70mm Precast Beam Galvanized Corrugated Pipe

Construction Guide for Prestressed Galvanized Corrugated Pipe

Prestressed galvanized corrugated pipes are widely used in post-tensioned prestressed concrete projects as protective sleeves for prestressing tendons (strands, wires, etc.). Their construction quality directly affects the safety and durability of the prestressed structure. Below is a detailed construction process and key considerations.

1. Pre-Construction Preparation

1.1 Material Inspection

• Corrugated Pipe Quality: Check for uniform zinc coating without damageHighway Metal Corrugated Pipe φ55/70mm Precast Beam Galvanized Corrugated Pipe, and ensure the pipe body is free from flattening or deformation.
• Sealing Performance: Ensure all joint accessories (e.g., connecting sleeves, waterproof tape) are complete to prevent grout leakage.
• Specification Matching: The diameter of the corrugated pipe should meet design requirements, typically 5~10mm larger than the prestressing tendon diameter.

1.2 Tool Preparation

• Cutting machine (dedicated corrugated pipe cutting tool, Highway Metal Corrugated Pipe φ55/70mm Precast Beam Galvanized Corrugated Pipe to avoid burrs)
• Waterproof tape/heat-shrink sleeves (for joint sealing)
• Tying wires/rebar supports (to secure the corrugated pipe position)
• Positioning and measuring instruments (to ensure accurate coordinates)

2. Corrugated Pipe Installation

2.1 Positioning and Fixing

• Positioning According to Design Coordinates: Use rebar supports or dedicated positioning bars to secure the corrugated pipe, with spacing ≤1m (reduced to 0.5m in curved sections).
• Curved Section Handling: Ensure smooth transitions and avoid sharp bends (minimum bending radius ≥30 times the pipe diameter).
• Height Control: The centerline of the corrugated pipe must align with the designed position of the prestressing tendon, with deviation ≤5mm.

2.2 Connection and Sealing

• Straight Pipe Connection: Use a corrugated pipe one size larger for sleeve connection, with overlap length ≥30cmHighway Metal Corrugated Pipe φ55/70mm Precast Beam Galvanized Corrugated Pipe, and wrap waterproof tape or apply heat-shrink sealing at the joint.
• Branch Pipe Connection: Use dedicated tees or cross fittings to ensure sealing.
• Vent Hole Setup: Reserve vent holes (Φ20mm plastic pipes) at the highest points of curves to prevent air accumulation during pouring.

2.3 Clogging Prevention Measures

• Insert temporary lining pipes (e.g., PE pipes or rubber rods) and remove them after initial concrete setting to prevent grout leakage and clogging.
• Check pipe patency before pouring, using high-pressure air blowers or hole cleaners if necessary.

3. Concrete Pouring Protection

• Avoid Vibrator Contact: Do not allow vibrators to directly contact the corrugated pipe to prevent damage or displacement.
• Leakage Inspection: Focus on monitoring joints; immediately flush the pipe with clean water if grout leakage is detected.
• Protection During Curing: Avoid external impacts or welding operations that could damage the zinc coating.

4. Prestressing Tendon Installation

• Installation Timing: Perform after concrete strength reaches 75% of the design value.
• Lubrication to Reduce Friction: Apply dedicated lubricant (e.g., wax-based material) inside the corrugated pipe before installation.
• Rust Prevention: Temporarily seal exposed ends of strands with waterproof tape after installation.

5. Common Issues and Solutions