Processing of Corrugated Pipes for C-50 Precast Beams and Plastic Corrugated Pipes for C-100 Prestressed Concrete Bridges

1. Product Overview

Prestressed plastic bamboo-joint pipes (also known as corrugated pipes or prestressed tendon sleeves) are corrugated pipes made of high-density polyethylene (HDPE) or polypropylene (PP), featuring a bamboo-joint-like structure on the surface. They are commonly used in post-tensioned prestressed concrete engineering to encase steel strands or reinforcement bars, preventing them from bonding with concrete while providing anti-corrosion and anti-seepage protection.

2. Construction Process

(1) Pre-construction Preparation

• Material Inspection: Ensure the bamboo-joint pipes are free from damage or deformation, and their specifications (inner diameter, ring stiffness, etc.) meet design requirements.
• Tool Preparation: Cutting knives, connecting sleeves, tape, positioning brackets, etc.
• Site Survey: Confirm the layout route of prestressed tendons and anchorage positions.

(2) Pipeline Installation

• Positioning and Installation: Fix the bamboo-joint pipes according to the design drawings, typically using reinforcement brackets or binding wires. The spacing for Processing of Corrugated Pipes for C-50 Precast Beams and Plastic Corrugated Pipes for C-100 Prestressed Concrete Bridges should be ≤1m, ensuring smoothness and avoiding sharp bends.
• Connection Handling:
  • Sleeve Connection Method: Use specialized connecting sleeves, insert both ends into the bamboo-joint pipes, and seal with tape.
  • Thermal Fusion Method: For HDPE pipes, thermal fusion welding can be used to ensure leak-free joints.
• Bend Handling: The bending radius must be ≥30 times the pipe diameter to avoid sharp angles.

(3) Prestressed Tendon Threading

• Pre-threading Inspection: Clear any debris inside the pipe to ensure unobstructed passage.
• Threading Method: Manual pushing or assisted by a traction machine can be used for Processing of Corrugated Pipes for C-50 Precast Beams and Plastic Corrugated Pipes for C-100 Prestressed Concrete Bridges, avoiding scratches on the pipe wall by steel strands.

(4) Setting of Grouting Holes and Vent Holes

• Set vent holes at high points and grouting holes at low points of the pipeline, with spacing preferably ≤30m.

(5) Concrete Pouring

• Avoid direct contact of vibrators with bamboo-joint pipes during pouring to prevent cracking or displacement.

(6) Prestressing Tensioning and Grouting

• After Tensioning Completion: Promptly inject cement grout (water-cement ratio of 0.4~0.45) from low to high points, and seal after thick grout flows out from vent holes.

3. Construction Precautions

• Protection Measures: Avoid stepping on or compressing the pipeline with heavy objects to prevent deformation.
• Sealing: All joints must be tightly sealed to prevent grout leakage.
• Environmental Adaptability: In low-temperature environments, choose cold-resistant pipes to avoid brittleness and cracking.