Highway Barrier Steel Mold

Highway barrier steel molds are used to produce precast concrete barriers, widely used in highways, railways, and urban roads to separate traffic flow, protect pedestrians, and enhance road safety. The molds must have high strength, durability, and high precision to ensure the dimensional consistency and surface quality of the concrete products.

Main Material: Q235 hot-rolled steel plate, generally 3-4mm thick, with some reinforced areas up to 5mm. Q235 has good plasticity and welding performance, suitable for mold processing.

Mold Structure

• Basic Structure: The mold consists of panels, stiffeners, a base plate, and connectors, forming a U-shape or rectangular structure. The interior can include solid or landscape hole designs (such as steel pipe through-holes).
• Size Specifications:
  • Common length: 2 meters (highway standard).
  • Height: 80-100cm, with a turnover edge design for easy demolding and installation.
  • Hole diameter: Small holes (<φ20mm) for assembly, large holes (≥φ36mm) for wiring or electrophoretic hanging.
• Types:
  • Plain Mouth Mold: Simple structure, suitable for standard barriers.
  • Tongue and Groove Mold: Easy to splice, suitable for complex road sections.

Processing Technology Flow

1. Design and Preparation

• Mold Design: Determine the mold dimensions, hole positions, and stiffener layout according to the barrier drawings, considering the concrete pouring pressure (approximately 0.5-1MPa) and demolding convenience. Use CAD or SolidWorks for 3D modeling to ensure accuracy.
• Material Preparation: Purchase fixed-size Q235 steel plates, check the surface quality (no cracks or rust), and cut them to the required dimensions.

2. Steel Plate Forming

• Stamping Forming:
  • Use a hydraulic press (1000-2000 tons) and forming molds to stamp the steel plate into a U-shape or rectangular structure.
  • The mold needs to be a modular design for easy product switching and to reduce flange rebound (control rebound rate <2%).

• Roll Forming:

  • The coil material is gradually deformed through multiple roll forming dies, suitable for linear molds, with high precision (tolerance ±0.5mm).
  • Subsequent plasma or laser cutting is required to trim the edges to ensure flatness.
• Precautions: Control the forming speed to avoid stress concentration in the steel plate. Preheating treatment (200-300°C) may be necessary to improve ductility.

3. Hole Processing

• Hole Position Design: 300-500 holes of more than 10 different diameters need to be processed on the molds web and flange surfaces. The distribution needs to be uniform to release stress and facilitate assembly.
• Processing Methods:
  • CNC Punching: Using a CNC punch press, suitable for multi-variety, small-batch production, with high efficiency (20-30 holes can be punched per minute).
  • Mold Punching: The first choice for mass production, requiring dedicated punching dies, with high precision but high mold adjustment costs.
  • Plasma Cutting: Used for large-size holes or blanking, with lower precision (±1mm).
  • Drilling Machine: Used for temporary adjustments or small-batch production.
• Precision Control: Hole position tolerance is controlled within ±0.2mm, and verticality deviation is <0.5° to ensure the quality of concrete products.

4. Welding and Assembly

• Welding: The panel and stiffeners are welded using arc welding or gas shielded welding. The weld seams need to be uniform and free of porosity to ensure structural strength.
• Stiffener Design: Stiffener thickness is 4-5mm, with a spacing of 200-300mm, to enhance the molds rigidity and prevent deformation during pouring.
• Connection Methods:
  • Riveting: Used to connect the base plate and side plates, with good vibration resistance, suitable for long-term use.
  • Bolt Connection: Easy to disassemble and adjust, requiring the use of high-strength bolts (grade 8.8 or above).
• Fixture Usage: Use dedicated fixtures during assembly to ensure dimensional accuracy (deviation <±1mm).

5. Surface Treatment

• Mechanical Treatment:
  • Shot Blasting/Sandblasting: Use high-speed abrasives (steel shot or sand particles) to remove the oxide layer and form uniform pits (surface roughness Ra 3.2-6.3μm) to enhance paint adhesion.
  • Dust removal equipment is required to control noise (<85dB).
• Chemical Treatment:
  • Pickling or steam cleaning to remove oil stains and rust, preventing mold corrosion.
• Spraying: Apply anti-corrosion paint or epoxy coating, with a thickness of 50-80μm, to extend the molds lifespan (5 years or more).

6. Quality Inspection

• Dimension Check: Use a coordinate measuring machine to verify the molds flatness and verticality (deviation <0.5mm).
• Surface Quality: Check the weld seams, hole positions, and coating uniformity to ensure no cracks, burrs, or peeling.
• Trial Molding: Pour concrete samples to check the demolding effect and the surface quality of the products (no air bubbles or cracks).