Box girder formwork

Box girder formwork is a specialized type of formwork system used to construct box girders, which are hollow structural members commonly used in bridge construction and elevated roadways. Box girders are highly efficient in carrying loads due to their closed cellular shape, which provides excellent strength-to-weight ratios and resistance to torsion.

Key Features of Box Girder Formwork

Custom Shape
Designed to create the rectangular or trapezoidal cross-section of box girders, with options for straight or curved profiles.

Internal and External Components
Includes external formwork to shape the outer surfaces and internal formwork for the hollow cavity.

High Precision
Ensures the exact dimensions, alignment, and structural integrity of the box girder.

Material Options
Made from durable materials like steel, aluminum, or plywood, depending on project requirements.

Reusability
Formwork can be reused for multiple casting cycles, making it cost-effective for large-scale projects.

Components of Box Girder Formwork

External Formwork

Creates the outer shape of the girder.

Includes side panels and soffit panels (bottom panels).

Internal Formwork

Supports the hollow cavity inside the girder.

Often collapsible for easy removal after curing.

End Shutters

Close the formwork at the ends of the casting section.

Support System

Includes scaffolding, falsework, and props to bear the load of the wet concrete.

Applications

Bridge Construction
Commonly used in the construction of segmental or continuous box girders for bridges.

Elevated Roadways
Used in viaducts and flyovers where torsional rigidity is critical.

Precast and Cast-in-Situ
Suitable for both precasting in a controlled environment and casting in place at the construction site.

Construction Process

Formwork Assembly

Install the external formwork on temporary supports or scaffolding.

Position the internal formwork within the external framework.

Reinforcement Placement

Place steel reinforcement within the formwork as per the structural design.

Concrete Pouring

Pour concrete into the formwork, ensuring even distribution and vibration to eliminate air pockets.

Curing

Allow the concrete to cure to gain the required strength.

Formwork Removal

Dismantle the formwork carefully without damaging the hardened concrete.

Advantages

Structural Precision
Ensures the dimensional accuracy and alignment of the girder.

Torsional Resistance
Box girders produced with this formwork are ideal for handling bending and torsion.

Modular and Reusable
Saves time and cost, especially for repetitive use in large projects.

Adaptability
Can be customized for different girder lengths, shapes, and curvatures.