Rebar Binding Process

Scope of Rebar Binding Process Application

This process standard applies to various components of pile foundation in bridge engineering, including:

• Cap
• Pier stud
• Cap beam
• T beam
• Other ground reinforcement binding projects

Preparation of Major Rebar Binding Process Application Standards and Specifications

1 Industry Standards

• Technical Code for Highway Bridge and Culvert Construction: JTJ 041-2000
• Highway Engineering Quality Inspection and Evaluation Standards: JTG F80/1-2004

2 National Standards

• Hot-rolled Round Steel Bars for Reinforced Concrete: GB 13013-91
• Hot-rolled Ribbed Steel Bars for Reinforced Concrete: GB 1499-1998
• Mild Steel Hot-rolled Disc Rod: GB 701-1997

Preparation for Construction

1 Technical Preparation

1. Drawings and Design: Familiarize yourself with construction drawings and prepare the organizational design for reinforcement binding.
2. Steel Bar Cutting: Cut steel bars according to the drawings’ specifications.
3. Technical Disclosure: Provide a written technical disclosure to each reinforcement team.

2 Preparation of Materials

1. Reinforcing Bars:
   • Ensure that reinforcing bars have factory certificates and inspection reports.
   • Inspect for rust and oil stains; sample for mechanical properties retest as required.
2. Iron Wire:
   • Use 20~22 gauge iron wire (for burnt wire) or galvanized iron wire.
   • Cut wire to meet usage requirements.
3. Cushion Block:
   • Select cushion blocks based on the protective layer thickness. Use cement mortar blocks with a strength grade matching the concrete design strength.
   • For pile foundations, use 3 cm or 5 cm thick plastic cushion blocks, ensuring sufficient compressive strength.
4. Steel Pipe:
   • Use as an auxiliary material for binding and hoisting steel skeletons. Ensure the frame is erected securely.

3 Preparation of Implements

• Main Tools: Rebar hooks, crowbar, wrench, wire brushes, handcart, chalk, rulers, etc.

4 Operating Conditions

1. Site Preparation:
   • Clean and level the steel bar stacking and processing site. Stack bars according to specification and numbering.
2. Rust Check:
   • Inspect bars for rust and remove it before transporting to the binding site.
3. Drawing Familiarization:
   • Check specifications, shape, quantity, and size of processed steel bars against design requirements.
4. Inspection:
   • Ensure bridge deck pavement mesh dimensions and welding quality are verified before use.
5. Binding Sequence:
   • Determine the sequence of steel bar placement based on design and process standards. Make technical disclosures to the team.
6. Positioning:
   • Use chalk to mark the position of main reinforcement on the bottom mold and reserve the protective layer thickness using cushion blocks.

Construction Operation Rebar Binding Process Process

1 Pile Foundation Reinforcement Binding Process

1.1 Process Flow

1. Steel Bar Welding: Continuously weld the main reinforcement.
2. Stiffener Ring Processing: Mark the position and weld stiffener rings.
3. Spiral Bars: Winding and lashing.

1.2 How-to

1. Welding and Stiffener Processing:
   • Use flash butt welding or arc welding for main reinforcement. Ensure stiffener rings are round with no elliptical distortion.
2. Position Line:
   • Draw stiffener circle positions based on drawing requirements. Ensure 5 cm from the bottom edge of the main reinforcement.
3. Welding Stiffeners:
   • Spot weld stiffeners ensuring full, uniform welds with no burns or defects.
4. Spiral Bars Binding:
   • Tighten spiral bars and main bars without gaps. Bind intersections firmly and use figure-eight buckles if needed. Add concrete cushion blocks to the reinforcement cage.

2 Cap Reinforcement Binding Process

2.1 Process Flow

1. Pile Head Reinforcement: Adjust and clean reinforcement.
2. Cushion Cap Reinforcement: Process and form parts as per design.
3. Mark and Bind:
   • Mark and bind main reinforcement on the cushion layer, bottom plate reinforcement, pier column reinforcement, and roof reinforcement.

2.2 How-to

1. Pile Head Adjustment:
   • Clean sludge and straighten reinforcement. Adjust spacing to meet design requirements, generally bending outward at 15 degrees.
2. Cap Reinforcement Processing:
   • Process steel bars according to design drawings ensuring cleanliness and straightness.
3. Mark Main Reinforcement:
   • Mark positions on the cushion based on spacing from the drawings.
4. Binding:
   • Place cushion blocks according to protective layer thickness. Ensure lap lengths and positions meet specifications. Use figure-eight binding where applicable.
5. Pier Column Reinforcement:
   • Ensure verticality and positioning of pier studs during hoisting.
6. Roof Reinforcement:
   • Ensure even spacing and proper binding of horizontal ribs, using full gang binding and figure-eight buckles.

3 Pier Stud Reinforcement Binding Process

3.1 Process Flow

1. Welding Main Reinforcement: Ensure proper welding connections.
2. Draw Stirrups: Mark stirrup spacing lines on main reinforcement.
3. Set Stirrups: Position stirrups according to spacing requirements.
4. Tie Stirrups: Securely bind stirrups to main reinforcement.

3.2 How-to

1. Main Reinforcement Connection:
   • Ensure the connection mode meets design requirements.
2. Stirrup Spacing:
   • Draw and calculate stirrup spacing based on drawings.
3. Set and Tie Stirrups:
   • Position stirrups and tie securely ensuring no displacement of protective layer hooks.
4. Circular Pier Stud:
   • Refer to pile foundation reinforcement binding if pier stud is circular.

4 Cap Beam Reinforcement Binding Process

4.1 Process Flow

1. Weld Main Reinforcement: Continuously.
2. Draw Stirrups: Mark spacing on the main reinforcement.
3. Set Stirrups: Position and bind stirrups.
4. Prestressed Bellows: Thread and seal.
5. Hoist: Lift into place.

4.2 How-to

1. Main Reinforcement Welding:
   • Ensure connections meet design requirements.
2. Draw Stirrups:
   • Mark stirrup positions on the main reinforcement.
3. Set and Tie Stirrups:
   • Place and bind stirrups ensuring proper length and quantity.
4. Prestressed Bellows:
   • Locate, weld positioning reinforcement, and thread bellows.
5. Hoisting:
   • Use cranes to lift and place the cap beam, removing shelf pipes.

5 T Beam and Box Girder Reinforcement Binding Process

5.1 Process Flow

1. Bottom Plate Binding: First, then web reinforcement, ends, middle beam, and roof reinforcement.

5.2 How-to

1. Bottom Plate:
   • Draw ground spacing, place and bind main reinforcement with horizontal ribs.
2. Web Reinforcement:
   • Ensure proper positioning and binding, with a focus on widening sections.
3. End and Middle Beam:
   • Bind according to drawing requirements ensuring correct angle and length.
4. Roof Reinforcement:
   • Ensure even spacing, add reinforcement braces, and tie intersection points.

Rebar Binding Process Quality Standards

1 Raw Materials

1. Steel Bar Inspection:
   • Perform mechanical property inspections and check product certificates and factory reports.
2. Visual Inspection:
   • Ensure bars are straight, undamaged, and free from rust or oil stains.
3. Special Inspections:
   • For brittle or poorly welded bars, conduct chemical composition testing or other special inspections.

2 Steel Bar Processing

1. Hooks and Bends:
   • Ensure compliance with design requirements for hook sizes and bending.
   • Perform inspections based on sample sizes per working shift.

By adhering to these standards, the reinforcement binding process for pile foundations in bridge engineering can achieve high-quality results and ensure structural integrity.