Practical Workshop – Hands-on Formwork Training

Module 7: Practical Workshop – Hands-on Formwork Training

1. Building a Complex Formwork Structure (Suspended Slab)

Objective: Construct a suspended slab (elevated concrete slab) to simulate real-world high-rise or bridge applications.

• Step-by-Step Execution:

• Design Review:

• Study shop drawings for beam/slab dimensions, prop spacing, and reinforcement clearances.

• Erecting Supports:

• Install adjustable steel props (e.g., Acrow props) at 1.2m intervals.

• Ensure base plates are on solid ground or shoring boards.

• Flying Form Installation:

• Assemble modular deck panels (plywood + H20 beams) and secure with dropheads.

• Edge Formwork:

• Fix timber/steel shutters for slab thickness control (e.g., 200mm).

• Bracing & Alignment:

• Diagonal braces to prevent lateral movement during pouring.

• Key Checks:

• Confirm prop load capacity matches design (e.g., 20 kN/prop).

• Verify no gaps at formwork joints to prevent leaks.

2. Laser Level Precision Alignment

Objective: Achieve ±3mm accuracy in formwork positioning.

• Procedure:

• Set up a rotating laser level (e.g., Leica Rugby) at a stable benchmark.

• Mark elevation points on vertical formwork (e.g., column molds).

• Adjust formwork until all marks align with the laser plane.

• Common Errors & Fixes:

• Error: Laser misalignment due to vibration.

• Fix: Use a remote trigger to minimize disturbance.

3. Demolition & Reuse Best Practices

Objective: Safely strip formwork while maximizing reuse cycles.

• Safe Stripping Sequence:

• **Wait for concrete to reach minimum strength (e.g., 15 MPa for slab props).

• Remove side forms first, then lower props gradually.

• Avoid prying—use timber wedges to prevent edge damage.

• Reuse Optimization:

• Plywood Care:

• Clean with plastic scrapers (no metal tools).

• Apply form oil before reuse.

• Steel/Aluminum Forms:

• Inspect for dents or bent edges; repair before reuse.

• Sustainability Focus:

• Recycle damaged plywood into filler pieces.

• Track reuse cycles to retire forms after max lifespan (e.g., 300 cycles for aluminum).

Workshop Safety Drill

• Scenario: Simulate a prop collapse during stripping.

• Response:

• Emergency shutdown, evacuate area.

• Reinforce with additional shoring before resuming.

Key Takeaways:

1. Suspended slabs require multi-level bracing and load-rated props.

2. Laser levels eliminate guesswork in alignment.

3. Gentle demolition extends formwork lifespan.