Here is a clear, site-ready explanation of the Specific Procedure for Single Strip / Box Seal Expansion Joint (Clause 9.16) rewritten in method statement format for easy understanding, reporting, or exam use.
1 Fixing Dimensions of Recess
- The recess (blockout) size in deck slab shall be decided based on:
- Required movement gap width
- Manufacturer’s drawings/design data.
- Dimensions must strictly match approved drawings.
✅ Purpose:
To accommodate joint movement safely without distress.
2 Shuttering of Recess
- Provide rigid and firm formwork for the recess.
- Shuttering shall:
- Maintain exact geometry.
- Prevent deformation during concreting.
- Ensure correct alignment and level.
✅ Key Requirement:
Dimensions shown in joint drawing must be maintained accurately.
3 Inspection of Presetting
Before installing the joint:
- Check preset gap setting.
- Measure actual structure temperature.
- Compare with presetting temperature used during fabrication.
If temperature differs:
- Adjust preset gap accordingly.
- Re-tighten all fixing brackets after correction.
✅ Purpose:
To ensure correct expansion/contraction movement.
4 Cleaning of Steel Cavity
Before inserting the seal:
- Remove:
- Dirt
- Welding spatter
- Dust
- Standing water
Cleaning methods:
- Wire brush
- Scraper
- Compressed air
✅ Result:
- Proper seating of seal.
- Easier installation.
- Improved watertightness.
5 Formation of Wearing Course Junction
- Provide a wedge-shaped joint between:
- Wearing coat/surfacing
- Blockout concrete or steel edge beam.
Requirements:
- Clean horizontal leg of edge beam before work.
- Apply sealing compound properly.
- Ensure thorough compaction of surfacing material.
⚠️ Importance:
- Prevents early settlement or depression near joint.
- Maintains riding comfort.
✅ Quick Flow
Recess Dimension Fixing
↓
Rigid Shuttering
↓
Presetting & Temperature Adjustment
↓
Cleaning Steel Cavity
↓
Seal Installation Preparation
↓
Wedge Joint Formation & Surfacing Compaction