Scope of supply
- Circumferential and vertical post-tensioning
- Self-climbing wall formwork, 24 units
- Vacuum grouting with recorded pressures
- Stressing records and third-party witness
Divisions involved
The problem
A full-containment tank wall has no tolerance for a tendon that will not stress to its calculated elongation, and the buttress arrangement meant every horizontal tendon turned through 240 degrees with high friction losses. The client required third-party witness on every stressing operation.
What we did
Friction was measured on site with a lift-off test on the first three tendons of each level and the calculation recalibrated to the measured coefficients before the rest were stressed. Formwork climbed on 24 self-climbing units so the wall progressed on a continuous 4.5 m lift cycle independent of crane time. Grouting was vacuum-assisted with pressure and volume logged per tendon.
What happened
All 312 horizontal tendons stressed within the ±5 % elongation band at first attempt. Wall completed in 32 lifts with no crane-driven delay to the stressing programme.
Measured outcome
- 165,000 m³
- Tank capacity
- 38.5 m
- Wall height
- 312
- Horizontal tendons
- 640 t
- Strand installed