CCL was awarded the structural modifications to the unbonded post-tensioning tendons contained in post-tensioned rib slabs for this large building constructed in the late 1990s. This complex project involves the use of the innovative CCL troubleshooting anchor.
CHALLENGE
CCL were engaged to deliver a robust method for isolating and re-anchoring existing unbonded tendons (15.7 mm super strand and 15.2 mm dyform strand), enabling Erith to demolish sections of the level 1–6 concrete structure for new stairways, cores, vertical circulation zones and an atrium requiring open space. All works had to be completed without access to the slab edges or original post-tensioning anchorages.
SOLUTION
To accommodate new stairs, lift cores, vertical circulation, and the atrium, CCL installed its Trouble Shooting Anchors (TS Anchors) at strategic locations within the slabs and selectively detensioned targeted sections of the existing unbonded tendons. This approach allowed the modification and removal of specific areas of the unbonded post-tensioned rib slabs on levels 1 to 6 without the need to detension entire tendons.
BENEFITS
- CCL’s TS Anchors allowed strategic isolation to zones of stress in the existing unbonded tendons
- Reduction in temporary works requirement
- Extended lifespan of existing assets
- Enables change of use without full rebuild
