One year after the completion of the structural works and during the execution of interior works, a fire started in the first basement level of the building causing damage to the concrete slab, beams and one column. The affected area covered approximately 350 m².
CCL was commissioned to carry out an on-site investigation and propose a solution to mitigate the effects of the fire on the post-tensioned slab and reinforced concrete column and beams.
After meetings with the main contractor and the consultant an initial site inspection was conducted to visually scrutinize the damage and identify the affected areas.
CCL carried out a visual inspection and grout inspection of all exposed tendons, jack force testing of the post-tensioned strands, non-destructive testing and material sampling. After analysing the information obtained from the tests, CCL was able to provide an efficient repair and strengthening solution.
Dirt and soot caused by black smoke on the affected concrete were removed using sand blasting, and any unsound concrete was removed mechanically. The exposed steel reinforcement was covered with specialised cementitious product for protection, and refurbishment of the damaged slabs was carried out by shotcreting.
An additional concrete section was added to the damaged column in the second basement level prior to commencing any repair work on the affected part of the column.
After repair work was completed, CCL carried out the structural strengthening for the post-tensioned slabs and beams by installing external post-tensioning and additional carbon fibre plates in some locations.
