“The core rose quite rapidly, with the diagrid structure following on closely to provide structural stability. Within the diagrid we have used different types of construction to create the floor plate. On the intermediate floors between the nodes, we have a concrete post-tension solution which allows for thin slabs and reducing the amount of reinforcement. At the node floors we have a steel beam solution with pre-cast units creating a deck between the beams.
Because of the building’s diamond shape and the geometry of the diagrid we have focal points at the nodes which cause forces to kick out from the building. As a result, we have to tie the building back in, and to do this we have engaged the whole structure, sharing the load between the perimeter tie beams, beams that tie back into the slab, and slab diaphragm and its structural topping, which is extensively reinforced, all creating a stiff disc.
Although none of these techniques are unique, bringing all the elements together makes for a very innovative solution resulting in a hybrid building that is very efficient.”
The node floors have been constructed using precast concrete slabs. This creates a platform from which to build the next 4 floors of the diagrid but it also separates the work above from the construction of the intermediate floors below. This means that a faster construction can be achieved. The intermediate floors are formed of post-tensioned concrete. The thinner slabs help to reduce the total self-weight of the building.