Climbing formwork is a special type formwork for vertical concrete structures that rises with the building process. While relatively complicated and costly, it can be an effective solution for buildings that are either very repetitive in form. Such a system has been adopted for the central core of the Pender Towers are will most probably be a common thing to use for the coming future high rise projects.
The climbing formwork structure normally does not only contain the formwork itself, but also usually provides working space / scaffolds for construction crews. It may also provide areas for machinery and screens for weather protection, up to being fully enclosed while yet staying modular around a changing building structure.
Three types of climbing formwork exist:
- Climbing formwork (crane-climbing): T the formwork around the structure is displaced upwards with the help of one or more cranes once the hardening of the concrete has proceeded far enough. This may entail lifting the whole section, or be achieved segmentally. The latter system is dependable of the use of a tower crane and therefore one would need to keep in mind that time on site will be lost until the formworks is shifted upwards
- Climbing formwork (self-climbing): The structure elevates itself with the help of mechanic leverage equipment (usually hydraulic). To do this, it is usually fixed to sacrificial cones or rails emplaced in the previously cast concrete. This is the system being currently adopted at Pendegardens T1T2 towers.
- Gliding formwork: This type of formwork is similar to the self-climbing type above. However, the climbing process is continuous instead of intermittent, and is usually only interrupted for a very short time (for example to fix the mounting mechanisms to new anchoring points). The advantage is that it will produce seamless structures, but it requires a continuous, uninterrupted process throughout, with serious potential quality and stability problems if the pour has to be stopped.
Typical photo illustrations are being including for better understanding of how the system is effectively used on site.