Laing O’Rourke are building a 40 storey tower in Elephant and Castle entirely out of precast concrete units. All the precast units are connected using a combination of bolts and rebar joints which are then filled with grout in situ.
One of the precast units used are structural columns that sit on the floor edges. To install, the tops of columns need to be topped with grout and top nuts also need to be tightened to four threaded bars which connect to an edge beam and column above.
This posed a potential risk of dropping grout, nuts and tools off of the leading edge whilst carrying out the installation:
A Column Hopper was designed to ensure that during install, if any of the above were to fall, the items would be caught and unable to fall further than the column face itself. The hopper is fixed to a column using a ratchet strap and rubber contact face to increase the friction force under stress.
The hopper is light weight making it easy to manoeuvre to the top of a column. The ratchet can then be fastened at the front face and the hopper will form a tight hold. The column is then lifted to the relevant floor. A safety chain is also included as an additional measure.
The hopper is removed by attaching a crane to the hopper lifting eyes via MEWP or podium. The ratchet and safety chain can then be released and the hopper removed.
- Mitigates risk of falling objects
- Prevents grout from falling, preventing staining of cladding below
- Easily manoeuvrable – can be lifted by crane and/or operative
- Fixing and removing the hopper does not require leading edge work
- Can be re-used
- Hopper size can be modified easily
- Cost effective.