Key milestone achieved on Ropemaker
Media
28/11/2007
Ropemaker achieved another key milestone with the completion of the 24 storey reinforced concrete core.
The core was constructed using the slipform method, where the formwork and attached working platforms are slowly moved up using hydraulic jacks so that the system ‘slides' up continuously throughout the day. At peak the slipform achieved a 2.2m height increase per day - climbing a total of 102m. 552 beam connection embedment plates were cast in during the process and the total concrete volume of the completed core was 2, 650m³.
The slipform incorporated two trailing platforms which allowed beam connection plates to be welded to the embedments as the slipform progressed, eliminating the need for the inefficient use of cranes at a later date. This also provided more programme certainty for the following steel frame erection. The platforms were also used to strike formwork and weatherproof the lift shaft openings, ensuring early access for lift installation ahead of the superstructure floor slabs.
Local authority and planning permission constraints dictated that the slipform could not work continuously, therefore the Ropemaker slip worked for twelve hours a day. Concreting operations had to finish by 6.00pm and quiet operations were allowed to be carried out until around 9.00pm. The works carried out in these quiet hours were critical to ensure the slipform was raised clear of the day's concrete while still plastic to ensure that the core remained plumb and within tolerance.
Ropemaker is a commercial development for British Land, currently on programme for completion in May 2009. Mace Group is providing a fully integrated service comprising project management, construction management, cost consultancy and fixed price organisation and logistics.
