MEVA's efficient solutions meet wide-ranging demands for Crowne Plaza
Efficient slab formwork
Upon completion in 2020, the Crowne Plaza currently under construction in Adelaide, South Australia will be the Australian city's tallest building. The 138 m high-rise, which is being erected by the local Kyren Group, will house the Crowne Plaza Hotel with 329 guest rooms located from the third to the 20th floor.
The floor-to-floor heights in the building vary according to use. For example, the bottom levels, which accommodate retail and parking facilities, have somewhat higher ceilings than the hotel area. At the same time, the plan area of the building core narrows with increasing building height. The Crowne Plaza scheme thus called for particularly flexible formwork solutions capable of adapting to the required geometries. The formwork experts at Mitcon duly opted for use of the efficient and reliable systems offered by MEVA. The local partner Novatec was able to provide these on site in the shortest possible time.
The building core was erected using the MAC automatic climbing system. Its high-performance hydraulics eliminate the need for a crane, which is consequently freed up for the other site operations. The building's smaller floorplates from the 11th floor upwards entail a corresponding reduction in building core size. The formwork was adjusted accordingly through the removal, in stages, of several shafts. Additionally, Novatec supplied the GT50 SGF climbing safety screens.
Tailored climbing system
As the MAC system is purpose-designed for every project, special provision was made for removing the beams and hydraulic units. With the formwork adaptations already factored into the design, the relevant components were easy to disassemble on the job to accommodate the change in floorplan. The system was similarly reconfigured on the 22nd storey, with the elimination of additional lift shafts. The rearrangements also involved removal of some of the beams. The scope of the adaptations are shown in the drawings on the right.
Mitcon's Nick Bairstow was full of praise for the system's flexibility: "We were able to set up the MAC system in under 12 days. And the preassembled components saved us a lot of time. As a result, everything ran smoothly and even the rearrangement operations were trouble-free."
Efficient slab formwork
The floor slabs for all the 37 storeys were cast in tandem with the building core. Here too, varying requirements necessitated a flexible solution for efficient slab shuttering. By selecting the MevaDec modular formwork, Mitcon enjoyed all the benefits of a system that combines different slab-forming methods.
Primary-and-secondary-beam method (HN)
For the lower section of the high-rise, the brief called for slab soffits with a exposed surface finish meeting architectural concrete requirements. The MevaDec HN method provides for the use of primary and secondary beams to create a base for the loose facings. At the same time, the system's provision for changing the direction of the primary beams allows continuous adaptation to different layouts. It was thus possible to form each of the 1,550 m² slab areas in two cycles while simultaneously achieving the required ceiling finish.
Drop-head-beam-panel method (FTE)
The floor slab plan area was reduced by half from the 11th storey upwards. As wood-finish fair-faced concrete was no longer required for these surfaces, the project team switched to the drop-head-beam-panel method. Here, the MevaDec slab formwork panels were placed between the primary beams. Moreover, use of the MevaDec drop head further accelerated progress on site. The drop head allows the primary beams to be lowered to facilitate removal of the panels, which can then be immediately reused on the next level. At the same time, the props with the drop head automatically remain in place for reshoring purposes. The ready availability of primary beams and panels for the next cycle thus serves to reduce on-site inventory.
"In some cases, reshoring was simultaneously needed on eight levels," says a satisfied Nick Bairstow. "In that way, the drop head really simplified our work. All in all, we safely met our targets. Which was also thanks to the major contribution made by MEVA's formwork systems."