Erection and dismantling of superstructure
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WARNING Risk of tipping over! If loads (primary beams, secondary beams, formwork sheets) are not centred, stability can be impaired! ➤ Always centre all loads. ➤ Make sure that the structure is sufficiently stable. |
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WARNING Risk of falling at open edges! ➤ Personnel must be trained to use personal fall-arrest systems (e.g. the Doka personal fall-arrest set) until all fall protection has been installed. ➤ Suitable anchorage points must be defined by an approved person appointed by the contractor. |
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A fall arrester such as the FreeFalcon provides a mobile anchorage point for the Doka personal fall-arrest set. |
Note:
Consider the loads from slab stop-ends. If the loads cannot be transferred directly, ensure all stop-end loads are designed and secured against pull out.
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NOTICE Take the following into account in planning: ▪ Because of manual handling in stripping out, the maximum weight of the primary beams should be < 50 kg! - For this reason, use Doka beams I tec 20, Alu box beams or Multi-purpose walings WS10 Top50 with a maximum length of 2.50 m. This is particularly important at closure zones and in towers that cannot be moved out for dismantling. ▪ In the edge zone, secure or fasten all secondary beams to prevent overturning (use secondary beam stabilisers, Waling clamps H20, etc.). ▪ In principle, the secondary beams should rest on only 2 primary beams. In the closure zone, the secondary beams can rest on 3 primary beams (because of an additional single primary beam). Avoid long cantilevers, to minimise the risk of overturning. ▪ In the closure zone, it is advisable to use Timber formwork beams H20, Alu box beams or Doka beams I tec 20. ▪ The top ‘storey’ should be constructed with a Staxo frame 1.20m. This gives the working height for installation of the superstructure. ▪ Replace the topmost horizontal crosses with assembly planking. ▪ Underneath the topmost ‘storey’, construct an uninterrupted assembly level extending for the entire area to be formed. Whenever possible, compensate for differences in height due to different frame heights, or install clearly visible steps. ▪ At downstand beams use only 0.90m frames in the first ‘storey’ to facilitate stripping out, for example by forklift truck. - Remove the lowest frames. - Then move out the towers underneath the downstand beam. ▪ For a higher load-bearing capacity, use the smaller frames 0.90m or 1.20m in the lowest and highest ‘storeys’. |
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