Formwork is the term given to either temporary or permanent moulds into which concrete is poured, keeping it in place until it cures – such as for columns, beams or slabs. In terms of vertical surfaces, formwork can usually be taken down after a 24-hour period. With beams and slabs, props and forms are usually left in place until the concrete has gained sufficient strength (28 days) or removed and back propping is used for horizontal surfaces. Formwork must bear all loads put on it by concreting and be sturdy and grout-tight during compaction/vibration, particularly for direct finishes; referred to as the off shutter finish which comes in different grades/classes; (typically the concrete is found to have the texture of the material used for the shuttering and also the shape of the panel used).
For the first two types, once the concrete has been poured into formwork and has set (or cured), the formwork is removed to expose the finished concrete. The removal ti me of the forms is dependent upon the strength needed to be achieved by the cured concrete. Release agents Chemical release agents are applied to mould and shutter surfaces prior to casting concrete, in order to achieve a clean and easier release of the shutter (formwork) from the concrete when stripping.
Scaffolding is a temporary platform carried by a framework erected on site, to give access for trades like (bricklaying, plastering, and painting) and to carry materials. It is usually a modular frame system of metal or aluminium, although it could be made out of other materials. Scaffold staging or tower scaffolds are usually of steel or aluminium, either of a prefabricated frame type that clip together or of a tubular type joined with fittings,, for example a putlog coupler.
Scaffold boards or planks that form the working deck of a scaffold, must be strong enough to carry the materials and workers. They are either wooden planks and should be at least 228mm wide and 50mm thick and not be longer than approximately 4,8m with a maximum support distance of 2,2m; or steel planks which clip into the framework and are typically 228mm wide. Scaffolds are rarely independent structures. To ensure a constant and workable space between the structure and the scaffold, ties are used to link the two, which also ensures the scaffold remains sturdy.
Steel builders trestles
A standard steel builders trestle can be used for almost every type of interior and external building activity up to about 2,4m (single storey buildings). It usually accommodates a four board working platform of approx. 1,0m wide, and is easily handled by one person and folds away for quick storage and transport. Trestles are usually available in the following heights:
Mobile scaffolding can be best described as any kind of speed framing or scaffold framing with rolling castors with a brake mechanism. The height of a mobile scaffold or tower should not exceed three times the smallest base dimensions i.e. if the smallest base width is 1.8m the height must not exceed 5.4m. When a mobile tower exceeds 6m in height it must be regarded as an independent scaffolding and where the same securing details
should be complied with. The castors will also need to be securely anchored to the ground to eliminate displacement.
NOTE: Safety is of utmost importance and any scaffold exceeding 3m in height should be inspected by a competent person or a structural or civil engineer, before any loading is placed on the scaffolding.
Concrete forms are engineered structures that are required to support loads such as fresh concrete, construction materials, equipment, workers, various impacts and sometimes wind.
Online formwork load monitor
The PERI Formwork Load Calculator supports the professional user in calculating the correct fresh concrete pressure in connection with the related pouring rate for selected PERI wall formwork systems. With this tool, the user obtains a very quick overview of the loads and deformations which leads to cost-effective utilization of the formwork system being used.
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Girder flex system using girders supported by steel props. The flex system allows for flexibility of design, making the system versatile to use for any layout.
Modular aluminium panel system supported by steel props. With a quick-stripping drop-head, to allow for early stripping and back-propping.
Standard steel frame panel system, with a plywood form-lining. The panel system reduces the number of ties and couplers required to increase formwork turnover times.
Standard steel frame panel system, with a plywood form-lining. With a new tie technology, this system allows for “single-sided” tie installation so only one man is required for the job. In addition the MX tie technology prevents the need for spacer tubes and cones.
DUO can be used for foundations, walls and columns as well as for slabs and beams. The system is characterised by the extremely simple handling and the minimum number of different system components. Almost all operations with DUO can be carried out without tools while the working steps are very easy to understand. Even those less experienced users of system formwork can work quickly and efficiently with DUO. New is not only the concept but also, in particular, the material used. Both the panels- including the formwork – and the DUO accessories are made of technical polymers. Due to the low weight, no crane is required for assembly operations.
Flexible forming of walls, columns and slabs using only one system
Ergonomic in all respects
Low weight, crane-free handling and intuitive application
Easy replacement of form-lining
Quick repair with just a few screws – without requiring any special skills