Types of Conventional Metal Systems
The conventional aluminum system, described above, is widely used and is selected as an example of conventional metal systems for purposes of comparison with other horizontal formwork systems. Other conventional metal systems include different combinations of wood, aluminum, and steel for joists and stringers. In all the systems listed below, a movable steel-scaffolding system or single steel post is used for shoring.
1. Plywood sheathing for decking supported by dimensional wood or laminated wood for joists and standard steel sections for stringers.
2. Plywood sheathing for decking supported by standard steel sections for joists and stringers. A movable aluminum or steel scaffolding system is used for shoring.
In these two systems, steel joists and stringers have the advantage of supporting greater spans, resulting in fewer vertical shores and fewer joists and stringers. The main problem with using steel as joists and stringers for forming concrete slabs is their heavy weight, which makes it difficult for one person to handle.
A standard steel W-section is used because its wide flange makes it easy to connect stringers with shore legs. It should be noted that stringers have to be well secured to the shore to prevent
stringers from being overturned. A special accessory is used to connect the steel beam to the shore head.