Many concrete contractors have worked on older-style (pre-1980) steel-frame buildings that had enough strength to support all the loads from deck forming and pouring operations without anything else to brace or hold them. Currently designed frames frequently lack that strength in the steel members and only achieve adequate design strength when the fully cured concrete is in place.
From our experience we have identified problem areas with three types of shored steel frames:
- Straight steel beams, no camber noted, and no shoring expected by the designer or builder. There may be gross deflections, which may or may not be acceptable. There is no shoring plan. If shoring is used, it comes after problems develop and in response to them.
- Cambered steel beams, with camber carefully called out on the beams but not on the slabs. The camber is specified to be maintained by shoring during concreting operations.
- Straight beams with site camber specified, requiring shoring and temporary site bracing to stand up when pouring loads are added.
Some of the specific problems and suggestions for dealing with them are detailed in the remainder of the article.