Stub girders

Architectural demands for square column grids with spacings up to 12 m (almost 40ft) led to the development of stub girder construction.

The stub girder comprises of:

• a bottom chord which acts in tension
• a series of short beams (the stubs) which connect the bottom beam to ...
• ... the top chord which is the concrete slab and acts in compression.
• secondary beams which span across the bottom chord, designed as continuous beams
• the voids created are used for services.

The major disadvantage of the system is that it requires temporary propping until the concrete has gained adequate strength for composite action.