One-way slab (simply supported slab)

< project: slabs10 >
The structural frame consists of four columns, two beams and one slab. Usually, when a slab is supported by a beam the support is considered to be pinned.


One-way slab model

The one-way slab is supported by two beams

The carpenter’s formwork drawing

The carpenter’s formwork drawing describes the shape of the slab’s moulds

Behaviour and reinforcement of one-way slab reinforced with bent up rebars

The steel fixer’s formwork drawing of one-way slab

In a one-way slab the need for reinforcement appears mainly in the span and along the bending direction. The necessary bars derive from the calculated required reinforcement. In this specific case the bars provided are Ø10/100. Apart from the primary reinforcement that is placed parallel to the deformation direction, there is also need for reinforcement in the other, the secondary direction. In that direction, the placed rebars are Ø8/240 which means that bars with a Ø8 diameter have been placed every 240 mm.

Support area reinforcement

The minimum required reinforcement in the support areas is provided in two alternative ways:

1st way: Half of the rebars placed in the span i.e. Ø 10/200 are shaped with bends at their ends (in every two bars one is straight and one is bend-up). The other half span rebars are formed with a straight length. This alternative has been followed in this specific example.

2nd way: All span rebars i.e. Ø 10/100 are manufactured and placed with a straight length while at the upper part of the support areas additional straight rebars are placed.

Free edge reinforcement

The free edges of slabs are more susceptible to stresses and therefore, in these areas hairpin reinforcement is placed. Its proper position is secured by means of two bars placed inside its corners.

Behaviour and reinforcement of one-way slab reinforced with straight-length bars

< project: slabs15>

When using straight-length rebars it is simpler and more economical to use industrial wire meshes as shown at the figure.

The steel fixer’s formwork drawing of a one-way slab, reinforced with straight-length bars

In case a slab is reinforced only with straight-length bars, which, as a rule, means reinforcement with wire meshes, the steel fixer’s formwork drawing is shown at the figure.