Beam and Slab Floor System

This system consists of beams framing into columns and supporting slabs spanning between the beams. It is a very traditional system. The relatively deep beams provide a stiff floor capable of long spans, and able to resist lateral loads. However, the complications of beam formwork, co-ordination of services, and overall depth of floor have led to a decrease in the popularity of this type of floor.

The traditional reinforced concrete beam-and-slab floor has an economical span ‘L’ of D x 15 for a single span and D x 20 for a multi-span, where D is the depth of the slab plus beam. The depth of slab between the beams can be initially sized using the span-to-depth ratios for a flat plate. Prestressing is not normally used with this system.

Advantages:

• Traditional effective solution
• Long spans.

Disadvantages:

• Penetrations through beams for large ducts difficult to handle
• Depth of floor
• Greater floor-to-floor height.