An in situ concrete suspended floor is one constructed with reinforced concrete and designed to carry its own weight and any imposed a loading, spanning between supporting members in a structure. Supports for floors are typically beams, columns or walls.
In situ concrete reinforced suspended floors can be designed to span one-way or two-ways between supports. Such floors can be designed and constructed to have a continuously flat soffit. Alternatively, the slab soffit can be formed with special moulds to give an indented profile to produce a `waffle` or `trough` floor.
In situ reinforced concrete suspended slabs can be economically designed as flat slabs to Eurocode 2. A flat slab may or may not have dropped sections at beam strips and column supports. It may be solid or have a coffered or waffle soffit profile.
Guidance and the maximum areas of pour and on the location of joints is given in Concrete Advice No. 02, Suspended concrete floors: maximum size of pour allowable and location of construction joints. Concrete Advice No. 23, Large area pours for suspended slabs outlines an approach for determining the reinforcement required to control cracking in large area pours.
Note copies of Advice Sheets can be downloaded from the Members Area of the Concrete Society web site.