Chapter 30Flat Slabs

30.1 General

The term flat slab means a reinforced concrete slab with or without drops, supported generally without beams, by columns with or without flared column heads (see Fig. 12). A flat slab may be solid slab or may have recesses formed on the soffit so that the soffit comprises a series of ribs in two directions. The recesses may be formed by removable or permanent filler blocks.

30.1.1 For the purpose of this clause, the following definitions shall apply:

a) Column strip — Column strip means a design strip having a width of $0 . 2 5 l _ { 2 } ,$ but not greater than $0 . 2 5 l _ { \mathrm { i } }$ on each side of the column centreline, where $l _ { 1 }$ is the span in the direction moments are being determined, measured centre-to-centre of supports and $l _ { z }$ is the span transverse to $l _ { \mathrm { { 1 } } } ,$ measured centre-to-centre of supports.

b) Middle strip — Middle strip means a design

strip bounded on each of its opposite sides by the column strip.

c) Panel — Panel means that part of a slab bounded on each of its four sides by the centreline of a column or centre-lines of adjacent spans.