1985 Ed.]
Building (Construction) Regulations
[CAP. 123
B 103
[Subsidiary]
(b) for negative moments, along lines joining the centres of the columns and around the perimeter of the column heads.
(7) The total bending moment in each direction for a panel shall be:
M1 = β2 [21 - 2D]2 WL2/10
and shall be distributed between the column strips and middle strip by the percentage specified in Table XXXVIII.
TABLE XXXVIII
Distribution of bending moments in panels of flat slabs designed by the empirical method
(a) Interior panels-
(i) with drops-
negative moments positive moments
(ii) without drops-
negative moments
positive moments
(b) Exterior panels
(i) with drops-
Distribution of moments expressed as a percentage of M1.
Column strip Middle strip
exterior negative moments SA 50 15
positive moments 20 15
interior negative moments #A 46 16
SMA 45 25
50 383
10 20
15
(ii) without drops-
exterior negative moments 41
positive moments 28 20
interior negative moments 46 =83
10 16
(8) (a) Slabs shall be reinforced in 2 directions and the reinforcement shall be so disposed that each strip is reinforced over its full width.
(b) In each strip not less than 50 per cent of the positive reinforcement shall extend in the lower part of the slab to not less than 0.125L from the line joining the centres of the columns.