1964_BUILDING_(CONSTRUCTION)_REGULATIONS — Page 81

1985 Ed.]

Building (Construction) Regulations

[CAP. 123

B 81

[Subsidiary]

as-

(i) the entire concrete section, ignoring the reinforcement;

(ii) the entire concrete section, including the reinforcement, on the basis of the modular ratio; or

(iii) the compression area of the concrete section, combined with the reinforcement on the basis of the modular ratio.

(b) The same method shall be adopted for the beams and the columns.

133. (1) The effective span of a beam or slab shall be taken as-

(a) the distance between the centres of bearings; or

(b) the clear distance between supports plus the effective depth of the beam or slab,

whichever is the lesser.

(2) In paragraph (1)(b) "effective depth" of a beam or slab is the distance between the centre of tension and the edge of the compression section.

134. (1) In T-beams the breadth of the flange assumed as taking compression shall not exceed-

(a) 1/3 of the effective span of the T-beams;

(b) the distance between the centres of the ribs of the T-beams; or

(c) the breadth of the rib plus 12 times the thickness of the slab,

whichever is the least.

(2) In L-beams the breadth of the flange assumed as taking compression shall not exceed---

(a) 1/6 of the effective span of the L-beams;

(b) the breadth of the rib plus 1/2 of the clear distance between ribs; or

(c) the breadth of the rib plus 4 times the thickness of the slab,

whichever is the least.

(3) When a part of a slab is considered as the flange of a T-beam or L-beam-

(a)

(i) the reinforcement in the slab transverse to the beam shall cross the full breadth of the flange; and

Effective span.

T-beams and L-beams.