Question

A T-beam roof section has the following particulars :

Thickness of slab : 120 mm
Width of rib : 300 mm
Depth of beam : 450 mm
Clear distance of beams : 7.0 m
Distance between points of contra flexure : 4.0 m
The effective width of flange of beam (in mm) is

• A. 1686.67

Answer 1

The correct option is A 1686.67
Effective width of T-beam
$b_f=\frac{l_0}{6}+b_w+6D_f\ngtr b$

where, $b_f$ = effective width of flange,
$l_0$ = distance between points of contraflexure ,
$b_w$ = width of web/rib,
$D_f$ = thickness of flange,
b = clear distance between the beams

$\therefore b_f=\frac{4000}{6}+300+6\times 120$

= 1686.67 mm $\ngtr$ 7000.00 mm (OK)