Question

Q.2.(a) A singly reinforced concrete beam is of 300 mm width and 500 mm effective depth. It is
reinforced with 6 Nos. of 16 mm HYSD bar. Assuming M 20 concrete, determine its
moment of resistance according to the working stress method.
​

Answer 1

Answer:

(d) 152mm

Explanation:

Characteristics strength of concrete, fck=20 N/mm2

(ii) Characteristics strength of reinforcing steel, fy=415 N/mm2

(iii) Width, b=250 mm

(iv) Effective depth, d=317 mm

(v) Neutral axis factor, xub

d

=

c

c+s

=

0.0035

0.0035+0.0038

=0.48

(vi) Position of neutral axis from the compression side, xub=

xub

d

d

=0.48 × 317.0

=151.9