Question

The design shear strength of a reinforced concrete rectangular beam with a width of 250 mm and an effective depth of 500 mm, is 0.3 MPa. The torsional moment capacity of the section (in kN.m) under pure torsion, as per IS 456:2000, is __________ (round off to one decimal place).
 

• A. 5.86
• B. 5.70
• C. 5.60
• D. 6.00

Hint:

Ensure all values are in consistent units before applying IS 456:2000 design formulas for torsion.

Answer 1

The Correct Option is A

Given:
Width, \( b = 250 \) mm
Effective depth, \( d = 500 \) mm
Design shear strength, \( \tau_c = 0.3 \) N/mm²

Step 1: Calculate shear force
\[ V_e = \tau_c \cdot b \cdot d = 0.3 \times 250 \times \frac{500}{1000} = 37.5 \text{ kN} \]
Step 2: Use IS 456:2000 torsion formula
\[ T_u = \frac{V_e \cdot b}{1.6 + \frac{1.67 b}{d}} = \frac{37.5 \times 0.25}{1.6} = 5.86 \text{ kN.m} \]
Hence, the torsional moment capacity is \(\boxed{5.86 \text{ kN.m}}\).