What Is the minimum area of tension reinforcement in beam when Fe415 bar is used, if width of beam is 200 mm and effective depth is 250 mm ? 

Explanation:

• A minimum area of tension steel is required in flexural members (like beams) in order to resist the effect of loads and also control the cracking in concrete due to shrinkage and temperature variations.
• Minimum flexural steel reinforcement in beams: CI. 26.5.1.1 of IS 456:2000 specify the minimum area of reinforcing steel as

\(\frac{{{A_{st\min }}}}{{bd}} \ge \frac{{0.85}}{{{f_y}}}\)

\(\frac{{{A_{st\min }}}}{{200\times 250}} \ge \frac{{0.85}}{{{415}}}\)

A_stmin = 102 mm²

Additional Information

• The maximum area of tension steel in beams(Intension beams as well as compression beams) provided as per IS 456:2000 = 4% of gross area = 0. 04 × bD
• The minimum area of tension steel in the slab is as per CI. 26.5.2 of IS 456:2000 
  • Astmin = 0.15% of gross area for Fe 250
  • Astmin = 0.12% of gross area for Fe 415