B-2Permissible stresses

B-2.1.1 Direct Tension

For members in direct tension, when full tension is taken by the reinforcement alone, the tensile stress shall be not greater than the values given below:

The tensile stress shall be calculated as $\frac{F_{\mathrm{t}}}{A_{\mathrm{e}}+m A_{\mathrm{st}}}$

where

• $\begin{aligned} F_{\mathrm{i}} & =\text { total tension on the member minus pre- } \\ & \text { tension in steel, if any, before concreting; }\end{aligned}$
• = cross-sectional area of concrete excluding any finishing material and reinforcing steel;
• $m=$ modular ratio; and
• $A_{s}=$ cross-sectional area of reinforcing steel in tension.

B-2.1.2 Bond Stress for Deformed Bars

In the case of deformed bars conforming to IS 1786, the bond stresses given in Table 21 may be increased by 60 percent.

B-2.2.1

In flexural members the value of $\sigma_{u}$ given in Table 22 is applicable at the centroid of the tensile reinforcement subject to the condition that when more than one layer of tensile reinforcement is provided, the stress at the centroid of the outermost layer shall not exceed by more than 10 percent the value given in Table 22.