2.3 GENERAL DESIGN REQUIREMENTS (I.S.I)
2.3.1 Plain Concrete Structures. Plain concrete member of reinforced
concrete liquid retaining structure may be designed against structural
failure by allowing tension in plain concrete as per the permissible limits
for tension in bending. This will automatically take care of failure due to
cracking. However, nominal reinforcement shall be provided, for plain
concrete structural members.
2.3.2. Permissible Stresses in Concrete.
(a) For resistance to cracking. For calculations relating to the resistance
of members to cracking, the permissible stresses in tension (direct and
due to bending) and shear shall confirm to the values specified in Table 1.
The permissible tensile stresses due to bending apply to the face of the
member in contact with the liquid. In members less than 225mm. thick and
in contact with liquid on one side these permissible stresses in bending
apply also to the face remote from the liquid.
(b) For strength calculations. In strength calculations the permissible
concrete stresses shall be in accordance with Table 1. Where the
calculated shear stress in concrete alone exceeds the permissible value,
reinforcement acting in conjunction with diagonal compression in the
concrete shall be provided to take the whole of the shear.