Provides design requirements for reinforced concrete structures storing liquids. The 2009 revision introduced the Limit State Method for design while continuing to permit the Working Stress Method, heavily emphasizing crack width control to ensure watertightness and durability.
Specifies requirements for design and construction of reinforced concrete structures for the storage of liquids.
Quick Reference Values
maximum crack width0.2 mm
minimum concrete grade RCCM30
permissible tensile stress deformed bars direct WSM130 N/mm2
permissible tensile stress deformed bars bending WSM130 N/mm2
maximum free wc ratio0.45
Key Formulas
W_cr = (3 * a_cr * e_m) / (1 + 2(a_cr - c_min) / (h - x)) — Design surface crack width
Practical Notes
Crack width checks are mandatory and usually govern the design of liquid retaining faces over ultimate limit state.
Adequate distribution reinforcement must be provided to control early thermal and long-term shrinkage cracks.
Always use in conjunction with IS 3370 (Part 1) which dictates general requirements like joint spacing and minimum reinforcement percentages.