This 1965 standard covers the design and detailing of reinforced concrete structures for storing liquids. It relies strictly on the Working Stress Method (WSM) to ensure uncracked sections under service loads, guaranteeing watertightness.
Covers requirements for the design and construction of reinforced concrete structures for storage of liquids.
Quick Reference Values
minimum reinforcement upto 100mm0.3% of gross concrete area
minimum reinforcement 450mm and above0.2% of gross concrete area
permissible tensile stress steel liquid face115 N/mm²
minimum clear cover25 mm or diameter of main bar
minimum grade of concreteM20 (for liquid retaining structures in 1965 version)
Key Formulas
Ast = T / σst — Area of steel required for pure hoop tension
fct = T / (Ac + m * Ast) — Direct tensile stress in concrete (must be less than permissible limit)
Practical Notes
This 1965 version dictates that liquid-retaining faces be designed for zero cracking using the Working Stress Method. It was superseded in 2009 by a revision that allows the Limit State Method with specific crack-width controls.
Ensure proper spacing and distribution of temperature and shrinkage reinforcement to prevent early-age thermal cracking.
Sections thicker than 225 mm require reinforcement to be provided in two layers, one near each face.