IS 3370:2009 Part 3 is the Indian Standard (BIS) for concrete structures for storage of liquids - prestressed concrete structures. This part of IS 3370 provides the code of practice for the structural design and detailing of prestressed concrete structures intended for the storage of liquids, ensuring stability, durability, and leak-tightness.
Provides guidelines for the design and construction of prestressed concrete structures used for the storage of liquids.
Quick Reference — IS 3370 Part 3:2009 Prestressed LRS
Prestressed liquid-retaining structures — concrete grade, permissible stresses, structural classes, cover, losses and transfer requirements.
| Reference | Value | Clause |
|---|
| Application | Prestressed liquid-retaining structures | Cl. 1 |
| Min concrete grade | M40 | Cl. 5 |
| Max water-cement ratio | 0.40 | Cl. 5 |
| Min cement content | 360 kg/m³ | Cl. 5 |
| Permissible compressive stress — at transfer | 0.45 fci | Cl. 6.2 |
| Permissible compressive stress — service (max) | 0.33 fck | Cl. 6.2 |
| Permissible tensile stress — bending (Class 1) | Zero | Cl. 6.3 |
| Permissible tensile stress — bending (Class 2) | ≤ 3 N/mm² (M40) | Cl. 6.3 |
| Class of structure — water tank (typical) | Class 1 (no tension under service) | Cl. 6.1 |
| Min cover — prestressing tendon (liquid face) | 50 mm | Cl. 7 |
| Min cover — non-prestressed reinforcement | 40 mm (liquid face) | Cl. 7 |
| Total prestress losses (typical assumed) | 20 – 25 % | Cl. 8 / refer IS 1343 |
| Transfer concrete strength (min) | fci ≥ 0.6 fck or 28 N/mm² (whichever larger) | Cl. 5 / IS 1343 Cl. 18.5 |
| Movement joint spacing | Per Part 1; PSC reduces frequency | Cl. 9 |
| Hydrostatic test | Per Part 1 (drop ≤ 1/500 depth) | Cl. 10 / Part 1 Cl. 11 |
| Min reinforcement (non-prestressed, each face) | 0.20 – 0.30 % per Part 1 | refer Part 1 Cl. 8.2 |
| Crack width limit — Class 2 | 0.1 mm (typical for liquid-retaining) | Cl. 6.3 |
⚠ Cross-references to IS 1343 govern detailed PSC provisions. Many sub-clause numbers depend on the 2009 reprint — verify against current BIS publication.
Overview
- Status
- Current
- Usage level
- Specialized
- Domain
- Structural Engineering — Structural Design and Loading
- Type
- Code of Practice
Also on InfraLens for IS 3370
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
Practical Notes
! Must be used in conjunction with IS 3370 (Part 1) for general requirements and IS 1343 for general prestressed concrete design.
! Special attention is required at wall-to-base junctions (sliding or pinned) to accommodate radial deformations caused by prestressing without causing severe secondary bending moments.
! Strict limits on tensile stresses at the liquid-retaining face are crucial to prevent cracking and ensure watertightness.
Frequently referenced clauses
prestressed concretehigh strength concreteprestressing steeltendons
International Equivalents
🌐
International Comparison — Coming Soon
We're adding equivalent international standards for this code.
Key Values4
Quick Reference Values
Minimum concrete grade for post-tensioned structuresM 30
Minimum concrete grade for pre-tensioned structuresM 40
Max allowable compressive stress in concrete at transfer0.5 fci
Max principal tensile stress in concrete0.24 √fck
Key Formulas
f = (P/A) ± (P·e/Z) ± (M/Z) — Resultant stress in concrete section
Tables & Referenced Sections
Key Clauses
Clause 4 - Materials
Clause 6 - General Design Requirements
Clause 7 - Basis of Design (Limit State Method)
Clause 8 - Limit State of Serviceability
Clause 9 - Detailing
Frequently Asked Questions3
What is the minimum grade of concrete allowed for post-tensioned liquid retaining structures?+
M 30.
What is the minimum grade of concrete allowed for pre-tensioned liquid retaining structures?+
M 40.
Are tensile stresses allowed in the liquid retaining face?+
Under limit state of serviceability, tensile stresses are generally restricted to ensure no cracking occurs, often requiring residual compression depending on the design criteria.
QA/QC Inspection Templates
📋
QA/QC templates coming soon for this code.