IS 9013 : 1978Method of test for water permeability of concrete

IS 9013 specifies the method of test for water permeability of concrete — measures how much water penetrates into hardened concrete under sustained pressure. Water permeability is one of the most important durability indicators for RCC: low permeability means low chloride / sulphate ingress, low corrosion of reinforcement, and long-term durability.

Use IS 9013 when: - Water-retaining structures (IS 3370 series) — design verification + acceptance - Marine + coastal exposure — corrosion resistance verification - Underground basements — waterproofing verification - Bridge decks — chloride resistance (IRC:112:2020 durability) - Sewage / industrial process tanks — chemical resistance verification - Mass concrete — internal void / crack assessment - High-performance concrete mix design qualification - Forensic investigation of leaking structures

Low permeability comes from: - Low water-cement ratio (≤ 0.45) - High cement content (≥ 350 kg/m³) - Use of pozzolans (PPC fly-ash, PSC slag, silica fume IS 15388:2003) - Adequate compaction - Long curing duration (≥ 14 days moist cure) - Integral waterproofing admixtures (IS 2645:1975)

The IS 9013 test is the headline laboratory test for permeability; for in-situ evaluation, RCPT (Rapid Chloride Penetration Test, ASTM C1202) is increasingly used.

Equipment: - Concrete cube specimen (150 × 150 × 150 mm) OR cylinder (150 × 300 mm) - Watertight chamber clamped to one face of specimen - Water pressure source (pump capable of 5-7 bar sustained) - Pressure gauge - Timer

Procedure: 1. Cast and cure concrete specimens to 28 days (or test age). 2. Clamp watertight chamber to one face of specimen, sealing periphery (avoid edge leakage). 3. Apply water pressure to chamber: - Initial 0.5 bar for 1 hour - Then 1.0 bar for 24 hours - Then 3.0 bar for 24 hours - Then 5.0 bar for 24 hours - Then 7.0 bar for 24 hours (or as per project spec) 4. After test, split specimen perpendicular to the wetted face. 5. Measure water penetration depth (visually + by oven-dry vs as-tested mass loss). 6. Report: depth of water penetration (in mm) at the specified pressure / time.

Standard pressure cycle (per IS 9013 default): - 1 bar for 24 hours, then 3 bar for 24 hours, then 7 bar for 24 hours = total 72 hours - Total water penetration depth measured

Acceptance criteria (per IS 9013 + product / project spec): - General concrete: depth ≤ 25 mm at 7-day cure equivalent - Water-retaining (IS 3370): depth ≤ 15-20 mm - Severe / marine exposure: depth ≤ 10 mm with high-performance mix - M40+ with IS 2645:1975 integral waterproofing: depth often < 5 mm

Permeability vs concrete grade (typical, 28-day):

| Concrete grade | Cement content (kg/m³) | w/c | Penetration depth (mm) | |---|---|---|---| | M15 | 240-280 | 0.55-0.65 | 50-100 | | M20 | 280-320 | 0.50-0.55 | 30-60 | | M25 | 320-380 | 0.45-0.50 | 20-40 | | M30 | 350-400 | 0.40-0.50 | 15-30 | | M40 | 380-450 | 0.40-0.45 | 10-25 | | M50 | 400-500 | 0.35-0.45 | 5-15 | | M60 (with silica fume) | 450-550 | 0.30-0.40 | < 5 | | Specialised (with IS 2645 integral waterproofing) | per design | per design | < 10 (verified by test) |

Permeability vs durability (chloride / sulphate exposure correlation): - Low permeability (< 10 mm) → very low chloride ingress → 75-100 year durability in marine - Medium permeability (10-25 mm) → moderate chloride ingress → 40-60 year durability - High permeability (> 25 mm) → significant chloride ingress → 20-40 year durability - Above 50 mm → poor durability; reinforcement corrosion within 10-20 years

Comparison to other permeability tests:

| Test | Method | Output | Use | |---|---|---|---| | IS 9013 | Water under pressure | Depth in mm | Lab + acceptance | | RCPT (ASTM C1202) | Electrical charge passed | Coulombs | Most-cited international metric | | Sorptivity (ASTM C1585) | Capillary water absorption | Sorptivity coefficient | Surface durability | | Air permeability (ASTM E2178) | Gas flow | Permeability index | Newer, less common |

RCPT chloride permeability classes (for reference): - < 1000 coulombs: Very low (very durable) - 1000-2000: Low - 2000-4000: Moderate - 4000-6000: High - > 6000: Very high (poor durability)

IS 9013 + RCPT together give comprehensive picture; IS 9013 is the BIS-aligned method for Indian acceptance.

Test sample requirement: - 3 specimens per concrete batch - Mean depth = batch result - Cure 28 days minimum (or specified age) - Specimens stored under standard conditions until test

• IS 456:2000 — RCC code (durability provisions, Clause 8).
• IS 3370 (Parts 1-4) — water-retaining structures (water permeability is design + acceptance criterion).
• IS 10262:2019 — concrete mix design (low-w/c mix design).
• IS 9103:1999 — admixtures (HRWR for low-w/c mix).
• IS 2645:1975 — integral cement waterproofing compounds.
• IS 15388:2003 — silica fume (high-performance pozzolan for low permeability).
• IS 1489 Part 1:2015 — PPC fly-ash (lower permeability than OPC).
• IS 1489 Part 2:2015 — PPC calcined clay.
• IS 12330:1988 — sulphate-resisting cement.
• IS 8112:1989 / IS 12269:2013 — OPC standards.
• IS 516 Part 1:2021 — compressive strength.
• IS 5816:1999 — split tensile strength.
• IS 13311 Part 1:1992 — UPV / rebound (in-situ verification).
• IS 9013:1978 (this code) — water permeability.
• IRC:112:2020 — concrete bridge code (durability provisions).
• IS 3085:1965 — older alternative permeability test method.
• ASTM C1202 — Rapid Chloride Penetration Test (RCPT — international counterpart).
• ASTM C1585 — Sorptivity (capillary absorption).

1. Test on under-cured specimen. Permeability hugely depends on cure; 7-day result is much higher than 28-day. Standard test at 28 days; report cure age. 2. Edge leakage during test. If chamber doesn't seal tightly to specimen face, water bypasses concrete; result over-estimates permeability. Use proper sealant + check before pressure increase. 3. Pressure not held for full duration. If pressure drops and is restored, water flow path complex; result unreliable. Use sustained pressure source. 4. Single specimen tested. Concrete heterogeneity means single result may not represent batch. Test minimum 3 specimens; report mean. 5. No comparison vs reference (control mix without admixture). Hard to interpret absolute number; compare against control to see admixture / pozzolan effect. 6. Accepting 'low permeability' claim from supplier without IS 9013 test. Verify by test; supplier datasheet alone insufficient. 7. High permeability accepted because cubes pass strength. Strength + permeability are partly independent; a strong but porous concrete fails durability over time. Both required. 8. No long-term monitoring of permeability in service. Permeability drifts with age (carbonation, micro-cracking); periodic in-situ test for critical structures (water tanks, bridges). 9. Substituting RCPT for IS 9013 without correlation. RCPT measures electrical conductivity (related but not identical to water permeability). IS 9013 is the BIS-aligned absolute measure. 10. Mix design optimisation skipped. Achieving low permeability requires deliberate mix design (low w/c, pozzolans, HRWR); not achievable with arbitrary high cement content. 11. Cure inadequate at site (vs lab). Lab result with 28-day moist cure ≠ field result with 7-day curing. Site-cure specimens parallel for in-situ comparison. 12. Permeability test on cracked concrete. Cracks dominate permeability; test result irrelevant. Inspect for cracks; if present, evaluate separately.

Durability assessment cascade for water-retaining / aggressive-exposure structure:

1. Design specification (IS 456:2000 + IS 3370): - Exposure category (Mild / Moderate / Severe / Very Severe / Extreme) - Cover requirement - Crack-width limit (0.2 mm Severe; 0.1 mm liquid-retaining) - Concrete grade + max w/c - Cement type per environment 2. Mix design (IS 10262:2019): - Optimise for low permeability (low w/c, pozzolan, admixture) - Include integral waterproofing if specified (IS 2645) 3. Trial mix verification: - Strength (IS 516 Part 1:2021) - Water permeability (IS 9013:1978 — this code) - RCPT (chloride permeability) - Sorptivity (surface absorption) 4. Procurement + acceptance: - Mix design qualified - Supply per qualified mix - Per-batch strength tests - Periodic permeability test (per project spec; typically 1 per 100 m³ or per consignment) 5. Construction: - Proper compaction (vibration) - Continuous curing 14-28 days - Crack control + waterstops at construction joints 6. In-situ verification: - Cores extracted post-cure - Permeability test on cores (per IS 9013) - UPV / rebound for compaction quality - Visual + crack inspection 7. Long-term monitoring (for critical structures): - Periodic crack inspection - Periodic permeability test on cores (every 5-10 years) - Carbonation depth + chloride profile measurement - Maintenance schedule (sealant refresh, repointing)

For different applications: - Standard RCC building: IS 9013 occasional, mainly compressive strength - Water-retaining: IS 9013 mandatory at design + acceptance + in-service - Bridge / marine: IS 9013 + RCPT; comprehensive durability programme - Tall building (basement): IS 9013 verification of waterproofing strategy

IS 9013 is the BIS-aligned permeability test; modern Indian practice is moving toward RCPT as well for chloride-specific evaluation, but IS 9013 remains the primary water-permeability acceptance test.