💧 Concrete water permeability
In short
Testing depth of water penetration under pressure in hardened concrete. The test is performed according to PN-EN 12390-8:2019; Water pressure: (500 ± 50) kPa (0.5 MPa). The procedure comprises 9 steps (about 3 days 1 h 40 min in total); it is used for: Quality control of ready-mix concrete on site (classes XD, XS, XA), Testing of concretes for hydraulic structures (dams, locks, tanks), Durability assessment of foundation concretes in aggressive soils.
At a glance
- Standard: PN-EN 12390-8:2019
- Category: Construction
- Procedure steps: 9
- Total time of stages: 3 days 1 h 40 min
- Water pressure: (500 ± 50) kPa (0.5 MPa)
- Test duration: (72 ± 2) h (3 days)
- Min. sample dimension: ≥150 mm (side or diameter)
Overview
Concrete water permeability is one of the most important durability parameters of reinforced concrete structures exposed to water — foundations, tanks, tunnels, bridges and hydraulic structures. Standard PN-EN 12390-8 describes a standard method for assessing water penetration depth under pressure, which is an indicator of concrete pore structure tightness.
Water penetration depth depends on w/c ratio (water/cement), cement type, presence of additives (fly ash, silica fume), degree of compaction, curing and concrete age. Standard PN-EN 206 defines exposure classes (XC, XD, XS, XF, XA), many of which require water permeability testing as a concrete acceptance criterion.
In Polish construction practice, waterproofness grades W2, W4, W6, W8, W10, W12 are used (according to former PN-88/B-06250), corresponding to maximum water pressure at which no seepage is observed. The European standard PN-EN 12390-8 uses penetration depth in mm at constant pressure 500 kPa for 72 h.
The test is performed in concrete plant laboratories, on construction sites (ready-mix concrete acceptance) and in research laboratories. It is mandatory for concretes of exposure classes XD, XS and XA according to PN-EN 206.
Method principle
Concrete sample (cube, cylinder or cuboid with side/diameter ≥150 mm) is placed in pressure device so that water under pressure (500±50) kPa acts on selected surface (usually molded surface) for (72±2) h. After test completion, sample is broken (split) perpendicular to surface on which water acted. On the fracture surface, a dark zone saturated with water is visible — maximum water penetration depth is measured in mm. The smaller the depth, the more waterproof the concrete.
Applications
- Quality control of ready-mix concrete on site (classes XD, XS, XA)
- Testing of concretes for hydraulic structures (dams, locks, tanks)
- Durability assessment of foundation concretes in aggressive soils
- Design of waterproof concrete mix (w/c selection, additives)
- Quality control of concrete precast elements (pipes, manholes)
- Comparative tests of sealing admixtures effect
- Construction expert opinions — assessment of existing structures condition
Key parameters
| Parameter | Value |
|---|---|
| Water pressure | (500 ± 50) kPa (0.5 MPa) |
| Test duration | (72 ± 2) h (3 days) |
| Min. sample dimension | ≥150 mm (side or diameter) |
| Sample age | ≥28 days |
| Result | Maximum penetration depth [mm] |
| Criterion (typical) | <50 mm — waterproof concrete; <20 mm — high waterproofness |
Standard
- Standard number
- PN-EN 12390-8:2019
- Title (PL)
- Badania betonu — Część 8: Głębokość penetracji wody pod ciśnieniem
- Title (EN)
- Testing hardened concrete — Part 8: Depth of penetration of water under pressure
Step-by-step procedure
-
Sample preparation
Cubic samples 150×150×150 mm or cylinders ∅150 mm after min. 28 days curing. Mark test surface (molded).
-
Surface drying
Dry test surface in air. Optionally seal side surfaces (paraffin, silicone) — prevent side leakage.
-
Sample mounting in apparatus
Place sample in pressure holder. Tighten clamping flanges with rubber gaskets. Check connection tightness.
-
Water pressure application
Turn on water supply. Set pressure (500±50) kPa. Check pressure stability in first 30 minutes.
-
Pressure maintenance
Maintain 500 kPa pressure for 72±2 h. Monitor pressure at least 2× daily. Correct any deviations.
-
Sample dismounting
After 72 h release pressure. Remove sample from apparatus. Dry external surface.
-
Sample splitting
Split sample perpendicular to surface on which water acted (splitting press or wedge). Immediately examine fracture.
-
Penetration depth measurement
On fracture mark boundary of dark zone (water-saturated). Measure maximum penetration depth with caliper to accuracy of 1 mm.
-
Results documentation
Note: maximum depth [mm], penetration front description, fracture photo. Compare with design requirements.
Required equipment and apparatus
| Equipment | Example | Indicative price |
|---|---|---|
| Concrete waterproofness testing apparatus | Multiserw-Morek, Controls 55-C0225, Matest C390 | 25 000–80 000 PLN |
| Air compressor / pressure pump | Piston compressor 10 bar, pressure regulator | 3 000–10 000 PLN |
| Press for splitting samples | Controls 50-C0220, Matest C070, Multiserw-Morek | 20 000–60 000 PLN |
| Caliper / steel ruler | Mitutoyo 500-196, accuracy 0.1 mm | 200–800 PLN |
| Rubber gaskets / clamping flanges | Sets for sealing samples in pressure apparatus | 500–2 000 PLN/set |
Reagents, media and consumables
| Reagent | CAS | Details |
|---|---|---|
| Tap water (test medium) | 7732-18-5 | Drinking water, temperature 20±5°C, applied under pressure to sample |
| Sealing material | — | Silicone, paraffin wax or epoxy resin for sealing side surfaces of sample (optional) |
Health and safety (OHS)
- Water pressure 500 kPa — risk of sudden leak! Safety goggles mandatory
- Splitting press — danger of crushing, protective shield and operator training
- Heavy concrete samples (>8 kg) — lifting ergonomics, work gloves
- Wet floor in laboratory — non-slip footwear
Frequently asked questions
Which standard describes this test?
The test is performed according to PN-EN 12390-8:2019 — “Testing hardened concrete — Part 8: Depth of penetration of water under pressure”.
How does this method work?
Concrete sample (cube, cylinder or cuboid with side/diameter ≥150 mm) is placed in pressure device so that water under pressure (500±50) kPa acts on selected surface (usually molded surface) for (72±2) h. After test completion, sample is broken (split) perpendicular to surface on which water acted.
What is the measuring range and accuracy?
Water pressure: (500 ± 50) kPa (0.5 MPa); Test duration: (72 ± 2) h (3 days); Min. sample dimension: ≥150 mm (side or diameter); Sample age: ≥28 days.
How long does the test take?
The times given for the individual stages add up to approximately 3 days 1 h 40 min. The procedure comprises 9 steps.
What equipment is required?
Concrete waterproofness testing apparatus, Air compressor / pressure pump, Press for splitting samples, Caliper / steel ruler, Rubber gaskets / clamping flanges. Indicative cost of the core instrument (Concrete waterproofness testing apparatus): 25 000–80 000 PLN.
Where is this test used?
Quality control of ready-mix concrete on site (classes XD, XS, XA); Testing of concretes for hydraulic structures (dams, locks, tanks); Durability assessment of foundation concretes in aggressive soils; Design of waterproof concrete mix (w/c selection, additives); Quality control of concrete precast elements (pipes, manholes); Comparative tests of sealing admixtures effect; Construction expert opinions — assessment of existing structures condition.
What safety precautions apply?
Water pressure 500 kPa — risk of sudden leak! Safety goggles mandatory; Splitting press — danger of crushing, protective shield and operator training; Heavy concrete samples (>8 kg) — lifting ergonomics, work gloves; Wet floor in laboratory — non-slip footwear.
Which laboratory can perform this test?
The test is performed by laboratories accredited to ISO/IEC 17025. On LabCoda you can find them by the standard number PN-EN 12390-8.